Otago UNIVERSITY OF FACULTY OF DENTISTRY RESEARCH REPORT 2005-2006
FACULTY OF DENTISTRYTable of ConTenTsIntroduction from the Dean 2Research in the Faculty of Dentistry 3An influential paper by Professor HP Pickerill 4Sir John Patrick Walsh KBE 5Establishment of the Sir John Walsh Research Institute 7Research Groups 8Biomaterials and Biomechanics 8Dental Epidemiology and Public Health 10Endodontic Microbiology 12Molecular Microbiology Laboratory 13Oral Implantology 15Oral Microbiology and Dental Health Research Theme 17Contact Email Addresses 19Faculty Research Profiles 20Graduate Student Research 51A Graduate Student Research Success Story 51Postgraduate Students Graduating in 2005-2006 52Enrolled Postgraduate Students 53Summer Studentships 57Visiting Research Fellows 59Research Funding 60Faculty Publications 63Invited Presentations 68Awards 71Sponsors 72A pdf of this document can be found at: www.otago.ac.nz/dentistry
RESEARCH REPORT 2005-2006InTroduCTIon from The dean It is with great pleasure that I present to you the Research report for the Faculty of Dentistry, University of Otago, in this, our centenary year. Although this report covers the period 2005–2006, the University of Otago has a proud history of Dental Research over the past 100 years. As can be seen from this report, this history of excellence in research is continuing today. The recent Performance- Based Research Funding exercise placed the University of Otago as the premier research University in New Zealand, with the Dental School having an exceptionally strong performance. This excellence in research is reflected in the development of the Sir John Walsh Research Institute. This Institute will provide a focus for dental research in New Zealand and will further enhance the international reputation of the School.I would like to thank Dr Brian Monk, the Faculty’s Research Committee and Mrs Margaret Guthrie, for theirefforts in putting together this report, as well as Professors Jules Kieser and Richard Cannon, who, as AssociateDeans for Research, have played a central role in establishing the research portfolio of the Faculty over the pasttwo years.Finally, I would like to acknowledge all the staff, both academic and general, who have contributed to theFaculty’s research effort. Well done, all of you.Gregory J. seymourDeanFaculty of DentistryPO Box 647University of OtagoDunedin 9054New ZealandEmail email@example.comWeb www.otago.ac.nz/dentistry
FACULTY OF DENTISTRYresearCh In The faCulTy of denTIsTryResearch underpins the teaching of dentistry, its clinical practice, and the identification of oral health-relatedproblems. The School of Dentistry produces graduates for the nation’s dental work force who understand thatreal-world dentistry depends on research. They naturally expect that their teachers will have practical experiencewith the evolving scientific basis of dentistry and oral health. Since its inception a century ago, research hasbeen a cornerstone of the activities of the Faculty of Dentistry, and the Faculty continues to provide a thrivingresearch nexus. The prescient insights in 1914 of the first Dean, Henry Pickerill, into caries and the protectiverole of saliva (page 4 of this report), and the contribution of the third Dean, Sir John Walsh, to the developmentof the modern high-speed dental handpiece in the 1950s and the fluoridation of New Zealand municipal watersupplies (see page 5) have their modern counterparts in research outputs from the Faculty that are highlightedin this report. Today’s Faculty researchers are engaged in the systematic development of new knowledge oforal health and how to best improve the oral health of the general public. A major strength of the Faculty hasbeen the establishment of substantive research groupings that include the Molecular Microbiology Laboratory,Biomaterials and Biomechanics, Epidemiology and Public Health, and Oral Implantology (pages 8-16). Thesegroups have sufficient critical mass to produce internationally recognised research in diverse areas that include:~ Understanding of drug resistance and antimicrobial discovery;~ Testing and modelling biomaterials used to construct oral prostheses;~ Obtaining new insights in forensic dentistry;~ Developing new approaches to the placement of implants; ~ Evaluating the role of periodontal disease in chronic human disease;~ Gauging the effectiveness of current policies on the oral health of New Zealanders. Many of the researchers in the Faculty also belong to the University of Otago research theme Oral Microbiologyand Dental Health (OMDH). The theme is a vehicle that connects our oral microbiology researchers and studentswith colleagues in other departments of the University and across New Zealand (see page 17).This report highlights the broad range of interesting and useful research that came from the Faculty of Dentistryduring 2005 and 2006. In this period, the Faculty has increased its research-active staff from the 29 listed in the2003-2004 report to the 43 listed here (pages 20 to 50 detail their research activities and accomplishments). In therecently reported 2006 Performance-Based Research Fund (PBRF) round, the Faculty of Dentistry dramaticallyincreased its quality rating from 2.0 to 3.9, the second largest increase recorded at the University of Otago. Thisincluded an increase from 3 to 6.25 FTE in the numbers of A-rated staff (the top research ranking) that wasbacked by impressive improvements in the rankings of other research-active staff.Obtaining the substantial research funding required to maintain and develop our portfolio of research continuesto be a daunting exercise that requires dedicated time and effort by Faculty members in a funding environmentwhere oral health has yet to be perceived as crucial to the national well-being. This contrasts with the abilityof the Faculty to attract very significant funding from international sources, including three grants from theprestigious National Institutes of Health in the United States. Lists of grants awarded during 2005 and 2006 andmajor outside sponsors of research in the Faculty are presented on pages 60-62 and page 72.In 2006, seed funding provided by the University led to the establishment of the Sir John Walsh ResearchInstitute (SJWRI, see page 7). In 2007, an internationally recruited professorial appointee is expected to headthis new department of the Faculty of Dentistry. By actively reaching out to all interested groups (includingFaculty, students, the dental profession and the wider community), the SJWRI will serve as a focus and advocatefor oral health research that will instil a research ethos throughout New Zealand. Many benefits are expectedto flow from the SJWRI, including a profile that will allow a more strategic and better-resourced approach toresearch excellence. Furthermore, the Faculty has instituted (from 2007) the Doctor of Clinical Dentistry Degreeto replace the MDS degree. This will introduce a substantial research component into the primary graduatequalification for dentists and better prepare them for the challenge of rapid change in dental practice that isinevitable in the first half of the 21st century.While many significant challenges are still to be met in its centennial year, the Faculty of Dentistry is particularlyencouraged by the increasing numbers of graduate students attracted to the School to undertake post-graduatestudy, including PhDs (page 52), and the oversubscription of summer studentships by the next generation ofundergraduate students wishing to undertake research in the School (pages 57-58).
RESEARCH REPORT 2005-2006an InfluenTIal paper by professor h. p. pICkerIll Professor Henry Percy Pickerill was the inaugural Dean of the Dental Faculty at the University of Otago. Although Pickerill was best known for his innovative work in plastic surgery, both on wartime injuries and cleft lip/palate, his major research contribution was in the study of dental caries. At the Sixth International Dental Congress in London in August 1914, he presented an authoritative and ultimately influential paper on dental caries. That paper was subsequently reported in a series of articles in the British Dental Journal (and thereafter in the New Zealand Dental Journal in 1915). His biographer1 has observed that Pickerill has not received due recognition for his insights into the importance of saliva in caries prevention.The first part of Pickerill’s seminal paper introduced the history and geographical distribution of caries, anddiscussed the socio-economic associations of the condition, together with the influence of heredity. He thencovered the bacteriology of the disease before dismantling the belief – commonly held at that time – that salivain some caries-susceptible people somehow contains carbohydrates which could be fermented into acid. Healso presented evidence that saliva was necessary for the enamel to reach maturity after the tooth had eruptedinto the mouth. Pickerill then made what is considered to be his most important contribution to cariology byemphasising saliva’s role in protecting against dental caries. Given what is known today about the disease ofdental caries, Pickerill’s insights were far-reaching and ahead of their time.He concluded his presentation with a call for ongoing research into the condition in order to better informpreventive efforts at the national level.It is unfortunate that the Congress itself was curtailed by the declaration of the First World War, and thatPickerill’s paper did not receive the immediate attention and discussion that it merited. Looking back more than90 years later, it is clear that this was a work of exceptional prescience, and that the University of Otago Facultyof Dentistry had well and truly made its first big impact in the world of oral health research.1 The writer of this brief overview is very grateful to Dr R. Harvey Brown for generously sharing his notes and insights. Dr Brown is, of course, well-known to us as a former Deputy Dean and Chairman of what was the Department of Community Dental Health, and the Editor of the New Zealand Dental Journal for almost three decades. Dr Brown’s biography of HP Pickerill was launched during the Queen’s Birthday Weekend celebration of the School of Dentistry’s centenary.
FACULTY OF DENTISTRYsIr John paTrICk Walsh kbemuCh GaIn and mInImIsed paIn Sir John Walsh made such a remarkable contribution to dentistry in New Zealand that Chapter 8 of Tom Brooking’s “A History of Dentistry in New Zealand” is entitled the “Walsh Era 1947-1972.” After graduating with a first class honours degree in dentistry (followed by a medical degree), and then serving as a medical officer in the Royal Australian Air Force, this self-described “brash Australian” was appointed as the 3rd Dean of the School of Dentistry at the University of Otago in 1946. Walsh’s appointment advanced dentistry at many levels. He served as a spokesperson for dentistry at the World Health Organisation, led a campaign that overcame vociferous opposition to fluoridate water supplies in New Zealand cities, and succeeded after 10 years of struggle with reluctant university authorities (and even more reluctant government) tobuild the iconic glass curtain building that now houses the Faculty of Dentistry and bears his name. Under hisleadership, the Faculty of Dentistry obtained the highest international standards by broadening its clinical andscientific base and reaching out to the Dental profession and the community. Walsh edited the New ZealandDental Journal for several years and had a reputation for being extremely scathing about dental practices thatequipped too many New Zealand adults with “false teeth faces” in the mid-20th century. Walsh was a powerfuladvocate of research. Staff members in the Faculty of Dentistry were encouraged to undertake PhD study,and the School of Dentistry set out to “grow” its own researchers by introducing the highly successful MDSgraduate programme. This focus on research was achieved with support of Walsh’s ally, Sir Charles Hercus in theMedical School (also a dental graduate). After more than 50 years, the MDS degree is now being replaced by theDoctorate in Clinical Dentistry. Most importantly, the change will increase the research experience and clinicalexpertise of graduates in a world where biological knowledge and its impact on clinical practice are changing atan unprecedented rate. This initiative to improve and more fully inform dental practice through research wouldundoubtedly have been endorsed by Walsh.Sir John Walsh’s contribution to the development of the modern high-speed dental handpiece was one ofhis most significant but least well-known achievements. Electric drills introduced near the beginning of theFirst World War were inefficient and, by operating at only about 3000 rpm, caused considerable discomfort topatients. While testing the hearing of Australian airmen discharged from service at the end of World War II,Walsh not only identified frequencies that caused pain but also those that did not. This led to the hypothesisthat the vibrational frequencies imparted by dental drills rotating at sufficiently high speeds would minimisepatient discomfort. With the assistance of H.F. Simmons from the University of Otago Department of Physics,an existing air-powered low-speed drill was modified to operate initially above the 42,000 rpm vibrationalthreshold and then at 60,000 rpm. In 1947, Walsh persuaded the Ministry of Science and Industry to underwritethe development of the air turbine handpiece at the Dominion Physics Laboratory in Lower Hutt. By 1949, aprototype was made available to Walsh, who then obtained the results that contributed to his DDSc from theUniversity of Melbourne and to the issue of a New Zealand patent. Although the prototype overcame the painproblem and required minimal operator force to work efficiently, its high-pitched noise, excessive exhaust ofair into the patient’s mouth, and the too-frequent seizure of its primitive bearings (due to overheating) made itdifficult to obtain further support from government or commercial sources. In 1952, Walsh’s research on the airturbine handpiece ceased due to lack of funding. American and Swedish research had overcome the technicalproblems by about 1955 and, in 1957, the Borden Airotor was marketed by the Dentists’ Supply Company. R.J.Nelson, who had produced a water-powered and cooled contra-angle handpiece, was then promoted (withthe editorial support of the Journal of one of his sponsors, the American Dental Association) as being solelyresponsible for the development of the high-speed drill. The precedence of Walsh’s development of a high-speedair turbine handpiece that closely resembles the modern-day device can be gleaned from the pages of the NewZealand Dental Journal and a summary in the British Dental Journal (136, 469-472, 1974). The parallel drawn byTom Brooking on the Walsh and Nelson contributions to dentistry with those of Richard Pearse and the Wrightbrothers to powered flight seems quite apt.Walsh’s attitude to research was very modern in its inclusiveness, while many of the barriers he faced in bringingits products into the clinic remain difficult to overcome. Walsh took a multidisciplinary approach to problems;he recruited the best people and obtained the best from them; he understood the risk inherent in cutting-
RESEARCH REPORT 2005-2006edge research and didn’t expect research or commercialisation to be easy; and he came to understand that theperspectives of companies and politicians are often myopic. Not fazed by the disappointment of being unableto advance the high-speed handpiece further, Walsh worked hard to expand research activity within the Facultyof Dentistry by attracting research funding, establishing the Biochemical Research Unit of the Dental Schoolin 1960, and supporting an electron microscopy suite. It is therefore fitting that the University of Otago isacknowledging his contribution to research in dentistry by supporting the establishment of the Sir John WalshResearch Institute in the Faculty of Dentistry. It will be the first Research Institute at the University of Otago. Itsroles in research and communication with the profession and wider community will seek to improve the oralhealth of New Zealanders, a modernisation of Walsh’s aspiration of giving people “teeth for life”. A patent drawing of the air turbine handpiece design Prototype Handpieces
FACULTY OF DENTISTRYesTablIshmenT of The sIr John Walsh researCh InsTITuTeIn 2006, the University of Otago provided seed funding to support the creation of the Sir John Walsh ResearchInstitute (SJWRI). The members of an international Advisory Panel led by Professor John Greenspan travelledto New Zealand and, with the assistance of Otago faculty members (Professor Gregory Seymour, AssociateProfessor Richard Cannon, Professor David Green and Professor Murray Thomson), met with the UniversityVice-Chancellor and other key members of the University administration, then with the Faculty of Dentistryand a range of stakeholders during workshop held on November 14th and 15th. These meetings informedthe Panel members of the strong support of the University for the concept of the SJWRI, and the role that theInstitute could play in achieving better health for New Zealanders by acting as a research and communicationsfocus. The Faculty of Dentistry received the Report of the Advisory Panel in January 2007.The Report outlined the Advisory Panel’s perception of the state of oral health in New Zealand. Its analysisincluded the demographic implications of current oral health policy, the identification of significant gaps indental health surveillance, and the emerging importance of links between oral and systemic health. The Reportsuggested a mission and vision for the SJWRI, and it discussed how dental research conducted in an innovativeand collaborative research environment can contribute to overall health in line with government directives,social needs, and the requirements of key stakeholders.Consistent with University policy, it was recommended that the SJWRI be established within the Faculty ofDentistry, and that academic staff from other Departments or units of the University be invited to participate asprogramme members where appropriate. The issues of governance, Institute structure and activity review wereaddressed in detail. The Panel’s suggestions included an outline of the responsibilities of the Institute Directorand the make-up of a Management Committee, an Internal Advisory Committee, a Scientific and CommunityAdvisory Committee, and an International Review Committee. The panel recommended that the SJWRI developsa Research Strategic Plan, and that the issues of research space and core facilities should be addressed.Funding of the SJWRI was regarded as a key problem, and it is considered that the research areas selected shouldbe capable of attracting substantial long-term funding. It was recommended that the SJWRI aim for an annualbudget of NZ$4-5 million by the 5th-6th year of its operation. It was suggested that the impending nationaloral health survey would provide a rich platform for future projects for an institute that seeks a sustainablebalance between basic, translational, practice-based and public health research. The establishment of the SJWRIwas recognised as an opportunity to develop and sustain a high-calibre research capacity consistent with theUniversity’s Strategic Plan for Research.The inception of the SJWRI signals a new opportunity for New Zealand oral health research. It will enhance thereputation and productivity of an already vigorous research setting which features energetic and internationallyrecognized researchers working across a broad range of oral health research projects.The Faculty of Dentistry is in the process of advertising for a professorial Director of the SJWRI based on theAdvisory Panel recommendations. An innovative and forward-thinking research leader will be sought to shapethe new research institute by building upon and refocusing a core of established research excellence within theUniversity of Otago, and by developing new research directions relevant to New Zealand and the wider Asia-Pacific region. It is anticipated that the appointee may be a senior scientist who will be a leading advocate fororal health research, or a mid-career scientist whose programme of research will complement and enhance theFaculty’s current research portfolio. The challenge for the Director will be to make the Sir John Walsh ResearchInstitute the national and Pacific focus for oral health research that meets the needs of the Faculty, the dentalprofession and the wider community.
RESEARCH REPORT 2005-2006researCh GroupsbIomaTerIals and bIomeChanICsGroup leadersProfessor M. Swain, Professor J. Kieserkey personnelDr R. Cook and I. Ichimpost-graduate students SupervisorsI. Ichim M. Swain J. Kieser and A. PayneN. Waddell M. Swain, J. Kieser and A. PayneR. Farrah M. Swain and B. DrummondD. Kuzmanovic M. Swain and R. LoveA. Quick J. Kieser, M. Swain, G. Johnson and P. HerbisonD. Kennedy J. Kieser and M. SwainThe Biomaterials and Biomechanics group is investigating a range of mechanically mediated responses of dentalmaterials and biological tissues. These topics range from the influence of mechanical forces on the stressesdeveloped in the mandible to the stresses and failure mechanics of restorations. This research has significantbearing on the design longevity and anticipated failure of implant-supported structures. In addition a rangeof forensic and accident-related skin impact mechanical problems are being investigated, as well as the effect ofcarious processes and developmental defects on enamel structure.primary research fociCritical property assessment of dental materialsMechanical properties of teeth and influence of diseaseMechanical properties of boneMechanisms and mechanics of dental restorative failuresNumerical modeling of craniofacial structuresNano-mechanics of materialsForensic sciencesresearch highlightsThe research of Ichim and colleagues has made major contributions to our understanding of the stressesdeveloped in craniofacial structures as a consequence of biting forces. The use of accurate CT- based images hasallowed computer modelling based on finite element analysis. This approach has been extended to predict themechanics of failure of complex dental restorative systems. It is anticipated that this will lead to more rationaldesign and selection of materials for tooth restorations.The main focus of Dr Richard Cook’s research has been the investigation of the biomechanics of cancellousbone tissue, with a specific focus on the bone condition osteoporosis. The research seeks to understand thefracture mechanics of the cancellous bone tissue with respect to tissue-specific independent variables such ascollagen cross-linking and density. Specific features of fracture propagation in cancellous tissue and the effectsof structural integrity on the fracture toughness of cancellous bone tissue are also being investigated.The forensic science research team led by Professor Jules Kieser are developing an understanding the response ofskin and the underlying structure to blunt trauma impact events. Over the past year, various models have beendeveloped which reliably replicate trauma.selected publicationsIchim, I., Swain, M.V., Kieser, J., (2006). Mandibular biomechanics and development of the human chin. Journal of Dental Research 85, 638-642. Ichim, I., Kieser, J., and Swain, M., (2006). Mandibular stiffness in humans: numerical predictions. Journal of Biomechanics 39:1903-13.
FACULTY OF DENTISTRYGrantsNZ Dental Research Foundation, Treatment of developmentally defective enamel. (M. Swain) $8,000 (2006)NZ Dental Research Foundation, Tongue pressure dynamics during eating and swallowing. (J. Kieser) $5,153Otago University Contestable Symposium Funding, Craniofacial Biomechanics Future Strategies (J. Kieser andM. Swain) $10,000New Zealand Lottery Grants Board, High resolution X-ray micro tomography (J. Kieser, M. Swain andH. Nicholson) $172,000outreachA number of significant collaborations have developed over the past 3 to 4 years. These include the advancesin numerical analysis, especially prediction of failure. This originates from collaboration with Professor JeffLoughran at James Cook University in Queensland and Dr Qing Li at Sydney University. This led to theinvitation to present a state of the art paper to the leading journal in this field, Biomaterials. We also collaboratewith the ETH University in Zurich and our work has attracted considerable interest from many dental materialsmanufacturers in Europe. In the Forensic Science area we have developed strong linkages and share PhD studentswith ESR. The other major collaboration has been with the Biomedical Engineering (Professor A. Pullan) groupat the University of Auckland and Professor John Bronlund of Massey University on the Biomouth project. Theforensic biomechanics collaboration is with Dr Michael Taylor of ESR. We were also involved in the organizationof the First Biomouth Workshop (Auckland, December 2006). Finite element modeling of the stresses developed in the mandible incorporating physiologically oriented muscle forces. Model developed from CT scanning of the mandible with localised loading of the premolar on one side of the mouth. The model was developed to quantify the role of the chin in imparting functional rigidity to the mandible. From Ichim, I., Swain, M., and Kieser J. (2006). Journal of Biomechanics 39, 1903-1913
RESEARCH REPORT 2005-2006denTal epIdemIoloGy and publIC healThGroup leaderProfessor W.M. Thomsonkey personnelJ.M. Broadbent, K. Ayers (to 2006)K. Morgaine (from mid-2006)The Dental Epidemiology and Public Health group investigates the oral health of populations (and what affectsit), with particular attention to the natural history of dental disease and health through childhood, adolescenceand adulthood. We also investigate the way in which dental health services work, how people use them, and whatcan be done to improve the delivery of oral health care.research fociDental epidemiologyWe study the occurrence, determinants and natural history of the common oral conditions. To do this, weemploy a number of standard dental epidemiological approaches (most notably the prospective cohort studyand the cross-sectional survey) and techniques. Multidisciplinary collaboration has proven to be a very fruitfulway of doing our work, as it combines the different strengths and knowledge bases of a number of researchers.Dental health services research (HSR)HSR is concerned with how the health system works, and the extent to which users are benefiting from it. Keyactivities are measuring oral health outcomes and increasing understanding of how (and why) people use (ordo not use) dental services. Our group has played an important role in the development and epidemiologicalvalidation of new measures for child oral-health-related quality of life, working in collaboration with a numberof overseas researchers. We are also rapidly developing our expertise and output in the field of dental workforceresearch.research highlightsThere has been satisfying progress with the group’s research endeavours in 2005-06, with 23 papers publishedin the international scientific literature, 19 peer-reviewed presentations to scientific conferences, and 7 keynoteaddresses. The successful completion of the age-32 assessment phase of the Dunedin Study in mid-2005 heraldeda period of intense data analysis and manuscript preparation which has already led to a number of publishedpapers, along with conference presentations in Baltimore, Orlando, Brisbane and Dublin. Jonathan Broadbent’sPhD work on dental caries trajectories was particularly well received internationally. PhD student Lyndie-FosterPage and Murray Thomson were awarded the biennial NZDA research award (given for research published inthe New Zealand Dental Journal). In 2005, Murray Thomson received a Fulbright Travel Award to enable him toattend and make presentations at Columbia University and the Baltimore IADR meeting.Katie Ayers left for the Waikato at the end of 2005, but continues to work with us as a PhD student. KateMorgaine joined the team in mid-2006. Her background and skills in health services research and healthpromotion complement those of the other team members very well, and some useful collaborations are alreadyin train.A number of postgraduate research projects were successfully supervised to completion during 2005-2006.These included one PhD completion, two MComDent completions, two MHealSc completions, and four MDScompletions. We are currently supervising a number of PhD and Masters students. Undergraduate researchsupervised by the group during 2005-06 included 17 final-year dental student elective projects, one summerstudentship project, and two final-year therapy/hygiene research projects.selected publicationsBroadbent J.M., Thomson W.M., Poulton R. (2006) Oral health beliefs from adolescence: determinants of oral health in young adulthood? Journal of Dental Research 85:339-343. Thomson W.M., Broadbent, J.M., Poulton, R., Beck, J.D. (2006). Changes in periodontal disease experience from age 26 to 32 in a birth cohort. Journal of Periodontology 77:947-954. 0
FACULTY OF DENTISTRYBroadbent, J.M., Thomson, W.M., Poulton, R., (2006). Progression of dental caries and tooth loss between the third and fourth decades of life: a birth cohort study. Caries Research 40:459-465.Thomson, W.M., Lawrence, H.P., Broadbent, J.M., Poulton, R. (2006). The impact of xerostomia on oral- health-related quality of life among younger adults. Health and Quality of Life Outcomes 4:86-92. GrantsWe continue to suffer from oral health’s perceived lack of relevance among funding bodies in New Zealand, buthave had some grant application successes. A major funding application for a study of the oral health of olderpeople (a steadily increasing group, and more and more New Zealanders are retaining their teeth into old age)was turned down by the Health Research Council in 2006, but, on the bright side, a related feasibility study grantwas awarded HRC funding of $112,516. In 2005, the Maurice and Phyllis Paykel Trust awarded Lyndie Foster-Page and Murray Thomson a grant-in-aid ($22,500) for the former’s PhD research.outreachCollaboration is very important to the work and impact of the group. Current collaborations include institutionsin New Zealand (Waikato, Taranaki, Capital Coast, and Nelson-Marlborough District Health Boards andthe Ministry of Health), Australia (the Universities of Adelaide and Melbourne), Canada (the University ofToronto), the USA (the University of North Carolina), and Britain (GKT Dental Institute, the University ofLondon). Presentations, including invited keynote addresses on our work, have been made in Australia, Japanand in the USA.While our impact on policy development is difficult to quantify, there have been outcomes affecting farm safety,the dental work force and the next national oral health survey. Kate Morgaine’s work on evaluating the nationalFarmSafe project has identified successful elements of a safety promotion programme supported by AccidentCompensation Corporation. Future expansion of this programme to other primary production sectors willincorporate this information. Murray Thomson has produced the annual workforce analysis reports for theDental Council of New Zealand, and has also continued to advocate for a third national oral health survey. Thisvitally important survey has now been allocated funding from the Ministry of Health and is to proceed underthe aegis of the Ministry’s Public Health Intelligence group.
RESEARCH REPORT 2005-2006endodonTIC mICrobIoloGyGroup leaderProfessor R. M. LoveThe study and practice of endodontics is aimed at preventingand treating pulp and periapical disease. An understandingof the mechanisms of bacterial invasion of dentinal tubules iscentral to these aims. Bacterial infection of dentine has beenrecognised for over a century, but only recently has this researchgroup identified the mechanisms involved in colonising. Anunderstanding of these mechanisms should lead to novel Transmission electron micrograph demonstrating aprophylactic and control treatments. colony of bacterial cells invading a dentinal tubule.research focusBacterial attachment, colonisation and dentinal tubule invasionBacteria initially adhere to the host tissue via a loose physical association to the surface of a tissue, then morepermanently through the binding of microbial cell surface adhesions to complementary host surface receptors.We have shown that invading bacterial cells physically attach to the wall of a dentinal tubule and show alteredmorphology at the zone of attachment. Tubule invasion requires specific bacterial-collagen adhesion reactionsinvolving streptococcal cell-surface antigen I/II polypeptides. Interaction between streptococcal cells andcollagen upregulates production of antigen I/II polypeptide and induces long-chaining of streptococcal cells.Abrogation of polypeptide expression or blocking with collagen inhibits bacterial invasion.The bound microbe needs to utilize available nutrients, compete or co-operate with other species in theimmediate environment, and contend with host defence mechanisms before it can colonize the host by formingcolonies at multiple sites. Nutrient limitation within a dentinal tubule may influence the depth of bacterialpenetration. For example, the presence of hemin within coronal or radicular dentine favours the growth andsurvival of organisms such as P. intermedia and P. micros (Love, 2007). Bacteria may compete for invasionof dentinal tubules, and they may co-operate via specific co-aggregation. For example, we have shown thatdentinal tubule invasion by P. gingivalis was promoted when co-cultivated with S. gordonii but not S. mutans.Tissue molecules and endogenous substances (such as albumin, fibrinogen, and IgG) inhibit bacterial invasionof radicular dentinal tubules by interacting with bacterial cells or physically occluding tubules and reducingdentine permeability. Certain species, such as Enterococcus faecalis, can overcome these molecules and infectdentinal tubules.Thus, our research shows that tubule invasion and development of the intertubular bacterial flora followspatterns seen in the formation of plaque biofilms. Initial attachment and colonization by primary streptococcalcolonizers then allows colonization by late colonizers such as P. intermedia and P. gingivalis. It is highly likelythat other interactions between host proteins and other bacteria influence tubule invasion.selected publicationLove, R.M. (2007). Hemin nutritional stress inhibits bacterial invasion of radicular dentine by two endodontic anaerobes. International Endodontic Journal 40:94-99.GrantsResearch during 2005-2006 was generously supported by the University of Otago, and the New Zealand DentalResearch Foundation.outreachThe Group collaborates with staff across the Faculty of Dentistry and the Department of Oral and DentalScience, University of Bristol, UK. Research is conducted within the Molecular Microbiology Laboratory.
FACULTY OF DENTISTRYmoleCular mICrobIoloGy laboraTorylaboratory academic leaderProfessor R. D. Cannonkey personnelDr A. Holmes, Dr E. Lamping, T. Milne, Dr B. Monk,Dr K. Niimi, Dr G. Tompkins, J. Upritchard (LaboratoryManager)associated researchers using the facilityProfessor M. Meikle, Professor G. Seymour and Dr M.Cullinan, Professor W.M. Thomson, Associate Professor A.Rich, Professor R. Love, Professor B. Monteith and K. LyonsThe Molecular Microbiology Laboratory (MML) is a core facility for the Faculty of Dentistry that providesthe expertise, equipment and laboratory environment (a PC2 containment laboratory) needed to study themolecular mechanisms underlying dental disease caused by microorganisms. In the last two years, it has alsosupported molecular research on craniofacial development and the relationship between dental disease andchronic human diseases, including atherosclerosis and diabetes.research foci and research highlightsMicroorganisms contribute to, or are responsible for many oral diseases, including dental caries, gingivitis,periodontitis and oral candidosis. Research in the Molecular Microbiology Laboratory uses molecular genetic,microbiological, and biochemical techniques to investigate microbial physiology, adhesion, colonisation,pathogenicity and drug resistance, with the aim of discovering how oral microorganisms cause disease andbecome resistant to current drugs. This information allows us to devise new ways of preventing oral (and manyother) microbial diseases. Researchers in the laboratory have developed novel genetic and biochemical systemsto study drug resistance and to screen for new drugs. These systems have wide applications across the dental,medical, and biological sciences.The main research programmes in the MML can conveniently be divided into three broad topics that offeropportunities for both elective undergraduate research projects and postgraduate study.microbial Colonisation and pathogenicityThe attachment of pathogenic microorganisms to host tissues is a crucial step in the initiation of infectionand involves specific molecules on microbial and host surfaces. We are investigating the adhesion of oralmicroorganisms, including Candida albicans and Streptococcus mutans, to oral surfaces. We are particularlyinterested in the roles of saliva components in both promoting and preventing adhesion to devices such as voiceprostheses, and we are working with industry to devise novel ways of interfering with adhesion interactions.Microbes secrete enzymes in order modify their environment and acquire nutrients. Such enzymes oftencontribute to pathogenesis. We are investigating the role of proteinases in the pathogenicity of Porphyromonasgingivalis, Prevotella intermedia and C. albicans. We are also using genetic approaches to identify factors affectingC. albicans pathogenicity mechanisms determining biofilm formation in the nasopharyngeal pathogen Moraxellacatarrhalis, and a possible link between C. albicans colonisation and pre-cancerous oral lesions.drug resistance and new drug Targets in fungi and bacteriaWith an ageing population and increasing numbers of immunocompromised individuals, infections causedby fungal species that are opportunistic human pathogens constitute a major clinical problem that is growingin significance. The concomitant increasing use of antifungal agents has led to the emergence of drug-resistantfungal strains, including species that are intrinsically resistant to widely used classes of antifungal drugs. Ourunderstanding of the mechanisms of drug resistance in fungi led us devise a novel hyper-expression system toexamine the function of drug resistance determinants in the model yeast Saccharomyces cerevisiae. We have usedthis system to help a pharmaceutical company evaluate a new antifungal drug, and we have screened our ownlibrary of ~2 million D-octapeptides to identify a specific inhibitor of the major efflux pump from C. albicans,have determined its mode of action and are now able to find more drug-like molecules that act in a similarway. The hyper-expression system has wide application for the study of membrane proteins of relevance tohuman health, including the purification and structural resolution of drug targets. The humanisation of the
RESEARCH REPORT 2005-2006system is expected to bring new opportunities for funding and commercial development in 2007. We now aimto use structure-directed drug design to identify inhibitors of fungal drug efflux pumps and broad-spectruminhibitors of the fungal proton pumping ATPase, an essential antifungal drug target that also circumventsmultiple mechanisms of drug resistance. Other projects exploiting our drug discovery expertise include researchto develop anti-infectives that target the MRSA superbug, Pseudomonas aeruginosa, and DNA gyrase, a drugtarget found in bacteria but not humans.Craniofacial developmentThe environmental effects of tooth movement on craniofacial tissues are being investigated by measuringcellular responses to physical forces in rat and tissue culture models using the techniques of molecular biology.Information on gene expression is expected to provide insights into the molecules and structures affected byorthodontic manipulation.Within these broad research themes, MML staff have developed specific research programmes in areas in whichthey are particularly experienced. These programmes are described in more detail in their individual researchprofiles. MML staff actively support the research of other Faculty members and welcome opportunities suchas the establishment in 2007 of the Sir John Walsh Research Institute and Immunopathology Group headed byProfessor Seymour.selected publicationsHolmes, A.R., Tsao, S., Ong, S., Lamping, E., Niimi, K., Monk, B.C., Niimi, M., Kaneko, A., Holland, B.R., Schmid, J. and Cannon, R.D. (2006). Heterozygosity and functional allelic variation in the Candida albicans efflux pump genes CDR1 and CDR2. Molecular Microbiology 62:170–186.Niimi, K., Maki, K., Ikeda, F., Holmes, A.R., Lamping, E., Niimi, M., Monk, B.C. and Cannon, R.D. (2006). Overexpression of Candida albicans CDR1, CDR2 and MDR1 does not produce significant changes in echinocandin susceptibility. Antimicrobial. Agents and Chemotherapy. 50:1148-1155.Monk, B.C., Niimi, K., Lin, S., Knight, A., Kardos, T.B., Cannon, R.D., Parshot, R., King, A., Lun, D. and Harding, D.R.K. (2005). Surface-active fungicidal D-peptide inhibitors of the plasma membrane proton pump that block azole resistance. Antimicrobial. Agents and Chemotherapy. 49:57-70.Wada, S., Tanabe, K., Yamazaki, A., Niimi, M., Uehara, Y., Niimi, K., Lamping, E., Cannon, R.D. and Monk, B.C. (2005). Phosphorylation of Candida glabrata ATP-binding cassette transporter Cdr1p regulates drug efflux activity and ATPase stability. Journal of Biological Chemistry 280:94-103.GrantsResearch in the MML during 2005-2006 has been generously supported by the University of Otago, the NewZealand Dental Research Foundation, the Marsden Fund, the New Zealand Lottery Grants Board, Astellas PharmaInc, and the Japan Health Science Foundation. Highlights have included awards of a pilot grant and then a fullgrant from the National Institutes of Health (USA) to Professor Richard Cannon’s group for a study designed tounderstand drug resistance in C. albicans and discover new drugs against this important oral pathogen.outreachThe laboratory maintains strong collaborations with staff across the Faculty of Dentistry and with theUniversity Departments of Biochemistry, Microbiology and Immunology, Pharmacy, Surgery, and Pathology(at the Wellington School of Medicine). The MML is a major component of the University of Otago OralMicrobiology and Dental Health Research Theme (http://www.otago.ac.nz/oralmicro). A significant strengthof MML is its close national collaboration with researchers at Massey University, and productive internationalcollaborations with the National Institute of Infectious Diseases, Tokyo, the Nippon Dental University, Niigata,Japan, the Membrane Protein Expression Center, University of California San Francisco and several Australianuniversities.In 2006, MML members hosted workshops on saliva and membrane proteins, and presented seminars on theirwork at conferences, University Departments and research institutes in Australia, Japan Europe and NorthAmerica. Members also took an active part in the establishment of the Sir John Walsh Research Institute.
FACULTY OF DENTISTRYoral ImplanToloGyGroup leaderAssociate Professor A. G. T. Paynekey personnelOral RehabilitationProfessor M. Swain, D. Purton, C. Hauman, N. Waddell,J. Aarts, J. Egan, I. van Staden and B. TorrOral SciencesProfessor W.M. Thomson, Professor J. Kieser, Dr W. Duncanand J. LeichterOral, Surgical and Diagnostic SciencesR. De Silva, D. Kuzmanovic and D. CampbellstudentsPhD SupervisorsN. Waddell M. Swain, A. Payne and J. KieserMDS (Prosthodontics) J. Hall A. Payne, D. Purton and W.M. ThomsonM. Al-Zubeadiai A. Payne and W.M. ThomsonA. Mackie A. Payne, W.M. Thomson and K. LyonsMHealSc J. Egan A. Payne and W.M. ThomsonJ. Aarts A. Payne and W.M. ThomsonWe conduct clinical and laboratory-based research relating to implant dentures and single-tooth implants thataims to improve the oral health-related quality of life of the ageing population. Our evidence-based treatmentapproach of reducing the delay between oral implant placement and loading with the prosthesis is internationallyrecognised.research focusResearch is focused on controlled prospective clinical research on implant-supported overdentures used to treatedentulous patients. Comparative evaluation between different dental implant systems has been completed formandibular (lower jaw) implant-supported overdenture patients. Controlled evaluation of different loadingstrategies for early functional loading of oral implants with overdentures in the mandible has provided thebackground for further prospective clinical research to rehabilitate the edentulous maxilla (upper jaw) usingthe same treatment approach. Current projects include a multicentre project on mandibular implant partialdentures, a randomized controlled clinical trial on conventional and immediate loading of single implantcrowns, evaluation of different occlusal schemes of implant overdentures, photo-elastic studies on oral implantssupporting partial dentures, and investigations into different ceramic systems for single-implant crowns.The Oral Implantology team at Otago has maintained an international reputation in research through acontinued, focused publication record in the field, as well as presenting at international conferences. We havecontributed to the establishment of the Sir John Walsh Research Institute, and have an established track record ofattracting postgraduate students (including international students for full-time PhD study) to conduct researchin our field. We have established international research collaboration with eight academic institutions in sevencountries together with significant national collaboration. Members of our research team continue to reviewfor, and be members of Editorial Boards of, prestigious international journals in oral implantology. They havealso contributed to the Cochrane Collaboration Oral Health Review Group on Randomized Controlled ClinicalTrials, based in Manchester, United Kingdom.selected publicationsWaddell, J.N., Payne, A.G.T., and Swain M.V. (2006). Physical and metallurgical considerations of failures of bar attachment systems for implant overdentures: A review of the literature. Journal of Prosthetic Dentistry 96:283-8.Hall, J.A.G., Payne, A.G.T., Purton, D., and Torr, B. (2006). A randomized controlled clinical trial of conventional and immediately loaded tapered implants with screw-retained crowns. International Journal of Prosthodontics 19:17-19.
RESEARCH REPORT 2005-2006key CollaborationsProfessor H. Nicholson, Anatomy and Structural Biology, University of OtagoProfessor M. MacEntee, University of British Columbia, Vancouver, CanadaProfessor J. Feine, McGill University, Montreal, CanadaProfessor R. Mericske-Stern, University of Berne, SwitzerlandProfessor P. Owen, Dr Y. Solomons, University of Witwatersrand, South AfricaProfessor J. Wennström, University of Göteborg, SwedenAssociate Professor T. Walton, University of Sydney, AustraliaDr A. Tawse-Smith, University of ColombiaDr D. Wismeijer, University of Amsterdam, NetherlandsDr M. Esposito, Cochrane Collaboration, University of Manchester, United KingdomProfessor L. Sennerby, Branemark Clinic, Göteborg, Sweden Implant at surgery with buccal exposure of threads. Resonance frequency analysis of implant stability at surgery. Immediate restoration implant provisional crown. Immediate restoration definitive implant crown at 1 year.
FACULTY OF DENTISTRYoral mICrobIoloGy and denTal healTh researCh ThemeTheme CoordinatorDr G. R. TompkinsThe mission of the University of Otago Oral Microbiologyand Dental Health (OMDH) Research Theme isto foster, support, and develop research into oral microbiologyas it relates to dental health. The research theme provides afocus of scholarship and research in oral microbiology for theUniversity of Otago, and for New Zealand.The Theme comprises approximately 60 members (see http://www.otago.ac.nz/oralmicro) at the University of Otago,including faculty, staff and students associated with the Schoolof Dentistry, the Department of Microbiology and Immunology, and the Department of Pathology, Universityof Otago Wellington. We also maintain links with an additional twenty scientists from around New Zealand withinterests in oral microbiology with whom Theme members have collaborative projects and who often attendTheme workshops. In the years 2005 and 2006, Theme members published 92 articles in peer-reviewed journalsand secured NZ$2.86 million in research funding. Major funding sources include: Health Research Councilof New Zealand, National Institutes of Health (USA), Lotteries Health and the New Zealand Dental ResearchFoundation Board. The theme also updates its members on recent developments in the field by sponsoring visitsto New Zealand of prestigious overseas scientists, including contributors to our specialist workshops.Visiting scientistsOverseas scientists sponsored by the Theme to visit New Zealand were:Professor L.P. Samaranayake (Professor and Chair of Oral Microbiology, University of Hong Kong), an authorityon the oral pathogenic fungus Candida. He was a keynote speaker at the Australia/New Zealand Divisional meetingof the International Association of Dental Research annual meeting in Queenstown (September 25-28, 2005).Professor P. Gilbert (University of Manchester), a pioneer in the study of microbial biofilm formation and dynamics.Professor Gilbert attended and participated in the Theme workshop (November 22) and was a guest speaker at theNew Zealand Microbiological Society’s annual scientific meeting in Dunedin (November 23-25, 2005).Dr M. Upton (University of Manchester) visited Otago from March 13 to May 15, 2006 undertaking a researchproject in the laboratory of Professor John Tagg (Dept. Microbiology and Immunology). Dr Upton participatedin the Theme workshop (April 10, 2006) giving a talk entitled: “Signalling in oral biofilms”.Dr V. Machiulskiene (Clinic of Dental and Oral Diseases, Kaunas Medical University, Lithuania) contributedto the Theme workshop (April 10, 2006) giving a talk entitled: “Clinical measurement of caries activity and itsimportance”.WorkshopsWorkshops organised by and involving Theme members:Oral Microbiology and Dental Health Research Theme Workshop (full day, November 22, 2005)Guest speaker: Professor P. Gilbert (University of Manchester).Issues in Dental Caries (full day, April 10, 2006)Guest speakers: Dr V. Machiulskiene (Kaunas Medical University) and Dr Matt Upton (University ofManchester).Saliva Components with Health Potential (full day, November 27, 2006)Funded by the University of Otago Research Committee Contestable Funds.Guest speaker: Professor C. Bingle (University of Sheffield Medical School, UK).
RESEARCH REPORT 2005-2006Frontiers of Biology: Expression, structure and function of membrane proteins (Two-day workshop November 28-29, 2006). This workshop was organised and funded jointly by the OMDH Research Theme and the FunctionalGenomics, Gene Expression and Proteomics Research Theme. Guest speakers: Professor K.M. Pos (University ofZurich, Switzerland) and Professor E. Padan (Hebrew University of Jerusalem, Israel).Conference supportThe Theme provided 24 grants-in-aid that allowed students and post-doctoral researchers to present their workand national and international meetings during 2005-6, and awarded seven bursaries to enable undergraduatestudents to undertake summer research projects.external CollaborationTheme members are involved in collaborative research with the following departments, companies andinstitutes:AgResearch Ltd., Ruakura, New ZealandDepartment of Medical and Surgical Sciences, University of Otago, Dunedin, New ZealandDepartment of Microbiology, Massey University, New ZealandPublic Health Research Institute, Newark, NY, USAUniversity of Queensland, AustraliaNippon Dental University, Niigata, JapanNational Institute of Infectious Diseases, Tokyo, JapanBlis Technologies, Dunedin, New ZealandEnvironmental Science and Research Ltd., Kenepuru, New ZealandMembrane Protein Expression Center, University of California San Francisco, USAAstellas Pharma, JapanPfizer Inc, USA
FACULTY OF DENTISTRYConTaCT emaIl addressesdepartment personnel email address pageOral Diagnostic John Broughton firstname.lastname@example.org 21and Surgical Sciences Norman Firth email@example.com 27 Dusan Kuzmanovic firstname.lastname@example.org 33 Robert Love email@example.com 35 Karl Lyons firstname.lastname@example.org 36 Eithne MacFadyen email@example.com 37 Alison Rich firstname.lastname@example.org 45 Rohana Kumara De Silva email@example.com 25 Darryl Tong firstname.lastname@example.org 50Oral Rehabilitation Vincent Bennani email@example.com 20 Nick Chandler firstname.lastname@example.org 23 Richard Cook email@example.com 24 Catharina Hauman firstname.lastname@example.org 27 Ionut Ichim email@example.com 30 Brian Monteith firstname.lastname@example.org 40 Alan Payne email@example.com 43 David Purton firstname.lastname@example.org 44 Michael Swain email@example.com 47 Neil Waddell firstname.lastname@example.org 50Oral Sciences Anuj Batra email@example.com 20 Jonathan Broadbent firstname.lastname@example.org 20 Richard Cannon email@example.com 22 Mary Cullinan firstname.lastname@example.org 24 Bernadette Drummond email@example.com 26 Warwick Duncan firstname.lastname@example.org 26 David Healey email@example.com 28 Doug Holborow firstname.lastname@example.org 28 Ann Holmes email@example.com 29 Tom Kardos firstname.lastname@example.org 31 Mikhail Keniya email@example.com 32 Jules Kieser firstname.lastname@example.org 32 Erwin Lamping email@example.com 34 Jonathan Leichter firstname.lastname@example.org 35 Murray Meikle email@example.com 37 Alison Meldrum firstname.lastname@example.org 38 Trudy Milne email@example.com 39 Brian Monk firstname.lastname@example.org 39 Kate Morgaine email@example.com 41 Kyoko Niimi firstname.lastname@example.org 42 Andrew Quick email@example.com 44 Gregory Seymour firstname.lastname@example.org 46 Murray Thomson email@example.com 48 Geoffrey Tompkins firstname.lastname@example.org 49
RESEARCH REPORT 2005-2006faCulTy researCh profIlesanuJ baTraBDSOral SciencesLecturerResearch on gross anatomy of the head and neck is conducted in collaboration with theDepartment of Anatomy and Structural Biology. Anuj Batra supervises human dissectionsand is an expert on head and neck anatomy.VInCenT bennanIDDSOral RehabilitationSenior LecturerResearch involves company-supported implant development and experimentation. A patenthas been granted entitled “Fabrication of an implanted-supported titanium framework usedas a surgical guide, and as the final framework”.Research CollaboratorEcole Nationale Superieure des Mines de Paris, Paris, FranceJonaThan m. broadbenTBDSOral SciencesResearch FellowDental Public Health and Epidemiology (Dental Epidemiology Laboratory)Jonathan Broadbent investigates the natural history of dental disease and health throughchildhood, adolescence and through adulthood. His particular focus is upon socialdisparities in oral health.Research and CollaborationJonathan is employed to collect, analyse, and report on data from the DunedinMultidisciplinary Health and Development Study (a prospective observational study of acohort of New Zealanders born in 1972-73). His research includes projects involving theepidemiology of dental caries, tooth loss, and periodontal disease (with emphasis uponlongitudinal research), and particularly upon social inequalities that exist in oral health. Heis currently engaged in PhD study on oral health inequalities. He also carries out researchpertaining to the New Zealand dental workforce.Selected Publications Broadbent, J.M., Williams, K.B., Thomson, W.M., and Williams, S.M. (2006). Dental restorations: a risk factor for periodontal attachment loss? Journal of Clinical Periodontology 33:803-810. Broadbent, J.M., Thomson, W.M., and Poulton, R. (2006). Oral health beliefs in adolescence and oral health in young adulthood. Journal of Dental Research 85:339-43.Broadbent, J.M., Thomson, W.M., and Poulton, R. (2006). Progression of dental caries and tooth loss between the third and fourth decades of life: a birth cohort study. Caries Research 40:459-465.0
FACULTY OF DENTISTRYBroadbent, J.M., Thomson, W.M., and Williams, S.M. (2005). Does caries in primary teeth predict enamel defects in permanent teeth? A longitudinal study. Journal of Dental Research 84: 260-264.Broadbent, J.M., and Thomson, W.M. (2005). For debate: problems with the DMF index pertinent to dental caries data analysis. Community Dentistry and Oral Epidemiology 33: 400-409. Research CollaboratorsProfessor W.M. Thomson, Oral Sciences, Faculty of Dentistry, University of Otago, Dunedin, New ZealandProfessor R. Poulton, School of Medicine, University of Otago, Dunedin, New ZealandJohn brouGhTonED BSc BDS PhD PGDipComDentOral Diagnostic and Surgical SciencesHauora Mäori (Mäori health). This is a broad area of research and Professor Broughton is responsible for a varied portfolio including oranga niho (Mäori oral health) and injury prevention. Research and CollaborationAssociate Professor Broughton completed a PhD thesis on Mäori oral health service provision. This thesis included Mäori concepts of oral health from pre-European times to the present day and reviewed the contemporary development of Mäori oral health services by Mäori.He has also entered into a working relationship with Raukura Hauora O Tainui, a large North Island-based Mäori health provider in a research project looking at the oral health of rangatahi (Mäori teenagers).PublicationPhD thesis (2006) Oranga Niho: A review of Mäori oral health service provision utilising a kaupapa Mäori methodology. (Supervisors: Professor W.M. Thomson, Associate Professor R.O. McGee).Research CollaboratorsDr D. Begg, R. Brookland, Professor J. Langley, Injury Prevention Research Unit Dunedin School of Medicine, University of Otago, Dunedin, New ZealandProfessors J. Kieser, G. Seymour and W.M. Thomson, Dr G. Tompkins, M. Cullinan, Oral Sciences, Faculty of Dentistry, University of Otago, Dunedin, New ZealandResearch Associate Professor C. Sissons, School of Medicine, University of Otago, Wellington New ZealandJ. Maipi and M. Person, Raukura Hauora O Tainui, Hamilton, New ZealandAssociate Professor S. Ameratunga, School of Population Health’s Injury Prevention Research Centre, University of Auckland, Auckland, New ZealandDr M. Williams, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
RESEARCH REPORT 2005-2006rIChard d. CannonMA PhDOral SciencesDirector, Molecular Microbiology LaboratoryProfessor Cannon’s main interest is in oral yeast: how they colonise the oral cavity; howthey cause disease; and ways of preventing them causing disease. His particular researchinterests focus on the human pathogen Candida albicans, which causes both oral candidosisand life-threatening disseminated disease. He uses molecular approaches to determine howC. albicans adheres in the mouth, what makes it pathogenic, how it becomes resistant toantifungal drugs, and how its drug resistance can be overcome.Research and Collaboration Candida albicans is a yeast that adheres to (and colonises) the mouths of many people.When these people’s normal defences are impaired, C. albicans can cause infections. Theinfections range from oral thrush to invasive, life-threatening disease. Often, people withoral Candida infections have to undergo prolonged treatment with antifungal drugs. Ifwe can stop the yeast from adhering to surfaces in the mouth, we may be able to preventthese people from developing Candida infections. In order to prevent adherence, we have tounderstand the mechanisms of oral colonisation. Professor Cannon aims to discover howC. albicans adheres in the mouth, and whether adhesion can be prevented. Understandingthese mechanisms of adherence could lead to new treatments to reduce the risk of peopledeveloping potentially lethal Candida infections.There are few drugs effective in treating people with Candida infections. A serious clinicalproblem is the prevalence of C. albicans strains which are resistant to the commonly usedantifungal drug fluconazole. Genes from C. albicans that encode potential drug pumps havebeen cloned and there is a correlation between fluconazole resistance and over-expressionof these genes. In collaboration with members of the Molecular Microbiology Laboratoryand Professors Robert Stroud and David Perlin, these genes are now being expressed in theyeast Saccharomyces cerevisiae in order to understand how the pumps work and to search fornovel pump inhibitors. Professor Cannon is also interested in discovering novel factors thatcontribute to the virulence of C. albicans, as these factors could prove to be new drug targets.In collaboration with Dr Jan Schmid at Massey University, he is comparing the genomesof virulent C. albicans strains with the genomes of less virulent strains in order to identifygenetic factors unique to the virulent strains. Also in collaboration with Dr Schmid andProfessor Pete Magee, he is investigating whether sexual reproduction in C. albicans stillprovides an advantage to this diploid eukaryote.Selected PublicationsCannon, R.D., and Firth, N.A. (2006). Fungi and fungal infections of the oral cavity. In Oral microbiology and immunology. R.J. Lamont, R.A. Burne, M.S. Lantz and D.J. LeBlanc (eds), ASM Press, Washington, pp 333-348.Holmes, A.R., Tsao, S., Ong, S., Lamping, E., Niimi, K., Monk, B.C., Niimi, M., Kaneko, A. Holland, B.R., Schmid, J., and Cannon, R.D. (2006). Heterozygosity and functional allelic variation in the Candida albicans efflux pump genes CDR1 and CDR2. Molecular Microbiology 62:170-186.Niimi, K., Maki, K., Ikeda, F., Holmes A.R., Lamping, E., Niimi, M., Monk, B.C., and Cannon, R.D. (2006). Over-expression of Candida albicans CDR1, CDR2 or MDR1 does not produce significant changes in echinocandin susceptibility. Antimicrobial Agents and Chemotherapy 50:1148-1155.Lamping, E., Tanabe K., Niimi, M., Uehara, Y., Monk, B.C., and Cannon, R.D. (2005). Characterization of the Saccharomyces cerevisiae sec6-4 mutation and tools to create S. cerevisiae strains containing the sec6-4 allele. Gene 361:57-66.Wada, S., Tanabe, K., Yamazaki, A., Niimi, M., Uehara, Y., Niimi, K., Lamping, E., Cannon, R.D., and Monk, B.C. (2005). Phosphorylation of Candida glabrata ATP-binding cassette transporter Cdr1p regulates drug efflux activity and ATPase stability. Journal of Biological Chemistry 280:94-103.
FACULTY OF DENTISTRYResearch CollaboratorsProfessor R. Stroud, University of California at San Francisco, San Francisco, USAProfessor P. Magee, University of Minnesota, Minneapolis, USAProfessor D. Perlin, University of Medicine and Dentistry of New Jersey, Newark, USAProfessor T. White, Seattle Biomedical Research Institute, Seattle, USAAssociate Professor S. Kajiwara, Tokyo Institute of Technology, Tokyo, JapanDr M. Niimi, National Institute of Infectious Diseases, Tokyo, JapanDr K. Nakamura, General Research Institute, Nippon Dental University, Niigata, JapanDr B. Holland, Dr J. Schmid, Massey University, Palmerston North, New ZealandResearch Associate Professor C. Sissons, School of Medicine, University of Otago, Wellington, New ZealandP. Dawes and D. Ruske, Dunedin School of Medicine, University of Otago, Dunedin, New ZealandAssociate Professor A. Rich, Oral Diagnostic and Surgical Sciences, Faculty of Dentistry, University of Otago, Dunedin, New ZealandDr A. Holmes, Dr B. Monk, Dr K. Niimi, Dr E. Lamping and Dr M. Keniya, Oral Sciences, Faculty of Dentistry, University of Otago, Dunedin, New ZealandnICholas p. ChandlerBDS MSc PhD LDSRCS FDSRCPS FDSRCS FFDRCSIOral RehabilitationAssociate Professor Chandler’s research interests are related directly to patient care andtreatment outcomes. These include: the assessment of the health of the dental pulp; pulpdimensions and their clinical implications; radiography as applied to endodontics; andmanagement of the resected root end during periapical surgery.Research and CollaborationStudies with Dr Robert O’Shea (Dept of Psychology, University of Otago) are investigatingpulp exposure size and the dimensions of cavities within the crowns of teeth and at theroot-end. It is hoped to establish whether common visual illusions influence judgment ofsize during dental treatment. With Professor Pitt Ford in London, studies of laser Dopplerflowmetry of molar teeth as a pulp vitality test are being concluded. Dentine measurementusing an electronic device is being investigated with Dr A. Qualtrough (University ofManchester), and a variety of radiographic studies are under way with Dr A. Oginni(Obafemi Awolowo University, Nigeria).Publications Healey, D.L., Plunkett, D.J. and Chandler, N.P. (2006). Orthodontic movement of two root fractured teeth. Case report. International Endodontic Journal 39:324-329.Gordon, M.P.J., Love, R.M. and Chandler, N.P. (2005). An evaluation of .06 tapered gutta-percha cones for filling of .06 taper prepared curved root canals. International Endodontic Journal 38:87-96.Chandler, N.P., Ng B.P. and Monteith, B.D. (2005). Radiographic recognition and distribution of approximal carious lesions in New Zealand undergraduate dental students. New Zealand Dental Journal 101:106-109.Research CollaboratorsProfessor T. Pitt Ford, GKT Dental Institute, King’s College London, University of London, London, EnglandDr A. Qualtrough, Turner Dental School, University of Manchester, Manchester, EnglandDr A. Oginni, Department of Restorative Dentistry, Obafemi Awolowo University, Ile Ife, NigeriaDr R. O’Shea, Department of Psychology, University of Otago, Dunedin, New Zealand
RESEARCH REPORT 2005-2006rIChard b. CookBMedSc PhDOral RehabilitationLecturerThe focus of Dr Cook’s research is into the biomechanics of human bone, in order to providea better understanding of the fracture mechanics of cancellous bone tissue, with particularinterest in the bone condition osteoporosis.Research and Collaboration The main focus of the research has been the investigation of the biomechanics of cancellousbone tissue, particularly on osteoporosis. An understanding is sought of the fracturemechanics of the cancellous bone tissue with respect to tissue-specific independentvariables. Some of this work was undertaken in collaboration with the collagen researchgroup at the University of Bristol (UK), looking at the collagen cross-linking within thefracture toughness samples. Dr Cook is now investigating specific features of the fracturepropagation in cancellous tissue and the effects of structural integrity on the fracturetoughness of cancellous bone tissue.Other work has included the mechanics of bone tissue from a mature elephant femur. Theproject was in collaboration with the Royal Veterinary College in the UK. The aim was toproduce a Finite Element Numerical Analysis model of the femur, in order to model theloading of the femur during walking.Research CollaboratorsDr S. Shefelbine, Bioengineering Department, Imperial College, London, EnglandDr J. Hutchinson, Structure and Motion Laboratory, The Royal Veterinary College, North Mymms, Herts, EnglandDr P. Zioupos, Biomechanics Laboratories, Cranfield University, DCMT Shrivenham, EnglandDr C. Curwen, Gloucestershire Royal Hospital, Gloucester, EnglandDr D. Collins, Department of Rheumatology, Great Western Hospital, Swindon, Englandmary p. CullInanBDS MSc FADIOral Sciences DepartmentSenior Research FellowMary Cullinan’s research is predominantly clinical in the field of periodontal disease and sheis currently working on several large multidisciplinary clinical studies. Her interests includemicrobiological, environmental and genetic risk factors for periodontal disease as well as therelationship between periodontal disease and systemic diseases such as cardiovascular diseaseand diabetes. She is also interested in the effect of interventions on health behaviour.Research and CollaborationCurrent projects are focused on the interface between oral health and general health,including periodontal infection and atherosclerosis and diabetes. Multidisciplinary clinicalstudies currently in progress include: CAPS (Cardiovascular and Periodontal Study), O-HELP (Oral Health Education, Logan Programme, ADAPT (Assessment of Diabetes AfterPeriodontal Treatment), Adult Oral Health Project in the Republic of Marshall Islands,ENIGMA- The effect of periodontal treatment on endothelial dysfunction and the Peri-implantitis Treatment Study.Selected Publications Ford, P.J., Gemmell, E., Chan, A., Carter, C.L., Walker, P.J., Bird, P.S., West, M.J., Cullinan, M.P. and Seymour, G.J. (2006). Inflammation, heat shock proteins and periodontal pathogens in atherosclerosis: an immunohistological study. Oral Microbiology and Immunology 21:206-211.
FACULTY OF DENTISTRYFord, P.J., Gemmell, E., Hamlet, S.M., Hasan, A., Walker, P.J., West, M.J., Cullinan, M.P. and Seymour, G.J. (2005). Cross-reactivity of GroEL antibodies with human heat shock protein 60 and quantification of pathogens in atherosclerosis. Oral Microbiology and Immunology 20:296-302. Ford, P., Gemmell, E., Walker, P., West, M., Cullinan, M. and Seymour, G.J. (2005). Characterization of heat shock protein-specific T cells in atherosclerosis Clinical and Diagnostic Laboratory Immunology, 12:259-267. Narayanan, D., Hamlet, S., Cullinan, M., Davies, R., Ellwood, R., Bird, P. and Seymour, G.J. (2005). The distribution of Tannerella forsythia in an adolescent and adult population. Journal of Periodontal Research 40:482–488. Research CollaboratorsProfessors G. Seymour, W.M. Thomson, Drs W Duncan and N. Heng, J. Leichter and D. Holborow, Oral Sciences, University of Otago, Dunedin, New ZealandProfessor M. West, Associate Professors D. Kavanagh and P. Walker, Drs B. Westerman, P. Ford and P. Bird, S. Hamlet and J. Palmer, University of Queensland, Brisbane, Australia Professor M. Faddy, Queensland University of Technology, Brisbane, Australia Drs T. Holcombe and D. Roberts, Oral Health Clinic, Logan Hospital, Brisbane, Australia Associate Professor L. Heitz-Mayfield, University of Western Australia, Perth, Australia Dr J. Taylor, University of Newcastle upon Tyne, United KingdomProfessor N. Lang and Dr M. Schatzle, University of Berne, Berne, Switzerland Drs K. Tut and O. Tut, Ministry of Health, Republic of Marshall Islands rohana k. de sIlVaBDS FDSRCPS FFDRCS FDSRCSOral Diagnostic and Surgical SciencesSenior LecturerRohana De Silva’s two main research areas are: management of post-operative pain afterremoval of wisdom teeth and evaluation of the metabolism of commonly used painkillersin the body; and the use of dental implants as a cost effective way to replace missing teeth ina shorter period of time in order to improve quality of life.Research and CollaborationA double-blind cross-over clinical trial was carried out in 2005 to evaluate thepharmacodynamic and pharmacokinetic effects of a high dose of paracetamol. This trialinvolved a collaboration with the researchers from the Department of Anaesthesia andIntensive Care at Dunedin Hospital, Pharmacology and Toxicology and the School ofPharmacy. The main intention of this trial was to identify the safe and effective dose ofparacetamol in healthy individuals after surgical removal of wisdom teeth.In 2005, two clinical trials were conducted with the dental implant team in the DentalSchool. One trial was as a multi-centre study to evaluate the use of dental implants in theretention of partial dentures in the lower jaw. This was done in collaboration with theresearchers in Amphia Teaching Hospital, Bredan, University of Amsterdam, Netherlands,and the Colombian Dental School, Bogota, South America.The other trial, conducted with the dental implant research team, evaluated the use of dentalimplants to replace missing upper front teeth as a one-day procedure. The results of this trialwere published in March 2007.Publication Lou, S.M-Y., Rich, A.M., De Silva, R.K., and Ferguson, M.M. (2006). Pleomorphic adenoma of a minor salivary gland. Oral Oncology Extra 42:170-172.
RESEARCH REPORT 2005-2006bernadeTTe k. drummondBDS MS PhD FRACDSOral SciencesCurrent research includes diagnosis and treatment of dental caries in primary and youngpermanent teeth, dental health related to diet and nutrition, dental caries prevention, andgenetic and general health influences on orofacial growth and development.Research Associate Professor Drummond’s main research interests are in the evaluation of the short-and long-term outcomes of dental care in young children. This involves evaluating thesuccess of different treatment procedures and the effects of the delivery of care, includingcare under general anaesthesia, using material that has been collected for almost 19 years. Sheis investigating the relationships of dental caries with general health, including overweightand obesity in young children, and continues to evaluate the effects of new preventivematerials on the progression (or prevention) of dental caries – especially in very youngchildren. Criteria are being developed to assess the caries risk of children by their firstbirthday, and the introduction of an early prevention programme for infants. The outcomeswill be monitored until the children are 5 years old. Another interest is assessing successfultreatment of hypomineralised and hypoplastic teeth. This involves identification of bothmaterials that improve the structure and hardness of the defective enamel, and restorativeprocedures for severely affected teeth that allow their long-term (lifetime) survival.PublicationCho, S.Y., and Drummond, B.K. (2006). Solitary median maxillary central incisor and normal stature: a report of three cases. International Journal of Paediatric Dentistry 16:128–134.WarWICk J. dunCanED BDS MDS PhD FRACDS(Perio)Oral SciencesSenior LecturerDr Duncan conducts dental implant research in humans and animals, investigatingtreatments that improve the bonding of titanium implants to jaw bone. He also researchesthe genetic basis for periodontal (gum) diseases and their relationship to other non-dentaldiseases and conditions.Research and Collaboration The use of the lower jaws of sheep for dental implant testing, an animal model unique toNew Zealand, was finalised with the completion of a PhD thesis in 2005. During 2006, acollaborative project commenced with Chonbuk University (South Korea), comparingvarious titanium dental implants treated using a novel process called spark discharge anodicoxidation. Delayed- and immediately-loaded implants are being tested in different sites inthe sheep (lower jaw, maxillary sinus, femur), replicating different qualities of bone foundin human patients. Additional projects are under way studying the use of bone-substitutesgrafted into the sinus, and the use of a novel growth factor around dental implants.Student projects under supervision include: (i) micro-computerised tomographic andhistological analysis of immediately-loaded dental implants in the sheep animal model;(ii) analysis of the long-term success of dental implants placed in the Dental School; (iii)clinical audit of implant and periodontal treatment at the Dental School; and (iv) gene-arrayanalysis of lymphocytes and fibroblasts in patients who smoke, patients with atherosclerosisand comparing patients who have gingivitis or periodontitis.Research CollaboratorsDr M. Lee, Chonbuk University, South Korea
FACULTY OF DENTISTRYProfessor G. Seymour, M. Cullinan, D. Holborow, J. Leichter, Oral Sciences, Faculty of Dentistry, University of Otago, Dunedin, New ZealandD. Kuzmanovic, Oral Diagnostic and Surgical Sciences, Faculty of Dentistry, University of Otago, Dunedin, New ZealandProfessor M. Swain, Oral Rehabilitation, Faculty of Dentistry, University of Otago, Dunedin, New Zealandnorman a. fIrThBDS MDSc FRACDS FFOP (RCPA)Oral Diagnostic and Surgical SciencesSenior LecturerNorman Firth investigates various diseases of the oral mucosa, including potentiallymalignant and malignant oral mucosal lesions and inflammatory lesions.Research and CollaborationStudies of components of basement membrane in these lesions are in progress. Other areasof interest include: histological changes in oral lichen planus, follow-up of patients withoral leukoplakia and squamous cell carcinoma, genetic profiles and cell proliferation inodontogenic cysts and aspects of forensic dentistry.PublicationCannon, R.D., and Firth, N.A. (2006). Fungi and fungal infections of the oral cavity. In Oral microbiology and immunology. R.J. Lamont, R.A. Burne, M.S. Lantz and D.J. LeBlanc (eds), ASM Press, Washington, pp 333-348.CaTharIna h.J. haumanBMedSci MMedSci BChD MDSOral RehabilitationSenior LecturerCatharina Hauman is interested in patient care and treatment outcomes. She investigatesbacterial viability in dentine by fluorescence, the use of polymer rotary instruments inselective caries removal, and the management of the resected root end.Research and CollaborationStudies with Dr Geoffrey Tompkins, Jonathan Leichter, Ionut Ichim, together with theOtago Electron and Confocal Microscope Unit, are investigating the efficacy of dentinedisinfection, including laser application, by determining the viability of bacteria in dentineusing fluorescence methods. Studies with Dusan Kuzmanovic are looking at the ability ofan existing polymer rotary instrument (“Smartprep”) to cut healthy dentine. This researchaims to develop improved instruments for selective caries removal.Publication Kieser, J., Kieser, D.C., and Hauman, C.H.J. (2005). Course and distribution of the inferior alveolar nerve. Journal of Craniofacial Surgery 16:6-9. Research CollaboratorsDr G. Tompkins, Oral Sciences, Faculty of Dentistry, University of Otago, Dunedin, New ZealandJ. Leichter, Oral Sciences, Faculty of Dentistry, University of Otago, Dunedin, New ZealandI. Ichim, Oral Rehabilitation, Faculty of Dentistry, University of Otago, Dunedin, New ZealandD. Kuzmanovic, Oral Diagnostic Surgical Sciences, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
RESEARCH REPORT 2005-2006daVId l. healeyBDS MDS MOrthRCSEdOral Sciences DepartmentSenior LecturerDavid Healey is currently enrolled for a PhD investigating Quality of Life issues surroundingorthodontic treatment and its outcomes; specifically, how well patient expectations arebeing met and how closely these are aligned with professionally set goals.Research A prospective study is assessing the orthodontic pre-treatment expectations of patient,parent and clinician, in comparison with post-treatment satisfaction and change in indicesof malocclusion. Other interests include orthodontics, third molars, computed tomography,craniometrics and reconstruction, forensic identification, obstructive sleep apnoea, andcleft lip and palate.Publications Healey, D.L., Plunkett, D.J., and Chandler, N.P. (2006). Orthodontic movement of two root fractured teeth. Review and Case report. International Endodontic Journal 39:324-329. Healey, D.L., and Kieser J. (2005). Unusual fatal dog attack in Dunedin, New Zealand. Journal of Forensic Odonto-Stomatology 23:51-4. Research CollaboratorsProfessor J. Kieser, Oral Sciences, Faculty of Dentistry, University of Otago, Dunedin, New ZealandAssociate Professor N. Chandler, Oral Rehabilitation, Faculty of Dentistry, University of Otago, Dunedin, New ZealandAssociate Professor R. Gauld, Department of Preventive and Social Medicine, Faculty of Medicine, University of Otago, Dunedin New ZealanddouGlas W. holboroWBDS FDSRCSOral SciencesSenior LecturerDouglas Holborow investigates the local delivery of antibacterial agents in the treatment ofperiodontal diseases. The aim is to identify effective, locally applied agents for treating gumdiseases. He also seeks to understand how students perceive that they learn clinical skills.CollaboratorDr C. Bond, Higher Education Development Centre, University of Otago
FACULTY OF DENTISTRYann holmesPhDOral SciencesSenior Research FellowDr Holmes investigates how the commensal microbial populations of the human mouth (inparticular, the fungus Candida albicans) interact with the host, and how diseases that canresult from these normally harmless organisms might be prevented.Research and Collaboration Candida albicans is a pathogenic yeast that causes superficial and systemic infections inimmunocompromised individuals, and adhesion of Candida cells to host epithelial surfacesis an initial event in the development of disease. C. albicans has been shown to bind to variousoral surfaces (such as dental materials and oral bacteria as well as saliva-coated epithelial cells),and a major theme of Dr Holmes’ research has been to study the mechanisms involved inthese interactions. This includes an analysis of interactions between saliva and Candida cellsin collaboration with Professor Richard Cannon and Mr Patrick Dawes, Mr Jamie Ryan andMr Dean Ruske, (Department of Medical and Surgical Sciences). She also collaborates withDr Cannon and Molecular Microbiology Laboratory members on a project entitled “Fungaltransporters: from resistance to new antifungals” under a research grant from the NationalInstitutes of Health, USA. Research achievements include construction of recombinant yeaststrains, and development of assay systems necessary for studying the function of fungalmembrane efflux pumps. These pumps determine drug resistance of opportunistic fungalpathogens such as C. albicans. A major achievement has been the discovery of significant allelicvariation affecting function in the efflux pump genes of C. albicans.Selected PublicationsHolmes, A.R., Tsao, S., Ong, S-W. Lamping, E., Niimi, K., Monk, B.C., Niimi, M., Kaneko, A., Holland, B.R., Schmid, J., and Cannon, R.D. (2006). Heterozygosity and functional allelic variation in the Candida albicans efflux pump genes CDR1 and CDR2. Molecular Microbiology 62:170-86.Holmes, A.R., Tsao, S., Lamping, E., Niimi, K., Monk, B.C., Tanabe, K., Niimi , M., and Cannon. R.D. (2006). Amino acid residues affecting drug pump function in Candida albicans. Japanese Journal of Medical Mycology 47:275-281.Holmes, A.R., van der Wielen, P., Cannon, R.D., Ruske, D., and Dawes, P.J.D. (2006). Candida albicans binds to saliva proteins selectively adsorbed to silicone. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 102:488-493.Niimi, K., Maki, K., Ikeda, F., Holmes, A.R., Lamping, E., Niimi, M., Monk, B.C., and Cannon, R.D. (2006). Overexpression of Candida albicans CDR1, CDR2, or MDR1 does not produce significant changes in echinocandin susceptibility. Antimicrobial Agents and Chemotherapy. 50:1148-55.Jeng, H-W., Holmes, A.R., and Cannon, R.D. (2005). Characterisation of two Candida albicans surface mannoprotein adhesions that bind immobilized saliva components. Medical Mycology 43:209-17.Research CollaborationsProfessor R. Cannon, Drs M. Keniya, E. Lamping, B. Monk and K. Niimi, Oral Sciences, Faculty of Dentistry, University of Otago, Dunedin, New ZealandAssociate Professor A. Rich, Oral Diagnostic and Surgical Sciences, Faculty of Dentistry, University of Otago, Dunedin, New ZealandP. Dawes and D. Ruske, Dunedin School of Medicine, University of Otago, Dunedin, New ZealandResearch Associate Professor C. Sissons, School of Medicine, University of Otago, Wellington, New ZealandDr A. Hodgkinson, AgResearch Ruakura, Hamilton, New ZealandDr M. Niimi, National Institute of Infectious Diseases, Tokyo, Japan Dr B. Haigh, AgResearch Ruakura, Hamilton, New ZealandDr T. Wheeler, AgResearch Ruakura, Hamilton, New ZealandDr C. Bingle, Division Genomic Medicine, The University of Sheffield Medical School, Sheffield, UK
RESEARCH REPORT 2005-2006IonuT p. IChImBDS MDSOral RehabilitationLecturerIonut Ichim researches masticatory biomechanics, including the shape-function relationshipof the teeth and jaws, and masticatory muscle recruitment. He studies biomechanicalintegration of dental restorations in the complex biomechanical environment of theoral cavity. He employs Finite Element Numerical Analysis in dental research, includingorthodontic tooth movement. Forensics and biomechanics of blunt trauma are alsostudied.Research and CollaborationThe problem of the human chin provided a model to study shape-function relationshipsof the jaws. Reverse-engineering and morphing techniques created “what if ” scenarios toselectively investigate the biomechanical role of the human chin. An analysis of the mandibulardynamics during mastication and muscle recruitment has been carried out in collaborationwith Auckland Institute of Bioengineering. The novel technique of predicting restorativematerial fracture using discrete element analysis was used to investigate the biomechanicalintegration of restorative materials. The problem of the failure of cervical restorations andthe optimal mechanical properties of the restorative materials were studied in collaborationwith the School of Mechanical Engineering, James Cook University, Australia and Schoolof Aerospace, Mechanical and Mechatronic Engineering, University of Sydney and Facultyof Dentistry, Zurich, Switzerland. Finite Element Analysis is being used to investigateorthodontic tooth movement with the School of Aerospace, Mechanical and MechatronicEngineering, University of Sydney. A chewing robot is being built in collaboration withFood Sciences at Massey University and Auckland Institute of Bioengineering BiomouthResearch Group.Recent PublicationsIchim, I., Kieser, J., and Swain, M. (2006). Mandibular stiffness in humans: numerical predictions. Journal of Biomechanics 39:1903-13.Ichim I., Kieser, J., and Swain, M. (2006). Mandibular Biomechanics and Development of the Human Chin. Journal of Dental Research 85:638-42.Ichim I., Kieser, J., and Swain, M. (2006). Functional significance of strain distribution in the human mandible under masticatory load: numerical predictions. Archives of Oral Biology. 39:1903-13.Ichim I., Love, R., and Kuzmanovic, D. (2006). A finite element analysis of ferrule design on restoration resistance and distribution of stress within a root. International Endodontic Journal 39:443–452.Li, Q., Ichim, I., Loughran, J., Li, W., Swain, M., and Kieser, J. (2006). Numerical simulation of crack formation in all ceramic dental bridge. Key Engineering Materials 312:293-298.Research CollaboratorsDr Q. Li, School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, AustraliaDr P. Schmidlin, Clinic for Preventive Dentistry, Periodontology and Cariology, Centre for Dental and Oral Medicine and Maxillo-Facial Surgery, University of Zurich, Switzerland Associate Professor J. Bronlund, Institute of Technology and Engineering, Massey University, Palmerston North, New ZealandDr O. Roehrle, Bioengineering Institute, University of Auckland, Auckland, New ZealandAssociate Professor A. Pullan, Bioengineering Institute, University of Auckland, Auckland, New Zealand Professor J. Loughran, School of Engineering, James Cook University, Townsville, Australia0