As cementum is one of the hard tissues of the Periodontium which is now being challenging structure to the researcher's, Effort is put forth in understanding the molecular and cellular level of the Cementum. The information is collected from one of the articles from Perio 2000 and also from the slide share forum.
This powerpoint gives you the gist and hopefully a better understanding for the learners.
Periodontitis is a chronic infectious inflammatory disease caused by microbes; however the presence of microbes is not enough for the cause of its complex nature of disease. Inflammation is the prime cause of periodontal disease. It commences with the aggregation of pathogenic microbes that induce the host to stimulate a cascade of inflammatory response reactions which in-turn leads to the destruction of the host tissues itself. There is a complex interplay of innate and adaptive immune responses which fights against the pathogens by direct interaction or by release of certain molecules including cytokines.
Cytokines are cell signalling molecules that aid cell to cell communication in immune responses and stimulate the movement of cells towards sites of inflammation, infection and trauma. Cytokine biology reveals that there are some subsets of cytokines which are pro-inflammatory cytokines which stimulate the inflammatory responses and cause tissue destruction.
A periodontist is expected to have a sound basis of the cytokine profile to understand the pathogenesis of periodontitis and also to discover the new treatment modality of anti-cytokine therapy.
Periodontitis is a chronic infectious inflammatory disease caused by microbes; however the presence of microbes is not enough for the cause of its complex nature of disease. Inflammation is the prime cause of periodontal disease. It commences with the aggregation of pathogenic microbes that induce the host to stimulate a cascade of inflammatory response reactions which in-turn leads to the destruction of the host tissues itself. There is a complex interplay of innate and adaptive immune responses which fights against the pathogens by direct interaction or by release of certain molecules including cytokines.
Cytokines are cell signalling molecules that aid cell to cell communication in immune responses and stimulate the movement of cells towards sites of inflammation, infection and trauma. Cytokine biology reveals that there are some subsets of cytokines which are pro-inflammatory cytokines which stimulate the inflammatory responses and cause tissue destruction.
A periodontist is expected to have a sound basis of the cytokine profile to understand the pathogenesis of periodontitis and also to discover the new treatment modality of anti-cytokine therapy.
T-cells is explained with a emphasis with humoral and adaptive immunity . And the diffrent subsets of t cells are well explained by Dr Harshavardhan Patwal here .
Porphyromonas gingivalis belongs to the phylum Bacteroidetes and is a nonmotile, Gram-negative, rod-shaped, anaerobic, pathogenic bacterium. It forms black colonies on blood agar.
It is found in the oral cavity, where it is implicated in certain forms of periodontal disease, as well as in the upper gastrointestinal tract, the respiratory tract, and the colon. It has also been isolated from women with bacterial vaginosis. Collagen degradation observed in chronic periodontal disease results in part from the collagenase enzymes of this species. It has been shown in an in vitro study that P. gingivalis can invade human gingival fibroblasts and can survive in them in the presence of considerable concentrations of antibiotics.P. gingivalis also invades gingival epithelial cells in high numbers, in which cases both bacteria and epithelial cells survive for extended periods of time. High levels of specific antibodies can be detected in patients harboring P. gingivalis. Dr Harshavardhan Patwal , explains the various enzymes enzyme peptidyl-arginine deiminase, which is involved in citrullination.[4] Patients with rheumatoid arthritis have an increased incidence of periodontal disease, and antibodies against the bacterium are significantly more common in these patients.
P. gingivalis is divided into K-serotypes based upon capsular antigenicity of the various types.
Blood supply,nerve supply and lymphatic drainage of the periodontium finalDr. Neha Pritam
Discussion of the various basic topics required to understand in the subject of periodontics. Periodontium being the tooth supporting tissue ,it is necessary to know the blood supply, nerve supply and the lymphatic drainage of the same in dentistry
Inflammation and Immunity in periodontitis pptPerio Files
Local destruction of periodontium occurs mostly by activation of immune and inflammatory response, initiated by plaque. First innate immune response is activated followed by specific immune response.
Useful for BDS and MDS students
T-cells is explained with a emphasis with humoral and adaptive immunity . And the diffrent subsets of t cells are well explained by Dr Harshavardhan Patwal here .
Porphyromonas gingivalis belongs to the phylum Bacteroidetes and is a nonmotile, Gram-negative, rod-shaped, anaerobic, pathogenic bacterium. It forms black colonies on blood agar.
It is found in the oral cavity, where it is implicated in certain forms of periodontal disease, as well as in the upper gastrointestinal tract, the respiratory tract, and the colon. It has also been isolated from women with bacterial vaginosis. Collagen degradation observed in chronic periodontal disease results in part from the collagenase enzymes of this species. It has been shown in an in vitro study that P. gingivalis can invade human gingival fibroblasts and can survive in them in the presence of considerable concentrations of antibiotics.P. gingivalis also invades gingival epithelial cells in high numbers, in which cases both bacteria and epithelial cells survive for extended periods of time. High levels of specific antibodies can be detected in patients harboring P. gingivalis. Dr Harshavardhan Patwal , explains the various enzymes enzyme peptidyl-arginine deiminase, which is involved in citrullination.[4] Patients with rheumatoid arthritis have an increased incidence of periodontal disease, and antibodies against the bacterium are significantly more common in these patients.
P. gingivalis is divided into K-serotypes based upon capsular antigenicity of the various types.
Blood supply,nerve supply and lymphatic drainage of the periodontium finalDr. Neha Pritam
Discussion of the various basic topics required to understand in the subject of periodontics. Periodontium being the tooth supporting tissue ,it is necessary to know the blood supply, nerve supply and the lymphatic drainage of the same in dentistry
Inflammation and Immunity in periodontitis pptPerio Files
Local destruction of periodontium occurs mostly by activation of immune and inflammatory response, initiated by plaque. First innate immune response is activated followed by specific immune response.
Useful for BDS and MDS students
As the periodontium consists of cementum and alveolar bone and periodontitis poss an immense insult to the periodontium, it is of utmost importance for a periodontist and implantologist to understand the basic molecular biology of cementum and alveolar bone to manage the cases of periodontitis more effectively.
CONTENTS:
Introduction
Some basic terminologies
Definition
Rational for use in dentistry
Effects of growth factors at various levels
Mode of action of growth factors
Receptors for growth factors
Common features of growth factors
Classification of growth factors
Type of growth factors and actions
Conclusion
References
INTRODUCTION:
Periodontal diseases result in destruction of periodontal tissues, including cementum, bone, and periodontal ligament (PDL), with eventual tooth loss if left untreated.
Traditional Method……Elimination of bacterial pathogens + Modulation of host response leads to Arrest / Slow disease progression.
Better understanding of the disease at the cellular and molecular level as well as events involved in tissue development, healing and regeneration has Improved therapies with Arrest Of Disease Progression & Ultimate goal is to regenerate the periodontal tissues.
SOME BASIC TERMINOLOGIES :
Repair:
Healing of a wound by tissue that does not fully restore the architecture or function of the part. (AAP, Glossary of periodontal terms, PAL). Repair simply restores the continuity of the diseased marginal gingiva and reestablishes a normal gingival sulcus at the same level on the root as the base of the preexistent periodontal pocket. This process called healing by scar, arrests bone destruction without necessarily increasing bone height (caranza).
Regeneration:
Is the growth and differentiation of new cells and intercellular substances to form new tissues or parts. Regeneration takes place by growth from the same type of tissue that has been destroyed or from it’s precursor. This is termed as wear and tear repair.
Reattachment:
The term has been used in past to refer to the restoration of the marginal periodontium.
As per (AAP-92) it is defined as the reunion of epithelial and connective tissues with root surfaces and bone such as occur after an incision or injury. It should not be confused with new attachment.
New attachment: is the embedding of new periodontal ligament fibers into new cementum and the attachment of the gingival epithelium to a tooth surface previously denuded by disease.
Epithelial adaptation:
Differs from new attachment in that it is the close apposition of the gingival epithelium to the tooth surface without complete obliteration of the pocket.
PERIODONTAL REGENERATION is defined as the restoration of lost periodontium or supporting tissues and includes formation of new alveolar bone, new cementum and new periodontal ligament.
There is a need, however, to improve the predictability of regenerative therapies.
This need has led to increased efforts, to establish the specific cells, factors, delivery systems, flap design, and host responses required for enhancing outcome of regenerative therapies.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
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June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
1. Cellular and Molecular
Biology of Cementum
Dr. K. Satya
Dr. Vaishnavi Sanglikar
1st
yearMDS
Dept of Periodontology
Maratha Mandal NGH
institute of Dental
sciences
2. Cementum is the calcified, avascular mesenchymal tissue that forms the outer covering of the
anatomic root. It furnishes a medium for the attachment of collagen fibers that bind the tooth
to surrounding structures (Sharpey’s fibers).
3. Contents
• Introduction
• Regulators of cementogenesis
• Factor-mediated cell activities
Receptor tyrosine kinases
G protein coupled receptors
Serine – threonine receptor kinases
Integrins
6. • Cells responsible for cementum formation:
• Cementoblasts: Primary source
Location : close apposition to cementum surface
Strongly resemble osteoblasts
• Cementocytes:
Location : within the mineralized matrix of cementum
Have a slightly lower level of matrix synthesis.
• Fibroblasts within the PDL:
Role is unclear
8. Regulators of Cementogenesis :
Overview : events, cells and factors associated with
cementum.
• Many events required for formation of cementum are well
established, the actual cells and factors required to form
this tissue during development as well as during
regeneration have yet to be defined.
9. • Ability of ideal agents
To promote migration and
attachment of appropriate cells to
the healing site with subsequent
orchestration of cells to allow for
cell differentiation.
To promote mineralization (new
cementum) along
the root surface, with insertion of
periodontal ligament
into cementum and opposing
alveolar bone to
form the periodontium.
EVENTS
10.
11. • PDL fibroblasts:
Responsible for ensuring a functional
PDL region.
• Osteoblasts & associated progenitor cells:
Responsible for preserving the
surrounding alveolar bone.
Histological examination of the healthy periodontium indicates that several
types of mesenchymal cells are important for maintenance of a healthy
periodontium.
12. • Cementoblasts & root surface lining cells:
appear to be limited in function in health but
may be activated during wound healing.
• Paravascular/marrow cells:
Provide the required local nutrients
at the site.
13.
14. Some of the factors that may trigger differentiation of follicle cells or
possibly transformation of Hertwig’s epithelial root sheath cells so as to
function as cementoblasts will be discussed
15. • Accumulating evidence exists to a support a role for
periodontal ligament fibroblasts as inhibitors of
mineralization.
• Thus, there may be distinct cell populations within the
periodontal ligament region that can both promote and
inhibit mineral tissue formation depending upon trigger
factors.
• Also, it is high likely that other sources of cementoblast
or osteoblast progenitor cells include marrow stroma
and paravascular and endosteal fibroblasts.
16. • Many factors have been implicated a role in controlling
several cell activities.
• These factors are known to be associated with
cementum either during development and/or maturation
and/or regeneration.
17. Molecular factors associated with cementum. Included factors (still under investigation) are
important for development/maintenance/regeneration of cementum.
Modified and updated from MacNeil et al.
18. Adhesion and chemotactic factors:
LIGAND
FIBRONECTINFIBRONECTIN
In addition to its role in tissue development, it also purported
to have a notable role in attracting and maintaining
appropriate cells at healing sites.
19. DevelopmentDevelopment
Adhesion molecules
• Osteopontin
• Bone sialoprotein
Mature tooth
Bone sialoprotein: remain localized to the root
surface.
Osteopontin : within the PDL region.
• Laminin: on dentin surface at initiation of
cementum formation speculated to serve a
role in attracting appropriate cementoblasts
like cells to the root surface.
cementoblasts
Early stage of tooth root
development
20. Further known factors, as well as yet to be identified
novel factors, secreted by epithelial cells may promote
migration and/or adhesion of appropriate cells to the root
surface.
Rationale behind the use of enamel matrix derivative is
that enamel matrix proteins may promote cementoblast
activity including proliferation, migration/adhesion, as
well as cell differentiation.
21. • Bone Sialoprotein
Act as an adhesion molecule to maintain applicable cells at
the root surface
As an initiator of mineral formation along the root surface
Importantly, the temporal and spatial expression of bone
sialoprotein during cementogenesis and bone formation is
consistent with a role for this molecule in promoting
mineral formation.
22. • Osteopontin:
This phosphoglycoprotein contains the well
recognized adhesion domain, arginine-glycine-
aspartic acid (RGD) targeted to specific integrin
receptors, as well as other adhesion regions that act
to promote migration and cell adhesion
23.
24. • Regeneration
• BSP and Osteopontin are expressed by cells linked to
formation of mineralized tissues, while osteopontin also
is expressed by cells within the newly forming
periodontal ligament.
25. • Maturation
Mature cementum contains the adhesion molecules
mentioned above as well as vitronectin and cementum
attachment protein.
• The actual specificity of cementum attachment protein to
cementum, or in fact whether this is a unique protein,
awaits further research and availability of DNA probes to
determine cells expressing cementum attachment protein
during tooth root development and maturation.
• Proteoglycans
26. Mitogens
Mapped during tooth root development include the
members of the transforming growth factor-ß
superfamily, growth hormone, insulin-like growth
factor-I/II and parathyroid hormone–related protein.
• In fact some transforming growth factor-ßs and
parathyroid hormone–related protein may have a role in
regulating cell differentiation and subsequently
mineralization
• Narayanan et al. - Cementum-derived growth factor
27.
28. Factor - mediated cell activities
Factor A Promotes mineralization
of mature Osteoblasts
PDL fibroblasts or
preosteoblasts
Lack ofappropriate
receptors
Factor B priming
Now express the
receptor required for
responding to factor A
29. Growth factors DNA synthesis Differentiation
cytoskeleton
initiate modulate
alter
•The short half life of Growth factors and their association with ECM
and GF binding protein ensure the local effects.
•The ECM molecules and GF’s exert effects through specific cell
surface receptors and when the receptor is bound it interacts with
cytoplasmic effector molecules to initiate a complex cascade of
intracellular events leading to an alteration in gene function.
30.
31.
32. CONTENTS
• Serine – threonine kinase receptor
• Integrins
• Regenerative therapies and cementogenesis in-vivo.
Therapies based on platelet-derived growth factor and
insulin-like growth factor.
Transforming growth factors –ß family members :
Bone morphogenetic proteins 2.3 ,4 and 7.
• Models to study cementogenesis.
• Conclusion
• References.
34. INTEGRINS
Integrins are transmembrane receptors that facilitate
cell-extracellular matrix adhesion.
They are obligate heterodimers.
They are also called as cell adhesion molecules
( CAD ).
35.
36. ROLE OF INTEGRINS
MM.DD.20XX
• Attachment of the cell to the ECM. i.e. extracellular
matrix.
• Signal transduction from the ECM to the cell.
37. MM.DD.20XXADD A FOOTER37
Saito and Narayan et al :-
mature cementum+ fibroblasts+ FAK
Future studies directed -
CAD + cementoblast maturation.
Few studies have focused on the role of these
integrins during the tooth development.
38. REGENERATIVE THERAPIES AND
CEMENTOGENESIS in-vivo
MM.DD.20XXADD A FOOTER38
This section focuses on pre-clinical and clinical
progress towards using growth factors for stimulating
periodontal regeneration, with an emphasis on the
cementum regeneration.
Regulators of periodontal tissue regeneration that
stimulate formation of bone , periodontal ligament
and the cementum include many different agents
categorized as follows
41. THERAPIES BASED ON PLATELET-
DERIVED GROWTH FACTOR AND INSULIN –
LIKE GROWTH FACTOR
MM.DD.20XXADD A FOOTER41
42. MM.DD.20XXADD A FOOTER42
• Some of the studies which used the combination or
without are as follows :
1. Park et al :-
Dog model + PDGF + GTR + Ankylosis.
2.1st
human clinical trial :-
Recombinant Combination therapy + 3 Groups
43. TRANSFORMING GROWTH FACTOR –ß
FAMILY MEMBERS:
BMP 2, 3( OSTEOGENIN ) , 4 & 7 ( OP-1 )
MM.DD.20XXADD A FOOTER43
The bone morphogenetic proteins have been
evaluated extensively in orthopaedic models for their
ability to induce osteogenesis.
BMP-2 is the most thoroughly researched member of
the transforming growth factor –ß superfamily for
the promotion of periodontal and peri-implant bone
regeneration..
44. BONE MORPHOGENETIC PROTEIN – 2,3,4 &
7
MM.DD.20XXADD A FOOTER44
Below are some studies reporting the effects of the
BMP’S :-
1)Sigurdsson et al :-
Recombinant BMP-2 + polymer + ankylosis.
2) Ripamonti et al :-
BMP-4 + topical.
45. MM.DD.20XXADD A FOOTER45
3) 1st
human study :-
BMP-3 + Demineralized bone allograft + × alone
+ pin-point ankylosis.
4)BMP -7 / OP-1 :-
Animal model + ankylosis.
47. TRANSFORMING GROWTH
FACTOR-ß
MM.DD.20XXADD A FOOTER47
Below are some studies reporting the effects of the
TGF-ß :-
1) Wikesjo et al :-
TGF-ß + PTFE
2)Cochran et al :-
BMP-2 +TGF-ß + implant
48. MODELS TO STUDY CEMENTOGENESIS
MM.DD.20XXADD A FOOTER48
• Investigations targeted at understanding the cellular
and molecular mechanisms controlling development
and regeneration of periodontal tissues have utilized
both in-vitro and in-vivo models.
Commonly used animals are the :
• Rodents
• Canines
• Felines
• Non-human primates
49. IN –VITRO MODELS
MM.DD.20XXADD A FOOTER49
Light and electron microscopy:- level have provided a detailed analysis
of cementum.
Immunocytochemical and in-situ hybridization :-studies provide
information as to the factors expressed by cells associated with the
periodontium.
50. MM.DD.20XXADD A FOOTER50
Transgenic / knock-out:- offer another tool to assist in determining the
role of specific molecules in controlling tissue functions.
Cell cultures:- provide an additional tool where advances in cell and
molecular techniques allow for selected manipulation of specific cell types.
In addition, cells isolated in culture can be reintroduced into a specific site
in animals and the activity of the cell type confirmed in vivo.
51. MM.DD.20XXADD A FOOTER51
• According to Grzesik et al :-
Cell phenotype first + then isolating subcloning human
population.
• In a study :-
Cementoblastoma + cementum attachment proteins.
52. IN –VIVO :- GENETICALLY ENGINEERED
ANIMALS
MM.DD.20XXADD A FOOTER52
The mouse is particularly useful as its genome is very well
characterized, and genes can therefore be manipulated with
relative ease.
55. MM.DD.20XXADD A FOOTER55
• The application of putative molecules to induce or modulate
periodontal regeneration is an area of intensive interest.
However the short half-lives of these molecules at the
healing site may reduce their effects in vivo. Therefore,
methods that provide stability of exogenous molecules at the
healing site may be advantageous toward maximizing wound
repair.
• Gene transfer can be performed with strategies for either ex
vivo or in vivo transfer of the desired transgene.
57. MM.DD.20XXADD A FOOTER57
• The most important advance for viruses as gene
transfer vectors was the generation of ‘‘packaging
cells’’ that permit the production of high titers of
replication-defective recombinant virus, free of
wild-type virus; also called gutless viruses.
• The use of gene transfer techniques should enable
one to modulate periodontal regeneration, as well as
assist in enhancing understanding of the
mechanisms involved in wound healing.
58. CONCLUSION
• Despite many years of research and the importance that cementum is thought to
play in the reparative process following periodontal disease, very little is known
about the cells responsible for formation of cementum, cementoblasts. The wealth
of what is known about cementum comes from numerous, detailed studies of its
histology and composition, which has been touched briefly.
• Protein extracts of mature cementum promote cell attachment, migration and
stimulate protein synthesis of gingival fibroblasts and periodontal ligament cells.
Investigation of these extracts revealed the presence of bone sialoprotein,
osteopontin, vitronectin and fibronectin.
• Immunocytochemistry and in situ hybridization confirmed the presence of these
proteins and further identified osteocalcin, g-carboxyglutamic acid, osteonectin,
proteoglycans and several growth factors.
• Two additional molecules, an adhesion molecule and a growth factor, have been
identified and initial data suggest that they may be unique to cementum. Cementum
attachment protein may prove to be a cementum-specific collagenlike molecule,
while a factor initially named cementum-derived growth factor, now considered to
be an insulin-like growth factor-I–like molecule may prove to have properties
similar to those of insulinlike growth factor-I.
59. • This is a dynamic time for researchers and clinicians devoted to
optimizing periodontal/implant regenerative therapies. The
explosion in understanding of regulators of cell function, coupled
with tools that allow researchers to engineer cells so as to express
specific factors, added to improved delivery systems for
controlling release of cells/factors at a given site, now allows
treatment modalities to be designed based on sound scientific data.
• Information gained from these studies should provide the
foundation required for designing more predictable regenerative
therapies when compared with those available at present.
60. REFERENCES
• Textbook : Carranza’s Clinical Periodontology {11th
edition}
• Textbook :Biology of periodontal connective
tissues {P.Mark Bartold, A.Sampath Narayan}
• Nazan E.Saygin , William g, Martha S. Molecular
and cell biology of cementum. 2000: (24), 73-98.
