Statement of problem. The replication of natural teeth, especially for single tooth restorations in patients with high
esthetic needs, represents a challenge.
Purpose. The purpose of the study was to analyze the color of the cervical portion of single metal ceramic crowns
fabricated with different metal framework designs.
Material and methods. The color, as measured on the CIELAB color scale, of 3 different groups of restorations
(n=10) fabricated with a high noble metal alloy (V-Deltaloy) and feldspathic porcelain (Noritake Super Porcelain) was
analyzed with a colorimeter. Conventional metal ceramic crowns with metal facial margins were compared to metal
ceramic crowns with porcelain facial margins and a horizontal reduction of the metal framework (1.0 mm reduction)
or an additional vertical reduction (1.0 mm reduction). In all specimens, the finish line was positioned at a subgingival
or equigingival level. The 6 groups obtained by the combination of the levels of the 2 factors (framework extension
and finish line location) were examined with an ANOVA Fisher’s F-test and a post hoc Tukey’s HSD test (=.05).
Results. The mean color difference for all the groups was clinically acceptable (!<3.7). Conventional metal ceramic
crowns showed higher differences in relation to finish line location (!=2.34), while a vertical reduction of the framework
was related to lower values (!=0.96). Mean Lab* values were reported for all the groups of crowns. Statistically
significant differences were present for L*, a*, and b* values when related to framework extension. Considering each
value in relation to the interaction between framework extension and finish line location factors, significant differences
were present only for L* and a* values.
Conclusions. No significant differences in base shade were present among the investigated crowns. Nevertheless metal
ceramic crowns with vertical cut-back and porcelain facial margins presented more consistent results that tended to
be closer to those of natural teeth. (J Prosthet Dent 2011;106:310-318)
The document discusses bioceramic materials used in endodontics, focusing on mineral trioxide aggregate (MTA). It provides details on the composition, properties, and clinical applications of MTA. MTA has favorable biocompatibility and bioactivity, stimulating tissue regeneration. It forms an excellent seal with good marginal adaptation and push-out bond strength to dentin. MTA is useful for pulp capping, pulpotomies, apexification, and other procedures due to its ability to encourage hard tissue formation.
This document summarizes a study evaluating the use of carbon fiber post systems for restoring teeth defects in children. 106 children with anterior tooth defects from trauma or decay were restored with carbon fiber posts, resin cores, and jacket crowns and observed for 3-5 years on average. The restorations were deemed successful in 121 cases (96.2%), with only 4 crowns lost. The study concluded that carbon fiber post systems can satisfactorily restore anterior teeth in children, with good esthetic and functional outcomes and ease of use for dentists.
Evaluation of Marginal integrity and Depth of Cure for three ‘bulk fill’ comp...pratiklovehoney
Evaluation of Marginal integrity and Depth of Cure for three ‘bulk fill’ composites : SDR, Tetric Evoceram Bulk Fill Composite and EverX Posterior Bulk Fill Composite - An In Vitro study
MONOBLOC IN ENDODONTICS - Root canal filling materials and concept of monoblocDeepa jinan
A description of the monobloc concept/ principle in endodontics including a detailed introduction and meaning of concept, classification of monoblocs in endodontics, various examples in monoblocs and a review of various studies undertaken using different monobloc systems and root canal filling materials
Bioactive materiasl have played significant role in endodontics since the introduction of MTA. other materials have been introduced into the market in order to achieve better results with good prognosis and improved quality in shorter period of time. hence we need to take a quick look on the common available Bioactive materials in the endodontic market in order to investigate the properties of each and to give the practitioner good idea to know how to select the materials.
The document discusses bioceramic materials used in endodontics, focusing on mineral trioxide aggregate (MTA). It provides details on the composition, properties, and clinical applications of MTA. MTA has favorable biocompatibility and bioactivity, stimulating tissue regeneration. It forms an excellent seal with good marginal adaptation and push-out bond strength to dentin. MTA is useful for pulp capping, pulpotomies, apexification, and other procedures due to its ability to encourage hard tissue formation.
This document summarizes a study evaluating the use of carbon fiber post systems for restoring teeth defects in children. 106 children with anterior tooth defects from trauma or decay were restored with carbon fiber posts, resin cores, and jacket crowns and observed for 3-5 years on average. The restorations were deemed successful in 121 cases (96.2%), with only 4 crowns lost. The study concluded that carbon fiber post systems can satisfactorily restore anterior teeth in children, with good esthetic and functional outcomes and ease of use for dentists.
Evaluation of Marginal integrity and Depth of Cure for three ‘bulk fill’ comp...pratiklovehoney
Evaluation of Marginal integrity and Depth of Cure for three ‘bulk fill’ composites : SDR, Tetric Evoceram Bulk Fill Composite and EverX Posterior Bulk Fill Composite - An In Vitro study
MONOBLOC IN ENDODONTICS - Root canal filling materials and concept of monoblocDeepa jinan
A description of the monobloc concept/ principle in endodontics including a detailed introduction and meaning of concept, classification of monoblocs in endodontics, various examples in monoblocs and a review of various studies undertaken using different monobloc systems and root canal filling materials
Bioactive materiasl have played significant role in endodontics since the introduction of MTA. other materials have been introduced into the market in order to achieve better results with good prognosis and improved quality in shorter period of time. hence we need to take a quick look on the common available Bioactive materials in the endodontic market in order to investigate the properties of each and to give the practitioner good idea to know how to select the materials.
This document discusses factors that affect bonding to intraradicular dentin in endodontics. It covers differences between coronal and radicular dentin, how instrumentation can create a smear layer, and how various endodontic materials and procedures like irrigation, bleaching, and retreatment can impact bonding. Root canal anatomy and the inability to control moisture present unique challenges for achieving effective adhesion. Resin-based sealers and core filling materials that utilize adhesive technology are also discussed as ways to potentially improve bonding and sealing of root canals.
Repair of teeth with cracks in crowns and roots: An observational clinical studyDR.AJAY BABU GUTTI M.D.S
1) An observational clinical study investigated the survival rate of teeth with longitudinal cracks (PRCT and DRCT) that underwent composite restoration.
2) 180 cracked teeth from 99 patients were included, with 26% surviving after 5 years. Survival was better for PRCT (75%) than DRCT (48%).
3) The adhesive composite restoration technique was found to promote bone repair in most cases and reduce risk of further crack progression or extraction.
While time-consuming, it provided a promising long-term prognosis for vertical root cracks.
Comparative evaluation of treatment of noncarious cervical hypersensitivity b...DR.AJAY BABU GUTTI M.D.S
Comparative evaluation of treatment of noncarious
cervical hypersensitivity by a fluoride varnish, a
dentin bonding agent, and Er, Cr:YSGG laser: An
in vivo study JCD 2020
Methods of detecting microleakage/ orthodontic course by indian dental academyIndian dental academy
This document discusses various methods used to detect microleakage between dental restorations and tooth structures. It describes several penetration studies methods using dyes, isotopes, bacteria, and chemical tracers to evaluate microleakage. Additional methods covered include air pressure testing, fluid conduction studies, electronic monitoring, and microscopic examination techniques like scanning electron microscopy and replication studies. The document provides an overview of the goals, procedures, and applications of different microleakage detection methods.
Article presentation: enamel repair with amorphous ceramicsDr. Ritu Gupta
this presentation simplifies and explains the mentioned article which describes newer technology for enamel repair, with this method regenerating enamel stronger and better than before
Single Visit Replacement of Central Maxillary Using Fiber-Reinforced Composi...Abu-Hussein Muhamad
Fiber reinforced composites are high strength filling materials composed of conventional composites and glass fibres. They exhibit extensive applications in different fields of dentistry. This clinical report present a case where FRC technology was successfully used to restore central maxillary incisor edentulous area in terms of esthetic-cosmetic values and functionality.
This document discusses denture base resins, including their history, composition, classifications, properties, and specifications. It notes that denture bases are commonly made from polymers like acrylic resins, which are chosen based on factors like availability, stability, and biocompatibility. The document outlines the various types of acrylic resins like heat-cured, self-cured, and light-cured and discusses how they have evolved over time from materials like vulcanite and wood. It also reviews the American Dental Association specifications for denture base resins and their ideal requirements.
A description of a new concept in dentin and enamel bonding - called the acid base resistant zone. points on features of the acid base resistant zone and summary of various studies
This document discusses bioceramic materials used in dentistry and endodontics. It provides details on various bioceramic materials including mineral trioxide aggregate (MTA), bioaggregate, biodentine, and totalfill. For each material, it outlines their composition, properties, advantages, disadvantages, and modifications over time. MTA was the first bioceramic developed in the 1990s and remains one of the most commonly used. More recent developments include biodentine, bioaggregate and totalfill which have improved properties such as strength, handling characteristics, and setting times.
Bioceramics are materials which include Alumina, Zirconia, Bioactive glass, Glass ceramics, Hydroxyapatite, resorbable Calcium phosphates.
Used in dentistry for
Filling up bony defects
Root repair materials
Apical fill materials
Aids in regeneration etc.
Bioinert: non-interactive with biological systems (Alumina, zirconia)
Bioactive: durable tissues that can undergo interfacial interactions with surrounding tissue (bioactive glasses, bioactive glass ceramics, hydroxyapatite, calcium silicates)
Biodegradable: soluble or resorbable, eventually replaced or incorporated into tissue (Tricalcium phosphate, Bioactive glasses).
This document discusses the concept of monoblocks in endodontics, which aims to create a single homogeneous unit within the root canal system. It describes primary, secondary, and tertiary monoblocks created using different root filling materials and posts. Resilon and MTA were discussed as materials used to create secondary and primary monoblocks, respectively. Finite element analysis found that stresses within roots increased with additional interfaces, and creating a primary monoblock reduced internal stresses. The ideal monoblock has yet to be achieved due to limitations such as polymerization shrinkage and insufficient strength or stiffness of materials.
This study evaluated the color stability and fluorescence of 6 brands of esthetic orthodontic archwires when immersed in a staining solution for 21 days. All brands showed some color change after 7 days of immersion, with the degree of staining varying between brands. The Optis archwire showed the most pronounced color change but staining was limited to areas near the ends. The Trianeiro and Ortho Organizers archwires showed less color change. Only the Optis archwire exhibited fluorescence similar to bovine teeth.
Esthethic And Functional Consideration in Restoring Endodontically Andres Cardona
1) Restoring endodontically treated teeth requires consideration of strength, form, function, and aesthetics. The color of the post and core can affect the shade of the final restoration.
2) Fiber posts have advantages like elasticity similar to dentin, but also disadvantages like debonding from the post space. Proper fit and cement thickness are important to avoid stress.
3) Adhesion of posts relies on the adhesive, luting material, and cementation procedure. Dual-cure resin cements allow both self- and light-curing for better polymerization. Translucent posts allow more light transmission for curing.
The document discusses fibre reinforced composite fixed prostheses. It provides background on the materials used such as glass fibres embedded in a resin matrix. Fibre reinforced composites provide an alternative to traditional metal-ceramic restorations. They are esthetic, bond well to tooth structure, and have improved mechanical properties over particulate composites alone. Indications for fibre reinforced composite fixed prostheses include conservative tooth preparations and situations where a metal-free prosthesis is desired. Case studies and clinical trials show promising results for survival and quality of fibre reinforced composite bridges.
JOURNAL CLUB: Diffusion of hydrogen ion and hydroxyl ion from varioussources...Urvashi Sodvadiya
This study examined the diffusion of hydrogen and hydroxyl ions through dentin from various acidic and alkaline sources. Samples of human teeth were exposed to zinc phosphate cement, calcium hydroxide paste, and phosphoric acid. The pH was measured in three layers of dentin chips removed from the pulpal surface. Hydrogen ions from strong acids like phosphoric acid diffused poorly through dentin compared to weaker acids and water, likely due to buffering by hydroxyapatite and other dentin components. Prolonged application of strong acids could change the outer dentin pH slightly in some cases but not beneath restorative materials.
Influence of abutment material on the gingival color of implant-supported all...elenaAbcdental
Purpose: The aim of this clinical research on implant-supported restorations is to analyze, through
spectrophotometric digital technology, the influence of the abutment material on the color of the
peri-implant soft tissue.
Material and methods: Twenty patients received an endosseous dental implant in the anterior
maxilla. At the time of each definitive prosthesis delivery, an all-ceramic crown has been tried on gold,
titanium and zirconia abutment. After the insertion of each single abutment, the peri-implant soft
tissue color has been measured through a spectrophotometer. Also, the thickness of the facial periimplant
soft tissue was measured at the level of the implant neck through a caliper. A specific software
has been utilized to identify a specific tissue area and to collect the data before the statistical analysis
in Labn color space. The normality of the quantitative variables was verified by means of the Shapiro–
Wilk test. Simple linear correlation between quantitative variables was evaluated by using Pearson’s
coefficient. The results on the performance of the abutment materials with regard to the color
measurements and the overall measurement DE were described by computing the least-square means.
The significance of differences among types of abutment was verified by means of the Scheffe test for
multiple comparisons.
Results: For all the abutments used, the color of the peri-implant soft tissue appeared to be
significantly different from the one of the contra-lateral tooth (DE48.5). Significantly higher (Po0.05)
difference were present with the use of titanium abutments (11 " 0.4) when compared with the
results of gold (8.9 " 0.4) and zirconia (8.5 " 0.4) abutments. No correlation has been demonstrated
between soft tissue thickness and degree of color difference (P40.25).
Conclusions: Within the limitation of the present study, the peri-implant soft tissue color appears to
be different from the soft tissue color around natural teeth, no matter which type of restorative
material is selected. When titanium abutment was selected, significantly higher differences were
present than those obtained with gold or zirconia abutments. The thickness of the peri-implant soft
tissue did not appear to be a crucial factor in the abutment impact on the soft tissue color.
Comparison of 2 Techniques of Subepithelial Connective Tissue Graft in the Tr...elenaAbcdental
This study compared two techniques for treating gingival recession defects using subepithelial connective tissue grafts (SCTG): 1) the envelope technique (E) and 2) coronally positioned flap combined with connective tissue graft (CP). Both techniques resulted in significant reduction of gingival recession, with 89.6% coverage for E and 94.7% for CP. While E increased keratinized tissue width, CP did not significantly change width. Postoperative keratinized tissue width was correlated with presurgical width and height of graft exposure.
contains descriptive and other studies on genetics and epigenetics and whole gene concepts from central dogma to future concepts . Dr Harshavardhan Patwal
The document discusses host modulation therapy for the treatment of periodontal disease. It defines key terms like host and modulation. It discusses how our understanding of periodontal disease progression has changed, recognizing that host response plays a major role in determining disease severity rather than just plaque levels. It describes how pharmacological agents can be used as adjuncts to conventional treatment to modulate the host response and reduce tissue destruction. Nonsteroidal anti-inflammatory drugs are provided as an example to inhibit prostaglandin formation and reduce bone loss, though long-term use can have side effects. The document outlines the role of arachidonic acid metabolites in pathogenesis and various studies investigating host modulation agents.
This document discusses factors that affect bonding to intraradicular dentin in endodontics. It covers differences between coronal and radicular dentin, how instrumentation can create a smear layer, and how various endodontic materials and procedures like irrigation, bleaching, and retreatment can impact bonding. Root canal anatomy and the inability to control moisture present unique challenges for achieving effective adhesion. Resin-based sealers and core filling materials that utilize adhesive technology are also discussed as ways to potentially improve bonding and sealing of root canals.
Repair of teeth with cracks in crowns and roots: An observational clinical studyDR.AJAY BABU GUTTI M.D.S
1) An observational clinical study investigated the survival rate of teeth with longitudinal cracks (PRCT and DRCT) that underwent composite restoration.
2) 180 cracked teeth from 99 patients were included, with 26% surviving after 5 years. Survival was better for PRCT (75%) than DRCT (48%).
3) The adhesive composite restoration technique was found to promote bone repair in most cases and reduce risk of further crack progression or extraction.
While time-consuming, it provided a promising long-term prognosis for vertical root cracks.
Comparative evaluation of treatment of noncarious cervical hypersensitivity b...DR.AJAY BABU GUTTI M.D.S
Comparative evaluation of treatment of noncarious
cervical hypersensitivity by a fluoride varnish, a
dentin bonding agent, and Er, Cr:YSGG laser: An
in vivo study JCD 2020
Methods of detecting microleakage/ orthodontic course by indian dental academyIndian dental academy
This document discusses various methods used to detect microleakage between dental restorations and tooth structures. It describes several penetration studies methods using dyes, isotopes, bacteria, and chemical tracers to evaluate microleakage. Additional methods covered include air pressure testing, fluid conduction studies, electronic monitoring, and microscopic examination techniques like scanning electron microscopy and replication studies. The document provides an overview of the goals, procedures, and applications of different microleakage detection methods.
Article presentation: enamel repair with amorphous ceramicsDr. Ritu Gupta
this presentation simplifies and explains the mentioned article which describes newer technology for enamel repair, with this method regenerating enamel stronger and better than before
Single Visit Replacement of Central Maxillary Using Fiber-Reinforced Composi...Abu-Hussein Muhamad
Fiber reinforced composites are high strength filling materials composed of conventional composites and glass fibres. They exhibit extensive applications in different fields of dentistry. This clinical report present a case where FRC technology was successfully used to restore central maxillary incisor edentulous area in terms of esthetic-cosmetic values and functionality.
This document discusses denture base resins, including their history, composition, classifications, properties, and specifications. It notes that denture bases are commonly made from polymers like acrylic resins, which are chosen based on factors like availability, stability, and biocompatibility. The document outlines the various types of acrylic resins like heat-cured, self-cured, and light-cured and discusses how they have evolved over time from materials like vulcanite and wood. It also reviews the American Dental Association specifications for denture base resins and their ideal requirements.
A description of a new concept in dentin and enamel bonding - called the acid base resistant zone. points on features of the acid base resistant zone and summary of various studies
This document discusses bioceramic materials used in dentistry and endodontics. It provides details on various bioceramic materials including mineral trioxide aggregate (MTA), bioaggregate, biodentine, and totalfill. For each material, it outlines their composition, properties, advantages, disadvantages, and modifications over time. MTA was the first bioceramic developed in the 1990s and remains one of the most commonly used. More recent developments include biodentine, bioaggregate and totalfill which have improved properties such as strength, handling characteristics, and setting times.
Bioceramics are materials which include Alumina, Zirconia, Bioactive glass, Glass ceramics, Hydroxyapatite, resorbable Calcium phosphates.
Used in dentistry for
Filling up bony defects
Root repair materials
Apical fill materials
Aids in regeneration etc.
Bioinert: non-interactive with biological systems (Alumina, zirconia)
Bioactive: durable tissues that can undergo interfacial interactions with surrounding tissue (bioactive glasses, bioactive glass ceramics, hydroxyapatite, calcium silicates)
Biodegradable: soluble or resorbable, eventually replaced or incorporated into tissue (Tricalcium phosphate, Bioactive glasses).
This document discusses the concept of monoblocks in endodontics, which aims to create a single homogeneous unit within the root canal system. It describes primary, secondary, and tertiary monoblocks created using different root filling materials and posts. Resilon and MTA were discussed as materials used to create secondary and primary monoblocks, respectively. Finite element analysis found that stresses within roots increased with additional interfaces, and creating a primary monoblock reduced internal stresses. The ideal monoblock has yet to be achieved due to limitations such as polymerization shrinkage and insufficient strength or stiffness of materials.
This study evaluated the color stability and fluorescence of 6 brands of esthetic orthodontic archwires when immersed in a staining solution for 21 days. All brands showed some color change after 7 days of immersion, with the degree of staining varying between brands. The Optis archwire showed the most pronounced color change but staining was limited to areas near the ends. The Trianeiro and Ortho Organizers archwires showed less color change. Only the Optis archwire exhibited fluorescence similar to bovine teeth.
Esthethic And Functional Consideration in Restoring Endodontically Andres Cardona
1) Restoring endodontically treated teeth requires consideration of strength, form, function, and aesthetics. The color of the post and core can affect the shade of the final restoration.
2) Fiber posts have advantages like elasticity similar to dentin, but also disadvantages like debonding from the post space. Proper fit and cement thickness are important to avoid stress.
3) Adhesion of posts relies on the adhesive, luting material, and cementation procedure. Dual-cure resin cements allow both self- and light-curing for better polymerization. Translucent posts allow more light transmission for curing.
The document discusses fibre reinforced composite fixed prostheses. It provides background on the materials used such as glass fibres embedded in a resin matrix. Fibre reinforced composites provide an alternative to traditional metal-ceramic restorations. They are esthetic, bond well to tooth structure, and have improved mechanical properties over particulate composites alone. Indications for fibre reinforced composite fixed prostheses include conservative tooth preparations and situations where a metal-free prosthesis is desired. Case studies and clinical trials show promising results for survival and quality of fibre reinforced composite bridges.
JOURNAL CLUB: Diffusion of hydrogen ion and hydroxyl ion from varioussources...Urvashi Sodvadiya
This study examined the diffusion of hydrogen and hydroxyl ions through dentin from various acidic and alkaline sources. Samples of human teeth were exposed to zinc phosphate cement, calcium hydroxide paste, and phosphoric acid. The pH was measured in three layers of dentin chips removed from the pulpal surface. Hydrogen ions from strong acids like phosphoric acid diffused poorly through dentin compared to weaker acids and water, likely due to buffering by hydroxyapatite and other dentin components. Prolonged application of strong acids could change the outer dentin pH slightly in some cases but not beneath restorative materials.
Influence of abutment material on the gingival color of implant-supported all...elenaAbcdental
Purpose: The aim of this clinical research on implant-supported restorations is to analyze, through
spectrophotometric digital technology, the influence of the abutment material on the color of the
peri-implant soft tissue.
Material and methods: Twenty patients received an endosseous dental implant in the anterior
maxilla. At the time of each definitive prosthesis delivery, an all-ceramic crown has been tried on gold,
titanium and zirconia abutment. After the insertion of each single abutment, the peri-implant soft
tissue color has been measured through a spectrophotometer. Also, the thickness of the facial periimplant
soft tissue was measured at the level of the implant neck through a caliper. A specific software
has been utilized to identify a specific tissue area and to collect the data before the statistical analysis
in Labn color space. The normality of the quantitative variables was verified by means of the Shapiro–
Wilk test. Simple linear correlation between quantitative variables was evaluated by using Pearson’s
coefficient. The results on the performance of the abutment materials with regard to the color
measurements and the overall measurement DE were described by computing the least-square means.
The significance of differences among types of abutment was verified by means of the Scheffe test for
multiple comparisons.
Results: For all the abutments used, the color of the peri-implant soft tissue appeared to be
significantly different from the one of the contra-lateral tooth (DE48.5). Significantly higher (Po0.05)
difference were present with the use of titanium abutments (11 " 0.4) when compared with the
results of gold (8.9 " 0.4) and zirconia (8.5 " 0.4) abutments. No correlation has been demonstrated
between soft tissue thickness and degree of color difference (P40.25).
Conclusions: Within the limitation of the present study, the peri-implant soft tissue color appears to
be different from the soft tissue color around natural teeth, no matter which type of restorative
material is selected. When titanium abutment was selected, significantly higher differences were
present than those obtained with gold or zirconia abutments. The thickness of the peri-implant soft
tissue did not appear to be a crucial factor in the abutment impact on the soft tissue color.
Comparison of 2 Techniques of Subepithelial Connective Tissue Graft in the Tr...elenaAbcdental
This study compared two techniques for treating gingival recession defects using subepithelial connective tissue grafts (SCTG): 1) the envelope technique (E) and 2) coronally positioned flap combined with connective tissue graft (CP). Both techniques resulted in significant reduction of gingival recession, with 89.6% coverage for E and 94.7% for CP. While E increased keratinized tissue width, CP did not significantly change width. Postoperative keratinized tissue width was correlated with presurgical width and height of graft exposure.
contains descriptive and other studies on genetics and epigenetics and whole gene concepts from central dogma to future concepts . Dr Harshavardhan Patwal
The document discusses host modulation therapy for the treatment of periodontal disease. It defines key terms like host and modulation. It discusses how our understanding of periodontal disease progression has changed, recognizing that host response plays a major role in determining disease severity rather than just plaque levels. It describes how pharmacological agents can be used as adjuncts to conventional treatment to modulate the host response and reduce tissue destruction. Nonsteroidal anti-inflammatory drugs are provided as an example to inhibit prostaglandin formation and reduce bone loss, though long-term use can have side effects. The document outlines the role of arachidonic acid metabolites in pathogenesis and various studies investigating host modulation agents.
Trigonometric functions are used extensively in calculus. When using trig functions in calculus, radian measure must be used for angles. Even trig functions like cosine are symmetric about the y-axis, while odd functions like sine change sign when x changes sign. Trig functions can be shifted, stretched, or shrunk by applying transformations to their graphs.
This document outlines a treatment plan for periodontal disease. It includes 5 phases: emergency, etiotropic (non-surgical), surgical, restorative, and maintenance. The etiotropic phase involves nonsurgical therapies like scaling, root planing, and oral hygiene instruction. The surgical phase uses various periodontal surgeries to further treat pockets and furcations. The restorative phase focuses on final restorations. Lastly, the maintenance phase provides periodic recall visits to monitor the patient's condition. The overall goal is to resolve inflammation and reduce pocket depths through a coordinated approach involving multiple dental specialists.
The document defines and describes periodontal pockets. It notes that periodontal pockets can be classified based on their location relative to the alveolar bone as either suprabony or infrabony. Suprabony pockets have bone loss horizontally while infrabony pockets have bone loss vertically. The document also discusses the pathogenesis of pocket formation, clinical features, histopathology, and diagnosis and probing of periodontal pockets.
Periodontal disease is a chronic bacterial infection that affects the gums and bone supporting the teeth. It ranges from gingivitis, a reversible early stage marked by red, swollen gums, to periodontitis, a more advanced stage involving irreversible bone and tissue destruction. Risk factors include smoking, diabetes, genetics, and certain medications. Symptoms include bad breath, bleeding gums, and loose teeth. Treatment involves deep cleaning below the gumline, antibiotics, and sometimes surgery to regenerate lost bone and tissue. Regular cleanings and proper brushing and flossing can help prevent periodontal disease.
Journal club on Surgical treatment of periiMplantitis using a bone substitute...Shilpa Shiv
This study evaluated the 5-year outcomes of surgical treatment of peri-implantitis using a bone substitute with or without a resorbable membrane. 38 patients with peri-implantitis were treated with either a bone substitute alone or with a membrane. At 5 years, clinical improvements from treatment were maintained, including reduced bleeding and probing depths. Radiographic bone fill increased by 1.1-1.3 mm with no significant difference between treatment groups. Strict post-surgical plaque control was important for successful treatment outcomes. The membrane did not provide additional benefit to bone fill.
Journal club on Minimally Invasive Single Implant Treatment (M.I.S.I.T.) base...Shilpa Shiv
Journal club on Minimally Invasive Single Implant Treatment (M.I.S.I.T.) based on ridge preservation and contour augmentation in patients with a high aesthetic risk profile, JCP 2015
JOURNAL CLUB ON CORONALLY ADVANCED FLAP vs THE POUCH TECHNIQUE COMBINED WITH ...Shilpa Shiv
CORONALLY ADVANCED FLAP vs THE POUCH TECHNIQUE COMBINED WITH A CONNECTIVE TISSUE GRAFT TO TREAT MILLER'S CLASS I GINGIVAL RECESSION, JCP 2014;41(4):387-395.
This document provides an overview of periimplantitis, including its definition, classification systems, epidemiology, etiology, pathogenesis, diagnosis, and treatment. Periimplantitis is defined as an inflammatory process involving both soft and hard tissues around a dental implant, resulting in loss of supporting bone. It is distinguished from peri-implant mucositis, which only involves inflammation of soft tissues. The document discusses various classification systems for periimplantitis and reviews potential etiologic factors such as plaque, biomechanical overload, genetic factors, and iatrogenic causes. Diagnosis involves clinical parameters like bleeding, probing depth, and radiographic bone loss. Treatment aims to eliminate infection and may include nonsurgical and surgical
1) Fiber-reinforced composite (FRC) posts made of glass or quartz fibers embedded in an epoxy or resin matrix became popular in the 1990s as they were esthetically superior to earlier carbon fiber posts.
2) FRC posts have a modulus of elasticity similar to dentin, which helps distribute stresses throughout the root and reduces the risk of root fracture compared to stiffer metal posts.
3) Success of teeth restored with FRC posts depends strongly on the amount of remaining tooth structure, especially the presence of an adequate ferrule above the finish line.
Die space to be maintained for the proper application of the spacer to maintain the contour and anatomy. in vitro studies were conducted to manage before applying in the patients study group. To attain axial,buccal, lingual and mesio-distal contours of the preparing tooth.
Class on "Porcelain layering on zirconia coping"
Presentation by Prof. Dr. Marco Ferrari MD, DMD, PhD.
http://www.dentalevo.it/dentistry-materials/porcelain-layering-zirconia-coping/
This document discusses indirect inlay restorations. It begins with an introduction that defines indirect restorations and provides examples. The document then discusses factors that influence preparation design such as the selected material and fabrication method. It also discusses geometrical considerations for preparation design. The document reviews traditional restorative materials like cast gold and composites as well as modern ceramic materials and fabrication methods. It discusses cementation techniques and the importance of adhesive cementation. In summary, the document provides an overview of indirect inlay restoration techniques and materials.
This study evaluated three composite resins (Z100, Clearfil Ray-Posterior, and Prisma TPH) used to restore 120 posterior teeth over 24 months. Clinical evaluations were performed every 6 months using Ryge criteria and stone casts, while direct evaluations assessed color match, margins, anatomy, etc. Results found that all materials were suitable for posterior restorations. Some Z100 and Prisma TPH restorations showed marginal crevices. Clearfil Ray-Posterior alone showed slight surface roughness. Direct and indirect evaluation results differed for Z100 and Prisma TPH, attributed to method sensitivity.
Aim: The present in vitro study evaluated the Color and Translucency of Colored and Pre-colored Monolithic Zirconia ceramics. Materials and methods: Twenty disks of Monolithic Zirconia with a diameter of 10 mm and a thickness of 1.5 mm were milled from White and Pre-colored Blanks. The disks milled from the White blanks were subjected to immersion in Coloring liquid. The disks were divided into Group I Colored Zirconia and Group II Pre-colored Zirconia. Twenty Co-Cr disks of diameter of 10◦mm and thickness of 2.5◦mm with a superficial hollow spacer of 8◦mm diameter and 0.1◦mm thickness were used in this study to serve as metallic substrates for the Zirconia disks. Using a Color Spectrophotometer, Color coordinates were observed. Color difference (AE) was measured overawhitebackdrop,metalsubstratebefore,andmetalsubstrateaftercementation.TheTranslucencyParameter (TP) was measured over a white and black backdrop. Independent ‘t-test and Mann Whitney U test were used to analyze the Color difference and Translucency Parameter data, respectively. Results: The Mean Color difference between Colored Zirconia and Pre-colored Zirconia against a white backdrop and metal substrate before cementation was 12.32 and 10.37, respectively. The Mean Color difference between Colored Zirconia and Pre-colored Zirconia against a white- backdrop and metal substrate after cementation was 2.48 and 3.41, respectively. The mean color difference between Colored and Pre-colored Zirconia against metal substrate before and after cementation was 8.37 and 9.13, respectively. Pre-colored Zirconia showed a statistically significantly higher color difference than Colored Zirconia (P◦<◦0.05). The mean Translucency parameter for Colored Zirconia and Pre-colored Zirconia was 7.73 and 8.83, respectively. The mean Translucency parameter for Colored Zirconia and Pre-colored Zirconia over metal substrate was 0.52 and 0.57, respectively. Conclusion: On comparison of Colored and Pre-colored Zirconia from a white background to the metal substrate before and after cementation, the Colored Zirconia showed lower color difference than the Pre-colored Zirconia, which suggests that Colored Zirconia has better masking ability than Pre-colored Zirconia. However, comparing these two materials for Translucency, the Pre-colored Zirconia material demonstrated higher translucency than the Colored Zirconia material before and after cementation over the metal substrate.
Journal club presentaion on zirconia fixed partial dentured on endodonticaloy...NAMITHA ANAND
The study investigated the effects of different post and core material combinations on surface strain of zirconia fixed partial denture (FPD) margins. Artificial abutment teeth were restored with either resin composite cores with glass fiber posts or cast metal alloy posts and cores. Strain gauges measured surface strain on the zirconia frameworks and abutment roots under static loading. The results showed that restoring the premolar with a cast post and core and the molar with a resin composite core reduced stress concentration in both the frameworks and abutment teeth compared to the other combination. The study suggests considering post and core material properties and differences in abutment tooth morphology when selecting materials for zirconia FPD
Ppt for the conferance effect of postoperative bleaching on clinical perfor...Ameer Al-Ameedee
This study evaluated the effect of in-office bleaching on the clinical performance of three contemporary composite resins over one year. Thirty-six class IV cavities were restored with giomer, ceromer, or ormocer composites and underwent four bleaching sessions. The restorations were evaluated at various intervals using modified Ryge criteria. While 60% of the ceromer restorations showed an acceptable color mismatch after bleaching, 10% were unacceptable after one year. In contrast, bleaching did not significantly affect the clinical performance of the giomer and ormocer composites over the study period based on retention, marginal integrity, surface roughness and other criteria.
Investigation of the Remineralization Effect Tnrough Scanning Electron Micros...IJERA Editor
Background: Local fluoride varnishes have been widely used as a method of non-operative treatment and for
caries preventive interventions for more than three decades.
Purpose: Evaluation of the remineralization effect by means of electron microscopy of mineralization varnish -
Clinpro ™ White Varnish with TCP (Tri-Calcium phosphate) (3M).
Materials and Methods: The material used is from 20 temporary intact teeth, extracted due to physiological
change with permanent teeth, with a completely preserved structure and anatomy of crowns and fully
physiologically resorbed roots. For the purposes of the study a scanning electron microscope JEOL JSM 6390 is
used with an attachment for element analysis (EDS INCA of Oxford). Prepared samples are pre-coated with
gold (cathode sputtering with apparatus JEOL JFC – 1200) to obtain a better contrast of the SEM image of early
carious lesions on the smooth surfaces of the temporary teeth, with predilection for development of caries with a
d1 threshold. For this purpose the two processes were monitored occurring continuously on the enamel surfacede-
and remineralization. Performed was computer processing of the digital images.
Results: There is presence of certain minerals deposited in the embossed enamel prisms after of
remineralization. The chemical analysis established the presence of calcium (Ca2 +
), around the organic matrix.
Demineralised surface has pores present of around 1%, which is visible through the enamel on the surface of the
deciduous teeth looking like filled and pores looking like partially covered, filled with newly formed and
growing crystals. The crystals, which are hydroxylapatite, fluorapatite or fluorhydroxiapatite gradually connect,
growing and forming mineral structure filling the microscopi defects and the pores from the demineralisation in
the surface enamel prismless layer.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
The document discusses principles of tooth preparation for restorations. It covers 3 main categories: biologic considerations to protect surrounding tissues, mechanical considerations to provide retention and resistance for the restoration, and esthetic considerations for appearance. Specific topics include margin placement, adaptation and geometry, conservation of tooth structure, prevention of pulpal damage, and providing adequate taper, surface area, and freedom of displacement for retention.
Ceramic inlays and onlays have improved as dental materials over time. They are indicated for small to moderate carious lesions, large lesions, endodontically treated teeth, and situations where metal is contraindicated. Contraindications include parafunction, poor oral hygiene, and inability to maintain isolation. Advantages include esthetics, strength, and biocompatibility, while disadvantages include cost, technique sensitivity, and inability to repair. Clinical procedures involve tooth preparation, impression, try-in, and cementation using bonding systems and resin cements to achieve adhesion between tooth and restoration.
A simple method for reconstruction of severely damaged primary anterior teethDR KARUNA SHARMA
The document discusses dental caries in primary teeth, also known as early childhood caries. It notes that extraction was traditionally used to treat severely decayed primary anterior teeth but results in issues. Alternative restorative treatments discussed include direct and indirect techniques using prefabricated crowns, biologic restorations, fiber or metal posts, and composite resins. It also introduces a "reverse metal post insertion technique" using a prefabricated metal post and composite resin to restore a severely decayed primary canine.
The document discusses all-ceramic dental restorations which are made entirely of porcelain without metal support. Key points include:
- All-ceramics offer esthetic, metal-free restorations that are biocompatible and able to match natural tooth shades.
- Their main limitation is brittleness, so careful preparation design, fabrication techniques, and luting methods are required.
- Modern ceramic materials and CAD/CAM systems have addressed these challenges and all-ceramic restorations are increasingly popular for their esthetics.
This study evaluated the influence of LED curing light type and selective enamel etching on the dentin microtensile bond strength (μTBS) of two self-etch adhesives (Clearfil SE and Clearfil S3) in class I composite restorations. For Clearfil S3, selective enamel etching resulted in lower dentin μTBS values compared to non-etched specimens. However, dentin μTBS of Clearfil SE was not affected by enamel etching. When curing the adhesives, the polywave LED yielded higher dentin μTBS for Clearfil SE than the single-peak LEDs. Enamel etching and LED type influenced dentin bonding of the self-etch ad
This study evaluated the 10-year clinical performance of 4 types of tooth-colored inlays: direct ceramic (Cerec), indirect ceramic (Vita Dur N), direct composite (Brilliant DI), and indirect composite (Estilux). 58 inlays were placed in 37 patients. After 10 years, the survival rate of the inlays still functioning (with or without repair) ranged from 77.4-80%. The survival rate without repair was lower, ranging from 50.8-80%. No significant differences in survival rates were found between the 4 inlay types.
Similar to Influence of framework design on the cervical color of metal ceramic crowns (20)
1. estudio clinico de 10 años de inlays direcra e indirecto de composite y ce...
Influence of framework design on the cervical color of metal ceramic crowns
1. cervical color of metal ceramic crowns
Gianluca Paniz, DDS, MS,a Yongjeong Kim, DDS, DMD, MS,b
Haythem Abualsaud, BDT, MS,c and Hiroshi Hirayama, DDS,
DMD, MSd
School of Dental Medicine, Tufts University, Boston, Mass;
University of Padova, Padova, Italy; College of Dentistry, King
Saud University, Riyadh, Saudi Arabia
Statement of problem. The replication of natural teeth, especially for single tooth restorations in patients with high
esthetic needs, represents a challenge.
Purpose. The purpose of the study was to analyze the color of the cervical portion of single metal ceramic crowns
fabricated with different metal framework designs.
Material and methods. The color, as measured on the CIELAB color scale, of 3 different groups of restorations
(n=10) fabricated with a high noble metal alloy (V-Deltaloy) and feldspathic porcelain (Noritake Super Porcelain) was
analyzed with a colorimeter. Conventional metal ceramic crowns with metal facial margins were compared to metal
ceramic crowns with porcelain facial margins and a horizontal reduction of the metal framework (1.0 mm reduction)
or an additional vertical reduction (1.0 mm reduction). In all specimens, the finish line was positioned at a subgingi-
val or equigingival level. The 6 groups obtained by the combination of the levels of the 2 factors (framework extension
and finish line location) were examined with an ANOVA Fisher’s F-test and a post hoc Tukey’s HSD test ( =.05).
Results. The mean color difference for all the groups was clinically acceptable (∆ <3.7). Conventional metal ceramic
crowns showed higher differences in relation to finish line location (∆ =2.34), while a vertical reduction of the frame-
work was related to lower values (∆ =0.96). Mean Lab* values were reported for all the groups of crowns. Statistically
significant differences were present for L*, a*, and b* values when related to framework extension. Considering each
value in relation to the interaction between framework extension and finish line location factors, significant differ-
ences were present only for L* and a* values.
Conclusions. No significant differences in base shade were present among the investigated crowns. Nevertheless metal
ceramic crowns with vertical cut-back and porcelain facial margins presented more consistent results that tended to
be closer to those of natural teeth. (J Prosthet Dent 2011;106:310-318)
If metal ceramic is selected as the restorative material for a crown in the esthetic zone, a
vertical cut-back of approximately 1 mm is recommended on the facial metal framework/
porcelain facial margin to achieve an adequate esthetic result. If a conventional metal frame-
work design is selected, deep subgingival margins might reduce the color impairment.
Presented as a poster at the Greater New York Academy of Prosthodontics Annual Meeting, December 2006, New York, NY.
a
Adjunct Assistant Professor, Graduate & Postgraduate Prosthodontics, Department of Prosthodontics and Operative Dentistry,
Tufts University; Adjunct Professor, Department of Prosthodontics, University of Padova, Dental School.
b
Associate Professor, Graduate and Postgraduate Prosthodontics, Department of Prosthodontics and Operative Dentistry.
c
Senior Specialist, College of Dentistry, King Saud University.
d
Professor, Division Head of Postgraduate Prosthodontics, Director of Graduate and Postgraduate Prosthodontics, Director of
Advanced Education in Esthetic Dentistry, and Director of Advanced Dental Technology and Research program, Tufts University,
School of Dental Medicine.
The Journal of Prosthetic Dentistry Paniz et al
2. November 2011 311
The replication of natural teeth metal framework reduction of 2 mm timate goal in achieving an accurate
with single tooth restorations in pa- coronally from the buccocervical line color match is to achieve the smallest
tients with high esthetic needs and angle. With this design, metal was not possible ∆E value.34 The correlation
expectations represents a challenging visible at the external crown surface, between ∆E and clinical observation
task in restorative dentistry.1-4 An im- light transmission was increased, and was analyzed in an in vivo study of
portant consideration is color repro- the opaquing effect of metal and subjects treated with composite resin
duction in the cervical portion, where opaque porcelain was eliminated in veneers. Within the limitation of the
a thinner layer of restorative material the cervical region. Recent studies study, 3.7 was the average color dif-
must be used to prevent harm to the have confirmed that the metal frame- ference among teeth rated as a match
pulpal tissue or interference with the work should be cut back a minimum in the oral environment.44 When ana-
proper emergence profile.5-7 of 2 mm away from the shoulder to lyzing metal ceramic crowns, different
Different materials and techniques avoid a color mismatch.33 However, results were obtained. Thresholds for
have been proposed to achieve an others show similar esthetic results acceptability were reduced to ∆E=1.7,
improved esthetic result. The metal with less reduction of the metal while perceptibility was reduced to
ceramic crown is one of the most framework, which also provides im- ∆E=0.4. In addition, observers were
popular restorations since it com- proved porcelain support.27 more sensitive to and critical of
bines good esthetics with adequate One of the objective methods crowns whose color differed in red-
strength, accurate fit, and long-term for evaluating color in dentistry is ness (∆a*) than crowns whose color
survival.8 Esthetic problems with this through colorimetric or spectropho- differed to the same extent in yellow-
type of restoration are related to the tometric analysis.34-40 These instru- ness (∆b*).45 More recently, different
opaque porcelain layer used to mask ments use the CIELAB color scale, thresholds for perceptibility (∆E<2.6)
the dark color of the underlying met- which identifies tooth color through and acceptability (∆E<5.5) of shade
al framework. Acting as a barrier to the black/white (L* value), green/red mismatch have been described in a
light transmission, this opaque layer (a* value) and yellow/blue dimen- clinical setting and used in experimen-
causes an impairment of color and sions (b* value).41 In an analysis of tal research.46,47
translucency, which is more evident the color of natural, maxillary central The purpose of this study was to
in the cervical portion, where the por- incisor teeth, Hasegawa et al42 found compare, through spectrophotomet-
celain is thinner.2, 9-11 Furthermore, the significant variations in Lab* values ric digital technology, the color of
presence of a facial, marginal metal along the axis of the surface of the the cervical portion of single metal
collar thick enough to support the teeth: L* was higher in the center; a* ceramic crowns fabricated with dif-
overlying layers of porcelain and resist was higher in the cervical region and ferent metal framework designs. Con-
metal deformation during porcelain significantly lower when approaching ventional metal ceramic crowns with
firing12,13 often becomes an esthetic the incisal edge; and b* was higher in metal margins (metal extended to the
issue.14 To fulfill the esthetic require- the cervical area but with gradual and finish line) were compared with col-
ments, collarless metal ceramic resto- significant reduction toward the in- larless metal ceramic crowns fabri-
rations have been suggested, limiting cisal area. Older subjects had darker cated with different metal extensions.
the extension of the metal framework and more yellowish color at the cen- Subgingival and equigingival margin
to a certain distance from the margin ter of the natural tooth. Both reddish positions were evaluated. The null hy-
of the preparation. Several techniques and yellowish colors of natural teeth pothesis was that there would be no
have been proposed to fabricate col- tended to increase from the incisal to color differences present in the cer-
larless metal ceramic restorations, in- the cervical area, whereas translucen- vical portion of single metal ceramic
cluding platinum foil techniques,14,15 cy decreased. In an in vitro study, the crowns fabricated with different met-
the direct-lift technique,16 and the distribution of color was identified for al framework design and tested with
wax technique.17-20 Research has con- 3 regions with respective mean Lab* equigingival and subgingival margin
firmed adequate marginal adapta- values of 71.4, 0.9, and 12.8 for the placement.
tion21-24 and fracture resistance25-31 for incisal portion, 72.4, 1.2, and 16.2
this type of restoration. In particular, for the middle portion, and 72.6, 1.5, MATERIAL AND METHODS
to achieve adequate strength, a deep and 18.4 for the gingival portion.43
chamfer preparation and no more The most commonly used method The color of 3 different margin
than 1 mm of unsupported ceramic for evaluating color differences among design groups of restorations (n=10)
are recommended.27 specimens is through ∆L*, ∆a*, and fabricated with high noble metal alloy
Analyzing the esthetic effect of ∆b*. Their combination is described (V-Deltaloy; Metalor Dental AG, Biel-
metal ceramic restorations through as color difference (∆E), which is de- Bienne, Switzerland) and feldspathic
transillumination and photography, termined by the following equation: porcelain, (Noritake Super Porcelain;
Geller and Kwiatkowski32 proposed a ∆E = (∆L*2+ ∆a*2+∆b*2)1/2.34 The ul- Noritake Dental Supply Co, Nagoya,
Paniz et al
3. 312
Japan) was measured with a color-
imeter (ShadeVision System; X-Rite,
Inc, Grand Rapids, Mich). The sam-
ple size was arbitrary as no a priori
power analysis was performed, and
no reliable estimate of within-group
standard deviation for the population
could be obtained. The conventional
metal ceramic crowns with metal
margins (group C) were compared
with metal ceramic crowns with 2
different designs of porcelain facial
margin. One group had a horizontal
reduction of the metal framework 1 Different designs of metal framework tested. Conventional metal
(group H: 1.0 mm reduction), and ceramic crowns (Cmc), metal ceramic crowns with horizontal re-
the second had an additional vertical duction of metal framework (Hmc), and metal ceramic crowns with
reduction (group V: 1.0 mm vertical additional vertical reduction of metal framework (Vmc).
reduction) (Fig. 1).
One extracted, intact, human Type and thickness of materials used for crowns
maxillary central incisor was prepared
to receive the crowns. The facial re- Materials Cervical
duction was 1.5 mm following the Crown Layers (Manufacturer) Thickness
depth of a rounded shoulder finishing
line. The margin was positioned at the Metal framework High noble metal alloy 0.3 mm
(V-Delta Alloy, Metalor)
level of the cement-enamel junction
and 2.0 mm of incisal reduction was
Opaque layer Porcelain opaque 0.1 mm
performed. Throughout the study, the (POA1, Noritake Porcelain)
tooth was stored in a 0.05 % thymol
and distilled water solution. The pre- Dentin porcelain Feldspathic porcelain 1.0 mm
pared tooth was duplicated with a (A1B, Noritake Porcelain)
vinyl polysiloxane impression mate-
rial (CapSil, Aquatrols Corporation of Enamel porcelain Feldspathic porcelain 0.1 mm
America, Paulsboro, NJ). Type IV den- (A1B, Noritake Porcelain)
tal stone (New Fuji-Rock, GC Corp,
Porcelain for Feldspathic porcelain Minimal
Tokyo, Japan) was used to fabricate
butt margin (MA1, Noritake Porcelain) achievable
the 30 dies, each corresponding to a
single crown. Cement medium Translucent cement Thin layer
A standardized framework was (Variolink II, trial-base,
cast for each die in a high noble metal Ivoclar Vivadent AG)
alloy (V-Delta; Metalor Dental AG).
After the heat treatment process, lingual side of the crown. For group applications of margin porcelain were
the intaglio surfaces were finished to V crowns, an additional 1.0 mm was applied to achieve adequate marginal
a uniform facial and interproximal added to the vertical reduction of the integrity. The thickness of the margin
thickness of 0.3 mm. For the conven- metal framework. porcelain was reduced as much as
tional margin design, group C, the Dental porcelain (Noritake Super possible. Two layers of dentin porce-
metal framework remained extended Porcelain; Noritake Dental Supply lain were applied to all 3 groups to
to the preparation finish line (Fig. Co) was applied to all groups with achieve proper contour and reduced
1). For group H crowns, the cervi- a brush-on technique according to to a cervical thickness of 1.4 mm.
cal margin of the metal framework the manufacturer’s recommenda- Enamel porcelain was then applied
was reduced at the axiocervical line tions and fired under vacuum in a over the dentin porcelain to achieve a
angle at a distance of 1.5 mm from porcelain furnace (Programat P300; proper final crown contour with a 1.5
the preparation finishing line; this re- Ivoclar Vivadent AG, Schaan, Liech- mm thickness at the cervical area. All
duction was made on the facial and tenstein). Three layers of opaque por- specimens were autoglazed according
interproximal margin, leaving 150 de- celain were applied to all of the metal to the manufacturer’s recommenda-
grees of metal collar exposure on the frameworks. For groups V and H, 2 tions. A caliper (Iwanson Decimal
The Journal of Prosthetic Dentistry Paniz et al
4. November 2011 313
conditions for each of the experimen-
tal margins. Six experimental groups
were evaluated in the study.
On the computer screen, the cervi-
cal portion of the teeth was selected
by using a transparent custom-made
plastic template, which was fabricat-
ed to fit the computer screen to better
identify the different tooth portions. A
4 mm length was considered enough
to represent the cervical portion since
2 Selected cervical portion in equigingival (left) and subgingival the initial length of the tooth before
(right) groups of metal ceramic crowns. Note that subgingival preparation was approximately 12
crowns have margin positioned 0.5 mm apical to gingival level. mm, and a standardized area, extend-
ing 2 mm from the gingival level, was
Groups analyzed. Variables included framework extension (3 selected in the cervical portion (Fig.
groups of specimens) and finish line location (total 6 study groups) 2). The measurements were recorded
in CIELAB coordinates.
Groups of Framework
The color difference among the
Specimens Extension Study Finish Line
experimental groups was determined
(n=30) (C, H, V) Groups Location (S, E)
with the equation: ∆E= [(∆L*)2 +
Cmc Finish line CST
(∆a*)2 + (∆b*)2]1/2,33,34 calculated
from the mean values of L*, a*, and
Hmc 1.5 mm horizontal reduction, HST b*. To determine clinical significance,
Subgingival the ∆E values were related to those
(buccocervical line angle)
(0.5mm) present in the literature, which range
Vmc 1 mm additional vertical VST
from 1.7 to 3.7. 44,45
A 2-way ANOVA was calculated
reduction
for each CIELAB coordinate (L*, a*,
and b* values) to show which of the 2
Cmc Finish line CET
factors (framework extension or finish
Hmc 1.5 mm horizontal reduction, HET
line location) had a significant impact
Equigingival on the values of each coordinate. A
(buccocervical line angle)
post hoc Tukey’s Honestly Significant
Difference (HSD) test was performed
Vmc 1 mm additional vertical VET
to determine statistically significant
reduction
differences among the group means.
Caliper; Asa Dental s.p.a., Lucca, cally (Fig. 2). To achieve repeatability RESULTS
Italy) with an accuracy of 0.05 mm of measurements, the position of the
was used to measure and adjust the tooth and of the measuring instru- The mean L*, a*, and b* values
final thicknesses, which are reported ment was standardized for all the are presented in Table III. When con-
in Table I. measurements with custom-position- sidering L* values through the analy-
The color of the cervical region of ing indices. Each measurement was sis of variance (2-way ANOVA), there
the crowns, fitted on a prepared max- performed 5 times to reduce mea- were significant differences (P=.012)
illary central incisor, was measured surement error. Since natural teeth among the different groups of crowns,
with a colorimeter (ShadeVision Sys- are usually observed in a wet environ- with framework extension having the
tem; X-Rite, Inc). The measurements ment, all measurements were made main effect (Table IV). The mean L*
were made in a dental mannequin with the specimens in a slightly moist value for the Vmc group (78.8) was
(KaVo Dental, Biberach/Riss, Germa- condition. All the crowns were mea- significantly lower (P=.027) than
ny) with the margin of the restoration sured with the application of trans- the mean value for the Cmc group
positioned either 0.5 mm subgingi- parent cement medium try-in paste (79.4) and also significantly lower
vally (subgroup S) or at the gingival (Variolink II; Ivoclar Vivadent AG). Ta- (P=.023) than the value for the Hmc
level (subgroup E) by moving the pre- bles I and II summarize the porcelain group (79.4) (Fig. 3). Considering L*
pared tooth 0.5 mm more or less api- layer thicknesses and measurement values in relation to framework ex-
Paniz et al
5. 314
Mean L* values, a* values, and b* values for each single group of crowns (n=6)
L* a* b*
Mean Mean Mean
Group Values SD Values SD Values SD
CST 78.48 0.93 3.77 0.34 12.26 0.65
HST 79.96 0.81 3.06 0.47 11.87 1.00
VST 78.89 0.55 3.64 0.07 13.33 0.60
CET 80.37 0.84 2.53 0.27 11.65 0.58
HET 78.92 0.68 2.31 0.23 11.78 1.15
VET 78.71 0.57 2.69 0.25 13.30 0.82
Two-way ANOVA table for L* value (main effects and interaction term)
Sum of Mean
Source Squares df Square F P
Framework extension 5.39 2 2.69 4.81 .12
Finish line location 0.74 1 0.74 1.33 .25
Framework extension × 22.5 2 11.25 20.07 <.001
Finish line location
Error 30.3 54 0.56
Framework Extension; LS Means Framework Extension* Finishing Line; LS Means
Current effect: (F2, 54) = 4.82, P=.012 Current effect: (F2, 54) = 20.0, P<.001
80.0 81.5
79.8 81.0 Sub-gingival
79.6 Equi-gingival
80.5
79.4
80.0
79.2
L*
L*
79.5
79.0
79.0
78.8
78.6 78.5
78.4 78.0
78.2 77.5
Cmc Hmc Vmc Cmc Hmc Vmc
Framework Extension Framework Extension
3 L* values in relation to framework extension factor. 4 L* values in relation to framework extension and fin-
ishing line location factors.
The Journal of Prosthetic Dentistry Paniz et al
6. November 2011
tension and finish line location fac- with framework extension having the measured subgingivally and 2.7 when
tors, significant differences (P<.001) main effect (Table V). Hmc crowns measured equigingivally (Fig. 6).
were present (Table IV). The post showed lower a* values (2.69) than When considering b* values, there
hoc Tukey test revealed no significant Cmc crowns (3.17) and Vmc crowns were significant differences (P<.001)
differences (P=.95) between subgin- (3.17) (Fig. 5). Considering a* values among the different groups of crowns,
gival (78.9) and equigingival (78.7) in relation to framework extension with framework extension having the
measurements within the Vmc group. and finish line location factors, signif- main effect (Table VI). Vmc crowns
However, significant differences were icant differences (P=.043) were pres- show higher values (13.3) than Cmc
present within the Cmc (P<.001) and ent (Table V). The post hoc Tukey’s (12, P<.001) and Hmc (11.9, P<.001)
Hmc (P=.035) groups. Conventional test showed that, for all of the groups crowns (Fig. 7). Considering b* val-
metal ceramic crowns had an L* value of crowns, mean values were signifi- ues in relation to framework exten-
of 78.4 when measured subgingivally cantly higher when measured subgin- sion and finish line location factors,
and 80.4 when measured equigingi- givally. Cmc crowns (P<.001) showed no significant differences (P=.488)
vally. Specimens from the Hmc group a value of 3.78 when measured sub- were present (Table VI and Fig. 8).
had a mean L* value of 80 when mea- gingivally and 2.54 when measured The ∆E values among the groups
sured subgingivally and 78.9 when equigingivally. Hmc crowns (P<.001) of crowns are represented in Table
measured equigingivally (Fig. 4). showed a value of 3.06 when mea- VII. Evaluating subgingival groups of
When considering a* values, there sured subgingivally and 2.31 when crowns, the base shade comparison
were significant differences (P<.001) measured equigingivally. Vmc crowns between Cmc crowns (CST) and Vmc
among the different groups of crowns, (P<.001) showed a value of 3.65 when crowns (VST) showed ∆ =1.15. The
Table V. Two-way ANOVA table for a* value (main effects and interaction term)
Sum of Mean
Source Squares df Square F P
Framework extension 3.03 2 1.51 16.85 <.001
Finish line location 14.4 1 14.4 159.4 <.001
Framework extension × 0.60 2 0.30 3.34 .04
Finish line location
Error 4.86 54 0.09
Framework Extension; LS Means Framework Extension* Finishing Line; LS Means
Current effect: (F2, 54) = 16.9 P<.001 Current effect: (F2, 54) = 3.3, P=.043
3.4 4.2
3.3 4.0
3.8
3.2
3.6
3.1
3.4
3.0 3.2 Sub-gingival
b*
2.9
L*
3.0 Equi-gingival
2.8 2.8
2.6
2.7
2.4
2.6
2.2
2.5 2.0
2.4 1.8
Cmc Hmc Vmc Cmc Hmc Vmc
Framework Extension Framework Extension
5 a* values in relation to framework extension factor. 6 a* values in relation to framework extension and fin-
ishing line location factors.
Paniz et al
7. 316
Two-way ANOVA for b* value (main effects and interaction term)
Sum of Mean
Source Squares df Square F P
Framework extension 27.1 2 13.6 19.53 <.001
Finish line location 0.89 1 0.89 1.28 .26
Framework extension × 1.01 2 0.50 0.72 .48
Finish line location
Error 37.5 54 0.69
Framework Extension; LS Means Framework Extension* Finishing Line; LS Means
Current effect: (F2, 54) = 19.5 P<.001 Current effect: (F2, 54) = 0.73, P=.488
14.0 14.5
14.0 Sub-gingival
13.5
13.5 Equi-gingival
13.0
13.0
b*
b*
12.5 12.5
12.0
12.0
11.5
11.5
11.0
11.0 10.5
Cmc Hmc Vmc Cmc Hmc Vmc
Framework Extension Framework Extension
7 b* values in relation to framework extension factor. 8 b* values in relation to framework extension and fin-
ishing line location factors.
∆E values among different groups of crowns
--- CST HST VST CET HET VET
CST --- 1.68 1.15 2.34 1.59 1.51
HST 1.68 --- 1.90 0.70 1.28 1.93
VST 1.15 1.90 --- 2.49 2.04 0.96
CET 2.34 0.70 2.49 --- 1.47 2.34
HET 1.59 1.28 2.04 1.47 --- 1.58
VET 1.51 1.93 0.96 2.34 1.58 ---
The Journal of Prosthetic Dentistry Paniz et al
8. November 2011 317
same comparison performed equig- strated ∆E to be lower than 1.7 (Table crowns (Hmc) showed lower values,
ingivally (CET vs. VET), found higher VII). Evaluating subgingival groups of indicating a color closer to that of
mean values (∆ =2.34). Consider- crowns, excluding the first 0.5 mm natural teeth.43
ing the color of each specific group coronal to the finish line (Fig. 2), the Considering b* values, equigingival
of specimens, Vmc crowns showed base shade comparison between Cmc and subgingival crowns showed simi-
∆ =0.96 when comparing equigin- crowns (CST) and Vmc crowns (VST) lar b* values, except for the analysis of
gival and subgingival groups, Hmc showed clinically acceptable results Cmc crowns, which showed lower val-
crowns showed ∆ =1.28, and Cmc (∆ =1.15). The same comparison ues when equigingival (Figs. 7, 8). In
crowns showed ∆ =2.34 (Table VII). performed equigingivally, including general, vertical cut-back crowns (Vmc)
the most apical 0.5 mm (CET vs VET), showed higher values, indicating a color
DISCUSSION found mean values above the limit closer to that of natural teeth.43
of acceptability (∆ =2.34). This re- The use of a dental mannequin
This study was designed to achieve sult suggests that, when the shade of with a plastic gingival substitute al-
a standardized evaluation of 3 differ- conventional metal ceramic crowns is lowed exclusion of portions of the
ent metal framework designs for the analyzed, there is significant color im- crowns, creating 2 different groups of
color of the cervical area of metal pairment in the most apical 0.5 mm specimens, subgingival (S) and equig-
ceramic restorations. The goal was of the restoration. Furthermore, the ingival (E). However, the plastic gingi-
to understand whether the technical color of the cervical portion of Vmc va did not replicate a clinical situation
challenges of fabricating and man- crowns is most consistent between since it eliminated the impact of the
aging a collarless metal ceramic res- the equigingival and subgingival crown on the soft tissue, whose color
toration19, 21-24, 26-32 were justified to groups (∆ =0.96), while that of the influences the final esthetic outcome.
achieve an improved esthetic result. Hmc crowns is moderate (∆ =1.28), Similarly, this study did not consider
The data support rejecting the null and that of the Cmc crowns is the the possibility of short-term or long-
hypothesis that no color differences worst (∆ =2.34) (Table VII). The pos- term tissue recession. The use of a dif-
would be present in the cervical por- sible positive esthetic implication of ferent gingival substitute could help
tion of single metal ceramic crowns the use of an additional millimeter of overcome these shortcomings in pos-
fabricated with different metal frame- metal framework reduction was not sible future research. Furthermore,
work designs. tested in this study because of the in- considering the development of ce-
In analyzing tooth color, the pri- creased fracture risk present with this ramic restorations, a similar study
mary concern was to obtain clinically type of restoration.25,27,28 design could be used to evaluate core
relevant results, and for this reason, Through the analysis of Lab* val- ceramic restorations.
the data obtained through the colo- ues, a deeper understanding of the
rimetric measurement were related to color differences and of influenc- CONCLUSION
the values reported in the literature. ing factors can be drawn (Figs. 3-8).
A natural tooth was not selected as a Considering L* values, Cmc crowns Within the limitations of this
standard since previously completed showed the highest value when equi- study, the following conclusions were
in vitro research clearly showed signif- gingival (CET), the lowest when sub- drawn:
icant color differences when compar- gingival (CST), and the highest differ- 1. No significant differences in
ing tooth structure to a metal ceramic ence of values between equigingival base shade were present among the
restoration. 33 According to Johnston and subgingival specimens (Figs. 3, investigated crowns.
and Kao,44 a ∆E > 3.7 indicates vi- 4). As discussed in the ∆E analysis, 2. Vertical cut-back crowns (Vmc)
sually perceivable color differences this confirmed that significant color had a cervical shade which was more
which are clinically unacceptable. By impairment occurs in the most apical consistent and appeared to be more
using this threshold and comparing 0.5 mm of the ceramic of metal ce- similar to that of a natural tooth.
the groups with the most clinical rel- ramic crowns. In contrast, when ana- 3. Conventional metal ceramic
evance, no clinical differences were lyzing Vmc crowns, the results were crowns (Cmc) were characterized by
noted (Table VII). A similar compari- more consistent and the color also significant color impairment in the
son can be made to other recent clini- closer to that of natural teeth.43 most apical 0.5 mm of the ceramic.
cal references.47 Even if Johnston and Considering a* values, consis- 4. Vertical cut-back crowns (Vmc)
Kao44 is often cited in the literature, tent differences were present be- tended to have mean L* and b* values
other values were considered for this tween equigingival (E) and subgingival closer to those of natural teeth, while
in vitro study. According to Douglas (S) crowns. In general, equigingival horizontal cut-back crowns (Hmc)
and Brewer,45 the threshold for accept- crowns demonstrated lower values tended to have closer mean a* values.
ability is ∆E=1.7 and for perceptibil- (Figs. 5 and 6). Among the different
ity, 0.4. Several comparisons demon- types of design, horizontal cutback
Paniz et al