Color stability of gingiva-colored restorative materials: an in vitro study.

The aim of this research was to determine the color stability of 3 gingival shades of dental restorative materials, Amaris Gingiva, Beautiful II Gingiva, and PermaFlo Pink, compared to a tooth-colored nanohybrid composite, Filtek Z250. Twenty-five specimens of each composite were fabricated in polytetrafluoroethylene-coated stainless steel molds and polished using a 4-step polishing regimen. The specimens were randomly assigned to groups for immersion in 1 of 5 solutions (n = 5): distilled water (control), red wine, tea, coffee, or curry (curry powder [containing turmeric] in a solution with distilled water). A desktop spectrophotometer was used to perform color measurements within the Commission Internationale de l'Eclairage L*a*b* color space, and mean overall color (E*) was calculated for each group before and after immersion for 7 days. The mean E* values of each composite before and after immersion were compared using paired t tests at the P < 0.05 level of significance. For all of the tested restorative materials, immersion in a solution of curry produced the greatest increase in mean E* values (P < 0.0001), with E* increasing 32-fold for Amaris Gingiva specimens, 27-fold for Beautiful II Gingiva, 34-fold for PermaFlo Pink, and 2-fold for Filtek Z250. There were smaller, but still significant, increases in E* for Amaris Gingiva, Beautiful II Gingiva, and PermaFlo Pink when immersed in coffee (P < 0.05). Curry caused the greatest change in E* values for all of the tested restorative materials, indicating that curry seasonings based on turmeric can cause unacceptable color change in all of the tested materials and such change can happen in a relatively short time. Coffee also has the potential to cause unacceptable color change in gingival shades of composite materials.

Exploring the versatility of gingiva-colored composite.

Gingival recession has a diverse etiology. The consequences may include gingivitis, periodontitis, and hypersensitivity. Whereas the management can include surgical treatment options, sometimes a more conservative, yet still esthetic approach may be required. The use of gingiva-colored composites provides one such alternative and can be applied to varying presentations of the problem. While surgical treatment can be successful in re-creating favorable esthetic anatomy as well as achieving accurate tissue contour in cases when minor amounts of tissue are reconstructed, long-term results vary because of the vascularity and complexity of the interdental space. Factors such as cost, healing time, discomfort, and variable long-term results make surgery an unpopular choice. If tooth-colored restorative materials are utilized to restore cervical tooth exposure as a result of severe recession, the disproportionate appearance of the visible crown may give a dissatisfying result. Gingiva-colored composite provides dental practitioners with a versatile material that can be used to directly restore cervical defects caused by gingival recession, thus correcting the appearance of the gingival anatomy. It offers a treatment option that may increase patient satisfaction through the provision of a cost-effective, minimally invasive solution with highly esthetic results.

Management of dentinogenesis imperfecta: a review of two case reports.

Dentinogenesis imperfecta (DI) is an inherited disorder that affects dentin and often manifests as tooth discoloration; in addition, the dentition is also extremely susceptible to wear. Treatment of DI focuses primarily on protecting affected dentin, reducing sensitivity, and improving esthetics. Routine restorative materials, such as amalgams and composites, may be used. In more severe cases, the treatment of choice is full coverage crowns, while bonding of veneers may be used to improve the esthetics of the anterior teeth. This study presents two cases of Type II DI in the same family and the management of each case. Restorative management included amalgams, composite veneers, crowns, bridges, and overdentures.

Radiographic evaluation of the technical quality of root canal fillings performed by dental students

The objective of this study was to evaluate radiographically the technical quality of root canal fillings performed by dental students at the School of Dentistry, University of the West Indies. The school's database between 2000 and 2004 was investigated for patients with completed root canal treatment. The final sample consisted of 198 patients with 288 root-filled teeth and 460 canals. The length, presence of voids, taper, curvature of canal and fractured instruments were recorded and scored. Chi-squared analysis was used to determine statistically significant differences between the technical quality of root fillings and tooth type. Sixty-three per cent, 27.6% and 72.2% of root-filled canals had adequate length, density and taper respectively. The overall acceptability of root fillings having adequate length and taper, absence of voids and no fractured instruments was found in 10.9% of canals. Changes in teaching methods may be required to improve the technical quality of root canal treatment done by dental students.

Radiographic evaluation of the technical quality of root canal fillings performed by dental students.

The objective of this study was to evaluate radiographically the technical quality of root canal fillings performed by dental students at the School of Dentistry, University of the West Indies. The school's database between 2000 and 2004 was investigated for patients with completed root canal treatment. The final sample consisted of 198 patients with 288 root-filled teeth and 460 canals. The length, presence of voids, taper, curvature of canal and fractured instruments were recorded and scored. Chi-squared analysis was used to determine statistically significant differences between the technical quality of root fillings and tooth type. Sixty-three per cent, 27.6% and 72.2% of root-filled canals had adequate length, density and taper respectively. The overall acceptability of root fillings having adequate length and taper, absence of voids and no fractured instruments was found in 10.9% of canals. Changes in teaching methods may be required to improve the technical quality of root canal treatment done by dental students.

Taper of full-veneer crown preparations by dental students at the University of the West Indies.

PURPOSE: The ideal taper recommended for a full-veneer crown is 4° to 14°, but this is very difficult to achieve clinically, and studies on taper achieved by dental students have found mean taper measurements ranging from 11° to 27°. The objective of this study was to examine and compare the taper of teeth prepared for full-veneer crowns by dental students on typodonts in the laboratory and on patients, and also to compare the results with those of other dental schools. MATERIALS AND METHODS: Preparations were scanned by specialized metrology equipment that gave the taper of the preparation in a buccolingual (BL) and mesiodistal (MD) plane. RESULTS: No undercut was detected on any of the laboratory specimens; however, 12.5% of clinical specimens were undercut. The mean taper of the laboratory anterior specimens were 26.7° BL and 14.9° MD, and the laboratory posterior specimens were 18.2° BL and 14.2° MD. The mean taper of the clinical anteriors were 31.6° BL and 16.8° MD, and the clinical posteriors were 16.8° BL and 22.4° MD. CONCLUSIONS: This study shows that although the taper achieved by dental students in the University of the West Indies when preparing teeth for full-veneer crowns was outside the ideal range of 4° to 14°, it is comparable to those achieved by dental students in other schools.

Cusp fracture resistance of maxillary premolars restored with the bonded amalgam technique using various luting agents.

Objective. This in vitro study uses measurements of fracture resistance to compare maxillary premolars restored with the bonded amalgam technique using a new resin luting cement, glass ionomer, and resin-modified glass ionomer as the bonding agents. Materials. Eighty-five sound maxillary premolars were selected and randomly assigned to one of five test groups of 17 teeth each. One group of intact teeth served as the control. The remaining groups were prepared to a standard cavity form relative to the dimensions of the overall tooth and restored with amalgam alone or a bonded amalgam using one of three luting agents: RelyX Arc (a new resin luting cement), RelyX luting (a resin-modified glass ionomer), or Ketac-Cem mu (a glass ionomer) as the bonding agents. Each tooth was then subjected to compressive testing until catastrophic failure occurred. The mean loads at failure of each group were statistically compared using ANOVA with a post hoc Bonferroni test. Results. It was found that regardless of the luting cement used for the amalgam bonding technique, there was little effect on the fracture resistance of teeth. Conclusion. Cusp fracture resistance of premolars prepared with conservative MOD cavity preparations is not improved by using an amalgam-bonding technique compared to similar cavities restored with amalgam alone.

Cusp fracture resistance of maxillary premolars restored with the bonded amalgam technique using various luting agents

OBJECTIVE. This in vitro study uses measurements of fracture resistance to compare maxillary premolars restored with the bonded amalgam technique using a new resin luting cement, glass ionomer, and resin-modified glass ionomer as the bonding agents. MATERIALS. Eighty-five sound maxillary premolars were selected and randomly assigned to one of five test groups of 17 teeth each. One group of intact teeth served as the control. The remaining groups were prepared to a standard cavity form relative to the dimensions of the overall tooth and restored with amalgam alone or a bonded amalgam using one of three luting agents: RelyX Arc (a new resin luting cement), RelyX luting (a resin-modified glass ionomer), or Ketac-Cem ì (a glass ionomer) as the bonding agents. Each tooth was then subjected to compressive testing until catastrophic failure occurred. The mean loads at failure of each group were statistically compared using ANOVA with a post hoc Bonferroni test. RESULTS. It was found that regardless of the luting cement used for the amalgam bonding technique, there was little effect on the fracture resistance of teeth. CONCLUSION. Cusp fracture resistance of premolars prepared with conservative MOD cavity preparations is not improved by using an amalgam-bonding technique compared to similar cavities restored with amalgam alone.

Cusp fracture resistance of maxillary premolars restored with the bonded amalgam technique using various luting agents.

Objective. This in vitro study uses measurements of fracture resistance to compare maxillary premolars restored with the bonded amalgam technique using a new resin luting cement, glass ionomer, and resin-modified glass ionomer as the bonding agents. Materials. Eighty-five sound maxillary premolars were selected and randomly assigned to one of five test groups of 17 teeth each. One group of intact teeth served as the control. The remaining groups were prepared to a standard cavity form relative to the dimensions of the overall tooth and restored with amalgam alone or a bonded amalgam using one of three luting agents: RelyX Arc (a new resin luting cement), RelyX luting (a resin-modified glass ionomer), or Ketac-Cem æ (a glass ionomer) as the bonding agents. Each tooth was then subjected to compressive testing until catastrophic failure occurred. The mean loads at failure of each group were statistically compared using ANOVA with a post hoc Bonferroni test. Results. It was found that regardless of the luting cement used for the amalgam bonding technique, there was little effect on the fracture resistance of teeth. Conclusion. Cusp fracture resistance of premolars prepared with conservative MOD cavity preparations is not improved by using an amalgam-bonding technique compared to similar cavities restored with amalgam alone.

The effects of heat treatment on selected properties of a conventional and a resin-modified glass ionomer cement.

This study investigated the effects of application of heat alone and heat & pressure on the compressive strength and modulus, the stress relaxation characteristics and the fluoride release of a conventional and a resin-modified glass ionomer cement. Cylindrical specimens were made from both materials and divided into 3 groups. One group was heat treated in an oven at 120 degrees C for 20 min, another group was subjected to heat & pressure at 120 degrees C for 20 min at 6-bar pressure. The third group acted as a control. The compressive strength and modulus, stress relaxation and fluoride release were tested over 56 days. The results of this investigation indicate that heat treatment had no significant effect on the conventional GIC used but significantly affected the resin modified GIC by increasing both the compressive strength and modulus and reducing the stress relaxation characteristics and the fluoride release. The use of GIC to produce inlay or onlay restorations that adhere to tooth tissue and release fluoride would be highly desirable. The results of this study indicate that it is possible to improve the strength of RMGIC with heat to a limited extent, but fluoride release may decrease.

Abutment taper of full cast crown preparations by dental students in the UWI School of Dentistry.

Retention of crowns has been shown to be inversely proportional to taper. The objective of this study was to compare the abutment taper of teeth prepared for full veneer crowns by students at the UWI School of Dentistry with those of other dental schools. Twenty five dies were scanned by a Co-ordinate Measuring Machine (CMM) and the mean taper and standard deviations were found to be 20.3 +/- 11.3 degrees mesio-distally and 18.3 +/- 8.5 degrees bucco-lingually. This study shows that the taper achieved by dental students at the UWI School of Dentistry preparing teeth for full veneer crowns is comparable to those achieved by other dental students in the US, UK, Europe and Japan.

Assessment of coronal microleakage of three materials used in endodontically treated teeth.

This study compared the coronal microleakage of three restorative materials used to seal the access cavity in root treated teeth. Thirty six teeth were prepared and three experimental groups were obturated and the access cavity filled with different materials; Group A--Intermediate Restorative Material, Group B--Fuji II and Group C--Dyract AP. Microleakage was assessed by Indian ink penetration. The mean coronal dye leakage for Group A was 0.895 mm, for Group B 1.914 mm and for Group C 3.245 mm. There was significantly (p < 0.05) more dye leakage in teeth restored with Dyract AP compared to those with Fuji II or IRM.

Perceived competency at graduation among dental alumni of the University of the West Indies.

The aims of this study were to describe levels of self-rated competency of dental graduates from the University of the West Indies (UWI) and to investigate relationships with gender and the effect of curriculum change. A thirty-two item self-reported postal questionnaire was sent to UWI dental alumni (1994-2002). The questionnaire included twenty-eight competencies that could be rated on a 5-point scale: 1 (not at all competent) to 5 (very competent). Overall preparedness for practice could also be rated from 1 (not at all prepared) to 5 (very prepared). The response rate was 77.4 percent, with a mean age of 29.3 years. Items with the highest mean scores were taking an adequate medical history (4.49), recognizing and treating dental caries (4.46), oral examination (4.36), and giving dental health education (4.35). Those with the lowest rating were designing and undertaking clinical research (2.29), dealing with practice management issues (2.52), designing and delivering crown and bridge work (3.33), and recognizing pathologic occlusions (3.33). Overall preparedness for practice was rated as 3.27. Female graduates rated four competencies significantly higher than males. Graduates exposed to the new curriculum perceived greater overall preparedness for general dental practice, suggesting the change to a competency-based curriculum was effective.