Comparative evaluation of the effect of impregnated retraction cord versus laser on gingival attachment level and pain perception following retraction for subgingival margins - A prospective, split-mouth, controlled, clinical study.

AIM: To evaluate and compare the effect of impregnated retraction cord vs Laser on gingival attachment level and pain perception following retraction for subgingival margins. SETTINGS AND DESIGN: Many methods for achieving and measuring the amount of gingival retraction in fixed prosthodontic work have been advocated. Though the gingival attachment level is crucial in Periodontology, the literature available regarding the effect of these retraction methods on the same is scarce. Hence, this clinical study was designed to compare the pain perception and amount of gingival recession when impregnated cord and laser were used for retraction. MATERIALS AND METHODS: In 40 subjects (age range of 20 to 40 years) with single missing maxillary incisor, the abutments were prepared with subgingival margins, to receive a full coverage metal-ceramic fixed dental prosthesis. The gingiva was retracted on one of the abutments with impregnated retraction cord and on the other with diode laser. Gingival attachment levels were compared at six sites per abutment using superimposition of digital scans, preoperative and four weeks after cementation of final prosthesis. STATISTICAL ANALYSIS USED: Statistical analysis of the data for gingival recession was done using t-test. Pain perception was analysed with Chi-square test. Pain perception by patients following retraction was compared with VAS scale. RESULTS: The average values of gingival recession on buccal side were 0.61 mm and 0.38 mm and on the palatal side were 0.58 mm and 0.35 mm for impregnated retraction cord and laser respectively. The P values of <0.01 indicated a highly significant difference between the two groups. Intragroup comparison did not show significant differences between various sites. Pain and discomfort produced by cord method was moderate in comparison with mild/no pain with diode laser and the difference was highly significant.Conclusion: Retraction cord produced more gingival recession than the diode laser, which was statistically highly significant on both buccal and palatal aspects of the teeth. Patients experience with diode laser technique was less painful in comparison with retraction cord method.

Comparative Evaluation of Wear of Natural Enamel Antagonist Against Glazed Monolithic Zirconia Crowns and Polished Monolithic Zirconia Crowns: An In Vivo Study.

PURPOSE: To comparatively evaluate the amount of wear of natural enamel against a glazed full coverage monolithic zirconia crown and a polished monolithic zirconia crown at 6 and 12 months. MATERIALS AND METHODS: Thirty subjects within the age range of 18 to 35 years participated in this study. The subjects received a total of 60 single crowns, which were divided into two groups: (1) 30 glazed monolithic zirconia crowns opposed by natural enamel (group A); and (2) 30 polished monolithic zirconia crowns opposed by natural enamel (group B). Each subject received a crown from both groups, placed bilaterally in endodontically treated maxillary or mandibular first molars. An impression was made of the opposing arch at 24 hours, 6 months, and 12 months. The resulting casts were scanned with a 3D optical scanner. The recall scans were superimposed and compared to baseline scans using 3D AutoCAD software. A control group was included to compare the wear values to natural enamel against natural enamel. RESULTS: No significant difference (P = .855) was found in enamel wear between groups A (42.80 µm) and B (42.50 µm) after 6 months of use. However, a significant difference (P < .05) in enamel wear was found between group A (81.87 µm) and group B (71.43 µm) after 12 months of use. CONCLUSION: Glazed monolithic zirconia crowns cause more wear to the opposing enamel than polished monolithic zirconia crowns after 12 months of clinical use.

A Clinical Comparative Evaluation Of The Wear Of Enamel Antagonist To Monolithic Zirconia And Metal-Ceramic Crowns.

PURPOSE: To evaluate and compare the wear of natural enamel against a metal-ceramic and a monolithic zirconia crown, with the null hypothesis that there is no difference in the wear of enamel between antagonist metal-ceramic and monolithic zirconia crowns. MATERIALS AND METHODS: In 30 subjects (irrespective of sex and within the age range of 18 to 40 years), two bilaterally opposing molars (maxillary/mandibular) were prepared to receive monolithic zirconia or metal-ceramic crowns with feldspathic porcelain veneer. A polyvinyl siloxane impression of the opposing arch was taken at the time of cementation and 1 year after cementation. Casts were poured in type III gypsum and scanned, and the images were superimposed on each other. AutoCAD was used to calculate the difference between two images, which corresponded to the linear wear of the antagonist teeth. Statistical analysis of the data was done using one-way analysis of variance (ANOVA) and post hoc Tukey honest significant difference test for intergroup comparison. The P value obtained by one-way ANOVA was 1.1102e-16 (< .05), and by post hoc Tukey test was .001 (< .01). RESULTS: The mean wear of enamel against enamel was 14.8 ± 1.3 µm, enamel against metal-ceramic was 87.1 ± 18.3 µm, and enamel against monolithic zirconia was 59.4 ± 13.6 µm. The P values obtained; ie, 1.1102e-16 (one-way ANOVA) and 0.001 (post hoc Tukey), indicated that the difference in wear of the antagonist tooth between monolithic zirconia and feldspathic porcelain was significant. CONCLUSION: It can be concluded that monolithic zirconia causes less wear of the antagonist tooth than feldspathic porcelain.

Wettability of 3 different artificial saliva substitutes on heat-polymerized acrylic resin.

STATEMENT OF PROBLEM: The prosthodontic problems faced by a patient with xerostomia are of great concern. To aid in retention, artificial saliva substitutes should exhibit good wettability on the denture base. PURPOSE: The purpose of this in vitro study was to evaluate the wettability of 3 different artificial saliva substitutes on heat-polymerized acrylic resin and to compare these properties with natural saliva and distilled water. MATERIAL AND METHODS: A total of 150 heat-polymerized acrylic resin specimens were prepared with 25×15×2 mm dimensions. The specimens were divided into 5 groups (n=30): human saliva, distilled water, Aqwet, Mouth Kote, and Stoppers 4. The advancing and receding contact angle values were measured by using a goniometer, and the contact angle hysteresis and equilibrium angle were calculated. One-way ANOVA and the Bonferroni multiple comparisons test were performed to determine the difference between contact angle values among the groups (α=.05). RESULTS: The means of the 5 groups differed significantly (P<.05). The comparison between human saliva and Aqwet showed no significant difference for advancing contact angle, receding contact angle, contact angle hysteresis, or equilibrium contact angle, while comparison between the remaining groups indicated statistically significant (P<.05) results. All 3 saliva substitutes used in this study (Aqwet, Mouth Kote, and Stoppers 4) had significantly better wetting properties than distilled water. CONCLUSIONS: Human saliva had the lowest advancing, receding, and equilibrium contact angle values and the highest angle of hysteresis on heat-polymerized acrylic resin. Aqwet had better wetting ability than the other artificial salivary substitutes tested and was comparable to the human saliva on heat-polymerized acrylic resin. All saliva substitutes have better wetting properties than distilled water.

Changing ocular prostheses in growing children: a 5-year follow-up clinical report.

Eye loss in children can be caused by trauma, glaucoma, or cancer, and may result in anxiety and depression. Recovery after eye loss involves a replacement with a custom-made eye prosthesis, but, as the patient ages, changes in the size and shape of the eye socket can result in a sunken appearance of the child's prosthetic eye. This article describes the fabrication of a custom-made eye and the necessity of changing ocular prostheses for a growing child, with a 5-year follow-up.