Use of a dental surveyor to ensure optimal seating of implant overdenture attachments.

Many implant overdenture attachments accommodate divergent abutments. However, there can be instances where the denture base resin surrounding the abutment may impede seating by binding on the axial surface(s) of the abutment. This article describes the use of a dental surveyor to aid clinicians in determining where the resin denture base might be preventing the seating of overdenture attachments. The surveyor can be used for judicious adjustment to allow optimal seating of the attachments.

Digital scanning to aid guiding plane and rest seat preparations for removable partial dentures.

This article describes the use of a digital intraoral scanner to aid clinicians making rest seat and guiding plane preparations, simplifying the procedure and reducing the time needed to analyze the abutment modifications. No additional equipment is required other than a diagnostic cast and a digital scanner with preparation comparison software.

Diagnosing denture problems using pressure-indicating media.

Pressure-indicating media have more diverse applications than merely the identification of areas on the denture base that cause mucosal pressure and pain. The purpose of this article is to provide guidelines for optimal use of the media and to identify alternative uses that could be considered in daily practice.

An evaluation of a technique to remove stains from teeth using microabrasion.

BACKGROUND: Microabrasion using a paste made of acid and pumice is a technique that has been used to remove white, yellow and brown stains from enamel. The authors evaluated the technique by studying the effectiveness of a proprietary microabrasion product. METHODS: One author used microabrasion to remove white, yellow and brown stains from within the outermost layer of the tooth enamel of 32 subjects. Standardized slides of the teeth were taken before and one week after treatment. Four prosthodontists evaluated the paired images, using a standardized questionnaire and visual analog scales ranging from 1 (no improvement in appearance or stain not removed at all) to 7 (exceptional improvement in appearance or stain totally removed). The evaluators were calibrated and blinded. RESULTS: The evaluators always identified a difference between the pretreatment slides and posttreatment slides; they found no difference between the control slides. In all cases but one (97 percent), the treated teeth had improved in appearance with more uniformity in color. Analysis of variance revealed no differences between evaluator ratings (P = .146). The intraclass correlation coefficient for ratings of individual cases by different evaluators was 0.72, representing a "good" level of correlation of the ratings for improvement of appearance and for stain removal. Mean (+/- standard deviation) ratings were 5.38 (+/- 1.26) for improvement of appearance and 5.06 (+/- 1.26) for stain removal. CONCLUSIONS: This study showed that enamel microabrasion could remove stains from within the outermost layer of tooth enamel, thereby improving the appearance of the teeth. CLINICAL IMPLICATIONS: This study supports recommendations that enamel microabrasion is an effective, atraumatic method of improving the appearance of teeth with stains in the outermost layer of enamel.

Effect of light source and specimen thickness on the surface hardness of resin composite.

PURPOSE: To compare the Knoop hardness of different thicknesses of resin composite irradiated using either a plasma arc curing (PAC) light, or a quartz tungsten halogen (QTH) light. MATERIALS AND METHODS: A 2.5-mm diameter hole was drilled through the center of 2, 3, 4, and 5-mm thick discs of enamel and dentin. This hole was filled with either Filtek P60 or Prodigy Condensable composite and irradiated in bulk using: (a) a PAC light with an 8-mm, 470 nm light guide for 3 seconds, (b) a QTH light with an 8-mm standard light guide for 40 seconds (QTH+S), or (c) a QTH light with a 13/8-mm Turbo light guide for 40 seconds (QTH+T). Immediately after irradiating the composite, the surface hardness was measured at the bottom and then the top. Hardness values were remeasured after 24-hour and 7-day storage in water at 37 degrees C. The hardness values were compared using the Analysis of Variance for Repeated Measures and Least Squares Means test for multiple comparisons (LSM test) at P< 0.05. RESULTS: The power density delivered by each light was: PAC over 1999 mW/cm2, QTH+S 588 mW/cm2, and QTH+T 844 mW/cm2. Both the thickness of the composite and the light source had a significant effect on the hardness. Overall, using the QTH+T produced the highest hardness values and the PAC light the lowest values. For all 2-mm thick specimens, irrespective of the light source, the hardness values at the bottom were not significantly different from their top hardness values measured at the same time. For the 3-mm thick specimens using the QTH+T, the hardness values at the bottom of both composites were not significantly different from their top hardness values at all time intervals. For the 3-mm thick specimens using the QTH+S, the bottom hardness values were not significantly different from those at the top for P60 only, and only at 24 hours and 7 days, but not when measured immediately. For all the 4 and 5-mm thick specimens, the hardness values at the bottom were all significantly different from those at the top measured at the same time interval.