Newer Class I cavity preparation for permanent teeth using air abrasion and composite restoration.

This study attempts to determine a more effective cavity preparation design, material selection and preparation technique for reducing microleakage in posterior Class I esthetic restorations. An in vitro study using four different cavity designs, for Class I restorations on permanent molars, prepared with two different methods, and restored with three different restorative materials (hybrid composites) was done to evaluate marginal microleakage, and voids occurrence. Two hundred and forty extracted permanent molars were chosen and evaluated for caries, visually, with a dental explorer, and with caries detector dye. The teeth were then randomly divided in two groups (n = 120). In the first group, Class I cavity preparations were performed with air-abrasion. In the second group Class I cavity preparations were performed with #330 bur. The results revealed that cavity preparations prepared with air-abrasion with or without chamfer, and for cavity preparations done with a #330 bur with chamfer and restored with Tetric Flow, had zero microleakage. Cavity preparations done with air-abrasion, without chamfer, and for cavity preparations prepared with #330 bur with chamfer and restored with Tetric Ceram, had zero microleakage score. Cavity preparations done with air-abrasion with chamfer and restored with Herculite had one tooth out of twenty with microleakage, and for cavities without chamfer two teeth had microleakage. Cavity preparations prepared with a #330 bur, without chamfer, and restored with Herculite XRV had four teeth out of twenty with microleakage, and with a chamfer, two teeth had microleakage. These differences were not statistically significant. When comparing Tetric Flow versus Herculite XRV for void formation in cavity preparations prepared with Air-abrasion and a chamfer, Tetric Flow had significantly less voids, p < 0.001. When comparing Tetric Ceram versus Herculite XRV for cavity preparations prepared with Air-abrasion and a chamfer, Tetric Ceram had significantly less void formation, p < 0.01 > 0.001. When comparing Tetric Flow versus Herculite XRV for cavity preparations prepared with #330 bur and without a chamfer, Tetric Flow had significantly less void formation, p < 0.02 > 0.01. When comparing Tetric Flow versus Herculite XRV for cavity preparations prepared with #330 bur and a chamfer, Tetric Flow had significantly less void formation, p < 0.001 > 0.001. Caries detection results revealed that the caries detector dye method had significantly higher caries detection scores than explorer p < 001, and than visual inspection p < 0.001. Also inspection with explorer had significantly higher scores than visual inspection p < 0.001.

Lingual arch appliance fabrication in the dental office.

Lingual arch is a mandibular fixed bilateral space maintaining appliance. It prevents the first permanent molar from drifting forward and preserves the available space, especially the leeway space in mixed dentition cases. The purpose of the present article is to present a simplified way of lingual arch appliance fabrication in the dental office, which will result in effective space maintenance and time savings for both the patient and the dentist.

Microleakage reduction from newer esthetic restorative materials in permanent molars.

Through use of new technologies, such as air-abrasive devices, caries detector dyes, modern technology can increase the speed, comfort and success of dental restorations. However the issue of marginal adaptation has been an ongoing technical problem. Today with the more frequent use of posterior composite resins, poor marginal adaptation of resin is still the major cause of failure of the restoration. Material contraction from polymerization and possibly inappropriate preparation design are key factors in the longevity of the restorations. This study attempts to determine the more effective material and technique for reducing microleakage in composite restorations. An in vitro study using three hybrid composite resins was done to evaluate marginal microleakage. Extracted molars were chosen and evaluated for caries through the use of caries detector dye. Using air-abrasion, caries were removed and minimal preparations were done. The samples were divided into two groups. First group was restored with Herculite XRV and Heliomolar paste composites resins. The second group was restored with Revolution flowable composite resin. Also Opti-bond and Fortify were used as a bonding agent and surface penetrating sealant respectively. The teeth were properly finished, thermocycled and evaluated for leakage using 2% basic fuschin detector dye. All data were subjected to the nonparametric Mann-Whitney Rank Sum Test. The results revealed that Herculite XRV and Heliomolar paste composites had significantly higher microleakage formation (P < 0.03), and also they presented higher void formation (P < 0.0001) than Revolution flowable composite resin.