silicon and tungsten-carbide

Highly polished enamel surfaces are recommended for axial tooth surfaces that will serve as guiding planes and be contacted by component parts of a removable partial denture. There is little evidence to support the assumption that this tooth modification will provide accurate adaptation of the framework and prevent build-up of plaque.. The aim of this investigation was to evaluate the surface roughness of the tooth enamel, prepared to serve as guiding planes, with different polishing systems.. Four different methods (designated A, B, C, and D) for finishing and polishing the prepared enamel surfaces of 20 freshly extracted third molar teeth were studied. Each method involved 3, 4, or 5 different steps. The roughness of each specimen was measured at the start of each method before recontouring, after recontouring, and after each step of the 4 finishing and polishing procedures. The 4 experimental finishing methods were applied after recontouring the axial surfaces (buccal, lingual, and proximal) of each tooth. Thus the 20 teeth (60 surfaces) were finished and polished by use of 1 of the experimental methods. Surface roughness was measured with a profilometer (microm); the readings of the unpolished enamel surfaces were recorded as control measurements. Results were statistically analyzed with one-way analysis of variance followed by Tukey's test at the 95% level of confidence.. The highest roughness mean values (14.41 microm to 16.44 microm) were found when the diamond bur was used at a high speed for tooth preparation. A significant decrease in roughness values was observed with the diamond bur at a low speed (P<.05). Analysis of the roughness values revealed that all polishing methods produced surface roughness similar to that of the corresponding control teeth.. Within the limitations of this study, all finishing procedures tested effectively promoted an enamel surface similar to the original unpolished enamel.

Topics: Analysis of Variance; Dental Abutments; Dental Enamel; Dental Instruments; Denture, Partial, Fixed; Diamond; Humans; Molar; Random Allocation; Silicates; Silicon; Statistics, Nonparametric; Surface Properties; Tin Compounds; Tooth Preparation, Prosthodontic; Tungsten Compounds

This study evaluated the results of polishing composite resin by using the following finishing and polishing techniques: Arkansas stone burs; eight-blade tungsten-carbide burs; diamond burs; aluminum-oxide disks; no polishing; and 12- and 30-blade tungsten-carbide burs. The results were compared to ascertain which technique delivers the smoothest surface. The study was done with 120 class V restorations on extracted human teeth distributed in two groups (I and II) of 60 restorations each. Group I teeth samples were filled with microfilled composite resin and Group II with a hybrid composite resin. Readings were made with a profilometer to evaluate the final polishing. The conclusions from the results of the study were that microfilled composite resins provided a better finish when treated with aluminum-oxide disks. These results were statistically significant (p < 0.001). When hybrid composites were used the control group recorded the lowest values.

Topics: Aluminum Oxide; Analysis of Variance; Bisphenol A-Glycidyl Methacrylate; Carbon; Carbon Compounds, Inorganic; Composite Resins; Dental Polishing; Diamond; Humans; Resin Cements; Silicon; Silicon Compounds; Surface Properties; Tungsten; Tungsten Compounds