Polishing occlusal surfaces of direct Class II composite restorations in vivo

This study evaluated the effects of four polishing methods on the occlusal surfaces of direct Class II composite restorations under clinical conditions. Forty premolars and 40 molars were treated with direct Class II restorations using the hybrid composite Herculite XRV (Kerr). After placement of the restorations, all of which were on occlusal surfaces, they were finished with a sequence of 30 microm diamonds and tungsten carbide instruments. Twenty restorations each, consisting of 10 premolars and 10 molars, were polished with one of the four following methods: (1) Diafix-oral (Mueller-Dental), (2) MPS gel (Premier), (3) P 403-W (Dentsply) and (4) Occlubrush (KerrHawe). Selection of the polishing methods followed a randomized protocol. Replicas of the restored teeth were fabricated and the occlusal surfaces were evaluated quantitatively for roughness with the help of profilometry. Qualitative assessment of the surfaces by SEM was done with respect to roundness of contours and surface roughness. The results were analyzed statistically by two-way ANOVA, chi-squared test for crosstables and Kruskal-Wallis test. Analysis of the quantitative data showed that there was no significant effect of the polishing methods on occlusal surface roughness (p>0.05). Localization of the restoration in premolars or molars had no effect on surface roughness (p>0.05). With respect to occlusal relief, SEM examination revealed that the use of the Occlubrush resulted in significantly more edged contours compared to the other polishing methods (p=0.008). Qualitative roughness evaluation showed that there were no significant differences among the four polishing methods (p>0.05).