PROXIMAL WEAR RATES BY TOOTH POSITION OF RESIN COMPOSITE RESTORATIONS

Objective: The purpose of this study was to evaluate restorations, pre viously placed in clinical trials, for the rate of wear of the proxima l surfaces, by tooth position. Materials and methods: Seventy resin co mposite restorations were evaluated in bicuspids and molars. Fifty res torations were direct placement restorations and 20 were indirect plac ement restorations. Thirty-five bicuspids and 35 molars were evaluated for proximal wear rate. All restorations were opposing unrestored ena mel proximal surfaces. Ten enamel to enamel proximal surfaces were cho sen as controls. At baseline, contacts were judged to be closed visual ly and with thin, unwaxed dental floss. Impressions were taken at base line and after 6, 12 and 24 months for the fabrication of models. Meas urements for proximal wear, as determined by a loss of space between i ndexed transfer copings, were made under a zoom stereomicroscope by tw o independent evaluators. A parametric ANOVA, Student-Newman-Keuls, an d log curve fit were applied to the data. Results: When all data were pooled regardless of material, there were no significant differences ( P < 0.05) in wear values for 1st and 2nd bicuspids and Ist and 2nd mol ars. Wear rates showed a high correlation (log curve fit R(2) > 0.950) regardless of actual amount of wear. Conclusions: Regardless of compo sites examined, there were no differences in the amount of proximal we ar with regard to tooth position in the arch.