Factors Affecting the Clinical Performance of Direct Posterior Restorations

A direct posterior restoration is still the first choice for the rehabilitation of tooth diseases in posterior region, thus the factors which might affect its clinical performance should be considered to improve its longevity. The purpose of this cross-sectional study was to evaluate the effects of factors related to restoration and patient on the clinical performance of direct posterior restorations.

Method:

A total of 433 direct posterior restorations including 283 amalgams and 150 composites, which had been performed in different clinical centres, were evaluated by two experienced observers in terms of retention, colour match, marginal adaptation, marginal discoloration, anatomical form, secondary caries, postoperative sensitivity and surface roughness using the Modified Ryge Criteria (USPHS). The variables related to the restoration such as restorative material, cavity classification, depth and age of restoration, type of dental service provider and the variables related to the patient such as oral hygiene and smoking habit were analysed using the logistic regression analysis.

Result:

The failure rates for amalgam and composite restorations were 43% and 39%, respectively. Restorations older than ten years (OR = 6.4, p=0.001), Class II (MOD) restorations (OR = 9.9, p = 0.000) and restorations made in public dental care centres (OR = 4.4, p = 0.038) were associated with the higher risk for failure in posterior region. 

Conclusion:

The present study showed that amalgam and composite posterior restorations had similar failure rates. Age of restoration, cavity classification and type of dental service provider significantly affected the clinical performance of direct posterior restorations.