Impacto dos fatores de risco em restaurações estéticas de dentes anteriores

Abstract

The use of composite resins has increased considerably in recent years making it widely indicated for restorations in anterior teeth in the most diverse situations. Despite the great aesthetic advancement of these materials, the literature presents few clinical studies accompanying the longevity and failure rates of the composite resins. In addition, studies evaluating patient-related factors such as caries risk, occlusal stress, and major restorative needs are needed to determine the longevity of the restorations comprehensively. Therefore, clinicians still have doubts regarding the functional, biological and aesthetic properties as well as longevity of these materials in the face of challenging clinical situations. Based on these principles, the objective of this thesis is to evaluate the impact of factors related to the patient, such as caries risk and occlusal stress in clinical performance, causes of failure, annual failure rate and longevity of different aesthetic restorative procedures of direct composite resin in anterior teeth. A prospective randomized clinical trial was carried out using nanohybrid resins (IPS Empress direct) and nanofilled (Z350 3M ESPE), adhesive single bond universal (3M ESPE) or single bond 2 (3M ESPE). Randomization was stratified by type of cavity (class III, class IV or veneers) and for the risk of caries. It was also observed the influence of the materials and risk factors surface and marginal staining, using the FDI criteria for the evaluation of the restorations. Follow up was up to 4 years. A total of 110 patients were included in this study. At randomization, 49 patients were allocated to the IPS Empress group and 61 to the Z350 group. During follow-up, 293 restorations were analyzed, 113 performed with the nanohybrid composite and 180 with the nanofilled composite. Follow-up average time was 1.9 years for success and 2 years for survival. The annual failure rates calculated at 2 and 4 years of follow-up were 15.80% and 15.93% for success and 8.02% and 15.51% for survival rates. The variables of the patient, age, sex, caries risk and tooth loss did not affect the success of the restorations, but the risk of occlusal stress did. The Hazard Ratio (HR) for high risk of occlusal stress was 1.47 (CI 0.85-2.54), compared to the low risk of occlusal stress. In dental variables, tooth type, number of surfaces, tooth vitality, adhesive system, and composite resin did not affect the success of restorations. The restoration type influences the survival of the restorations, with HR of 4.50 (CI 1.75-11.51) for class IV and 2.90 (CI 1.13-7.44) for the veneers when compared to class III. From the results, we conclude that dental loss, restoration type and occlusal stress are of the main determinants of failure of anterior teeth restorations and that patient risk factors are determinant in the longevity of restorations and should be widely evaluated and investigated in future prospective clinical studies.