Evaluation of Two Resin Composites and Two Adhesives for a Novel Restorative Protocol to Treat Cervical Lesions

Evaluation of Two Resin Composites and Two Adhesives for a Novel Surgical-restorative Protocol for the Treatment of Non-carious Cervical Lesions Associated With Gingival Recession: a Randomized Controlled Clinical Trial

Non-carious cervical lesion is frequently associated with gingival recession, resulting in a combined lesion that has a different treatment prognosis when the two lesions appear alone. The literature presents few studies that propose a multidisciplinary approach (restorative and root coverage surgery procedures) to optimize the treatment of this combined lesion. The previously proposed approaches and materials have limitations and an optimal clinical protocol has not been established yet. Thus the aim of this study is to evaluate a novel multidisciplinary protocol with two resin composites and two different adhesive systems through a randomized clinical trial and laboratory studies. 120 combined lesions will be randomly assigned to one of the following groups: NP + TE (n = 30) - Partial restoration of cervical lesions with nanofilled composite and total-etch adhesive system and periodontal surgery for root coverage, NP + UA (n = 30) - partial restoration of cervical lesions with nanofilled composite and self-etching adhesive system and periodontal surgery for root coverage, MH + TE (n = 30) - partial restoration of cervical lesions with microhybrid composite and total-etch adhesive system and periodontal surgery for root coverage, MH + UA (n = 30) - partial restoration of cervical lesions with microhybrid composite and self-etching adhesive system and periodontal surgery for root coverage. Restorations will be assessed using the USPHS criteria after one week, six months and twelve months.

Inclusion Criteria:

• Individuals presenting one or more combined defect, i.e. a NCCL classified as B+ (Pini-Prato et al., 2010): presenting more than 1mm in depth, affecting dental crown and root associated with Miller's class I or II gingival recession in canines or premolars with pulp vitality;
• Healthy patients (systemically and periodontally), 18 years old, with at least 20 teeth in occlusion;
• Plaque index ≤ 20% (Ainamo & Bay, 1975);
• NCCL cavo-surface margin without involvement of more than 50% of enamel;
• In tooth included in the study and the adjacent elements of the following must be observed: probing depth less than 3 mm; do not show bleeding on probing (periodontal health) and no insertion loss in the proximal and palatal areas; Provide formal consent to participate in research, after the explanation of the risks and benefits by an individual not involved in it (Resolution #196 October 1996 and the Code of Dental Professional Ethics - C.F.O. - 179/93).

Exclusion Criteria:

• NCCL previously restored;
• Presence of caries;
• Patients with periodontitis;
• Patients with bruxism or teeth clenching;
• Patients with orthodontic treatment in progress;
• Pregnant patients or smokers;
• Patients with systemic problems (cardiovascular, blood dyscrasias, immunodeficiency, diabetes and others), which contraindicate the surgical procedure; Previous periodontal surgery in the area of interest of the present study.