Outcome of cusp coverage restorations on endodontically treated premolars with cervical defects: a retrospective study

This study aimed to assess the outcome of cusp coverage restorations on endodontically treated premolars with cervical defects after 6-24 months of follow-up.

A total of 40 premolars with cervical defects from 28 patients who received endodontic treatment and cusp coverage restorations were included. All teeth were preoperatively diagnosed with irreversible pulpitis or apical periodontitis. Clinical and radiographic data were collected, including a 1-week postoperative assessment as the baseline and available follow-up data at various time points ranging from 6 to 24 months. Modified Fédération Dentaire Internationale (FDI) criteria and a radiographic classification were used to assess restorations and endodontic outcomes by 2 evaluators, respectively. When both FDI scores of 1-2 (1. excellent with defect-free; 2. acceptable with minor imperfections) and radiographic categories of 4-6 (periapical lesion dynamics: 4. reduction; 5. absence; 6. no lesions before and after treatment) were fulfilled, a success was determined. The maintenance of success without deterioration in the FDI score comparing with baseline was defined as stability. McNemar's test and Fisher's exact test were used for statistical analysis. A patient satisfaction questionnaire was done.

At a mean follow-up of 11 months, 36 premolars from 24 patients were evaluated at recall, representing recall rates of 90% for teeth and 86% for patients. Twenty-two teeth were restored using composite resin, and the other fourteen were restored using ceramic. The patient satisfaction rate reached 97%. Neither tooth fracture nor extraction occurred during 6 to 24 months follow-up period. No failed cases were found. All teeth demonstrated FDI scores of 1-2 with radiographic categories of 4-6, showing that 22% (n = 8) of restorations were rated as FDI score 1 and 78% (n = 28) as score 2. The overall stability rate was 80.6%, with 7 cases exhibiting deterioration from FDI score 1 to score 2 in staining, marginal adaptation, or gingivitis at recall. Respective stability rates for ceramic and composite resin restorations were 93% (13/14) and 73% (16/22), respectively (P = 0.020).

Acceptable performance of cusp coverage restorations for 36 endodontically treated premolars with cervical defects was reported at short-term follow-up.