Clinical assessments
DENTAL PLAQUE
Evaluation of oral hygiene, dental plaque accumulation and gingival health were performed with a periodontal probe and a dental mirror at baseline, 1, 6, 12 and 18 months. Greene and Vermillion simplified oral hygiene index (OHI-S) [For each crown, the following parameters were also evaluated at the recall periods: retention, marginal extension (level) of the crown (supragingival, subgingival and at the gingival margin), marginal adaptation (A: No discrepancies detected with an explorer, B: Detectable discrepancies but clinically acceptable (slight discontinuity in the margin that explorer catches but does not penetrate into any crevice and also radiograph shows a crown ledging < 1 mm), C: Detectable discrepancies (explorer penetrates into buccal, palatal or lingual crevice and also radiograph shows a crown ledging ≥ 1 mm, replacement required) [