Does using a calcium hydroxide liner is necessary in restorations of deep cavities? Controlled randomized clinical trial

Abstract

Objectives: This clinical trial evaluated the effectiveness of provisional restoration with resin-modified glass ionomer (RMGI) during stepwise caries removal when compared to using a calcium hydroxide liner. Material and Methods: Caries lesions involving the inner third of dentin in posterior teeth were included in the study. Dentin thickness was radiographically measured, followed by analysis of clinical aspects (color, consistency and humidity) of dentin and bacteria counting. After partial caries removal, the cavities were restored with RMGI using (control) or not (experimental) a liner with calcium hydroxide. The patients returned after 60 days, while the symptom of irreversible pulpit/ necrosis (primary outcome) were assessed. The provisional restorations were removed after the delay period and the clinical aspects, dentin thickness and presence of bacteria were assessed. The relative risk to irreversible pulpit/necrosis was calculated. The effect of treatment and time of assessment on secondary outcomes was also statistically analyzed. Results: The treatment did not affect the risk to irreversible pulpit/ necrosis, while restorations with this outcome presented thinner dentin on pulpal wall. In general; darker, harder, drier and less contaminated dentin was observed after the provisional restorations, regardless the treatment; while control resulted in darker dentin. No difference on dentin thickness was observed between the treatments. Conclusions: RMGI seems be suitable to provisionally restore cavities during stepwise caries removal. Clinical relevance: Applying calcium hydroxide liner seems does not provide any additional beneficial effect when used under restorations of deep carious lesions.