Spectrophotometric method for assessing dentin moisture in clinical settings: a randomized controlled clinical trial

BACKGROUND: Air-drying exposed dentin with open dentinal tubules is ineffective because rapid rehydration (refilling of the tubules with dentinal fluid) occurs within a very short time, effectively nullifying the procedure. As a result, penetration of dentinal fluid into the adhesive system of composite restorations is inevitable. Developing methods to mitigate the adverse effects of dentinal fluid on composite bonding — guided by objective, instrument-based assessment of dentin moisture — is a timely priority in contemporary dentistry. AIM: This trial aimed to develop a clinical method for evaluating dentin moisture using spectrophotometry. METHODS: A VITA Easyshade spectrophotometer (VITA Zahnfabrik H. Rauter GmbH Co. KG, Germany) was used to assess dentin moisture due to dentinal fluid. Dentin moisture was assessed by analyzing its color parameters — lightness (L), chroma (C), and hue (H) — which change over time as dentinal fluid accumulates on the dentin surface. RESULTS: In dentin not treated with 3% sodium hypochlorite, lightness (L) decreased from 82.6 to 73.1 units (−11.8%) and chroma (C) decreased from 25.5 to 20.2 units (−20.8%) within 5 minutes, indicating increased dentin density. In dentin treated with 3% sodium hypochlorite for 5 minutes, lightness (L) decreased from 76.5 to 74.6 units (−2.5%), and chroma (C) decreased from 22.4 to 21.1 units (−5.9%). CONCLUSION: Spectrophotometry can be used as an objective method for evaluating dentin moisture in vital teeth under clinical conditions. Pretreatment of dentin with 3% sodium hypochlorite before composite restoration substantially reduces dentin moisture and has a beneficial effect on adhesion.