A clinical, radiographic, and scanning electron microscopic evaluation of adhesive restorations on carious dentin in primary teeth

Objective: The purpose of this project was to evaluate the performance of a dentin adhesive system on carious and noncarious primary dentin in vivo. M ethod and materials: Forty-eight primary molars with carious lesions were r andomly assigned to 2 different treatments: group 1 (control, n = 24)-All i dentifiable, irreversibly infected dentin was removed prior to the applicat ion of the bonding agent and restorative material; group 2 (experimental, n = 24)-Irreversibly infected dentin was partially removed prior to the appl ication of the bonding agent and restorative material. The control and expe rimental teeth were clinically monitored every 3 months and evaluated 12 mo nths after restoration. The teeth were extracted around the time of exfolia tion and processed for scanning electron microscopy. Results: Retention rat e, marginal integrity, and pulpal symptoms were identical in both groups. R adiographically, the radiolucent area associated with the experimental rest orations did not increase with time in 75% of the cases. For the control gr oup, the adhesive system formed a hybrid layer. In the experimental group, there was morphologic evidence of the formation of an acid-resistant "alter ed hybrid layer." An acid-resistant tissue, resulting from the interdiffusi on of adhesive resin within the area of carious dentin, was observed adjace nt to and under the altered hybrid layer. Conclusion: Application of an adh esive restorative system to irreversibly infected dentin did not affect the clinical performance of the restoration.