Influence of local anaesthesia on the quality of class II glass ionomer restorations

Objective. To investigate the influence of local anaesthesia on the quality of class II glass ionomer restorations with discomfort as cofactor. Material and methods. The study population consisted of 6- to 7-year-old schoolchildren in Paramaribo and its environs. To be included, each child needed to have a proximally situated cavity in a primary molar that was accessible to hand instruments and where no pulp exposure was expected. They were randomly divided into four treatment groups: conventional method with and without local anaesthesia and atraumatic restorative treatment method (ART) with and without local anaesthesia. The restoration quality was scored using the evaluation criteria for ART restorations (successful if restoration is correct or has a minor defect and fails if defects are larger than 0.5 mm, if secondary caries is observed, if the restoration is fractured, partly or totally lost or if the pulp is involved) at 6 and 30 months after treatment. The extent of discomfort was registered by assessing the behaviour (modified Venham score) and observing the heart rate during treatment. Results. For this study 153 children were treated with hand instruments (ART) and 146 children with rotary instruments (conventional method). A total of 198 restorations were evaluated during follow-up periods. There were no significant differences in patient discomfort between the ART and the conventional group and between the anaesthesia and the non-anaesthesia group. The conventional restorations demonstrated significantly higher success rates than ART restorations after 6 (P = 0.001) and 30 months (P = 0.032). There were no significant differences in success rate between the anaesthesia and the non-anaesthesia group. Conclusion. Local anaesthesia has no influence on discomfort during treatment. Furthermore, discomfort during treatment does not affect the success rate of restorations.