Post-operative Sensitivity of Selective-etch and Total-etch Techniques in Composite Resin Restorations: An In-vivo Study

Abstract

Introduction: Composite restorations placed using selective-etch technique has been claimed to induce significantly lower postoperative sensitivity than a three-step etch and rinse technique. Selective-etch technique overcomes the main drawback of self-etch technique, which is suboptimal etching of mineralised enamel, by acid etching only the enamel prior to using the adhesive. The newer universal bonding agent can be used in a self-etch, selective-etch, or etch and rinse mode. Aim: To evaluate the influence of selective-etch versus total-etch techniques of using Scotchbond universal adhesive on the postoperative sensitivity in composite restorations placed by undergraduate students. Materials and Methods: Sixty patients with ICDAS code 4 or 5 cavities for composite restorations by undergraduate students were randomly allocated into two groups. Restorations were done using Filtek Z350 XT and Scotchbond™ Universal Adhesive. In total-etch group, the entire preparation was acid etched for 20 seconds, and rinsed with water spray for 15 seconds. In selective-etch group, only the enamel was acid etched for 20 seconds, and rinsed. The postoperative sensitivity of the restorations was evaluated preoperatively, immediately after treatment, 24 hours and 2 weeks after treatment. Sensitivity scores were generated from the patient’s response to a Visual Analogue Scale (VAS) having scores from 0 to 10. The results were statistically analysed using Mann Whitney U-test and Friedman test. The level of significance was set at p-value less than 0.05. Results: There was no significant difference in the sensitivity between total-etch and selective-etch groups pre-treatment and during three postoperative follow-up periods (p-value >0.05). However, there was statistically significant decrease in the sensitivity at 24 hours and 2 weeks after treatment when compared with baseline scores in both total-etch and selective-etch groups (p-value <0.001). Conclusion: Both total-etch and selective-etch techniques of bonding using universal adhesive systems can be safely practiced by dental undergraduate students without the fear of developing postoperative sensitivity in patients.

Keywords

• acid etching
• composite bonding
• dentin sensitivity
• universal adhesive system
• visual analogue scale