• Nuchjaree Bunphawatthanarak, D.D.S.
• Peraya Puapichartdumrong, D.D.S., Ph.D.
• Thosapol Piyapattamin, D.D.S., Ph.D.

Objective To study the effect of chlorhexidine (CHX) as a vehicle for sodium perborate (SP) on
microleakage of resin composite by using glucose filtration.

Materials and methods Thirty six single-rooted teeth were used. The specimens with cavity were
prepared and divided into three groups: Group 1, SP mixed with 2% CHX; Group 2, SP mixed with
distilled water; Group 3, SP mixed with 30% hydrogen peroxide. With a total conduction of three
times, bleaching agent was applied in the cavities for 1 week and rinsed. The cavities were then filled
with resin composite. The specimens were thermocycled for 500 cycles, followed by a microleakage
determination (glucose filtration). The concentration of leaked glucose was analyzed by spectrophotometer.
Dentin surfaces of each group were prepared and observed under SEM.

Results Mean concentrations and standard deviations of leaked glucose (mM) were 1.001 ± 0.147,
1.005 ± 0.093, and 1.304 ± 0.406, in Groups 1, 2, and 3, respectively. Inter-group significant differences
were found by a one-way ANOVA (p < 0.05). Using the post-hoc Tukey HSDûs test analysis, some
significant differences were found between Groups 1 and 3, together with Groups 2 and 3 (p < 0.05).
The morphology of dentin surfaces under SEM of Group 1 showed mild erosion similar to that of
Group 2. Group 3 showed more eroded dentin.

Conclusion Using CHX as a vehicle for SP in this study did not affect the microleakage of resin
composite and dentin. Clinically, CHX may be a good vehicle for non-vital tooth bleaching.

(CU Dent J. 2016;39:9-18)