Spectrophotometric analysis of discoloration and internal bleaching after use of different antibiotic pastes.

OBJECTIVES: To investigate teeth's antibiotic-induced color differences after bleaching using two different techniques. MATERIALS AND METHODS: One hundred twenty extracted maxillar human incisors were examined. The specimens were randomly divided into six groups, each receiving one of six antibiotic paste fillings: (1) triple antibiotic paste (TAP) with minocycline, (2) double antibiotic paste (DAP), (3) TAP with amoxicillin, (4) TAP with cefaclor, (5) TAP with doxycycline, and (6) no filling (control group). Spectrophotometric measurements were obtained at baseline and then during the first, second, and third weeks after paste placement. The specimens discolored by antibiotics pastes were randomly divided into two subgroups: (1) internal bleaching with hydrogen peroxide (H2O2) and (2) internal bleaching with H2O2 plus Nd-YAG laser irradiation. The ∆E value was calculated and analyzed using a two-way analysis of variance and post-hoc Tukey's test (α = 0.05). RESULTS: The ∆E for all groups showed color differences exceeding the perceptibility threshold (∆E Ëƒ 3.7) at all time points except in the control and DAP groups. Minocycline-induced TAP showed the most severe coronal discoloration (32.42). When the ∆E was examined, thermo/photo bleaching (22.01 ± 8.23) caused more bleaching than walking bleaching (19.73 ± 5.73) at every time point (P = 0.19). No group returned to the original color after bleaching (P < 0.05). CONCLUSIONS: Except for DAP, all antibiotic pastes caused discoloration. Internal bleaching with Nd-YAG laser can be useful for bleaching/removing this discoloration. CLINICAL RELEVANCE: For clinically successful final appearances, understanding the effects of bleaching procedures on antibiotic paste discoloration is important.