Spectrophotometric analysis of crown discoloration induced by various antibiotic pastes used in revascularization

Antibiotic pastes are used for disinfection in regenerative endodontic procedures. This study evaluated the crown discoloration induced by various antibiotic pastes including the mixture of metronidazole and ciprofloxacin with minocycline, doxycycline, amoxicillin, or cefaclor.

Seventy extracted bovine incisors were sectioned to obtain a standardized root length of 10 mm above the facial cementoenamel junction. After pulp tissue removal, irrigation with sodium hypochlorite and the placement of temporary filling material and cotton pellet were performed from the apical aspect. The specimens were then randomly divided into 7 groups (n = 10 for each group), and each group received the following antibiotic paste fillings: no filling (control group), calcium hydroxide, double antibiotic paste (DAP), triple antibiotic paste (TAP) with minocycline, TAP with doxycycline, TAP with amoxicillin, and TAP with cefaclor. Spectrophotometric readings were obtained on the buccal surfaces of the crown on day 1 to week 3 after filling, and the ΔE value was calculated. Data were analyzed with 2-way analysis of variance and the Tukey post hoc tests (P = .05), and the human perceptibility threshold was set to 3.7.

TAP with minocycline, doxycycline, and cefaclor induced more coronal discoloration compared with the control group (P < .05). The control, calcium hydroxide, and DAP groups showed no color changes exceeding the perceptibility threshold at all time points.

The results indicated that all antibiotic pastes, except DAP, induced crown discoloration.