Effect of Selected Therapies on Healing in Rat Calvarial Defects

Healing of osseous defects may be affected by medications such as doxycycline (D) and alendronate (A). Enamel matrix derivative (E) has been shown to enhance osseous healing but it is not known if its effect could be modified by systemic D and/or A. Objective: To determine the effect of systemic D and/or A on the healing of calvarial osseous defects in rats treated with or without E. Methods: 40 mature Sprague-Dawley rats each received bilateral standardized defects in the calvarium with all of the animals receiving topical E in one defect and nothing in the contralateral defect, all defects were covered with dense polytetrafluorethylene membranes (d-PTFE). Animals were further randomly subdivided into 4 groups of 10. Group 1 received nothing (control), group 2 systemic doxycycline, group 3 systemic alendronate and group 4 received both D and A systemically. After 3 weeks of healing the animals were sacrificed, the calvaria removed, decalcified, and histological H&E-stained sections prepared. Healing was measured from digital images using Image J software. The investigator was blinded as to group and treatment. Statistical analysis of treatment vs. control was done using t-Test and Wilcoxon test. Results: Healing was evident in most groups. Statistically significant differences were found between control and: E, D, D+E, and D+A+E (all at p<0.05). Conclusions: In this model, alendronate reduced osseous healing of the wound except when used with D. Doxycycline enhanced the healing outcome in all the groups.