Clinical and Microbiological Effects of Systemic, Local, and Combined Application of Doxycycline in the Treatment of Periodontitis

Periodontitis is a complex multifactorial inflammatory disease characterized by progressive destruction of tooth-supporting tissues, including periodontal ligaments and alveolar bone. This disease contributes to tooth loss and masticatory dysfunction. It has a negative impact on patients’ nutrition, speech, aesthetics, and general health, which in turn impairs their quality of life and self-esteem.

This study aimed to evaluate the clinical and microbiological effects of four different modalities, such as Scaling and Root Planning (SRP) alone, SRP with systemic doxycycline (systemic Dox), SRP with local doxycycline (local Dox), and SRP with systemic and local Dox in the treatment of periodontitis.

A clinical study of 90-day duration was conducted and included 60 patients (33 males and 27 females) diagnosed with stage II and stage III periodontal cases divided into four groups of 15 patients each: SRP alone, SRP with systemic Dox, SRP with local Dox, and SRP with systemic and local Dox. Four clinical parameters, namely, Plaque Index (PI), Gingival Index (GI), Probing Pocket Depth (PPD), and Clinical Attachment Level (CAL), as well as one microbiological parameter, such as bacterial count (Colony-Forming Units, CFUs) were recorded at baseline, day 45, and day 90. The data were documented and statistically analyzed, with a statistical significance set at p < 0.05 for all tests.

The clinical and microbiological parameters improved at the 45 and 90 days of visit compared with day 0 (baseline) in all groups. Moreover, PI and GI had the most statistically significant difference (p < 0.001) in SRP with systemic and local Dox group, followed by SRP with

systemic Dox group, then SRP with local Dox group and SRP only group. The most statistically significant differences in PPD, CAL, and CFUs (p < 0.001) were found in SRP with systemic and local Dox group, followed by SRP with local Dox group, then SRP with systemic Dox group, and with SRP only.

All the different modalities improved the clinical and microbiological parameters in patients with stages II and III periodontitis at both 45 and 90 days. Using SRP with doxycycline provided a higher improvement in clinical and microbiological parameters than that of SRP alone.