Pharyngeal spreading of peri-implant infections under antiresorptive/antiangiogenic therapy

OBJECTIVES: To assess the influence of antiresorptive/antiangiogenic therapy on the spreading of peri-implant infections in the pharyngeal region. MATERIAL AND METHODS: This analysis was based on tissue biopsies obtained from a total of twenty-five albino rats having either received (1) amino-bisphosphonate (Zoledronate) (Zo) (n=4), (2) RANKL inhibitor (Denosumab) (De) (n=4), (3) antiangiogenic medication (Bevacizumab) (Be) (n=4), (4) Zo+Be (n=3), (5) De+Be (n=5), or (6) no medication (Co) (n=5). Drug administration was repeated at 12 weeks. Chronic-type peri-implant infections were induced at titanium implants located in the upper jaws. The surface area (%) of infiltrated connective tissue (ICT) and CD68-positive cells was assessed within the lateral pharyngeal/retropharyngeal connective tissue zone. RESULTS: Mean (±SD) and median ICT% values and CD68 counts were markedly highest in the De+Be (11.10±6.04; 11.81; 95% CI − 3.89; 26.11) and De (5.70±5.06; 6.19; 95% CI − 2.34; 13.75) groups, reaching statistical significance for De CD68 counts over the Co (0.18±0.25; 0.18; 95% CI −2.14; 2.51) group. In both De+Be and De groups, the ICTs were occasionally associated with an ulceration of the epithelial compartment. CONCLUSIONS: Induced peri-implant infections were not associated with any inflammatory lesions in pharyngeal tissues. While these findings were similar under Zo and Be medication, De and De+Be had a marked effect on ICT and CD68 values. The clinical relevance of these adverse findings needs further investigation.