Submucosal implantation of soft tissue expanders does not affect microcirculation

Abstract

Aim: To investigate the effect of submucosal implantation of self-filling osmotic tissue expanders on mucosal microcirculation.

Material and methods: In ten beagle dogs, all premolars were extracted on both sides of the mandible. Tooth-supporting bone and excess soft tissue were removed to mimic a severely resorbed edentulous ridge. Six weeks later, tissue expanders with 0.7 ml final volume were implanted into a submucosal pouch at randomly selected test sites, while contralateral sites served as untreated controls. Microcirculation was assessed in perfusion units (PU) before surgery, after local anaesthesia, directly after surgery, and after 1 and 3 days, using Laser Doppler flowmetry.

Results: Local anaesthesia caused a significant decrease of blood flow from baseline (zero) to -6.4 PU (median; Q1 -10.5; Q3 -0.9; P = 0.006); however, no additional significant decrease was recorded after completion of surgery. Blood flow showed significant increases to -3.6 PU (median; Q1 -11.3, Q3 2.1; P = 0.02) and -4.0 PU (median; Q1 -9.2, Q3 1.1; P = 0.013) after 1 and 3 days, respectively, when compared to the measurements obtained after application of local anaesthesia and completion of surgery. Blood flow had returned to unimpaired baseline levels 1 day after surgery (P > 0.05).

Conclusions: Submucosal implantation of self-filling osmotic tissue expanders results in only momentary disturbance of microcirculation. The minor impairment of perfusion may explain the consistently good outcomes of submucosal implantation of these tissue expanders.

Keywords: Laser Doppler flowmetry; microcirculation; soft tissue expansion; tissue expanders.