Implant site preparation with piezosurgery or conventional drills – Histological randomized study in humans

Background

Piezoelectric surgery is a soft tissue-sparing bone-cutting technique that reduce iatrogenic damage of neurological and vascular structures. Recent studies have shown that piezoelectric surgery may modify and improve initial histological phases of implant osseointegration. However, only in vivo studies and no human study are available

Aim/Hypothesis

The aim of this randomized clinical trial is aimed to compare histological, histomorphometric, and immunohistochemical outcomes of piezosurgery approach and conventional drill approach for implant site preparation

Material and Methods

This study was designed as a pilot, split-mouth, double blinded, randomized clinical trial, approved by ethical committee of University of Bologna. Six patients were enrolled to rehabilitate 12 different edentulous sextants and they were randomized into 2 groups (T0)- Group A (piezoelectric implant site preparation) (Piezo-group) and Group B (conventional drill preparation) (Drill-group). In each sextants, one additional implant (study fixture) was placed to be retrieved after 4 weeks. After 28 days (T1), in both groups the study-fixtures were biopsied for histological, histomorphometric and immunohistochemical analysis. Inflammatory infiltrate, necrotic bone area (NBA%), newly-formed bone (nFBA%),, and total bone area rates (TBA) were evaluated. Neo-angiogenesis and osseointegration markers (CD31 and STAB-2) were also analyzed. Statistical comparison was made and statistical significance was set at = 0.05. STATA software was used for statistical analysis (significance = 0.05)

Results

In total, 12 edentulous ridges in six patients were completely treated according to the split-mouth protocol. No drop-outs occurred. Histological features were similar in the two study groups- residual trabecular bone, bone necrosis areas, and bone formation areas. Three histological zones were evident- Zone 1, Zone 2 and Zone 3 according to histological findings (i.e. chronic inflammatory infiltrates). Considering immuno-histochemical markers, piezo-group showed statistically higher rates of SATB2 and CD31 than those of drill-group. No surgical or healing complication was recorded during T0 and T1 surgery. STATA software was used for statistical analysis (significance = 0.05).

Conclusion and Clinical Implications

This pilot study suggests that piezosurgery implant site preparation gives a small amount of necrotic bone, higher bone activity, and higher vessel proliferation compared to drill implant site preparation. Further studies are needed to confirm histological, histomorphometric, and immunohistochemical improvements of this surgical approach