Correction of Peri-Implant Buccal Bone Dehiscence Following Sub-Periosteal Peri-Implant Augmented Layer Technique With Either Block or Particulate Xenograft: A Retrospective Study.

OBJECTIVE: To evaluate the effectiveness of Sub-periosteal Peri-implant Augmented Layer (SPAL) technique performed with deproteinized bovine bone mineral (DBBM), delivered either as particulate (pDBBM) or block (bDBBM), in correcting a peri implant bone dehiscence (PIBD). Implants showing a thick (>/= 2 mm) peri-implant buccal bone plate (PBBP) at placement were also examined. MATERIAL AND METHODS: Patients with a PIBD >/= 1 mm, treated with SPAL with either pDBBM (SPAL(particulate)) or bDBBM (SPAL(block)), and patients with an implant showing a PBBP >/= 2 mm at insertion (CONTROL) were included. Re-entry was performed either at 6 months (SPAL groups) or 3 months (CONTROL). The rate of patients presenting no PIBD at re-entry was the primary outcome. Bone dehiscence height (BDH) and width (BDW), thickness of buccal tissues (BTT) and marginal bone level (MBL) were secondary outcomes. RESULTS: Thirty-nine implants in 39 patients (14 in SPAL(particulate),14 in SPAL(block) and 11 in CONTROL) were analyzed. No PIBD were found in SPAL(particulate) whereas in SPAL(block) one PIBD was present. Two patients in CONTROL presented a PIBD. A reduction in both BDH and BDW was observed in both SPAL(particulate) (2.7 +/- 1.6 mm for BDH and 3.9 +/- 0.2 mm for BDW) and SPAL(block) (2.5 +/- 1.8 mm for BDH and 3.8 +/- 1.1 mm for BDW). SPAL(block) showed a higher BTT than SPAL(particulate) at re-entry (3.6 +/- 1.3 mm for SPAL(block) and 2.6 +/- 0.6 mm for SPAL(particulate), p = 0.0160). All groups showed similar MBL. CONCLUSION: SPAL performed with either a pDBBM or bDBBM is similarly effective in correcting a PIBD as well as in increasing BTT.