Simplified SPAL technique to provide adequate peri-implant phenotype: A pilot study

Correction of peri-implant bone dehiscence (PIBD) and optimization of the peri-implant soft-tissue phenotype are critical for long-term peri-implant tissues stability. A simplified, one-stage, transmucosal variant of the subperiosteal peri-implant augmented layer (sSPAL) technique was appraised and evaluated.

Eight systemically healthy patients with posterior mandibular edentulous sites showing an overt dehiscence received tissue-level implants combined with sSPAL using particulate deproteinized bovine bone mineral within a periosteal pouch. Clinical (keratinized mucosa, marginal soft-tissue level, probing depth (PD), and bleeding/suppuration) and radiographic (peri-implant bone dehiscence, buccal bone thickness (BBT), and interproximal bone levels) parameters were assessed at 12 months.

At the 12-month follow-up, all treated patients exhibited complete resolution of PIBDs and a BBT of ≥1.5 mm. Moreover, all implants presented a keratinized mucosa height ≥2 mm associated with stable soft-tissue margins, shallow PDs, minimal bleeding, and no suppuration.

Within the limitations of this preliminary case series, sSPAL appears to be a feasible approach to modify the peri-implant phenotype by both reconstructing the hard-tissue component and providing adequate dimensions of the soft-tissue component.

The study was performed in order to assess whether and to what extent sSPAL may allow to manage both hard- and soft-peri-implant phenotype components; The isolation of the coronal full-thickness portion of the flap as well as a careful dissection of the periosteal layer taking care of maintaining its integrity are of paramount importance in order to successfully perform the surgical procedure. Finally, the adaptation of the flap should allow for the displacement of the full-thickness portion of the flap around the healing abutment in order to create adequate dimension of the soft-tissue peri-implant phenotype; The absence of at least 6 mm of keratinized tissue above the edentulous ridge as well as a limited thickness of the mucosa lining the bone crest, thus not ensuring adequate dimensions of the soft-tissue phenotype on both buccal and lingual aspects of the implant, may represent a contraindication for the execution of sSPAL.

The present study pointed out the use of a novel surgical technique, namely the simplified subperiosteal peri-implant augmented layer technique (sSPAL), aimed at managing both hard and softperi-implant tissues in a single surgical intervention. The procedure derives from a published and validated two-stage technique (SPAL technique) aimed at correcting a peri-implant bone dehiscence (PIBD) simultaneously with implant placement. The present pilot study involved eight patients presenting one implant each that was treated with the sSPAL. No implant presented a PIBD at the 12-month CBCT examination, whereas seven of eight patients presented adequate (≥2 mm) dimensions of the peri-implant soft tissues. Therefore, despite taking into account the limitations of the present study due to its exploratory nature, it can be concluded that sSPAL may represent a valuable, simplified alternative to the conventional two-stage SPAL technique.