Clinical study on the association between keratinized mucosa and peri-implant health when external hexagon implants are installed in the posterior region of the maxilla and mandible: a cohort study.

This study evaluated the association between keratinized mucosa (KM) and peri-implant health of external hexagon implants in the posterior region in 84 patients with 242 implants. Modified plaque index (MPI), modified sulcular bleeding index (MSBI), probing depth (PD), keratinized mucosa (KM) width, and peri-implant bone loss were evaluated. The implants were divided according to the KM: (1) absence of KM, (2) KM width >0 and <2 mm, and (3) KM width ≥2 mm. Of the 242 implants evaluated, 63 (26.0%) had no KM band, 56 (23.1%) had KM width <2 mm, and 123 (50.8%) had KM width ≥2 mm. One hundred and sixty-seven (69.0%) were used in multiple unit restorations and 75 (31.0%) in single tooth restorations; 66.9% were placed in the mandible and 33.1% in the maxilla. For single tooth and multiple unit implant restorations, MPI (P=0.069 and P=0.387, respectively), MSBI (P=0.695 and P=0.947, respectively), PD (P=0.270 and P=0.258, respectively), and mesial bone loss (P=0.121 and P=0.239, respectively) were not affected by the KM width. On the distal surface, bone loss was influenced by the absence of KM when single tooth implant restorations were used (P=0.032). No association was found between KM width and the peri-implant tissue health.

Short-term use of an exposed polypropylene barrier in the preservation of alveolar bone after extraction: randomized clinical trial.

This study was performed to evaluate the short-term preservation of alveolar bone volume with or without a polypropylene barrier and exposure of the area after extractions. Thirty posterior tooth extraction sockets were distributed randomly to a control group (n=15; extraction and suture) and a barrier group (n=15; extraction, barrier, and suture). All sutures and barriers were removed 10 days postoperatively. Cone beam computed tomography scans taken with the aid of a tomographic guide were obtained preoperatively, immediately postoperative, and at 120 days postoperative. A visual analysis of the coronal sections of the alveolus was performed, and vertical loss in the mesial, distal, buccal, and lingual bone ridges and horizontal thickness were evaluated. The mean vertical loss after extraction did not differ significantly between the control and barrier groups (Student t-test: mesial P= 0.989, buccal P= 0.997, lingual/palatal P= 0.070, distal P= 0.107). The mean vertical loss at 120 days postoperative did not differ significantly between the control (0.65 mm) and barrier (0.52 mm) groups (P> 0.05), with an effect size of 0.13 mm. At 120 days, the barrier group presented a mean resorption in thickness (0.45 mm) that was significantly lower than that in the control group (0.76 mm) (P= 0.021), with an effect size of 0.31 mm. The polypropylene barrier reduced the horizontal resorption in sockets of posterior teeth after extraction.