Comparison Between Corticocancellous Allograft and Bovine Xenograft for Sinus Augmentation: A Radiographic, Histologic, and Histomorphometric Clinical Study.

Sinus floor augmentation is one of the most common approaches to obtain sufficient bone availability for placing implants in cases with severe bone atrophy in the posterior maxilla. Several bone substitutes are indicated for sinus augmentation, but they may achieve different clinical outcomes. This study aims to compare bovine bone mineral (BBM) with freeze-dried bone allograft (FDBA) in a two-stage lateral window sinus grafting approach. Twenty patients received a lateral window sinus elevation with either FDBA or BBM. Postoperative graft height was measured with CBCT. Implants were placed 6 months later, at which time biopsy samples were taken for histologic analysis and new CBCT scans were performed to measure graft height. The mean height reduction at 6 months was 20.27% ± 4.94% for FDBA samples and 5.36% ± 2.41% for BBM samples. The histologic analysis revealed a mean ratio of newly formed bone of 43.70% ± 5.29% for the FDBA group and 38.11% ± 4.03% for the BBM group. The FDBA group also showed a higher amount of residual biomaterial (17.25% ± 10.10%) and connective tissue (14.63% ± 4.38%) compared to the BBM group (15.53% ± 5.42% and 13.11% ± 4.42%, respectively). The differences between groups were statistically significant for the height reduction and newly formed bone (P ≤ .05) but not for the amounts of residual biomaterial and nonmineralized connective tissue (P ≥ .05). Six months after performing a lateral window sinus elevation, the percentage of newly formed bone was significantly higher when using FDBA than when using BBM, although the graft height reduction was also significantly higher for the FDBA group.

Comparision between cortico-cancellous allograft and bovine xenograft for sinus augmentation: a radiographic, histologic and histomorphometric clinical study.

Sinus floor augmentation is one of the most used approaches to obtain sufficient bone availability to place dental implants in cases with severe bone atrophy in the posterior maxilla. Several bone substitutes are indicated for sinus augmentation but they may obtain different clinical outcomes. This study aims to compare bovine bone mineral (BBM) with freeze dried bone allograft (FDBA) in two- stage lateral window sinus grafting approach. 20 patients received a lateral window sinus lift with either FDBA or BBM. Post-operative graft height was measured with a cone-beam computerized tomography (CBCT). 6 months later implants were placed. Biopsies were taken for histological analysis and new CBCts were performed to measure graft height at this point. 6 months after procedure, there was a height reduction of 20,27 ± 4,94 % for the FDBA sample and 5,36 ± 2,41% for the BBM group. The histological analysis revealed a ratio of newly formed bone of 43,70 ± 5,29% for the FDBA and 38,11 ± 4,03% for the BBM group. The FDBA also showed a higher amount of residual biomaterial 17,25 ± 10,10% and connective tissue 14,63 ± 4,38% compared to the BBM 15,53 ± 5,42% and 13,11 ± 4,42%. The differences between groups were statistically significant for the height reduction and for the newly formed bone (p ≤ 0.05) but not for the residual biomaterial amount and the non-mineralized connective tissue (p ≥ 0.05). It could be concluded that the percentage of newly formed bone 6 months after performing a lateral window sinus lift using FDBA was significantly higher than when using BBM, although the graft height reduction was also significantly higher for the FDBA group.

Palatal bone plate to repair a deficient site in the esthetic zone.

Implants in the esthetic area are challenging for many reasons, all the more so when the hard and soft tissue are deficient at the beginning of the procedure. Numerous grafting techniques are available for the clinician, each one with its own strengths and weaknesses. It is important to understand these differences and to carry out a thorough diagnosis and case selection in order to make the right choice for each patient. The present article describes the treatment of a deficient maxillary central incisor site after extracting an ankylosed tooth. A palatal bone plate was utilized to reconstruct the missing buccal wall in the first place. Three months later, an implant was inserted and at the same time the soft tissue was augmented with a connective tissue graft. The case was successfully restored and finalized with a satisfactory esthetic outcome. The morbidity related to autogenous bone and soft tissue harvesting is discussed, but the shorter healing periods and optimal tissue quality obtained are highlighted.

Prevalence of Favorable Anatomy for Palatal Emergence of an Immediate Implant in the Maxillary Central Incisor Post-Extraction Site.

The purpose of this study was to determine the prevalence of favorable anatomy for palatal emergence of an immediate flapless implant in the maxillary central incisor post-extraction site. Implants were virtually placed into maxillary central incisor sites using 3-dimensional implant planning software. Following a strict implant placement criterion to keep a safe distance to the buccal plate and other anatomical structures, sockets were assessed to determine their suitability for an implant emerging from the palatal aspect. From 321 patients included in this study, 62.3% presented a suitable socket anatomy for an immediate implant to be placed with an angulation suitable for a screw-retained crown. In 29% of the cases, the implants had to be labially tilted to maintain a minimum distance to the buccal plate; 8.7% were unsuitable for immediate implants due to anatomic limitations. The position and angulation for an immediate implant in the maxillary central incisor socket should be carefully assessed preoperatively with 3-dimensional images, as many sites will not be candidates for a palatal emergence and thus a screw-retained restoration.

Open flap strategies in socket-shield therapy.

The socket-shield technique shows promising results in the esthetic zone. It is a technically challenging procedure but is effective in maintaining the buccal plate after tooth extraction and avoiding tissue collapse. Therefore, it could be considered a valid option in the immediate implant scenario. A careful shield preparation and handling are paramount for the success of the treatment and to minimize complications. Raising a flap can improve visibility and simplify the procedure. This article reports on a case in which a small crestal approach is used to visualize the root and the buccal plate, combined with a buccal semilunar flap, to gain access to the apical area. This surgical management is especially indicated when long roots are involved, in order to determine the correct axis for cutting and sectioning the root and to remove the apex if conventional drills are not long enough. Possible esthetic complications of raising a flap are also discussed.

Open flap socket shield in the esthetic zone.

Implants in the esthetic zone can be challenging due to the buccal plate resorption that occurs after tooth extraction. The socket shield technique has proven to maintain the buccal bone and midfacial tissue, minimizing the risk of tissue loss that can lead to an unesthetic emergence of the implant restoration. The socket shield technique is, however, a technically difficult procedure to perform. Key aspects for achieving a successful treatment outcome are a careful extraction of the palatal portion of the root, a meticulous buccal shield preparation, and accurate implant drilling and placement. A flapless approach has been described classically in the postextraction socket shield implant scenario. This case report describes an immediate implant in the maxillary right central incisor on a patient with a high lip line and exacting cosmetic demands. An open flap approach to improve the visibility of the partial extraction and to minimize potential complications derived from an inadequate shield preparation is described. No adverse effects such as soft tissue scarring were visible after 1 year of loading, and tissue volume, color, and contour were maintained during the observation period.

Accuracy of mucosa supported guided dental implant surgery.

Implant deviation at platform and apex was comparable to that seen in similar studies, showing that Mucosa Supported Guided Dental Implant Surgery can be a safe implant placement technique. Implant diameter and length, bone density and density deviations showed moderate strong correlation with apical deviation.