This evaluation correlates maxillary sinus 3D morphology with bone regeneration. In 39 patients with crestal bone ≤ 2 mm, mineralized human bone allografts were used to augment the sinus floor through the crestal window sinus elevation approach. CBCT was used to measure the buccopalatal diameter (BPD), mesiodistal diameter (MDD), and hemi-ellipsoidal volume (Vh) in all sinuses. A bone core biopsy sample was taken at implant placement (4 to 5 months after sinus augmentation). Microradiographs of methacrylate-embedded sections were used to evaluate the amounts of bone, residual graft, and soft tissue. All 51 implants placed in the 39 patients successfully osseointegrated. A linear regression analysis showed that as BPD, MMD, and Vh increased, the amount of bone gain decreased and the amount of soft tissue increased (P < .05). The amount of residual graft was little affected by sinus morphology. Microradiographic data were grouped into four different sinus types (from small to great) using BPD and Vh medians. The best amount of bone formation was achieved in the narrow and short sinus type, while no great differences were found in the remaining three sinus types. Understanding of 3D sinus cavity morphology, especially the buccopalatal diameter and mesiodistal dimensions, is fundamental for achieving the best possible sinus augmentation outcomes.

This clinical and histologic case series aims to evaluate a novel flapless approach to alveolar ridge reconstruction (ARR) of compromised extraction sockets by means of collagenated xenograft sealed with three resorbable layers of hole-punched membrane. Eight postextraction sockets without buccal and/or palatal bone walls and with adjacent natural teeth from eight consecutive patients were included. Pretreatment CBCT scanning was performed. After debridement of the selected sites, a flapless grafting procedure was carried out, and the three-membrane protection was applied. After 6 to 17 months, at implant placement, a posttreatment alveolar ridge CBCT was taken, and a bone core biopsy sample was harvested for histologic and morphometric analyses. Clinical outcomes showed predictable horizontal bone regeneration in all postextraction sockets with good preservation of soft tissue architecture. Pretreatment ridge CBCT measurements showed limited bone width (2.6 ± 1.08 mm). Posttreatment measurements revealed adequate bone width (9.05 ± 1.29 mm) with a mean bone gain of 6.4 ± 1.34 mm. Histologic and morphometric analyses revealed the absence of inflammatory cells and the presence of 25.4% ± 8.7% of new bone and 31.8% ± 8.3% of graft particles inside the biopsy samples. Many graft particles were surrounded and interconnected by new bone, thus demonstrating the formation of a bone-graft network. Rare osteoclasts were found. This novel technique seems to be effective in treating alveolar sockets prior to implant placement, preventing inflammation and bone resorption and promoting bone regeneration.

Purpose: To investigate the influence of vertical mucosal thickness on marginal bone loss around implants with short and long prosthetic abutments and the marginal bone loss progression rate up to 18 months after prosthetic loading. Materials and methods: Internal hex platform-switched implants were placed equicrestally using a two-stage protocol in the posterior mandible of two groups of patients with different vertical mucosal thickness, thin (≤ 2.0 mm) and thick (> 2.0 mm). Elevated prosthetic abutments of different heights (1 mm or 3 mm) were randomly assigned for single screw-retained crowns in both groups. Mesial and distal marginal bone loss were measured at implant placement (T0) and crown delivery (after 4 months [T1]), and after 6 (T2), 12 (T3) and 18 months (T4) of functional loading. Results: Eighty implants were placed in eighty patients. Three patients dropped out at T2. At T4, 74 out of 77 implants were functioning, resulting in a 96% survival rate. Marginal bone loss (mean ± SE) at T2 was significantly greater in the 1-mm abutment groups (0.61 ± 0.09 mm with thin mucosa; 0.64 ± 0.07 mm with thick mucosa) than in the 3-mm abutment groups (0.32 ± 0.07 mm with thin mucosa; 0.26 ± 0.04 mm with thick mucosa). The marginal bone loss pattern over 18 months of loading showed that the greatest amount of marginal bone loss occurred during the first 6 months of function. Conclusions: Internal hex platform-switched implants placed equicrestally and restored with 1-mm abutments presented greater marginal bone loss than identical implants with 3-mm abutments, with vertical mucosal thickness having no significant influence. Schlagwörter: abutment height, marginal bone loss, platform switching, vertical mucosal thickness Conflict-of-interest statement: The authors have no direct or indirect financial interest in the products listed or information presented in this article.

Alveolar bone resorption and maxillary sinus pneumatization occurring after dental extraction in the posterior region of the maxilla may be problematic when planning implant-supported rehabilitation. Various regenerative options are available, including guided bone regeneration, bone block grafts, and lateral sinus augmentation. These procedures are associated with significant complication rates, high morbidity, increased therapy duration, and high cost. Less invasive approaches, such as transcrestal sinus floor elevation, and using short implants have been proposed in an attempt to reduce these drawbacks. The aim of this study is to analyze available evidence to suggest predictable options and identify minimally invasive management of implant-supported rehabilitation in the posterior maxilla. This article concerns biologic mechanisms regulating new bone formation after maxillary sinus augmentation and examines characteristics of available implants and grafting materials to help the clinician select the most rational and convenient surgical approach according to specific situations.

Insufficient crestal bone is a common feature encountered in the edentulous posterior maxilla due to atrophy of the alveolar ridge and maxillary sinus pneumatization. Numerous surgical techniques, grafting materials, and timing protocols have been proposed for implant-supported rehabilitation of posterior maxillae with limited bone height. In the majority of potential implant sites, residual bone height is less than 8 mm and the clinician has to select either a lateral or transcrestal sinus-elevation technique or placing short implants as the correct surgical option. Nevertheless, guidelines for selecting the best option remains mostly based on the personal experience and skills of the surgeon. The role of sinus anatomy in healing and graft remodeling after sinus floor augmentation is crucial. In addition to the evaluation of residual bone height, the clinician should consider that histologic and clinical outcomes are also influenced by the buccal-palatal bone wall distance. Therefore, three main clinical scenarios may be identified and treated with either a lateral or transcrestal sinus-elevation technique or short implants. This article introduces a new decision tree for a minimally invasive approach based on current evidence to help the clinician safely and predictably manage implant-supported treatment of the atrophic posterior maxilla.

Purpose: This retrospective study quantitatively analyzed the minimum prosthetic abutment height to eliminate bone loss after 4.7-mm-diameter implant placement in maxillary bone and how grafting techniques can affect the marginal bone loss in implants placed in maxillary areas. Materials and Methods: Two different implant types with a similar neck design were singularly placed in two groups of patients: the test group, with platformswitched implants, and the control group, with conventional (non-platform-switched) implants. Patients requiring bone augmentation underwent unilateral sinus augmentation using a transcrestal technique with mineralized xenograft. Radiographs were taken immediately after implant placement, after delivery of the prosthetic restoration, and after 12 months of loading. Results: The average mesial and distal marginal bone loss of the control group (25 patients) was significantly more than twice that of the test group (26 patients), while their average abutment height was similar. Linear regression analysis highlighted a statistically significant inverse relationship between marginal bone loss and abutment height in both groups; however, the intercept of the regression line, both mesially and distally, was 50% lower for the test group than for the control group. The marginal bone loss was annulled with an abutment height of 2.5 mm for the test group and 3.0 mm for the control group. No statistically significant differences were found regarding marginal bone loss of implants placed in native maxillary bone compared with those placed in the grafted areas. Conclusion: The results suggest that the shorter the abutment height, the greater the marginal bone loss in cement-retained prostheses. Abutment height showed a greater influence in platform-switched than in non-platform-switched implants on the limitation of marginal bone loss. Schlagwörter: abutment height, crestal sinus floor augmentation, dental implants, marginal bone loss, platform switching

This preliminary clinical and radiographic study examined the survival of, the marginal bone loss (MBL) around, and the influence of prosthetic abutment height (AH) on MBL around hybrid implants placed in two groups of partially edentulous patients: healthy (HPs) and periodontally compromised (PCPs) patients. A total of 93 patients requiring single or multiunit implant restoration, in the mandible or maxilla, were treated while undergoing cement-retained prosthetic restoration. A total of 54 implants (35 in the maxilla and 19 in the mandible) were placed in 45 HPs, and 56 implants (31 in the maxilla and 25 in the mandible) in 48 PCPs. All 110 hybrid implants positioned in pristine bone provided a 100% survival rate in both HPs and PCPs. No statistical differences were recorded comparing the MBL values of maxillae with those of mandibles. In HPs and PCPs, a similar and limited amount of MBL was recorded, and it was found that the higher the AH, the less MBL. In conclusion, results indicate that the hybrid implants examined could reduce the risk of peri-implantitis due to their coronal machined surfaces and improve osseointegration due to their apical rough surfaces.

The aim of this clinical case series was to evaluate buccal bone thickness using cone beam computed tomography and to demonstrate optimal clinical outcomes for implants placed into extraction sockets in the anterior maxilla with a thin biotype, by placing a graft of mineralized and demineralized human bone allograft into the buccal gap. The preliminary outcomes showed good preservation of soft and hard tissue architecture after 1 year in function. In particular, in eight patients, this allograft mixture appeared to minimize the amount of buccal contour change in the extraction site ridge with a thin buccal plate.

Objective: To assess clinical survival and success rates of one-piece implants placed at the time of tooth extraction with immediate provisionalization and to evaluate radiographic peri-implant bone loss around one-piece implants 1 year after functional loading. Method and Materials: Forty-six patients (20 men and 26 women) with a mean age of 45.5 years (range, 24 to 74 years) were recruited from four centers for this case series report. Immediately following the extraction of untreatable teeth, all patients received one-piece implants. The implants were immediately restored and placed into function with no occlusal contact. Outcome assessments included clinical and radiographic evaluations. Results: Of the one-piece implants placed after extraction in the maxilla and mandible, 95.7% integrated successfully. The mean marginal bone loss after 1 year was 0.80 mm (SD, 0.53 mm). Overall peri-implant bone loss at maxillary sites was compared with overall bone loss at mandibular sites. At the 1-year follow-up, no statistically significant difference was found. The deeper the implants were placed below the crest, the more marginal bone loss was observed. However, no difference in marginal bone loss was observed as a consequence of the following three variables: implant length (10, 11.5, or 13 mm), implant diameter (3, 3.7, or 4.7 mm); and 3- and 6-month time periods after implant prosthesis placement. Conclusion: Based on data obtained from this sample size study, it can be concluded that one-piece implants can be successfully placed immediately after extraction with minimal peri-implant bone loss. Schlagwörter: bone loss, extraction socket, immediate loading, one-piece dental implant, radiographic evaluation, survival rate