The influence of sinus membrane thickness upon membrane perforation during lateral window sinus augmentation.

OBJECTIVES: To investigate: (1) sinus membrane thickness in patients receiving lateral window sinus augmentation via cone-beam computed tomography (CBCT) and (2) the influence of Schneiderian membrane thickness upon membrane perforation during lateral window approach. MATERIAL AND METHODS: A total of 73 subjects with 81 sinus lift procedures between years 2010 and 2013 were recruited consequently. Each patient selected had CBCT images in initial and immediately after surgery. The values and correlation between variables of membrane thickness, perforation rate, membrane morphology, residual bone height, and elevated bone height were evaluated. RESULTS: The mean thickness of the Schneiderian membrane was 1.32 ± 0.87 mm. Perforation rate was lowest (7.14%) when membrane thickness was 1-1.5 mm. As membrane became thicker (≥2 mm) or thinner (<1 mm), the perforation rate increased abruptly. When examined the membrane thickness category, Class B (between ≥1 mm and <2 mm) had the lowest perforation rate. Statistically significant correlation was found between the perforation and the membrane thickness. The amount of the remaining bone height did not significantly correlate to the membrane thickness nor influence the membrane perforation. CONCLUSIONS: This study demonstrated that membrane thickness was related to the sinus perforation during lateral window sinus augmentation. The perforation rate was lowest when the membrane thickness was 1-1.5 mm.

The influence of sinus membrane thickness upon membrane perforation during transcrestal sinus lift procedure.

OBJECTIVES: Schneiderian membrane perforation is one of the main complications during sinus augmentation. The reasons may be associated with surgical technique, septum, inadequate ridge height, and membrane thickness. However, reports that used cone-beam computed tomography (CBCT) to quantify the thickness of sinus membrane were limited. The aims of this retrospective study were: to study the correlation between membrane thickness and perforation rate during transcrestal sinus lift and to propose a classification system of sinus membrane thickness based upon CBCT data. MATERIAL AND METHODS: One hundred and twenty-two subjects who received dental implant restorations over posterior maxilla with a total of 185 transcrestal sinus lift procedures between years 2010 to 2013 were selected consequently. Each patient selected had to have taken CBCT in the initial examination and immediately after surgery. The membrane thickness, perforation rate, residual bone height, and elevated bone height were recorded and processed for statistical analysis. RESULTS: The mean thickness of the Schneiderian membrane was 1.78 ± 1.99 mm. There was a significant correlation between membrane thickness and perforation rate (P < 0.05), and the perforation rate was higher in thicker (≥3 mm) and thinner membrane (≤0.5 mm). Among the thickness group, Class B (between ≥1 and <2 mm) had the lowest perforation rate. No significant difference was between the perforation and the membrane morphology. A negative relationship between residual bone height and membrane thickness was found. Trend showed that in the thicker and the thinner residual bone height, the higher the perforation rate would be. CONCLUSIONS: There was a significant correlation between membrane thickness and perforation rate. The perforation rate was lowest when the thickness was 1.5-2 mm.

Utilizing Individualized Titanium Frames for Protected Alveolar Bone Augmentation: A Feasibility Case Series.

Despite the various treatments proposed with barrier membranes, one of the main challenges for guided bone regeneration (GBR) is maintaining space for large defects and ensuring an adequate blood supply. The presented feasibility case series aims to introduce an original titanium frame (TF) design, customized for each defect, as a modification of well-known principles and materials for GBR to achieve an enhanced and more predictable horizontal and vertical bone augmentation. Three patients with significant horizontal defects were treated with pre-trimmed TFs to create needed space, and then a 50/50 mixture of autograft and bovine xenograft was placed and covered with a collagen membrane. After 8 months of healing, the sites were reopened, and the titanium screws were removed with the frame. An average of 8.0 ± 1.0 mm of horizontal and 3.0 ± 0.0 mm of vertical bone gain were achieved at the time of reentry and implant placement surgery. Bone core biopsy sample was obtained during the implant placement. Histomorphometric analysis revealed that 42.8% of the sample was new vital bone, 18.8% was residual bone graft particles, and 38.4% was bone marrow-like structures. After 3 to 4 months from implant placement, the implants were restored with provisional crowns and then finalized with zirconia screw-retained crowns. This case series suggests that GBR utilizing TFs with or without collagen membranes can be considered a suitable approach for horizontal and vertical bone augmentation. However, based on only three reported cases, the results should be carefully interpreted.

Establishing a novel deep learning model for detecting peri-implantitis.

BACKGROUND/PURPOSE: The diagnosis of peri-implantitis using periapical radiographs is crucial. Recently, artificial intelligence may apply in radiographic image analysis effectively. The aim of this study was to differentiate the degree of marginal bone loss of an implant, and also to classify the severity of peri-implantitis using a deep learning model. MATERIALS AND METHODS: A dataset of 800 periapical radiographic images were divided into training (n = 600), validation (n = 100), and test (n = 100) datasets with implants used for deep learning. An object detection algorithm (YOLOv7) was used to identify peri-implantitis. The classification performance of this model was evaluated using metrics, including the specificity, precision, recall, and F1 score. RESULTS: Considering the classification performance, the specificity was 100%, precision was 100%, recall was 94.44%, and F1 score was 97.10%. CONCLUSION: Results of this study suggested that implants can be identified from periapical radiographic images using deep learning-based object detection. This identification system could help dentists and patients suffering from implant problems. However, more images of other implant systems are needed to increase the learning performance to apply this system in clinical practice.

Indications for implant-supported rehabilitation of the posterior atrophic maxilla: A multidisciplinary consensus among experts in the field utilising the modified Delphi method.

PURPOSE: To establish consensus-driven guidelines that could support the clinical decision-making process for implant-supported rehabilitation of the posterior atrophic maxilla and ultimately improve long-term treatment outcomes and patient satisfaction. MATERIALS AND METHODS: A total of 33 participants were enrolled (18 active members of the Italian Academy of Osseointegration and 15 international experts). Based on the available evidence, the development group discussed and proposed an initial list of 20 statements, which were later evalu-ated by all participants. After the forms were completed, the responses were sent for blinded ana-lysis. In most cases, when a consensus was not reached, the statements were rephrased and sent to the participants for another round of evaluation. Three rounds were planned. RESULTS: After the first round of voting, participants came close to reaching a consensus on six statements, but no consensus was achieved for the other fourteen. Following this, nineteen statements were rephrased and sent to participants again for the second round of voting, after which a consensus was reached for six statements and almost reached for three statements, but no consensus was achieved for the other ten. All 13 statements upon which no consensus was reached were rephrased and included in the third round. After this round, a consensus was achieved for an additional nine statements and almost achieved for three statements, but no consensus was reached for the remaining statement. CONCLUSION: This Delphi consensus highlights the importance of accurate preoperative planning, taking into consideration the maxillomandibular relationship to meet the functional and aesthetic requirements of the final restoration. Emphasis is placed on the role played by the sinus bony walls and floor in providing essential elements for bone formation, and on evaluation of bucco-palatal sinus width for choosing between lateral and transcrestal sinus floor elevation. Tilted and trans-sinus implants are considered viable options, whereas caution is advised when placing pterygoid implants. Zygomatic implants are seen as a potential option in specific cases, such as for completely edentulous elderly or oncological patients, for whom conventional alternatives are unsuitable.

Submerged vs non-submerged reconstructive approach for surgical treatment of peri-implantitis: Re-analysis of two prospective clinical studies.

AIM: This report stems from a homogeneous patient cohort from two similarly designed prospective controlled studies in the same center on surgical reconstructive treatment of peri-implantitis. The aim of this re-analysis study was exploring prognostic factors associated with surgical outcomes. MATERIALS AND METHODS: Individual patient data of both studies were gathered. The initial study employed a submerged healing approach via primary wound closure with implant supra-structure removal and complete coverage of grafted sites. The second study employed a non-submerged healing protocol in which healing abutments were kept in place and the implant was not fully submerged. Both studies measured all outcomes at similar timepoints throughout 1 year, to include clinical and radiographic defect fill (DF and RDF), reduction of pocket depth (PDR) and bleeding on probing (BOP). Multi-level regression was used for statistical assessment of outcomes, relative to the impact of site-/local-, surgical- and patient-related variables. RESULTS: Overall, 59 implants (30 in submerged and 29 in the non-submerged group) were treated. A statistically significant higher DF (on average 0.9 mm higher), RDF (1.7 mm) and PDR (1.3 mm) were observed when a submerged reconstructive approach was performed, whereas BOP reduction was similar. After controlling for treatment (submerged/non-submerged), there were no other significant associations with patient- (age, gender, smoking, prior periodontitis etc.), or implant-related (previous prosthesis type, arch, KTW, etc.) factors. CONCLUSION: Within its limitations, we conclude that a submerged reconstructive approach for surgical management of peri-implantitis leads to significantly enhanced clinical and radiographic outcomes when compared to a non-submerged approach.

Utilizing Individualized Titanium Frames (ITFs) for Protected Alveolar Bone Augmentation: A feasibility case series.

Despite the various barrier membranes proposed, one of the main challenges for guided bone regeneration (GBR) is space maintenance for large defects as well as ensure adequate blood supply. The presented feasibility case series aims to introduce an original titanium frame (TF) design, customized for each defect, as a modification of well-known principles and materials for GBR, for an enhanced and more predictable horizontal and vertical bone augmentation. Three patients with significant horizontal defects were treated with pre-trimmed TFs to create needed space, a 50%-50% mixture of autograft and bovine xenograft was placed, and then covered with collagen membrane. After 8 months of healing, the sites were reopened, the titanium screws were removed with the frame. An average of 8.0 ± 1.0mm horizontal and 3.0 ± 0.0mm vertical bone gain was achieved at the time of re-entry and implant placement surgery. Bone core biopsy was obtained during the implant placement. Histomorphometric analysis revealed that 42.8% of the sample was new vital bone, 18.8% was residual bone graft particles, and 38.4% was bone marrow like structures. After 3-4 months from implant placement, the implants were restored with provisional crowns and then finalized with zirconia screw-retained crowns. This case series suggests that GBR utilizing TFs with or without collagen membranes can be considered a suitable approach for horizontal and vertical bone augmentation. However, based on only three reported cases, the result should be carefully interpreted.

Surgical reconstructive treatment for infraosseous peri-implantitis defects with a submerged healing approach: A prospective controlled study.

BACKGROUND: The aim of this study was to assess the reconstructive potential of a submerged healing approach for the treatment of infraosseous peri-implantitis defects. METHODS: Patients with a diagnosis of peri-implantitis were recruited. Implant suprastructures were removed before the surgical treatment, which included implant surface and defect detoxification using implantoplasty, air-power driven devices, and locally delivered antibiotics. The augmentation procedure included a composite bone graft and a non-resorbable membrane followed by primary wound coverage and a submerged healing of 8 months, at which point membranes were removed, and peri-implant defect measurements were obtained as the primary outcome. Secondary endpoints included assessment of cone-beam computed tomography (CBCT) and probing depth (PD) reductions. RESULTS: Thirty implants in 22 patients were treated. A significant clinical bone gain of 3.22 ± 0.41 mm was observed at 8 months. Radiographic analysis also showed an average gain of 3.47 ± 0.41 mm. Three months after installment of new crowns, final PD measures showed a significant reduction compared to initial examinations and a significant reduction in bleeding on probing compared to examinations at the pre-surgical visit. CONCLUSIONS: Reconstruction of infraosseous peri-implantitis defects is feasible with thorough detoxification of implant sites, and a submerged regenerative healing approach.

Non-submerged reconstructive approach for peri-implantitis osseous defect with removal of implant crowns: One-year outcomes of a prospective case series study.

BACKGROUND: The aim of this study was to test a non-submerged reconstructive approach for peri-implantitis osseous defects, by removing the prosthetic components, augmenting of the infraosseous bony compartment, and flap readaptation around the replaced healing abutments, without obtaining a primary wound closure. METHODS: Twenty-nine implants in 24 patients were treated. Implant suprastructures were removed at the time of the intervention, to aid with the debridement process which included curettage, implantoplasty, air-power driven devices, and locally delivered antibiotics. The infraosseous part of peri-implant defects were augmented using a composite bone graft and an absorbable membrane to be secured around the replaced healing abutments without attempting to submerge the implants. After 8 months, direct peri-implant defect measurements were obtained to serve as the primary outcome. Secondary outcomes included of radiographic bone changes, and probing depth (PD) and bleeding on probing (BOP) changes at 12 months. RESULTS: At the time of the surgical re-entry (8 months), a statistically significant clinical and radiographic defect fill was observed (average of 2.33 and 1.63 mm, respectively). Approximately 3 months after crown replacement, 12 months from the surgical intervention, a significant PD (1.51 mm) and BOP (65%) reduction were also noted. CONCLUSIONS: Considering its limitations, the use of a non-submerged approach (with removal of implant crowns) led to significant improvements in clinical (defect fill, PD, BOP) and radiographic outcomes.

Time analysis of alveolar ridge preservation using a combination of mineralized bone-plug and dense-polytetrafluoroethylene membrane: A histomorphometric study.

BACKGROUND: The objective of this study was to histologically evaluate and compare vital bone formation, residual graft particles, and fraction of connective tissue (CT)/other tissues between three different time points at 2-month intervals after alveolar ridge preservation with a cancellous allograft and dense-polytetrafluoroethylene (d-PTFE) membrane. METHODS: Ridge preservation with a cancellous allograft and d-PTFE membrane was performed at 49 extraction sockets (one per patient). Volunteers were assigned to implant placement at three different time points of 2, 4, and 6 months, at which time core biopsies were obtained. Histomorphometric analysis was performed to determine the percentages of vital bone, residual graft particles, and connective tissue/other non-bone components, and subjected to statistical analyses. RESULTS: There was a statistically significant difference in the amount of vital bone at every time point from 28.31% to 40.87% to 64.11% (at 2-, 4-, and 6-month groups, respectively) (P < 0.05). The percentage of residual graft particles ranged from 44.57% to 36.16% to 14.86%, showing statistical significance from 4 to 6 months (21.29%, P < 0.001), and 2 to 6 months (29.71%, P < 0.001), while there were no significant differences for the amount of CT/other tissue among the different time points. CONCLUSIONS: This study provided the first histologic comparison of alveolar ridge preservation using a cancellous allograft and d-PTFE membrane at three different time points. Extraction sockets that healed for 6 months produced the highest amount of vital bone in combination with the least percentage of residual graft particles, while similar results were observed for the fraction of CT/other tissues between the three time points.

Regeneration of Peri-implantitis Infrabony Defects: Report on Three Cases.

This paper presents a surgical treatment protocol known as EP-DDS (etiology identification, primary wound closure, debridement, decontamination, and stability of wound). The treatment protocol can be achieved in five steps. First, identify etiologic factors associated with peri-implantitis to determine whether or not the defects can be treated with this protocol. Second, in order to achieve primary wound coverage, ensure there is undisturbed wound healing, which may involve using procedures such as removing an existing prosthesis and performing tension-releasing flap design. Third, perform proper debridement of the inflamed granulomatous tissues to ensure the wound is free of any inflamed remnants. Fourth, conduct implant-surface decontamination by using a titanium brush or lasers. And finally, place appropriate space fillers (bone grafts and membrane) for wound stability. The three cases that have been successfully treated with the EP-DDS surgical protocol suggest it is a feasible surgical approach to obtain good infrabony defect bone fill (5.5-mm average) around the defects (buccal, mesial, lingual, and distal). Nonetheless, future randomized clinical trials with larger sample sizes and longer follow-ups are needed to further validate this treatment protocol.

The potential of the three-dimensional printed titanium mesh implant for cranioplasty surgery applications: Biomechanical behaviors and surface properties.

The aim of the present study was to investigate the biomechanical behaviors of the pre-shaped titanium (PS-Ti) cranial mesh implants with different pore structures and thicknesses as well as the surface characteristics of the three-dimensional printed Ti (3DP-Ti) cranial mesh implant. The biomechanical behaviors of the PS-Ti cranial mesh implants with different pore structures (square, circular and triangular) and thicknesses (0.2, 0.6 and 1 mm) were simulated using finite element analysis. Surface properties of the 3DP-Ti cranial mesh implant were performed by means of scanning electron microscopy, X-ray diffraction and static contact angle goniometer. It was found that the stress distribution and peak Von Mises stress of the PS-Ti cranial mesh implants significantly decreased at the thickness of 1 mm. The PS-Ti mesh implant with the circular pore structure created a relatively lower Von Mises stress on the bone defect area as compared to the PS-Ti mesh implant with the triangular pore structure and square pore structure. Moreover, the spherical-like Ti particle structures were formed on the surface of the 3DP-Ti cranial mesh implant. The microstructure of the 3DP-Ti mesh implant was composed of α and rutile-TiO2 phases. For wettability evaluation, the 3DP-Ti cranial mesh implant possessed a good hydrophilicity surface. Therefore, the 3DP-Ti cranial mesh implant with the thickness of 1 mm and circular pore structure is a promising biomaterial for cranioplasty surgery applications.

Application of a Promising Bone Graft Substitute in Bone Tissue Regeneration: Characterization, Biocompatibility, and In Vivo Animal Study.

The purpose of the present study was to investigate the effect of local hydroxyapatite (HA) combined with extracted sea cucumber (Stichopus hermanni) collagen as a promising bone graft substitute on bone remodeling. Fourier-transform infrared spectroscopy, X-ray diffractometry, transmission electron microscopy, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and Sprague-Dawley rat model were used to characterize the microstructure, in vitro cytotoxicity, and in vivo bone-healing properties of the investigated biocomposite material. Analytical results found that the hydrothermal reaction-synthesized local HA had a hexagonal close-packed structure. The addition of extracted S. hermanni collagen did not influence the microstructure and functional groups of the local HA. Moreover, the MTT assay indicated that the investigated biocomposite material possessed a good in vitro biocompatibility. The in vivo animal study also revealed that the investigated biocomposite material exhibited the highest number of osteoblasts after 14 days of healing. Therefore, the results demonstrate that the local HA combined with extracted S. hermanni collagen could potentially enhance osteoblast formation in promoting bone healing and regeneration.

Effect of Deproteinized Bovine Bone Mineral at Implant Dehiscence Defects Grafted by the Sandwich Bone Augmentation Technique.

The aim of this study was to compare the amount of radiographic horizontal buccal bone thickness (BBT) at implant dehiscence defects grafted with the sandwich bone augmentation (SBA) and modified sandwich bone augmentation (MSBA) techniques. Compared to the SBA technique, the MSBA approach involved an additional outer layer of deproteinized bovine bone mineral (DBBM) to maintain the space for bone regeneration for longer periods. A total of 19 patients, each with a buccal implant dehiscence defect, were recruited. The control group was treated with SBA technique (n = 10), while the test group was treated with MSBA technique. Cone beam computed tomography (CBCT) scans, taken at three time points (before and immediately after implant surgery, and 6 months post-treatment) were used to assess the BBT at the implant platform (-1.8 mm), the rough-smooth junction (0 mm), and 2, 4, 6, 8, and 10 mm apical to the rough-smooth junction. At 6 months postsurgery, the mean BBT in control and test groups was 1.69 ± 0.38 mm and 2.55 ± 0.21 mm, respectively. Mean BBT was significantly greater in the test group at 2, 4, 6, and 8 mm apical to the rough-smooth junction. There was no statistical difference in the mean BBT at the implant platform, the rough-smooth junction, and 10 mm apical to the rough-smooth junction between the two groups (P > .05). Within the limitations of this study, it was concluded that the additional layer of DBBM enhanced BBT along the implant, except at the smooth collar.

Classification and management of antral septa for maxillary sinus augmentation.

The antral septum, a commonly found anatomical variation, has been related to the occurrence of membrane perforation during sinus augmentation. The aims of this study were to review features of antral septa and to propose a classification system and options for managing antral septa during sinus augmentation. A literature search of the PubMed database was performed to identify articles investigating antral septa. Manuscripts using three-dimensional computed tomography, providing direct measurements of human subjects or cadavers, and reporting features of antral septa besides the prevalence were included. Antral septa presented in approximately 20% to 35% of maxillary sinuses. Single septum was much more common than multiple septa. Mediolaterally (transversely) oriented septa were more frequently found than anteroposteriorly (sagittally) oriented septa. Their size varies and commonly increases from the lateral to medial segment within one septum. The proposed classification consists of three categories--easy (E), moderate (M), and difficult (D)--based on the location, number, orientation, and size of antral septa. Corresponding treatment approaches were suggested for each category. Sinus augmentation is complicated by the presence of antral septa, the features of which determine the degree of surgical difficulty. Based on the results of the included studies and clinical experiences, a classification system and treatment strategies of antral septa were proposed and may assist surgeons in managing antral septa during sinus augmentation.