Schneiderian Membrane Perforation Research Articles

Osseodensification technique in crestal maxillary sinus elevation-A narrative review.

Osseodensification is a novel approach that has significantly advanced the field of implant dentistry, particularly in the context of transcrestal maxillary sinus floor elevation. This technique involves the use of specially designed burs that compact and densify bone along the osteotomy walls, thereby enhancing implant primary stability and facilitating osseointegration in low-density bone. This article reviews the historical evolution of implant site preparation, and the biomechanical, histological, and clinical evidence of osseodensification with a special focus on its application in sinus floor augmentation. The integration of this technique into contemporary practice represents a paradigm shift, offering a minimally invasive and efficient solution for addressing the challenges of posterior maxilla, with improved patient-reported outcomes and low complication rate. Three different protocols for sinus lift and implant placement using osseodensification burs are proposed based on available literature, and risk factors for Schneiderian membrane perforation based on residual bone height are discussed, along with implant-related outcomes and patient-reported outcome measures. The potential for osseodensification to become a standard practice in sinus floor augmentation is emphasized, highlighting key aspects such as surgical protocol and patient selection.

ОПЕРАЦИЯ СИНУС-ЛИФТИНГА: ФАКТОРЫ РИСКА ПЕРФОРАЦИИ МЕМБРАНЫ ШНЕЙДЕРА

The number of patients of middle and old age with loss of teeth continues to increase despite the advances in preventive dentistry. The prosthesis on implants is the most predictable rehabilitation method for the patients with various defects in dental rows. This paper presents a modern look at possible risk factors for Schneiderian membrane perforation connected not only to open sinus lifting techniques, but also to anatomical peculiarities of the facial scull bones which shall be taken into account when planning dental implantation in the posterior region of the maxilla.

The impact of antiplatelet and anticoagulant medications on early implant failure following sinus floor augmentation: A retrospective cohort analysis.

The effect of antiplatelet and anticoagulant medications on the outcomes of sinus floor augmentation remains unclear. This retrospective cohort study analyzed data from electronic medical records of consecutive patients undergoing sinus floor augmentation at a single medical center. Patients were categorized into three categories: patients under antiplatelet medications, patients under anticoagulation medications, and healthy individuals. Data collected included tobacco smoking, residual alveolar bone height, timing of implant placement, materials used, vertical bone gain, early implant failure (EIF), and complications such as Schneiderian membrane perforation and postoperative bleeding. Multivariable analysis was performed to assess risk factors for EIF. Statistical significance was considered below 5%. Among 110 patients with 305 implants, EIF occurred in 10% of patients and 4.65% of implants. No significant difference in postoperative bleeding or EIF was found between study groups. Univariate and multivariable analyses highlighted tobacco smoking (odds ratio [OR] = 7.92), lower residual alveolar ridge height (OR = 0.81), and staged implant placement (OR = 4.64) as significant EIF risk factors in this cohort. Anticoagulant and antiplatelet therapies do not significantly elevate the risk of EIF or postoperative bleeding following sinus floor augmentation. Tobacco smoking, residual alveolar ridge height and staged sinus floor augmentation were risk factors for EIF in patients using antiplatelet or anticoagulation medications undergoing sinus floor augmentation.

Comparison of Short-term Outcomes Between Schneiderian Membrane Perforation and Non-perforation Patients after Simultaneous External Elevation and Implantation.

To compare short-term outcomes between membrane perforation and non-perforation patients after simultaneous external elevation with implantation. In this retrospective observational study, 60 maxillary posterior tooth-loss patients with an insufficient amount of residual bone for direct implantation were enrolled. All patients underwent simultaneous external elevation and implantation, and were divided into perforation and non-perforation groups according to the postoperative Schneiderian membrane status. Of the 60 patients, 30 cases (35 implants) were assigned to the membrane perforation group, and 30 (44 implants) were allocated to the non-perforation group. There were no statistically significant differences in baseline data (p>0.05). In the perforation group, the mean vertical bone gain (VBG) at 6 and 12 months was 6.02±2.14 mm and 5.37±2.22 mm, resp., compared to 6.78±2.59 mm and 6.42±2.64 mm in the non-perforation group, resp. (both p>0.05). Preoperative median Schneiderian membrane thickness (SMT) in the perforation group was 0.77 mm, which was statistically significantly thinner than the 1.24 mm measure in the non-perforation group (p< 0.05); however, there was no statistically significant difference between two groups at 12 months postoperatively (0.80 mm vs 1.25 mm, p>0.05). The marginal bone loss at 1 year after implant restoration in the perforation and non-perforation groups was 0.16±0.10 mm and 0.22±0.12 mm, resp. During postoperative follow-up, the implant survival rate was 100% in the two groups. The incidence of postoperative nasal bleeding in the perforation group was statistically significantly higher compared with that in the non-perforation group (50% vs 16.7%, p<0.05), whereas no statistically significant differences were observed in the incidence of facial swelling, intraoral bleeding, wound dehiscence and acute/chronic sinusitis between the two groups (p>0.05). Schneiderian membrane perforation after simultaneous external elevation and implantation do not adversely affect short-term clinical and radiographic outcomes.

Influence of Schneiderian Membrane Perforation on Implant Survival Rate: Systematic Review and Meta-Analysis.

Background: Maxillary sinus lift is a well-documented and accepted technique in the rehabilitation of the posterior maxilla. Schneiderian membrane perforation is the most common complication and may occur in between 7% and 56% of cases. Different materials and techniques have been described to achieve reparation of the perforation. The aim of this study was to establish whether the perforation of the Schneiderian membrane and its repair during maxillary sinus lift surgery results in a lower implant survival rate compared to those cases where the membrane has not been perforated. Materials and methods: A systematic review and meta-analysis of studies assessing the survival rate of implants placed in regenerated sinus using the lateral window approach, where the perforation of the Schneiderian membrane occur, was carried out. Statistical analysis was performed with Open Meta-Analyst, calculating the odds ratio of implants placed in perforated sinuses and non-perforated sinuses. Results: Ten articles were included in the qualitative analysis and seven articles in the quantitative analysis or meta-analysis. A total of 1224 maxillary sinus augmentation surgeries were performed without perforation of the Schneiderian membrane and 2725 implants were placed; 62 implants failed during the follow-up period with an overall survival rate of 97.7%. In 480 perforated sinuses, 1044 implants were placed, of which 30 failed; the overall survival rate was 97.1%. There were no significant differences between the implant survival rate of the implants in the two groups (OR = 0.78; CI = 0.49-2.23; p = 0.28 and I2 heterogeneity: 0%, p = 0.44). Conclusions: Schneiderian membrane perforation, as long as it is repaired, does not appear to negatively influence implant survival rate. Membrane perforation should not be considered a reason to abort the procedure or an absolute contraindication to implant placement.

Croco Eye Technique: Mucous Retention Cyst Excision with Immediate Open Sinus Lift-A Retrospective Cohort Study.

Objectives: A mucous retention cyst is a common, asymptomatic lesion that may cause complications during or after the sinus lift procedure. The goal of this study is to assess the effectiveness of the Croco Eye Technique (CET), which allows simultaneous excision of the cyst and sinus floor elevation. Methods: The technique was thoroughly described in two versions, and the group of 33 patients was analyzed. Patients who qualified for this procedure had insufficient alveolar ridge height, and their CBCT showed radiological images typical for retention cysts. Analyzed parameters included the version of CET, demographic data, anatomical parameters, intraoperative complications, recurrence of the cyst, success rate of the sinus lift and implants, and the follow-up period. Results: Out of the 33 cases, 9 were of the primary version (27.27%) and 24 of the final version (72.73%). The average height of a retention cyst was 24.05 mm, with the average alveolar ridge height of 1.86 mm. In three cases (9.09%), implants were placed immediately. The prevalence of uncontrolled Schneiderian membrane perforation was reduced from 55.56% to 4.17% between the primary and final versions. The cyst's recurrence rate was 3.13%. The implant survival rate was 100%. The mean follow-up period was 48.625 months (max 110 months). Conclusions: The Croco Eye Technique, despite the perforation of the Schneiderian membrane, enables successful sinus lift and implantation with a success rate of 100%. Excision of the retention cyst, which is the cause of perforation, allows for limiting the risk of the cyst's recurrence.

The safety of maxillary sinus floor elevation and the accuracy of implant placement using dynamic navigation.

To date, it remains a challenge to conduct maxillary sinus floor elevation (MSFE) owing to heterogeneity of anatomical structures and limited operative visibility of the maxillary sinus. The aim of this study is to investigate the safety of MSFE and the accuracy of implant placement using dynamic navigation. Forty-two implants were placed in thirty-five patients requiring implantation in posterior maxilla with dynamic navigation. They were assigned to either lateral window sinus floor elevation (LWSFE) group (n = 22) or transcrestal sinus floor elevation (TSFE) group (n = 20) according to the residual alveolar bone height (RBH). Platform deviation, apex deviation and angular deviation between actual and planned implant placement were measured in precision evaluation software. Three deviations of two groups were compared via SPSS 22.0 software. Neither accidental bleeding nor perforation of Schneiderian membrane occurred in any patients. The actual window position of LWSFE was consistent with the preoperative design. There were no significant differences in platform, apex and angular deviations between the two groups (P > 0.05). In this study the dynamic navigation harvested clinically acceptable safety of MSFE and accuracy for implant placement in posterior maxillary region. The dynamic navigation would provide the clinician with assistance in achieving precise preoperative planning and reducing complications in surgical procedures. The granular bone grafts used in the LWSFE did not significantly affection on the accuracy of the simultaneous implant placement under the guidance of dynamic navigation.

Lateral Sinus Floor Elevation in Cases of an Intact and Perforated Schneiderian Membrane

The study comprised 20 lateral sinus floor elevation cases performed in 18 patients. During surgery, in four cases, a perforation of the Schneiderian membrane was detected. An attempt to suture the perforated membrane may increase the risk of enlarging the perforation. Therefore, we suggest a more conservative protocol be applied in all four cases where perforation occurred. The procedure consists of the 3-layer technique: an absorbable oxidized cellulose gauze moisturized with Dicynone was placed in this area. Under it, as a second layer, a PRF membrane is applied and then covered with a slow-resorbable collagen membrane. At that point, the surgery continues with the placement of the bone substitute material, and the sinus-lifting is finalized according to the selected protocol.&#x0D; The clinical studies demonstrate that the bone graft has a slower healing rate in areas with perforation, which is a proof of the osteogenic properties of the Schneiderian membrane. The cases described reveal that using this surgical protocol is risk-free and has a high success rate.

Anatomy of Maxillary Sinus: Focus on Vascularization and Underwood Septa via 3D Imaging.

The study of the maxillary sinus anatomy should consider the presence of two features of clinical importance. The arterial supply course and the presence of the so-called Underwood septa are two important factors to consider when planning surgical treatment to reduce the risk of surgical complications such as excessive bleeding and Schneiderian membrane perforations. This study aimed to investigate the above-mentioned anatomical structures to improve the management of eventual vascular and surgical complications in this area. This study included a total of 200 cone-beam computed topographies (CBCTs) divided into two groups of 100 CBCTs to evaluate the arterial supply (AAa) course through the lateral sinus wall and Underwood's septa, respectively. The main parameters considered on 3D imaging were the presence of the AAa in the antral wall, the length of the arterial pathway, the height of the maxillary bone crest, the branch sizes of the artery in the first group, and the position of the septa, the length of the septa, and their gender associations in the second group. The CBCT analysis showed the presence of the arterial supply through the bone wall in 100% of the examined patients, with an average size of 1.07 mm. With regard to the septa, 19% of patients presented variations, and no gender difference was found to be statistically significant. The findings add to the current understanding of the clinical structure of the maxillary sinus, equipping medical professionals with vital details for surgical preparation and prevention of possible complications.

Factors influencing intraoperative and postoperative complication occurrence: A series of 1135 periodontal and implant-related surgeries.

In periodontology, it is widely recognized that evidence characterizing the incidence and effect of treatment complications is lacking. The objective of this study was to assess the influence of operator-, procedure-, patient-, and site-associated factors on intraoperative and postoperative complication occurrence. A single investigator reviewed records of patients treated by eight periodontics residents from July 2018 through June 2022. For each procedure, the investigator recorded each intraoperative and postoperative complication or indicated that no complication had occurred. These outcomes were analyzed against a panel of explanatory covariates. In addition, the severity of each postoperative complication was assessed using a standardized grading system. A total of 1135 procedures were included in the analysis. Intraoperative and postoperative complications were identified in 2.8% and 15.2% of procedures, respectively. The most common intraoperative complications were Schneiderian membrane perforation (1.3%) and gingival flap perforation/tear (1%), and the most common postoperative complications were dentin hypersensitivity (2.6%), excessive pain (2.5%), and infection (2.2%). Subepithelial connective tissue graft (odds ratio [OR]: 3.2, 95%confidence interval [CI]: 1.6, 6.1; p < .001), guided bone regeneration (OR: 3.0, 95% CI: 1.4, 6.5; p = .004), and guided bone regeneration with implant placement (OR: 3.1, 95% CI: 1.3, 7.6; p = .011) were associated with higher odds of postoperative complication, whereas lateral sinus elevation (OR: 102.5, 95% CI: 12.3, 852.9; p < .001), transalveolar sinus elevation (OR: 22.4, 95% CI: 2.2, 224.5; p = .008), open flap debridement (OR: 36.4, 95% CI: 3.0, 440.7; p = .005), and surgically facilitated orthodontic therapy (OR: 20.5, 95% CI: 1.2, 358.4; p = .039) were associated with higher odds of intraoperative complication occurrence. Consistent with previous reports, procedure type appears to be the predominant factor driving complication occurrence. As analyses of treatment complications increase, individualized risk-benefit assessments will become progressively meaningful for patients.

Risk factors, Consequences and Treatment Alternatives of Schneiderian Membrane Perforation: Case Report and Review of the Literature

Maxillary sinuses are the greatest sinus cavities in the human cranium and they are the closest to the oral cavity. Thus, perforation of the Schneiderian membrane is a common complication that may be encountered during various oral surgery procedures in the molar and premolar regions of the maxilla such as teeth extractions, implant placement or sinus augmentation procedures. Membrane perforations lead to oroantral communications, which may later turn into oroantral fistulas. Moreover, these perforations may cause infections, loss of graft or implant if encountered during sinus augmentation procedures. The purpose of this review was to determine the risk factors associated with this complication and present the various treatment alternatives used to manage this type of complication. In the literature, the selected surgical technique, the thickness of the sinus membrane, the quality and quantity of the residual alveolar bone, the anatomy of the area and patients’ habits such as smoking were reported as points to be considered. A case of Schneiderian membrane perforation during implant placement and successful management of the complication was also presented.

Association between sinus septa and lateral wall thickness with risk of perforation during maxillary sinus lift surgery: A systematic review and meta-analysis.

Sinus membrane perforation is a common complication of sinus lift surgery. This review aimed to examine if anatomical factors such as the presence of septa and lateral wall thickness influence the risk of membrane perforation. This study was registered on PROSPERO (CRD42023488259). PubMed, Embase, and Web of Science were searched for relevant studies published up to 26th June 2024. The outcome of interest was the risk of perforation based on presence of septa and lateral wall thickness. Random-effects meta-analysis was conducted with dichotomous data to obtain the odds ratio (OR) of perforation using Review Manager. Ten studies with 1865 patients undergoing 2168 "lateral" sinus lift procedures were included. The total incidence of Schneiderian membrane perforations was 19% (405 cases). Schneiderian membrane perforation was present in 169/425 cases (39.76%) with sinus septa and 184/1492 cases (12.33%) without septa. Meta-analysis showed that septa were significantly associated with an increased risk of perforation (OR: 4.03 95% CI: 1.77, 9.19) with high heterogeneity (I2 = 87%). The certainty of the evidence was very low. Data on lateral wall thickness and risk of perforation was too heterogeneous for a meta-analysis. Studies reported mixed results on the risk of perforation based on lateral wall thickness. Our results show, with very low-quality evidence, that the presence of septa significantly increases the risk of perforations during maxillary sinus lift surgery. Evidence on the association between lateral wall thickness and a risk of perforations during sinus lift surgery is conflicting, and no clear conclusions can be derived at this stage.

A technical feasibility study on adaptation of a microsurgical robotic system to an intraoperative complication management in dental implantology: perforated Schneiderian membrane repair using Symani® Surgical System

The aim of the current study was to test the technical and clinical feasibility of a robotic system and investigate its potential in the surgical repair of perforated Schneiderian membranes using an ex-vivo porcine model. Eight pig heads were operated conventionally via a surgical loop and eight pig heads with the surgical robot “Symani® Surgical System” (Medical Microinstruments, Inc., Pisa, Italy). On each specimen, the Schneiderian membrane was incised over a length of 0.7 mm resembling a perforation. Operation time, the maximum sinusoidal pressure, the course of the pressure and the filling volume were measured. Additionally, adaptation of the wound edges has been detected via scanning electron microscopy. There were no significant differences for the pressure maximum (p = 0.528), for the time until the pressure maximum was reached (p = 0.528), or for the maximum filling volume (p = 0.674). The time needed for the suturing of the membrane via robotic surgery was significantly longer (p < 0.001). However, the scanning electron microscope revealed a better adaptation of the wound edges with robotic surgery. The technical feasibility of robot-assisted suturing of Schneiderian membrane laceration using the robotic system has been confirmed for the first time. No differences considering the pressure resistance compared to the conventional repair could be observed, but advantages in wound adaptation could be found with an electron microscope. Regarding the material and training costs and limited indications spectrum, robotic surgery systems still might not present financially feasible options in the daily dental practice yet.

USE OF MEDICAL ADHESIVES FOR CLOSING SCHNEIDER MEMBRANE PERFORATION DURING OPEN SINUS LIFTING (LITERATURE REVIEW)

The open sinus lifting procedure during dental implantation can cause perforation of Schneiderian membrane. Nowadays there are many methods of closing perforation of the sinus membrane. However, frequent intraoperative and postoperative complications require to search new methods and materials for increasing the productivity of the operation and reducing the duration of surgical treatment of patients.&#x0D; The purpose of the research: to analyze of modern Ukrainian and foreign scientific literature about the use of medical adhesives for closing the perforation of Schneiderian membrane during open sinus lifting surgery and to assess their effectiveness.&#x0D; Scientific information on the research topic was obtained from the resources of search engines: the electronic library of abstracts and dissertations of Vernadsky V.I. National Library of Ukraine, PubMed, Medline, MedNet, Embase, BMJ Group, Free Medical Journals, Free Medical Book, Scirus.&#x0D; Based on the analysis of the literature data, it has been found that medical bioadhesives are the newest materials used in dental practice, have the advantages of fast and painless application, resistance to infection, hemostatic properties, lack of toxicity, good sealing of wound surfaces, high tissue strength and are comfortable for patients. The use of compounds with new positive qualities in maxillofacial surgery, along with the introduction of modern technologies, equipment and tools, will increase the productivity of open sinus lifting surgery during dental implantation, reduce the number of intraoperative and postoperative complications, the duration of surgical interventions, and will allow performing operations with the least risk to the patient at a high professional level.

SMOKERS MAY BE SUBJECT TO A HIGHER RISK OF SCHNEIDERIAN MEMBRANE PERFORATION THAN NONSMOKERS DURING MAXILLARY SINUS AUGMENTATION.

Association between smoking and Schneiderian membrane perforation during maxillary sinus floor augmentation: A systematic review and meta-analysis. Wang, X., Ma, S., Lin, L., & Yao, Q. Clinical Implant Dentistry and Related Research. 2022., 25.1: 166-176. National Natural Science Foundation of China, Grant/Award Number: 81801021; Hunan Provincial Health Commission, Grant/Award Number: B202308056991. Systematic review and meta-analysis.

Clinical efficacy of transcrestal sinus floor augmentation, in comparison with lateral approach, in sites with residual bone height ≤6 mm: A systematic review and meta-analysis.

This paper addressed two focused questions: Focused question 1 (Q1) "what is the clinical efficacy of transcrestal sinus floor augmentation (TSFA), as compared to lateral sinus floor augmentation (LSFA) in sites with residual bone height (RBH) ≤6 mm, in randomized clinical trials (RCTs) and controlled clinical trials (CCTs)?"; Focused question 2 (Q2) "what is the estimated effectiveness of TSFA for outcomes in Q1, in RCTs, CCTs or cohort studies?" An electronic search (PubMed, EMBASE, The Cochrane Central Register of Controlled Trials) and hand search were conducted from January 1986 until December 2022. All eligible clinical studies expressly reporting TSFA in sites with RBH ≤6 mm were included. The data were extracted, and the risk of bias in individual studies was evaluated. Meta-analysis was performed whenever possible. Seven RCTs were included for Q1 and 25 studies (9 RCTs, 2 CCTs, 14 single arm cohort studies) for Q2. Q1: Meta-analysis did not show significant difference in the implant survival, sinus membrane perforation and marginal bone loss between TSFA and LSFA groups. Q2: Meta-analysis showed TSFA had a high implant survival rate (96.5%, 95% CI: 93.2%-98.9%) at least 1 year after surgery, and limited sinus membrane perforation (5.4%, 95% CI: 2.7%-8.8%). The results also presented higher patient satisfaction for TSFA. With the limitations of the present study (high risk of bias in individual studies), it can be concluded that there was no significant difference in implant survival, Schneiderian membrane perforation and MBL between two approaches in sites with RBH ≤6 mm.

Lateral sinus floor elevation in patients with sinus floor defects: A retrospective study with a 1- to 9-year follow-up.

We aimed to retrospectively evaluate the long-term clinical outcomes of lateral sinus floor elevation (LSFE) in patients with sinus floor defects. Between 2008 and 2020, patients with sinus floor defects were recruited after confirmation on preoperative cone-beam computed tomography (CBCT). The split-thickness flap technique with a palatal crestal incision was used to manage tissue adhesion in the bone defects area. A resorbable collagen membrane was used to close the sinus floor defects from the crestal side before bone substitute placement. Of 58 implants, 47 (81.0%) were placed after an 8-month healing period, whereas 11 were placed simultaneously. Patients were followed up by radiography and clinical examination for 1-9 years. Finally, the cumulative survival rate (CSR) of implants, surgical complications, and marginal bone loss (MBL) were recorded and analyzed. In total, LSFE was performed in 36 sinuses (35 patients) with sinus floor defects, of which surgery was completed in 35 sinuses (97.2%) in the first attempt. Schneiderian membrane perforations (SMP) occurred in 10/36 (27.8%) sinuses; nine were repaired carefully, whereas one surgery was suspended due to complicated SMP, and successful re-entry LSFE was performed 4 months later. After a follow-up period of 1-9 years, the CSR was 96.5% at the 1-year, 3-year, 5-year, and 7-year follow-ups and 64.3% at the 8-year follow-up. Within the limitations of this study, sinus floor defects seem not to compromise LSFE therapy after appropriate management and long-term clinical outcomes are predictable.

Which factors affect the risk of membrane perforation in lateral window maxillary sinus elevation? A prospective cohort study

It was the aim of this prospective cohort study to assess the various anatomical and other patient-related factors that increase membrane perforation risk. Patients underwent cone-beam computed tomography (CBCT) before surgery. The presence of septa, presence of mucous retention cyst, lateral wall thickness, membrane thickness, and residual bone height were predictive factors. Age, gender, and smoking were covariates for the study. The presence or absence of membrane perforation was the study outcome.In total, 140 subjects were studied. The hazard ratio (HR) for the presence of septa with membrane perforation was 8.07 (2.93–22.29) (p < 0.001). The HR for perforation with a single edentulous area relating to two or more teeth was 68.09 (9.52–49.16). The risk of membrane perforation in smokers was 25 times more than in non-smokers — HR 25 (7.58–82.51) (p < 0.001). The HR for membrane perforation in subjects with mucous retention cysts compared with subjects without retention cysts was 27.75 (8.73–88.23) (p < 0.001). Within the limitations of the study it seems that anatomical, habitual, and pathological factors may increase the risk of Schneiderian membrane perforation when a lateral window approach is used for sinus floor augmentation.

Effectiveness and complications of transcrestal sinus floor elevation using the cushioned grind-out technique: A retrospective cohort study with up to 7 years of follow-up.

To evaluate the effectiveness and complications of the cushioned grind-out technique. The primary outcome was endo-sinus bone gain (ESBG), while secondary outcomes included the Schneiderian membrane perforation rate and mid- to long-term implant survival. In this retrospective study, we compared the cushioned grind-out technique with the classic osteotome technique, establishing statistical models to assess ESBG, membrane perforation rate and implant survival rate. A total of 259 patients and 340 implants were included. The mean ESBG was 5.31 mm for the cushioned grind-out group and 4.64 mm for the osteotome group. Multivariable regression analysis revealed that the cushioned grind-out technique significantly facilitated ESBG (p = .028). Nineteen preparation sites experienced membrane perforation, with rates of 5.5% and 6.4% for the cushioned grind-out and osteotome groups, respectively. However, the difference was not statistically significant (p = .920). Additionally, the cumulative survival rate of the implants for 7 years was 95.2% and 91.4%, respectively, with the surgical technique not significantly influencing the results. With 6 months to 7 years of post-prosthetic restoration review data, our findings show that the cushioned grind-out technique facilitates a higher ESBG, with no significant difference in membrane perforation or implant failure rate.

Cushioned grind-out technique transcrestal sinus floor elevation for simultaneous implantation in severe atrophic maxilla: A retrospective study with up to 7 years of follow-up.

This study aimed to evaluate the effects of the cushioned grind-out technique transcrestal sinus floor elevation for simultaneous implant placement with ≤4 mm of residual bone height (RBH). This was a retrospective propensity score matching (PSM) study. Five PSM analyses included the confounding variables of Schneiderian membrane perforation, early and late implant failure, and peri-implant apical and marginal bone resorption. After PSM, we compared the difference in five aspects between the RBH ≤ 4 and >4 mm groups. A total of 214 patients with 306 implants were included in this study. After PSM, the generalized linear mixed model (GLMM) indicated that RBH ≤ 4 mm had no significantly higher risk of Schneiderian membrane perforation and early and late implant failure (p = .897, p = .140, p = .991, respectively). The implant cumulative 7-year survival rate of the RBH ≤ 4 and >4 mm groups was 95.5% and 93.9%, respectively (log-rank test: p = .900). Within at least 40 cases per group after PSM, two multivariate GLMMs indicated that RBH ≤ 4 mm could not be identified as the promotive factor of bone resorption of either endo-sinus bone gain or crest bone level (RBH × time interaction p = .850, p = .698, respectively). Within the limitations, 3 months to 7 years of post-prosthetic restoration review data indicated an acceptable mid-term survival and success rate of applying the cushioned grind-out technique in RBH ≤ 4 mm cases.