Effectiveness of Graftless Maxillary Sinus Floor Augmentation on Alveolar Crest Height and Implant Survival: A Review of Randomized Controlled Studies

Dental implants combined with sinus augmentation: What is the merit of bone grafting? A systematic review.

This project aims to systematically review and synthesise the data found in the literature regarding the survival of implants, complications, and gain in bone height using the hydraulic pressure technique to elevate the maxillary sinus floor. A comprehensive literature search was conducted using databases including PubMed, Scopus, Embase, and Cochrane, covering studies from 2005 to July 2024. A total of 24 studies were included, comprising randomised control trials, cohort studies, and case series. The main outcomes evaluated were implant survival, complication rates, and endo-sinus bone gain. The review included 3053 implants placed in 2290 Sinuses of 2231 patients. The patients' ages ranged from 23 to 84, with a mean of 51.6 years. The included studies reported a pooled implant survival rate of 98.40% over follow-up periods ranging from 6 months to 8 years. The rate of sinus membrane perforation was relatively low (2.05%), and other complications, such as hematoma, sinusitis, nasal discharge, or oedema, occurred in 0.49% of cases. The average endo-sinus bone gain achieved using this technique was 6.72 mm. The hydraulic pressure technique for sinus floor elevation is one of the many proposed solutions to provide predictable, safe, and efficient sinus floor elevation. The results from this review provide some cause for optimism, with high survival rates, low complication rates, and adequate gain in bone height. There is still a need for further long-term, high-quality research by independent third parties to confirm the effectiveness and safety of this technique. There is limited information available for the hydraulic pressure technique for sinus floor elevation. It has only been briefly mentioned in a limited number of literary reviews, none of which quantify the available data. This study presents the first systematic review of the hydraulic pressure technique, synthesising the available data and suggesting that the hydraulic pressure technique demonstrates high success and safety. This review is registered in PROSPERO under ID: 1070614.

I had the chance to read a recently published article by Yoon et al.1 entitled 'Survival rate of Astra Tech implants with maxillary sinus lift'. The authors performed a retrospective evaluation of the clinical survival rate of TiO-blast surface-treated Astra Tech implants after transalveolar or lateral approach sinus floor elevation with bone grafts. Although their clinical survival rate was 90.9% (n=99) and this was considered a success, there are still several concerning factors to consider. With my limited knowledge and experience, I would like to express some of my opinions for authors' kind review. First of all, this study would have been greatly improved if the author set more detailed inclusion/exclusion criteria. The authors included too many types of grafting materials without considering the outcome of a corresponding material in different sinus augmentation techniques; lateral and transalveolar technique. There are too many variables to consider in this study. Although the authors provided references indicating that there are no statistical differences related to the type of bone graft materials or approach, this does not necessary mean that those criteria are completely nonsignificant factors in implant survival. I would like to carefully state that the authors generalized and over-simplified factors based on limited references. Specifically, the authors referenced a study by Jurisic et al.2 to support that there are not significant differences between the two sinus floor elevation techniques1. However, the minimum alveolar bone height for sinus elevation in Jurisic et al.'s study2 was 4 mm, whereas that of Yoon et al.'s study1 was 1.2 mm. A study by Geurs et al.3 found a significant difference in implant loss when residual bone height was less than 4 mm, as compared to 5 mm or greater. The authors should not have drawn a conclusion solely based on one other similar study. The referenced study by Jurisic et al.2 is not the same as the study done by Yoon et al.1, and thus the authors should have provided their own statistical analysis as to whether or not there was a correlation between the two different techniques and implant survival. The same could be said of bone grafting type. Even though xenogenic bone grafting has been used in many cases, as the authors stated, it would have been nice if statistical analysis was provided. Furthermore, the authors concluded that there was no correlation between approach to the maxillary sinus or bone graft material used and implant failure, but again, no statistical analysis was applied to provide evidence for such a conclusion. Additionally, I would expect a more explicit explanation for implant failure. Perhaps implants failed due to low alveolar bone height, eventful resorption of bone grafts or complications from surgery. Furthermore, the authors failed to provide some surgical details, such as how many implants and what kind of sinus floor elevation approach were used, and whether a one- or two-stage technique was employed. Lastly, the survival rate should be compared to other published studies4,5. The presented survival rate was 90.9%1, while the most recent systemic reviews stated that the annual rough surface implant survival rate using the lateral window technique with bone graft was 96.5% after 3 years4. Survival of implants using the transalveolar technique after 3 years and at least 1 year of functional loading was 92.8%5. Although Yoon et al.'s study included both transalveolar and lateral approaches in calculating survival rate, it is still important to describe the meaning of their acquired survival rate. The authors should be credited for their hard work in preparing this extensive retrospective study. However, the lack of reader-friendly and detailed tables remains a limitation of this study, followed by the lack of statistical analysis and discussion. A sufficient number of sample sizes with a uniform implant system indicate that the study was well designed. I would be delighted to actively participate in your future basic and clinical implant dentistry research. Also, I would be thrilled to read better quality work from these authors in the near future.

Maxillary sinus floor elevation: review of anatomy and two techniques.

This retrospective study investigated the predictability of the osteotome technique for sinus floor elevation in the presence of antral pseudocysts. A retrospective study was carried out in patients treated with the osteotome technique for sinus floor elevation in the presence of antral pseudocysts and simultaneous implant placement between 2005 and 2009. Pseudocyst cases were collected from the patient population during that period based on faint dome-shaped radiographic findings in the elevated sinus floor. Data were recorded and evaluated in terms of bone gain and alterations in the sinus floor and peri-implant parameters. Twenty-one patients were diagnosed with antral pseudocysts in the sinus floor, with 21 implants placed underneath. All implants osseointegrated uneventfully, and all but one implant radiographically appeared to gain bone around the apex. Mean residual bone height was 6.85 ± 1.22 mm and the mean length of implants protruding into the sinus was 2.96 ± 1.16 mm. The mean endosinus bone gain after the healing period was 3.40 ± 1.78 mm, with an average crestal bone loss of 0.85 ± 0.42 mm. Thirteen implants showed healed bone graft extending all around the apices, three implants had major bony coverage (50% to 100%) of the apically protruding portion, and four implants showed less coverage (< 50%). The survival rate of implants was 100% (mean follow-up, 27.26 ± 15.22 months), and at that time, mean crestal bone loss was 0.50 ± 0.33 mm, modified Plaque Index was 1.30 ± 0.67, modified Bleeding Index was 0.60 ± 0.70, and mean probing depth was 3.35 ± 0.74 mm. Based upon a retrospective study of 21 implants placed beneath pseudocysts for a mean time of 27 months, it appears that implants that extend into the maxillary sinus can remain functionally stable after osteotome sinus elevation in the presence of antral pseudocysts.

BackgroundThe volume of residual alveolar bone is critical to the survival of dental implants. When the volume of alveolar bone in the posterior maxillary region is less than 4 mm, maxillary sinus floor elevation (MSFE) with the lateral approach is an effective option. Traditionally, this standard approach is usually conducted at 4–6 months after tooth extraction (standard MSFE). However, defective dentition due to extraction can impair mastication during the period of bone remodeling, especially if the molars on both sides are severely compromised and must be extracted. MSFE before extraction (modified MSFE) can take full advantage of residual tooth strength. However, the effectiveness and practicability of the modified MSFE procedure remain unknown. Therefore, the aim of this study was to compare the clinical outcomes of modified vs. standard MSFE, in order to provide references to periodontists.Methods/designThe study cohort included 25 adult patients (50 surgery sites) recruited from Peking University Hospital and School of Stomatology who met the inclusion criteria. The two sides of each patient will be randomly divided into two groups: a test group-modified MSFE or a control group-standard MSFE. The surgical duration and patient-reported outcomes (visual analog scale for discomfort) will be documented. Clinical indicators, including implant survival rates, mucosal conditions, and complications, will be recorded every 6 months during the 5-year follow-up period. The volume of the alveolar bone and marginal bone level will be assessed radiographically (cone-beam CT and periapical films) every 6 months. Histological analysis of biopsy samples retrieved from both sides will be performed to evaluate the biological features of the bone.DiscussionThe current study will explore the implant survival rates, safety, reliability, effectiveness, and practicability of the modified MSFE procedure. Moreover, the extent of osteogenesis on the sinus floor will also be assessed. The results of this trial will provide strategies for the modified MSFE procedure to achieve ideal clinical outcomes.Trial registrationInternational Clinical Trials Registry Platform ChiCTR1900020648. Registered on 1 January 2019

The objectives of this systematic review were to assess the survival rate of grafts and implants placed with sinus floor elevation. An electronic search was conducted to identify studies on sinus floor elevation, with a mean follow-up time of at least 1 year after functional loading. The search provided 839 titles. Full-text analysis was performed for 175 articles resulting in 48 studies that met the inclusion criteria, reporting on 12,020 implants. Meta-analysis indicated an estimated annual failure rate of 3.48% [95% confidence interval (CI): 2.48%-4.88%] translating into a 3-year implant survival of 90.1% (95% CI: 86.4%-92.8%). However, when failure rates was analyzed on the subject level, the estimated annual failure was 6.04% (95% CI: 3.87%-9.43%) translating into 16.6% (95% CI: 10.9%-24.6%) of the subjects experiencing implant loss over 3 years. The insertion of dental implants in combination with maxillary sinus floor elevation is a predictable treatment method showing high implant survival rates and low incidences of surgical complications. The best results (98.3% implant survival after 3 years) were obtained using rough surface implants with membrane coverage of the lateral window.

Sinus floor elevation (SFE) is a widely established surgical procedure for dental implant placement in the atrophic posterior maxilla. However, the presence of maxillary sinus cysts (MSCs) can significantly complicate this intervention. This study presents and evaluates the efficacy and safety of the Digitally Guided Aspiration Technique (DGAT), a novel approach for managing MSCs during SFE procedures. Implant survival and success rates were evaluated according to established criteria, and all complications were systematically documented. Three-dimensional measurements, including MSC volume, residual bone height (BH) surrounding the implants, and apical bone coverage, were obtained using cone beam computed tomography (CBCT). Marginal bone loss (MBL) was assessed through standardized periapical radiographs following prosthetic loading. The accuracy of implant positioning was evaluated by measuring the three-dimensional deviations between virtually planned and actually placed implants. Comprehensive cytological and histological analyses were conducted on aspirated cystic fluid and harvested bone specimens, respectively. Patient-reported outcomes were assessed using questionnaires at the 6-month post-restoration follow-up. The study comprised seven patients with seven cysts receiving a total of 10 implants. At the 6-month follow-up, the implant survival rate was 100% with no biological or technical complications observed. Volumetric analysis revealed a significant mean reduction in MSC volume of 45.34% ± 33.08% (p = 0.012). Postoperative measurements demonstrated a statistically significant increase in BH compared to baseline values (p < 0.001). This gain remained largely stable throughout the 6-month observation period, with minimal resorption noted in the buccal aspect (p = 0.03) and mean value (p = 0.05). Prior to second-stage surgery, radiographic evaluation confirmed complete bone coverage of all implants, with 60% exhibiting > 2 mm of apical bone coverage. MBL remained within physiological limits. Analysis of implant positioning accuracy showed that coronal global and vertical deviations fell within acceptable clinical parameters, while apical global deviation and angular deviation marginally exceeded recommended thresholds. Cytological analysis of the aspirated cystic fluid revealed no evidence of infection, while histological examination of the regenerated tissue demonstrated mature bone formation with abundant vascularization. Patient-reported outcomes indicated high satisfaction levels. DGAT can reduce the volume of MSCs, achieve favorable bone grafting and dental implant outcomes with a low incidence of complications. The safety and effectiveness of this procedure need to be compared to the traditional aspiration technique in future randomized controlled trials. Chinese Clinical Trial Registry: ChiCTR2400083235. This clinical trial was not registered prior to participant recruitment and randomization.

PurposeCurrently, maxillary sinus floor (SF) elevation is based on off-the-shelf allogeneic, xenogeneic or synthetic bone augmentation materials (BAM) that are implanted via an open lateral sinus wall approach (OSFE). However, this invasive method is associated with postoperative complications caused by an inadequate blood supply of the alveolar ridge. Balloon-assisted procedures are minimal invasive alternatives with lower complication rates. The aim was to evaluate local new bone (NB) formation in the SF following the application of a particulate BAM (Easy graft) via two different SF elevation techniques in a split mouth mini-pig sinus augmentation model.Material and methodsSeven adult Goettingen minipigs were used for evaluation of a biphasic ceramic (PLGA/ß-TCP) BAM in the elevated SF region. Treatments were randomized to the contralateral sinus sites and included two procedures: OSFE (control group) versus minimally invasive SF elevation by a balloon-lift-control system (BLC) (treatment group). The animals were euthanized after 28 and 56 days for analysis of new bone (NB) formation.ResultsThe biphasic synthetic BAM implanted via BLC increased more NB formation (5.2 ± 1.9 mm and 4.9 ± 1.6 mm vs. 2.6 ± 0.5 mm) and osseointegration of the particles (18.0 ± 6.0% and 25.1 ± 18.2% vs. 10.1 ± 8.0%, p < 0.05) compared to the control.ConclusionsImplantation of a biphasic synthetic BAM enhanced NB formation in the mini-pig maxillary sinus at both time points and in both groups, although BLC resulted in a slightly better total NB formation compared to the control.Graphical abstract

BackgroundAnorganic bovine bone (Bio-Oss®) has been extensively used for reconstruction of posterior area of maxilla in sinus lift procedure; however, a new graft material (Lumina-Bone Porous®), that has a different manufacturing process, has not been yet compared in clinical and histological terms. The manufacturing process of bovine bone graft is related to size and porosity of the particles, and this can change osteoconductive property of the material and bone formation. The use of Lumina-Porus® could improve bone formation, reduce the remaining particles of the biomaterial using a low-cost material. The aim of this research was to compare the clinical, radiological, and histomorphometrical results from maxillary sinus lift with two different anorganic bovine bone substitutes Bio-Oss® (control) and Lumina-Bone Porous® (test).ResultsA split-mouth study was performed with 13 volunteers. The mean bone ridge height in the deepest portion of maxillary sinuses floor was 3.11 ± 0.83 mm in the Bio-Oss® and 2.38 ± 0.75 mm in the Lumina-Bone Porous®. After sinus lift, the Bio-Oss® group shows bone ridge height of 11.56 ± 2.03 mm and Lumina-Bone® of 10.62 ± 1.93 mm. The increase in alveolar bone height scores was significant between pre-augmentation and 6 months after SL in both groups (p < 0.001). No statistical significant difference in newly formed bone in the Bio-Oss® group (20.4 ± 5.4%), and Lumina-Bone Porous® (22.8 ± 8.5%) was histomorphological observed (p > 0.05). On the other hand, the residual graft particles showed significant difference between the Bio-Oss® group (19.9 ± 8.6%) and Lumina-Bone Porous® (14.6 ± 5.6%) (p < 0.05). The survival rate of dental implants for augmented area with Lumina Bone Porous® was 88.88%, while for Bio-Oss® group was 100%.ConclusionBoth materials Bio-Oss® and Lumina-Bone Porous® can be used in the maxillary sinus floor augmentation with good predictability in clinical, radiographical, and histological point of view.

PurposeTo investigate clinical and radiographic outcomes of transcrestal maxillary sinus floor elevation performed with an injectable xenograft in gel form, analyzing general, local and surgical variables possibly influencing the results.MethodsPatients with residual crestal height < 5 mm underwent transcrestal sinus floor elevation with xenograft in gel form to allow the placement of a single implant. Simultaneous implant placement was performed when primary stability was ≥ 15 Ncm. Graft height was measured immediately after surgery (T0) and after 6 months of healing (T1). Univariate and multivariate regression models were built to assess associations between clinical variables with implant survival and graft height at T1.Results71 patients underwent transcrestal sinus floor elevation and 54 implants were simultaneously placed. Delayed implant placement (at T1) was possible in 5 cases out of 17 (29.4%), whereas in 12 patients (70.6%) implant insertion was not possible or required additional sinus grafting. Implant survival rate, with a follow-up varying from 12 to 32 months after loading, was 100%. Mean pre-operative bone height was 3.8 ± 1.0 mm, at T0 was 13.9 ± 2.2 mm and at T1 was 9.9 ± 2.8 mm. Bone height at T1 was negatively influenced by membrane perforation at surgery (p = 0.004) and positively influenced by immediate implant insertion (p < 0.001).ConclusionsTranscrestal sinus floor elevation performed with injectable xenograft gel resulted in 100% implant survival rate. However, immediate implant insertion seems a crucial factor to preserve vertical bone gain: one-stage technique seems to be the most predictable approach to optimize clinical outcomes with this approach.Trial registration clinicaltrials.gov, NCT05305521. Registered 31 March 2022—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT05305521.

Very few controlled studies have compared short and long implants placed with appropriate sinus floor elevation techniques. To compare the 2-year outcomes of 6.5-mm hydrophilic implants placed with osteotome sinus floor elevation (OSFE) and standard implants placed with lateral sinus floor elevation in patients with a severely atrophic posterior maxilla. Thirty-eight patients with a residual bone height of 4-5 mm were randomized to receive one of the two above-mentioned treatments. Intra- and postoperative complications were recorded. The implant survival rate, peri-implant bone level, and periapical endosinus bone gain were assessed. Of the 80 inserted implants, one in the long implant group failed because of abscess formation. The peri-implant bone level change (0.35 ± 0.60 mm vs 0.40 ± 0.71 mm) was not significantly different between the two groups. The endosinus bone gain was 2.94 ± 0.81 mm and 10.19 ± 0.95 mm in the short and long implant groups, respectively. No serious adverse events related to implant surgery were recorded. The results suggest that the placement of 6.5-mm short implants with OSFE is an effective alternative for the rehabilitation of a severely atrophic posterior maxilla.

BackgroundThe success of dental implant restoration is significantly influenced by the volume and density of alveolar bone in the surgical area. Maxillary sinus floor elevation (MSFE) surgery is a reliable method to increase residual bone height (RBH) before implantation. This study aimed to evaluate the impact of platelet-derived bone enhancers, namely platelet-rich plasma (PRP), platelet-rich fibrin (PRF) and platelet-rich growth factor (PRGF), when used as adjuncts to deproteinized bovine bone matrix (DBBM) in MSFE on bone neoformation, implant stability, and implant survival.MethodsA systematic review and meta-analysis were conducted following the PRISMA guideline. Electronic databases, including PubMed, Embase, CENTRAL, Web of Science, Scopus, and Google Scholar, were searched up to February 2025. Randomized controlled trials (RCTs), and case-control studies assessing the effect of PRP/PRF/PRGF as an adjuvant to DBBM in MSFE were included. Mean difference (MD) or risk ratio (RR) was selected as the effect size to perform the meta analysis.ResultsSixteen studies met the inclusion criteria, involving 372 patients and 455 surgical procedures. The meta-analysis revealed a significant enhancement of bone neoformation (MD = 5.92, 95%CI: 2.17 ~ 9.67, p = 0.002) and reduced residual graft volume (MD = -1.93, 95%CI: -2.25 ~ -1.61, p < 0.001) when PRP/PRF/PRGF was added to DBBM. However, there was no significant difference in graft resorption rate, percentage of fibrous tissue, immediate implant stability, and implant survival rate, between the two groups. Subgroup analyses showed that PRF subgroup, and subgroups with 4 m or 6 m healing intervals and with DBBM particles of 0.25-1 mm are related to significantly enhanced bone neoformation; all subgroups except for the PRP subgroup are related to significantly decreased residual graft.ConclusionsThe addition of PRF or PRGF to DBBM in the first stage of MSFE significantly enhances new bone formation and reduces residual graft volume, providing a more reliable alveolar bone matrix for subsequent implant placement. No evidence support the application of PRP as an effective enhancer to DBBM in MSFE procedure. In addition, PRP/PRF/PRGF does not significantly affect the immediate stability or survival of implants in the second stage.

SUMMARYA one-step surgical procedure is presented, including maxillary sinus floor elevation in association with functional endoscopic sinus surgery to remove rhino-sinusal malformations or pathoses that might contraindicate sinus floor elevation. Over a 2-year period, 10 patients requiring a sinus floor augmentation procedure to restore the missing dentition with endosseous implants, but presenting with local and reversible rhinologic contraindications to the augmentation procedure were consecutively treated with a surgical approach that included simultaneously functional endoscopic sinus surgery and a sinus floor elevation procedure through an intra-oral approach. Then 4-6 months after this procedure, oral implants were inserted and after a further waiting period, ranging from 3 to 6 months, patients were restored with prostheses and followed for 1 to 3 years after the completion of prosthetic restoration. In all 10 patients, complete recovery of para-nasal sinuses function was demonstrated and occurred in all cases within one month. All cases showed good integration and consolidation of the graft material used for maxillary sinus floor augmentation. None of the implants placed were lost during the follow-up period after completion of prosthetic loading. In conclusion, despite the limits of this study (which included only 10 patients), the combination of maxillary sinus augmentation procedures and functional endoscopic sinus surgery, to treat local contraindications to sinus augmentation has proven to be both effective and safe and has allowed the patient to avoid a second surgical procedure and a longer waiting period before final prosthetic rehabilitation. No sinusal complications related to sinus floor augmentation were encountered and the survival rate of implants placed in the augmented areas was consistent with those reported in cases of sinus floor augmentation performed in patients presenting with a healthy rhino-sinusal system.

Objective: To investigate the clinical effect of disk-up sinus reamer (DSR) in maxillary sinus floor elevation with maxillary sinus septum. Methods: Twenty-four patients were included between January 2019 to January 2020 in Department of Oral Implantology, The Affiliated Hospital of Qingdao University. There were 10 males and 14 females with the age of (39.3±11.7) years old (range 22-56 years). Pre-operative(T0) cone-beam CT (CBCT) was taken for measurement and analysis. All patients were divided into group E (easy situations, septum located anterior to the zygo-matic process), group M (moderate situations, septum located pos-terior to the zygo-matic process) and group D (difficult situations, sagittally oriented septum). The maxillary sinus floor was grafted through the crestal approach by DSR and implants were placed simultaneously. Permanent repair was performed 6-8 months after operation. All patients underwent CBCT before surgery, after surgery immediately (T1), 6 months after surgery(T2), 1 year after surgery(T3), 2 year after surgery(T4). The residual bone height (RBH) and the vertical bone height (VBH) were analyzed. The mucosal perforation rate, implant survival rate were counted. Results: All the 24 patients completed the Maxillary sinus lift surgery successfully and 24 implants were placed simultaneously. All patients had no headache, dizziness. The mucosal perforation rate was 0. The survival rate of implants during the healing period was 100%(24/24). The RBH was (5.81±2.56) mm pre-operation, the VBHT1, VBHT2, VBHT3 and VBHT4 were (11.82±1.09), (10.98±0.52), (10.66±0.44) and (10.40±0.33) mm, respectively. The differences between the groups by pairing test were statistically significant (F=187.70, P0.001), expect VBHT3 and VBHT4 (P=0.071). Bone resorption and remodeling mainly occurred 1 year after surgery. One patient developed peri-implantitis 18 months after surgery. Conclusions: With the RBH of implant site>2 mm and existence of maxillary sinus septum, using DSR for sinus floor elevation has a high success rate. It can obtain enough bone height and complete the simultaneous implantation to form a good osseointegration. The DSR is simple, safe and controllable, and can shorten the operation time.