Sinus floor elevation procedures to enable implant placement and integration: techniques, biological aspects and clinical outcomes

Effectiveness of concentrated growth factors with or without grafting materials in maxillary sinus augmentation: a systematic review

Concentrated Growth Factor (CGF) is a highly effective biomaterial known for its ability to promote tissue regeneration. While it's been studied extensively in intraoral procedures and bone grafting, its benefits in maxillary sinus lifting lack substantial evidence. This review aimed to evaluate CGF's effectiveness in maxillary sinus augmentation, focusing on clinical, radiographic, and histological outcomes.A comprehensive literature search was conducted across PubMed, Scopus, Web of Science, Google Scholar, and Cochrane Library databases using specific mesh terms and keywords and adhered to PRISMA guidelines. Studies up to March 2024 involving transcrestal or lateral maxillary sinus floor elevation with CGF, either alone or in combination with grafting materials, were included.Out of 783 publications, 13 studies met the eligibility criteria. The review assessed CGF's role in minimizing postoperative complications, enhancing new bone formation, and improving implant survival. Despite data variability among studies, the majority reported that CGF positively influenced maxillary sinus augmentation outcomes.While more robust randomized clinical trials are required to draw definitive conclusions, initial results are promising, and the findings suggest that CGF utilization in maxillary sinus augmentation seems to enhance clinical outcomes by promoting vascularization and regeneration at the surgical sites and improving both the quality and quantity of newly formed sinus bone. Furthermore, it exhibits potential for improving postoperative sequelae and achieving high implant survival rates.

Comparison of three approaches for treating the bony access window in lateral sinus floor elevation: a retrospective analysis

The aim of this study was to retrospectively determine the effects of applying different treatment methods to the bony access window on the healing outcomes in lateral sinus floor elevation (SFE). Lateral SFE with implant placement was performed in 131 sinuses of 105 patients. The following three treatment methods were applied to the bony access window: application of a collagen barrier (group CB), repositioning the bone fragment (group RW) and untreated (group UT). Radiographic healing in the window area, augmented bone height changes and marginal bone level changes were examined. Mixed logistic and mixed linear models were analyzed. Over 4.3 ± 1.4 years of follow-up, the implant survival rate was 100% in groups CB and UT, and 96.9% in group RW. The treatment applied to the window did not significantly influence the radiographic healing in the window area, augmented bone height changes or marginal bone level changes (p > 0.05). The healed window areas had generally flat morphologies and were fully corticalized. The mean changes in the augmented bone were less than 1.5 mm in all groups. Marginal bone level changes were minimal. In conclusion, Healing outcomes were not different among three different methods to treat the bony access window in lateral SFE.

Assessment of soft and hard tissue changes following micro crestal flap-Alveolar ridge preservation and augmentation at molar extraction sites in patients with stage III/IV periodontitis: A randomized controlled trial

AIM

This study aimed to assess hard and soft tissue contour changes following micro crestal flap-alveolar ridge preservation (MCF-ARP) and natural healing (NH) in periodontally compromised molar extraction sites and to analyse the feasibility and need for bone augmentation during implant therapy.

MATERIALS AND METHODS

Fifty-six patients with 70 sites were randomized into two groups at the site level (35 sites from 31 patients in the test group and 35 sites from 29 patients in the control group). Among whom, four patients contributed one tooth to the control group and one tooth to the test group. Hard tissue indicators were measured using cone beam computed tomography performed before tooth extraction and 6 months after surgery. Soft tissue contour changes were assessed using intraoral scanning performed before and immediately after surgery and also 2 weeks and 1, 3 and 6 months after surgery.

RESULTS

Six months after surgery, the MCF-ARP group showed less resorption in buccal bone height (p = .032) and greater augmentation in central bone height (p = .001) and ridge width (p = .009). The mean, vertical and horizontal collapse of buccal soft tissue contour in the MCF-ARP group were 0.95 mm (p = .010), 0.61 mm (p = .019) and 0.56 mm (p = .013) less than that in the NH group, respectively. There were significantly (p = .007) fewer sites in the MCF-ARP group than in the NH group (0% vs. 26.7%) for staged bone augmentation and more sites that could be treated with simple implant procedure in the MCF-ARP group than in the NH group (71.9% vs. 56.6%).

CONCLUSIONS

Compared with NH, MCF-ARP reduced bone resorption in periodontally compromised molar extraction sites and maintained the buccal soft tissue contour. MCF-ARP reduces the need for complex bone augmentation procedures in implant therapy.

TRIAL REGISTRATION

Chinese Clinical Trial Register (ChiCTR) ChiCTR2200056335. Registered on 4 February 2022, Version 1.0.

Maxillary sinus lift augmentation: A randomized clinical trial with histological data comparing deproteinized bovine bone grafting vs graftless procedure with a 5-12-year follow-up

INTRODUCTION

Different protocols and procedures for sinus lift and implant placement are available, generally involving the use of grafts to increase the tissue volume and/or prevent the Schneiderian membrane from collapsing. Among xenografts, deproteinised bovine bone graft (DBBP) is frequently used in sinus lift procedures. Leaving an ungrafted space following membrane elevation has proven to have a bony regenerative potential as well. This study aimed to compare the clinical and histological features of sinus lift surgery performed with or without biomaterials.

METHODS

Patients with severe maxillary posterior atrophy (residual bone height 2-6 mm and residual crest thickness ≥4 mm), and in need of sinus lift surgery to allow the placement of three implants were enrolled and randomly divided into two groups. They underwent sinus lifts with DBBP (control) or with a graftless technique (test) and immediate placement of two implants (a mesial and distal one). After 6 months, a bone sample was retrieved from the area between the previously inserted fixtures, and a third, central implant was placed. The collected bone samples were analyzed morphologically and histomorphometrically. The patients were provided with prosthetic restorations after 6 months and followed up for 5-12 years.

RESULTS

Ten patients were enrolled in the test and nine in the control group. The 6-month follow-up showed in the control group an average augmentation of 10.31 mm (±2.12), while in the test group it was 8.5 mm (±1.41) and a success rate of 96.3% in the control and 86.7% in the test group (p > 0.05). The histological analysis evidenced the presence of new bone tissue surrounded by immature osteoid matrix in the test group, and a variable number of DBBP particles surrounded by an immature woven bone matrix in the control group.

CONCLUSION

The results of the present trial indicate that, with residual bone height of 2-6 mm and residual crest thickness ≥4 mm, sinus lift surgery with or without biomaterials followed by implant restoration, produces similar clinical and histological outcomes.

A transcrestal sinus floor elevation strategy based on a haptic robot system: An in vitro study

OBJECTIVES

To reveal the force profiles recorded by haptic autonomous robotic force feedback during the transcrestal sinus floor elevation (TSFE) process, providing a reference for the surgery strategy during TSFE.

MATERIALS AND METHODS

A total of 42 maxillary sinus models with different angles of the sinus floor (30°, 40°, 50°, 60°, 70°, 80°, and 90°, compared to vertical plane) were 3D printed. Implant site preparation was performed using a robotic system, and the total force (Ft) and axial force along the drill (Fz) during the surgery were recorded by the haptic robotic arm. The actual initial breakthrough point (drill contacting sinus floor) and complete breakthrough point (drill penetrating the sinus floor) were defined visually (the actual IBP and the actual CBP). The theoretical initial breakthrough point (the theoretical IBP) and the theoretical complete breakthrough point (the theoretical CBP) defined by the robot-guided system and the CBCT were determined by real-time force feedback and imaging distance measurement, respectively. The distance from the bottom of the resin model to the actual IBP and the actual CBP was defined as Di and Dt, respectively.

RESULTS

The difference in Fz began to increase significantly at 70°, while the difference in Ft became significant at 60°. When the angle was greater than 70°, there was no significant difference in the discrepancy between the actual and theoretical perforation points. Compared to judging the breakthrough point by CBCT, real-time force feedback TSFE under robotic surgery achieved more accurate initial breakthrough point detection.

CONCLUSIONS

The smaller the angle, the larger the breakthrough force for the drill. The real-time force feedback of haptic robotic system during TSFE could provide reliable reference for dentists. More clinical studies are needed to further validate the application of robotic surgery assisted TSFE.

Patient and implant-related risk factors for implant failure of one-stage lateral sinus floor elevation: A 2- to 10-year retrospective study

OBJECTIVES

This retrospective study aimed to evaluate the early and late implant failure rates of one-stage lateral sinus floor elevation (LSFE) and to identify the patient and implant-related risk factors associated with these failures.

MATERIALS AND METHODS

All patients treated with one-stage LSFE from January 2014 to December 2021 were evaluated for inclusion. A total of 618 patients with 936 implants met the inclusion criteria. Clinical and radiographic information about patient and implants was collected. Univariate and multivariate Cox proportional hazards frailty regression models were performed to identify risk factors for early and late implant failure.

RESULTS

The cumulative implant survival rate was 95.62% (95% CI 93.90%-97.68%), with 16 early implant failures and 25 late implant failures. The Cox analysis indicated that ≤3 mm residual bone height (RBH) was associated with a higher early failure rate. For late implant failure, smoking habit, ≤3 mm RBH, and certain implant brand were independent risk factors. Narrow sinus ostium, long infundibulum, and flat thickening of Schneiderian membrane might be non-independent risk factors for late implant failure. No significance was found in other variables, including age, periodontitis history, implant characteristics (position, diameter, length, protrusion length, marginal bone loss), surgeon experience, healing time, opposing dentition, and prosthesis.

CONCLUSIONS

One-stage LSFE is a predictable treatment for patients with atrophic maxilla. ≤3 mm RBH increased the risk of early implant failure, while smoking habit, ≤3 mm RBH, and certain implant brand were independent risk factors for late implant failure.

Radiographic outcomes of lateral sinus floor elevation at sites without perforations and sites with perforations managed with a resorbable membrane: A retrospective study

AIM

To evaluate the radiographic outcomes of lateral sinus floor elevation with simultaneous implant placement at sites without sinus membrane perforation (SMP) and sites with SMP managed with a resorbable membrane.

MATERIALS AND METHODS

One hundred and thirty-nine patients and 170 implants (56 perforation, 114 non-perforation) were included. Cone-beam computed tomography (CBCT) images were taken before surgery (T0), immediately after surgery (T1) and 6 months after surgery (T2). Post-operative augmentation parameters, including endo-sinus bone gain (ESBG) along the implant axis, mean new bone height (NBH) surrounding the implant and augmentation volume (AV), were measured at T1 and T2.

RESULTS

At T1, there were no significant differences in ESBG, NBH and AV between the two groups. At T2, although ESBG did not significantly differ between the two groups, NBH (8.50 ± 1.99 mm vs. 9.99 ± 2.52 mm, p = .039) and AV (519.37 ± 258.38 mm3 vs. 700.99 ± 346.53 mm3, p < .001) were significantly lower in the perforation group. The shrinkage of graft material from T1 to T2, including ΔESBG (p = .002), ΔNBH (p < .001) and ΔAV (p < .001), was higher in the perforation group.

CONCLUSIONS

SMP during LSFE with simultaneous implant placement is associated with greater resorption of the grafted area at a 6-month follow-up.

Sinus Floor Augmentation with Synthetic Hydroxyapatite (NanoBone®) in Combination with Platelet-Rich Fibrin: A Case Series

Several techniques have been described for maxillary sinus graft augmentation, including the lateral window technique and crestal approach with osteotomes or osseodensification. Platelet-rich fibrin has been used in maxillary sinus lift procedures due to its ability to accelerate soft and hard tissue healing. The aim of this study was to evaluate the potential of PRF in combination with the synthetic hydroxyapatite NanoBone® to enhance bone regeneration in sinus floor elevation with the lateral window technique. Out of the 50 individuals screened in a preoperative assessment visit from the CESPU-Famalicão clinical unit and intervened upon between January 2023 and December 2023, only 6 patients who met the study's inclusion criteria consented to participate. In a split-mouth study, twelve sinus graft surgeries were carried out. Our observations reveal that for the test group (NanoBone®/PRF), there is a 27.5 ± 4.9% increase new vital bone, 23.0 ± 3.7% increase in inert bone particles, and 49.4 ± 2.8% increase in connective tissue. Meanwhile, for the control group (NanoBone®), there is a 19.5 ± 3.0% increase in new vital bone, 23.4 ± 5.7% increase in inert bone particles, and 57.0 ± 3.5% increase in connective tissue. The results strongly indicate that mixing liquid PRF with NanoBone® does not have a negative influence on the amount of viable bone formation, and it seems to slightly increase the amount of new bone formation and revascularization in sinus bone graft procedures with the lateral window technique compared to the single use of NanoBone®.

Implant stability and clinical outcome between implant placement using internal sinus floor elevation with alloplastic bone material grafting and without grafting: A 1-year randomized clinical trial

OBJECTIVE

To compare implant stability and clinical outcome in implant placement between osteotome sinus floor elevation (OSFE) with biphasic calcium phosphate (BCP) which consisted of 30% of hydroxyapatite (HA) and 70% of beta-tricalcium phosphate (β -TCP) grafting material and OSFE without using bone grafting material. The research questions is whether the BCP provides any benefit in OSFE or not.

MATERIALS AND METHODS

Thirty patients (30 implants) with a single edentulous area of upper premolar or molar were randomly separated into OSFE with BCP (n = 15) and OSFE without grafting (n = 15). The patients were reevaluated 3, 6, 9, and 12 months after implant loading. The clinical assessments (implant stability quotient (ISQ), implant survival-failure rate, and surgical complication) were analyzed. Together with radiographic assessments in 2D (endo-sinus bone gain (ESBG), mean marginal bone change (MMBC)) and 3D (endo-sinus bone gain in CBCT (ESBG-CT)) were evaluated, with a mean follow-up time of at least 12 months of functional loading and prosthetic complication.

RESULTS

20 remaining implants (OSFE with BCP, n = 10; OSFE without grafting, n = 10) were analyzed. Mean ISQ was 79.18 ± 3.43 in 1-year follow-up (ISQ; OSFE with BCP = 78.72 ± 3.46, OSFE without grafting = 79.65 ± 3.52). ISQ in both groups increased steadily without significant differences in each follow-up. (p = 0.56). In radiographic evaluation, at 6-, 9-, and 12-month, OSFE without grafting group showed statistically significant lower MMBC (p < 0.05). The 1-year clinical results showed that 2 implants failed in OSFE with BCP, and 1 implant failed in OSFE without grafting.

CONCLUSIONS

Graft material "BCP" (HA30:TCP70) coupled with OSFE presents no extraordinary benefit in implant stability, clinical and radiographic outcome in 1-year follow-up.

CLINICAL RELEVANCE

Clinically, OSFE with grafting materials provides no additional benefit.

CLINICAL TRIAL REGISTRATION NUMBER

TCTR20210517008 (date of registration: May 17, 2021).

Clinical outcomes and risk factor analysis of dental implants inserted with lateral maxillary sinus floor augmentation: A 3- to 8-year retrospective study

AIM

To evaluate the 3- to 8-year outcomes of dental implants placed with lateral sinus floor augmentation (LSFA) and to identify factors affecting implant survival.

MATERIALS AND METHODS

This retrospective study was performed by screening all implants placed with LSFA procedures, which were conducted between January 2012 and December 2016. Subantral bone gain (SABG) and apical bone height (ABH) were assessed using panoramic radiographs. The cumulative survival rate of implants was analysed using life-table analysis and Kaplan-Meier survival curves. The influential risk factors affecting survival were assessed using univariate log-rank tests and multivariable mixture cure rate model. Implant complications were recorded.

RESULTS

Based on the established criteria, a total of 449 patients (760 implants) were included in this study. In the 3- to 8-year follow-up (mean ± SD, 5.81 ± 1.33 years), 15 implants in 14 patients failed, with a CRS of 96.81% on an implant basis and 95.07% on a patient basis. A history of periodontitis and poor compliance with supportive periodontal treatment was associated with a significantly higher risk of implant failure at both implant and patient levels. Significant decreases in ABH occurred during each yearly interval except for 3 years. A similar trend has been observed for SABG at 1, 2, 6 and 8 years. The total complication rate was 31.84% on implant basis, with peri-implant mucositis (21.58%) being the most frequent biologic complication and porcelain cracking (5.00%) being the most common technical complication.

CONCLUSIONS

Implant with LSFA is a reliable treatment option in atrophic maxilla. A history of periodontitis without regular supportive periodontal treatment was identified as a predictor for implant failure. Slight but significant shrinkage of vertically augmented bone can be observed after implant placement.

Maxillary sinus augmentation via the bone lid technique: A prospective, radiographic case series

BACKGROUND

Maxillary sinus augmentation is one of the most performed procedures to increase the bone quantity of the atrophic maxilla to allow implant placement. The aim of the present case series was to describe a surgical protocol to perform maxillary sinus augmentation with the "bone lid technique," and its outcomes in a cohort of patients eligible for the procedure.

METHODS

After the initial clinical evaluation, a cone-beam computed tomography (CBCT) examination was performed for preoperative assessment. Patients were then scheduled for surgical intervention. At 6-9 months follow-up, patients underwent a second CBCT scan to evaluate bone height following bone graft and to schedule implant placement.

RESULTS

A total of 11 patients were enrolled in the study with a total of 13 sinus lift procedures. Membrane perforation was registered in 4 cases (30.76%). Mean surgical time was 67.69 min (SD 6.51). Postoperative period was uneventful in all patients, in the absence of complications. The mean graft volume increase was 2.46 cm3 (SD 0.85), and the mean height increase was 14.27 mm (SD 3.18). Mean membrane thickness was 1.40 mm (SD 0.75). In all the 4 cases with sinus membrane perforation, the membrane had a thickness lower than 1 mm.

CONCLUSIONS

The present study highlights that the maxillary sinus augmentation with bone lid repositioning could provide repeatable results in terms of bone height increase. The technique appears reliable both in terms of bone gain and absence of complications.

KEY POINTS

The bone lid technique for maxillary sinus augmentation provides repeatable results in terms of bone height increase. The favorable clinical outcomes can be related to an enhancement of bone formation due to the unique osteoconductive and osteoinductive properties of autogenous bone, along with a reduction of soft tissue ingrowth. Complications were not observed in any of the patients following the surgical procedures. The risk of Schneiderian membrane perforation is inversely proportional to membrane thickness; the thinner the membrane is, the higher the risk to perforate it.

Sinus floor augmentation using mineralized freeze-dried bone allograft combined with recombinant human bone morphogenetic protein-2 (rhBMP-2): A long-term retrospective study

Background/purpose

The combination of recombinant human bone morphogenetic protein-2 (rhBMP-2) with a carrier material has not been extensively studied. This study aimed to evaluate the clinical, radiological, and histomorphometric outcomes of sinus floor augmentation using a 3:7 mixture of cancellous and cortical freeze-dried bone allografts (mixed AG) combined with rhBMP-2.

Materials and methods

Mixed AG was used for sinus floor augmentation in a total of 21 patients with a residual alveolar bone height <5 mm. Among the total 47 sites, augmentation with and without rhBMP-2 was performed in 26 and 21 sites, respectively. Radiographic parameters were assessed using cone-beam computed tomography. After a six-month healing period, core biopsies were harvested for histomorphometric analysis.

Results

The bone gain after healing was 13.36 ± 3.9 mm and 12.07 ± 3.8 mm in the mixed AG alone and mixed AG with rhBMP-2 groups, respectively. The survival rate of implants in both groups was 100% during the follow-up period. The proportion of newly formed bone was 24.6 ± 10.2% and 39.7 ± 18.3% in the mixed AG alone and mixed AG with rhBMP-2 groups, respectively (P < 0.05). Moreover, the percentage of residual graft material was 21.0 ± 12.2% and 9.6 ± 10.0% in the mixed AG alone and mixed AG with rhBMP-2 groups, respectively (P < 0.05).

Conclusion

Mixed AG combined with rhBMP-2 could be a suitable material for sinus floor augmentation. This combination may reduce the treatment time and improve the predictability of implant placement.

The Use of Platelet-Rich Fibrin in Sinus Floor Augmentation Surgery: a Systematic Review

Objectives

This systematic review aims to critically assess the impact of platelet-rich fibrin on maxillary sinus floor augmentation and outline the specific aspects of new bone formation, bone height, implant stability quotient, and Schneiderian membrane thickness.

Material and Methods

A systematic review and meta-analysis were conducted, analysing studies from MEDLINE (PubMed), the Cochrane Library, and ScienceDirect databases, published from January 29, 2018 until January 29, 2024 that compared maxillary sinus floor augmentation (MSFA) using bone graft material with and without platelet-rich fibrin (PRF). This review focused on patients 18 years and older who undergone MSFA before the dental implant placement. It systematically examined five studies, encompassing randomized controlled trials, and reported on 112 MSFA procedures conducted in 84 patients.

Results

The meta-analysis reveals a marginal significance in new bone formation with PRF, suggesting a trend towards beneficial outcomes that were not statistically significant. No significant impact on bone height was observed. However, a notable improvement in implant stability quotient (ISQ) was recorded, indicating enhanced implant stability with PRF. The Schneiderian membrane thickness did not show significant changes post-treatment with PRF.

Conclusions

While platelet-rich fibrin shows promise in enhancing implant stability, its effects on new bone formation and Schneiderian membrane thickness are inconclusive, highlighting the need for further research. Platelet-rich fibrin did not significantly affect bone height. The findings support platelet-rich fibrin's potential as a beneficial adjunct in maxillary sinus floor augmentation, particularly for implant stability.

[Graftless maxillary sinus lift with simultaneous implant placement: a case report]

A maxillary sinus lift was performed without bone grafting in a 23-year-old female patient who required the placement of a dental implant in the edentulous area of tooth 16. The clinical and tomographic evaluation made it possible to plan and perform the maxillary sinus lift using the transcrestal approach and without the need for bone grafting. The residual ridge of 6mm allowed the placement of a simultaneous dental implant. After 6 months of tomographic follow-up, before prosthetic loading, a vertical bone height of 8.83 mm was achieved, resulting in a vertical bone gain of 2.83 mm. Additionally, an adequate integration of the dental implant was observed without postoperative complications. Transcrestal sinus lift without the use of bone graft is shown to be a viable, safe and effective technique for the simultaneous placement of dental implants in patients with bone atrophy in the maxillary area. This technique offers advantages such as reduced surgical time, less morbidity, lower cost and a faster healing process compared to conventional methods.

A Novel Approach for the Treatment of Recurrent Oroantral Fistula Occurring at an Infected Sinus Augmentation Site

Closing a recurrent oroantral fistula (OAF) that occurs at an infected sinus augmentation site is a challenge for clinicians. The recurrent OAF has a detrimental impact on bone regeneration and subsequent implant placement. This case report includes three cases in which sinus graft infection and OAF occurred after maxillary sinus augmentation (MSA). In these cases, treatments to control sinus infection were performed using an otolaryngologist; then, intraoral interventions comprising mucosal flap procedures, bone grafts, and barrier membrane applications were performed 2-5 times by oral surgeons. Nevertheless, OAF recurred persistently. The failure to stop OAF recurrence may be due to the inability to effectively block air pressure at the OAF site. Following a comprehensive debridement of the infected tissue at the previous sinus augmentation site, a pouch was created through sinus mucosal elevation. The perforated sinus mucosa at the OAF site was covered with a non-resorbable membrane in one case and with resorbable collagen membranes in the other two cases, followed by bone grafting within the pouch. Lastly, this procedure was completed by blocking the entrance of the pouch with a cortical bone shell graft and a resorbable collagen membrane. The cortical bone shell graft, obstructing the air pressure from the nasal cavity, facilitated bone formation, and, ultimately, allowed for implant placement. Within the limitations of the present case report, the application of a guided bone regeneration technique involving a cortical bone shell graft and a barrier membrane enabled the closure of the recurrent OAF and subsequent implant placement.

Quantitative analysis of change in bone volume 5 years after sinus floor elevation using plate-shaped bone substitutes: a prospective observational study

PURPOSE

Tricalcium phosphate (TCP) has osteoconductive ability and reportedly offers similar clinical results as autogenous bone grafts in dental implant treatment. However, few reports quantify temporal changes in augmented bone volume after sinus augmentation. We aimed to establish a three-dimensional (3D) quantification method to assess bone volume after sinus augmentation and to evaluate biocompatibility of the TCP plate.

METHODS

Maxillary sinus floor augmentation was performed employing the lateral window technique, and plate-shaped β-TCP (TCP plate) was used instead of granular bone grafting materials. After lifting the sinus membrane, the TCP plate was inserted and supported by dental implants or micro-screws. The changes in bone volumes in the maxillary sinus before and after surgery were recorded using cone-beam computed tomography, saved as Digital Imaging and Communications in Medicine-formatted files, and transformed to Standard Triangle Language (STL)-formatted files. Pre- and post-operative STL data of bone volume were superimposed, and the augmented bone volume was calculated. Moreover, changes in bone volumes, TCP plate resorption rates, and bone heights surrounding the implants were three dimensionally quantified.

RESULTS

Fifteen implants in nine subjects were included in this study. TCP plates secured long-term space making, with results similar to those of granular bone substitutes. Newly formed bone was identified around the implant without bone graft material. TCP plate was absorbed and gradually disappeared.

CONCLUSIONS

A novel 3D quantification method was established to evaluate changes in bone volume. Clinical application of TCP plate in sinus augmentation could be a better procedure in terms of prognosis and safety.

The transalveolar approach with the small segmentation method for inclined maxillary sinus floor elevation: A retrospective study

OBJECTIVE

To evaluate the clinical outcome of the transalveolar approach with the small segmentation method for inclined maxillary sinus floor elevation.

METHODS

Sixty-one patients with an inclined maxillary sinus floor (tilt angle ≥ 10°) and insufficient residual bone height in the posterior maxilla were included and grouped according to the tilt angle of the sinus floor, with group A having patients with the tilt angle ≥ 10° and ≤ 30° and group B having patients with the tilt angle > 30°. After completing sinus membrane elevation and bone augmentation using bone substitute materials, the implants were inserted at the same appointment, and the restoration was completed after 5-6 months of osseointegration. The preoperative sinus floor level and sinus floor elevation achieved postoperatively were assessed and recorded. At pre- and post-operative timepoints, the sagittal plane of the cone beam computed tomography was used to evaluate the bone height changes at the peak, middle and valley points in the slope segment intended for implant implantation.

RESULTS

Osseointegration was evident in all 61 patients, and the final restoration was completed with functional loading. After assessing the normality and homogeneity of variance, two-sample t-test or nonparametric tests were employed to estimate the differences in the bone height changes. The degrees of freedom (df) for this analysis were 59. The elevation attained at the middle point in groups A and B were 6.71 ± 1.38 and 5.75 ± 1.56 mm, respectively, demonstrating a significant difference (p < 0.05). Furthermore, at the peak and valley points, group A exhibited bone height changes of 5.79 ± 1.74 and 6.06 ± 1.45 mm, respectively, compared to group B with changes measuring 4.63 ± 2.18 and 5.58 ± 2.39 mm, respectively, with no significant difference in the two groups (p ≥ 0.05). The prevalence of intraoperative sinus membrane perforation was assessed using the chi-square test. It was found that four cases in group A and five cases in group B experienced sinus membrane perforation, with no significant difference in the two groups (p ≥ 0.05, df  = 1).

CONCLUSION

The transalveolar approach using the small segmentation method suggests a promising approach for elevating the inclined maxillary sinus floor.

Clinical and patient-centered outcomes following rehabilitation of atrophic edentulous maxilla using six implants placed simultaneously with bilateral maxillary sinus augmentation: A retrospective case series

OBJECTIVES

To evaluate treatment success, patient satisfaction, and oral health-related quality of life (OHRQoL) after rehabilitation of atrophic edentulous maxilla (AEM) with six implants placed simultaneously with bilateral maxillary sinus floor augmentation (MSFA).

MATERIALS AND METHODS

The selected patients were fully edentulous with atrophic maxillary posterior residual ridges and rehabilitated with six implants placed simultaneously with bilateral MSFA and immediate All-on-4 provisional fixed prosthesis (PFP). After 7-12 months of implant surgery, all patients have received an All-on-6 definitive fixed prosthesis (DFP). After at least one year of function with DFP, clinical and radiographic examinations were performed. Patient satisfaction was assessed through a visual analog scale (VAS). The OHRQoL before treatment (T0), during provisional (T1), and after definitive prosthesis (T2) was evaluated using OHI-14.

RESULTS

20 maxillary edentulous patients were rehabilitated with 120 implants, 20 immediate All-on-4 PFP, and 20 All-on-6 DFP. Of those, 12 patients have passed at least a year follow-up after DFP insertion and were eligible to be included in the assessment of treatment success. After a mean of 20 (12-36) months follow-up, the implant and prosthesis survival rates were 100%. The success rate at the implant level was 98.6%. The mean marginal bone loss (MBL) was 0.09 ± 0.06 mm. No prosthetic or postoperative complications, and the mean general satisfaction was (91.75 ± 7.06). There was a significant improvement in all OHIP-14 domains during the final All-on-6 prosthesis (T2) (P < 0.01).

CONCLUSIONS

Rehabilitation of atrophic edentulous maxilla using six implants with simultaneous bilateral MSFA and immediate All-on-4 PFP is a successful treatment approach associated with minimal postoperative complications and significant improvement in OHRQoL.

Survival analysis of implants placed simultaneously with lateral sinus floor elevation in severely atrophic maxilla: A 3- to 12-year retrospective cohort study

OBJECTIVES

To retrospectively evaluate whether implants placed simultaneously with lateral sinus floor elevation (LSFE) in severely atrophic maxilla (residual bone height [RBH] ≤3 mm) could achieve long-term survival and comprehensively analyze the factors influencing their survival rates.

MATERIALS AND METHODS

A total of 123 patients receiving LSFE and simultaneous implant placement from 2010 to 2019 and their 123 implants in sites with RBH ≤3 mm were included in this study. Basic characteristics of patients and implants were collected from the medical record system and cone-beam computed tomography (CBCT) images. Kaplan-Meier survival curves were applied to estimate cumulative survival rates (CSRs) and Cox proportional hazards regression models were used to detect factors influencing implant survival.

RESULTS

The 6-year and 12-year CSR of implants placed in sites with RBH ≤3 mm were 95.7% (95% confidence interval [CI]: 92.1%-99.5%) and 76.6% (95% CI: 58.1%-100%), respectively. Eight patients presented late implant failure. Univariate and multivariate Cox regression analyses demonstrated that RBH ≤2 mm (hazard ratio [HR]: 20.63, p = 0.000) and smoking habit (HR: 6.055, p = 0.024) were significantly associated with long-term implant survival. Specifically, the 10-year CSR of implants in sites with RBH ≤2 mm (53.3%, 95% CI: 27.5%-100%) was dramatically lower than those in sites with RBH >2 mm (92.9%, 95% CI: 81.7%-100%, p = 0.000).

CONCLUSIONS

Implants placed simultaneously with LSFE in sites with RBH ≤3 mm can achieve long-term survival. However, caution is required especially for implantation in sites with RBH ≤2 mm. Besides, the smoking habit is also considered a risk factor jeopardizing long-term implant survival.

Maxillary sinus membrane elevation and coagulum compared with maxillary sinus floor augmentation and a composite graft: A 1-year single-blinded randomized controlled trial

OBJECTIVE

The aim was to evaluate the 1-year implant outcome and patient-related outcome measures (PROMs) after maxillary sinus membrane elevation and coagulum (test) compared with maxillary sinus floor augmentation and a 1:1 ratio of autogenous bone graft from the buccal antrostomy and deproteinised porcine bone mineral (DPBM) (control).

MATERIALS AND METHODS

Forty patients (30 female, 10 male) with a mean age of 50 years (range 25-71 years) and an alveolar ridge height between 4 and 7 mm were randomly allocated to test or control. Outcome measures included survival of suprastructures and implants, implant stability quotient, health status of the peri-implant tissue, peri-implant marginal bone loss, frequency of complications and PROMs using Oral Health Impact Profile-14 combined with questionnaires assessing patient's perception of the peri-implant soft tissue, implant crown, function of the implant, and total implant treatment outcome using visual analogue scale. Mean differences were expressed with standard deviation and 95% confidence interval. Level of significance was 0.05.

RESULTS

All suprastructures and implants were well-functioning after 1-year of functional implant loading. No significant difference in any of the applied outcome measures was observed between test and control. Both treatments revealed high patient satisfaction scores and significant improvement in oral health-related quality of life.

CONCLUSION

There were no significant differences in implant outcome and PROMs between test and control, after 1-year of functional implant loading. Neither of the treatments can therefore be considered better than the other. Thus, long-term randomized controlled trials are needed before definitive conclusions can be provided about the two treatment modalities.

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

OBJECTIVE

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?"

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

Analysis of the accuracy of a dynamic navigation system when performing dental implant surgery with transcrestal sinus floor elevation: A pilot study

Background/purpose

The success of transcrestal sinus floor elevation (TSFE) is primarily reliant upon the experience of the surgeon owing to the limited operative visibility. To evaluate the accuracy associated with the use of a dynamic navigation system when conducting posterior maxilla implant surgery with TSFE.

Materials and methods

Twenty-eight implants were placed in 28 patients requiring implantation in the posterior maxilla via a TSFE approach. The drills were used to access the planned position (within 1 mm of the bottom of the maxillary sinus floor) under dynamic navigation system. TSFE was then accomplished using osteotomes and a piezoelectric device. Lastly, the implant was inserted under the dynamic navigation. Three effective deviations between planned and actual implant placement were then measured including angular deviation (AD, degrees), entry point horizontal deviation (EPHD, mm), and apical point horizontal deviation (APHD, mm).

Results

The AD, EPHD, and APHD between the planned and actual implant placement were 3.656 ± 1.665°, 1.073 ± 0.686 mm, and 1.086 ± 0.667 mm, respectively. Premolar site AD values were less than those for molar sites (P = 0.004). No significant differences in these outcomes were observed in different surgeons. Obvious sinus perforation was not detected by immediate postoperative cone beam computed tomography imaging.

Conclusion

The accuracy associated with using a dynamic navigation system when conducting posterior maxilla implant surgery via a TSFE approach using piezoelectric devices was comparable. This technique thus achieved appropriate interventional precision and safety while decreasing the morbidity associated with the TSFE approach.

Transcriptome analysis of osteogenic differentiation of human maxillary sinus mesenchymal stem cells using RNA-Seq

Recent studies have demonstrated that human maxillary sinus mesenchymal stem cells (hMSMSCs) have osteogenic potential and can be osteogenically induced. Here, we investigated pivotal molecular functions and candidates that contribute to the osteogenic differentiation of hMSMSCs. Human maxillary sinus membranes were harvested from 3 patients with jaw deformities. hMSMSCs from human maxillary sinus membranes were osteogenically induced for 0 or 21 days. Subsequently, their functional profiles were analysed by RNA sequencing and validated by quantitative PCR. Compared with control hMSMSCs, osteogenically induced hMSMSCs showed (1) osteogenic differentiation phenotype, as evidenced by the cell nodes, alizarin red staining, osteogenesis-related protein, and RNA expression; (2) accelerated osteogenic process of ossification and calcium signalling, as demonstrated by Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway; (3) enriched osteogenesis gene expression of SMOC2, OMD, IGF1, JUNB, BMP5, ADRA1A, and IGF2, which was validated by quantitative PCR. Based on by these results, we demonstrated that accelerated ossification process, calcium signalling, and upregulation of SMOC2, OMD, IGF1, JUNB, BMP5, ADRA1A and IGF2, may contribute to the osteogenic differentiation of hMSMSCs.

Maxillary sinus floor augmentation: a review of current evidence on anatomical factors and a decision tree

Maxillary sinus floor augmentation using lateral window and crestal technique is considered as predictable methods to increase the residual bone height; however, this surgery is commonly complicated by Schneiderian membrane perforation, which is closely related to anatomical factors. This article aimed to assess anatomical factors on successful augmentation procedures. After review of the current evidence on sinus augmentation techniques, anatomical factors related to the stretching potential of Schneiderian membrane were assessed and a decision tree for the rational choice of surgical approaches was proposed. Schneiderian membrane perforation might occur when local tension exceeds its stretching potential, which is closely related to anatomical variations of the maxillary sinus. Choice of a surgical approach and clinical outcomes are influenced by the stretching potential of Schneiderian membrane. In addition to the residual bone height, clinicians should also consider the stretching potential affected by the membrane health condition, the contours of the maxillary sinus, and the presence of antral septa when evaluating the choice of surgical approaches and clinical outcomes.

Intraosseous arterial alteration of maxilla influencing implant-related surgeries

OBJECTIVES

To investigate the intraosseous arterial pathways and anastomoses in the alveolar aspects of the maxilla in order to better understand the arterial scattering pattern.

MATERIALS AND METHODS

Eleven cadavers were selected for macroscopic intraosseous arterial analyses by corrosion casting. The red-colored acrylic resin was injected into the external carotid arteries. The specimens were kept in an enzymatic solution at 36 °C for about 60 days, depending on the process progression. After removal of the soft tissues and drying, the bone was macerated by potassium hydroxide to analyze the course and the mean diameters of the intraosseous anastomoses.

RESULTS

Vertico-oblique and horizontal intraosseous arteries and anastomoses between the greater palatine-, posterior superior alveolar-, and infraorbital arteries were detected. The vertico-oblique anastomoses were found on the anterolateral wall of the maxilla and the alveolar crest with a mean diameter of 0.46 mm; nevertheless, the horizontal (transalveolar) anastomoses were identified in the interdental septum/alveolar crest with the mean diameter of 0.41 mm. From the horizontal anastomoses, small intraseptal branches supplied the territory of the alveolar socket in various directions.

CONCLUSIONS

The localization of intraosseous arterial anastomoses is critical in implant-related surgeries, predominantly to maintain proper circulation.

CLINICAL RELEVANCE

Based on vertico-oblique and transalveolar anastomoses, simultaneous buccal- and palatal flap elevation (particularly on the palatal side) should be avoided to minimize patient morbidity and intra- or postoperative complications. Moreover, preserving transverse loops in the interdental septum is essential during implant surgeries, which can significantly influence collateral periosteal and osteal circulation to prevent ischemia.

Early tissue and healing responses after maxillary sinus augmentation using horizontal platelet rich fibrin bone blocks

BACKGROUND

The effects of horizontal platelet-rich fibrin (H-PRF) bone block on the healing and immune response during sinus augmentation have not been fully investigated histologically at early time points.

METHODS

Eighteenth male New Zealand white rabbits underwent bilateral sinus augmentation and were divided into two groups: deproteinized bovine bone mineral (DBBM) alone and H-PRF + DBBM (H-PRF bone block) group. Maxilla samples were collected at 3, 7 and 14 days post sinus augmentation procedures and analyzed using histological staining for the number of inflammatory cells, new blood vessels and evidence for early osteoclast bone turnover/remodeling. Furthermore, the effects of H-PRF bone blocks on the migration of osteoblasts and THP-1 macrophages were evaluated using a Transwell assay in vitro.

RESULTS

A higher number of immune cells were found in the H-PRF bone block group at 3 and 7 days post-surgery when compared to the DBBM alone group,most notably in the regions close to the mucosal lining and bone plates. Furthermore, a significantly greater number of new blood vessel formations and early signs of osteoclast development were found in the H-PRF bone block group at 14 days. The in vitro transwell assay further confirmed that culture medium from H-PRF bone block markedly promote the migration of osteoblasts and THP-1 macrophages.

CONCLUSIONS

The findings from this study have shown that H-PRF bone block is capable of increasing early immune cell infiltration leading to the acceleration of neovascularization and speeding the process of bone metabolism in vivo following maxillary sinus grafting with DBBM.

Six-year extension results of a randomized trial comparing transcrestal and lateral sinus floor elevation at sites with 3-6 mm of residual bone

OBJECTIVES

To comparatively evaluate the 6-year outcomes of transcrestal and lateral sinus floor elevation (tSFE and lSFE, respectively).

METHODS

The 54 patients representing the per-protocol population of a randomized trial comparing implant placement with simultaneous tSFE versus lSFE at sites with a residual bone height of 3-6 mm were invited to participate in the 6-year follow-up visit. Study assessments included: peri-implant marginal bone level at the mesial (mMBL) and distal (dMBL) aspects of the implant, proportion of the entire implant surface in direct contact with the radiopaque area (totCON%), probing depth, bleeding on probing, suppuration on probing, and modified plaque index. Also, the conditions of the peri-implant tissues at 6-year visit were diagnosed according to the case definitions of peri-implant health, mucositis, and peri-implantitis from the 2017 World Workshop.

RESULTS

Forty-three patients (21 treated with tSFE and 22 treated with lSFE) participated in the 6-year visit. Implant survival was 100%. At 6 years, totCON% was 96% (IR: 88%-100%) in tSFE group and 100% (IR: 98%-100%) in lSFE group (p = .036). No significant intergroup difference in patient distribution according to the diagnosis of peri-implant health/disease was observed. Median dMBL was 0.3 mm in tSFE group and 0 mm in lSFE group (p = .024).

CONCLUSIONS

At 6 years following placement concomitantly with tSFE and lSFE, implants showed similar conditions of peri-implant health. Peri-implant bone support was high in both groups and was slightly but significantly lower in tSFE group.

SinusC-Net for automatic classification of surgical plans for maxillary sinus augmentation using a 3D distance-guided network

The objective of this study was to automatically classify surgical plans for maxillary sinus floor augmentation in implant placement at the maxillary posterior edentulous region using a 3D distance-guided network on CBCT images. We applied a modified ABC classification method consisting of five surgical approaches for the deep learning model. The proposed deep learning model (SinusC-Net) consisted of two stages of detection and classification according to the modified classification method. In detection, five landmarks on CBCT images were automatically detected using a volumetric regression network; in classification, the CBCT images were automatically classified as to the five surgical approaches using a 3D distance-guided network. The mean MRE for landmark detection was 0.87 mm, and SDR for 2 mm or lower, 95.47%. The mean accuracy, sensitivity, specificity, and AUC for classification by the SinusC-Net were 0.97, 0.92, 0.98, and 0.95, respectively. The deep learning model using 3D distance-guidance demonstrated accurate detection of 3D anatomical landmarks, and automatic and accurate classification of surgical approaches for sinus floor augmentation in implant placement at the maxillary posterior edentulous region.

Minimally invasive techniques for lateral maxillary sinus floor elevation: small lateral window and one-stage surgery-a 2-5-year retrospective study

This study aimed to introduce a minimally invasive technique for maxillary sinus floor elevation using the lateral approach (lSFE) and to determine the factors that influence the stability of the grafted area in the sinus cavity. Thirty patients (30 implants) treated with lSFE using minimally invasive techniques from 2015 to 2019 were included in the study. Five aspects of the implant (central, mesial, distal, buccal, and palatal bone heights [BHs]) were measured using cone-beam computed tomography (CBCT) before implant surgery, immediately after surgery (T0), 6 months after surgery (T1), and at the last follow-up visit (T2). Patients' characteristics were collected. A small bone window (height, (4.40 ± 0.74) mm; length, (6.26 ± 1.03) mm) was prepared. No implant failed during the follow-up period (3.67 ± 1.75) years. Three of the 30 implants exhibited perforations. Changes in BH of the five aspects of implants showed strong correlations with each other and BH decreased dramatically before second-stage surgery. Residual bone height (RBH) did not significantly influence BH changes, whereas smoking status and type of bone graft materials were the potentially influential factors. During the approximate three-year observation period, lSFE with a minimally invasive technique demonstrated high implant survival rate and limited bone reduction in grafted area. In conclusion, lSFE using minimally invasive techniques was a viable treatment option. Patients who were nonsmokers and whose sinus cavity was filled with deproteinized bovine bone mineral (DBBM) had significantly limited bone resorption in grafted area.

Maxillary Sinus Augmentation Using Autologous Platelet Concentrates (Platelet-Rich Plasma, Platelet-Rich Fibrin, and Concentrated Growth Factor) Combined with Bone Graft: A Systematic Review

BACKGROUND

The current review aims to provide an overview of the most recent research on the potentials of concentrated growth factors used in the maxillary sinus lift technique.

MATERIALS AND METHODS

"PRP", "PRF", "L-PRF", "CGF", "oral surgery", "sticky bone", "sinus lift" were the search terms utilized in the databases Scopus, Web of Science, and Pubmed, with the Boolean operator "AND" and "OR".

RESULTS

Of these 1534 studies, 22 publications were included for this review.

DISCUSSION

The autologous growth factors released from platelet concentrates can help to promote bone remodeling and cell proliferation, and the application of platelet concentrates appears to reduce the amount of autologous bone required during regenerative surgery. Many authors agree that growth factors considerably enhance early vascularization in bone grafts and have a significantly positive pro-angiogenic influence in vivo when combined with alloplastic and xenogeneic materials, reducing inflammation and postoperative pain and stimulating the regeneration of injured tissues and accelerating their healing.

CONCLUSIONS

Even if further studies are still needed, the use of autologous platelet concentrates can improve clinical results where a large elevation of the sinus is needed by improving bone height, thickness and vascularization of surgical sites, and post-operative healing.

Efficacy of Two Different Hydrodynamic Sinus Lift Systems for Atraumatic Elevation in Immediate Implant Placement

Purpose

To evaluate the efficacy of two hydrodynamic sinus lifting procedures and to successfully place immediate implants in maxillary posterior sites that have a compromised native bone as a result of periodontal or endodontic disease.

Patients and Methods

A total of 26 patient sites were enrolled with 13 sites each in the Minimally Invasive Antral Membrane Balloon Elevation (MIAMBE) and Drill Integrated Hydrodynamics for the transcrestal sinus floor elevation (DIHSFE) groups who received transcrestal sinus floor elevation followed by immediate implant placement. Clinical parameters such as sinus membrane perforations, nasal bleeding, postoperative sinusitis, VAS scores at Day-7 for pain and discomfort, primary implant stability and time taken were evaluated.

Results

The DIHSFE had greater sinus membrane perforations and incidence of nasal bleeding when compared with MIAMBE with (p = 0.066) and (p = 0.141). Post-operative sinusitis was evident in both the groups with (p = 0.619). The mean VAS score was statistically significant between both the groups (p ≤ 0.005). The insertion torque values, and mean time taken for surgical procedure was not statistically significant between groups.

Conclusion

The present study highlighted that MIAMBE is superior to DIHSFE in its ability to cause less severe patient morbidities and post-operative complications.

Modified transcrestal sinus floor elevation with concomitant implant placement in edentulous posterior maxillae with residual bone height of 5 mm or less: a non-controlled prospective study

The aim of this study was to describe a modified transcrestal sinus floor elevation (mTSFE) technique and to evaluate its clinical effectiveness and reliability when residual bone height is severely reduced. Forty-three maxillary edentulous patients who met the inclusion criteria were enrolled. All patients underwent the mTSFE technique; 66 dental implants were inserted simultaneously. Patient-reported outcomes were assessed 2 weeks after surgery. Prosthetic crowns were placed 6 months after surgery. Radiographic analyses and clinical analyses were conducted to assess the clinical effectiveness and feasibility of mTSFE during a follow-up period of 2-8 years. The mean vertical bone increase after surgery was 8.09 mm, and it decreased to 6.56 mm at 6 months after surgery. Two cases of membrane perforation occurred during surgery and one implant was lost in the third year after surgery; the survival rate at the implant level was 98.48%. No severe postoperative complication was reported and the subjective feeling of patients was acceptable. This mTSFE technique could simplify the operative procedure and might be helpful to reduce intraoperative trauma, as well as to alleviate postoperative discomfort.

Effects of different grafting materials on volumetric changes in the Schneiderian membrane following lateral maxillary sinus floor elevation: a preliminary study

OBJECTIVES

To investigate the potential influence of different grafting materials on maxillary sinus membrane dimensions and ostium patency following lateral sinus floor elevation (SFE) as assessed using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

A total of 40 sinuses in 40 patients were included. Twenty sinuses were referred for SFE with deproteinized bovine bone mineral (DBBM), and the remaining 20 sinuses were grafted with calcium phosphate (CP). CBCT was performed prior to and 3 to 4 days after surgery. The dimensions of the Schneiderian membrane volume and ostium patency were evaluated, and potential relationships between volumetric changes and any associated factors were analyzed.

RESULTS

The median increase in membrane-whole cavity volume ratios was 43.97% in the DBBM group and 67.58% in the CP group, demonstrating no statistically significant difference (p = 0.17). The rates of increased obstruction after SFE were 11.1% for the DBBM group versus 44.4% for the CP group (p = 0.03). The graft volume was found to be positively correlated with the postoperative membrane-whole cavity volume ratio (r = 0.79; p < 0.01) and the membrane-whole cavity volume ratio increase (r = 0.71; p < 0.01).

CONCLUSIONS

The two grafting materials seem to have a similar effect on transient volumetric changes in the sinus mucosa. However, the choice of grafting material should still be made with caution since sinuses grafted using DBBM exhibited less swelling and less ostium obstruction.

Radiographic outcomes of lateral sinus floor elevation with and without bone window repositioning: one-year results of a randomized controlled trial

The objective of this study was to perform a comparative evaluation of the radiographic outcomes of lateral sinus floor elevation with and without bone window repositioning (BLSFE and LSFE, respectively) when applied concomitantly with implant placement. A randomized controlled clinical trial was conducted between February 1, 2016 and May 1, 2017 including 26 individuals with at least one missing tooth. Participants were randomized 1:1 to undergo BLSFE (10 participants, 16 implants) or LSFE (13 participants, 19 implants). Bovine-derived xenograft was used in both groups and the implants were inserted concomitantly. In the BLSFE group, the antrostomy was covered with a repositioned bone window and then with a concentrated growth factors (CGF) membrane. In the LSFE group, the antrostomy was covered with a CGF membrane. Panoramic radiographs were taken before surgery (T0), immediately postoperative (T1), and at 12 months postoperative (6 months after loading) (T2). Marginal bone loss (MBL), apical bone gain, augmented alveolar bone height, and intra-sinus bone augmentation were evaluated on panoramic radiographs at T2. A linear regression analysis with generalized estimating equation models was performed. The implant survival rate was 100% at 1 year after implant surgery. The residual alveolar bone height at T0 was comparable in the BLSFE and LSFE groups (3.58 ± 1.49 mm vs 4.12 ± 1.61, P = 0.32), as was the alveolar bone height at T1 (13.61 ± 1.82 mm vs 12.38 ± 1.82 mm, P = 0.06). At T2_, significantly higher alveolar bone height, intra-sinus bone augmentation, and apical bone gain, and lower distal MBL were observed in the BLSFE group when compared to the LSFE group, with adjusting for covariates (β = 2.44, 95% CI 1.42-3.46, P < 0.0001; β = 2.38, 95% CI 1.35-3.41, P < 0.0001; β = 2.33, 95% CI 1.23-3.42, P < 0.0001; and β = -0.43, 95% CI -0.83 to -0.02, P = 0.038, respectively). No significant difference was observed for mesial MBL or apical bone resorption at T2. Lateral sinus floor elevation with bone window repositioning may result in higher bone augmentation after 1 year than the traditional approach. Further research is needed to elucidate the effect of lateral sinus floor elevation with bone window repositioning.

Clinical and Radiological Evaluation of a Self-Condensing Bone Implant in One-Stage Sinus Augmentation: A 3-Year Follow-Up Retrospective Study

Stabilization of dental implants in the sinus region with a bone height below 4 mm gen-erally requires a two-stage sinus floor elevation surgery. To improve this aspect, the aim of this retrospective study was to demonstrate the feasibility of performing a one-stage maxillary sinus augmentation using an innovative self-condensing implant design, even in case of a bone height close to 2 mm. Clinical and radiological outcomes from 54 patients (26 females; 28 males; 69 total implants positioned) were analyzed 3 years post-surgery. The three-dimensional grafts change was evaluated by Cone-Beam Computed Tomography (CBCT) before surgery (T0), immediately after surgery (T1), and 1-year post-surgery (T2). The sinus floor levels measured at the medial (M-W), middle (MD-W), and lateral (L-W) walls reported: M-W of 1.9 ± 2.4 mm (T1) and 1.7 ± 2.6 mm (T2); MD-W of -0.1 ± 2.7 mm (T1) and 0.7 ± 2.4 mm (T2); L-W of 3.1 ± 3.0 mm (T1) and 3.1 ± 3.0 mm (T2); besides a bone crest height (C-F) of 4.6 ± 2.0 mm (T1) and 12.1 ± 1.4 mm (T2). Moreover, after 3 years only 1 implant was lost, and so an implant survival rate of 98.55% was recorded. In conclusion, these results suggest the efficacy of using this implant design for a one-stage sinus lift approach, not only in terms of increased implant survival rate and decreased marginal bone loss, but also for its potential applicability in case of reduced bone height.

Appropriate Implant Rehabilitation in Patients With Iatrogenic Oroantral Fistula and Odontogenic Maxillary Sinusitis

Oroantral fistula (OAF) is the most common etiology for odontogenic maxillary sinusitis that can be caused by tooth extractions, failed maxillary sinus lifts, bone grafts, and poor positioning of dental implant fixtures. A 52-year-old man presented with an OAF and maxillary sinusitis after implant placement and bone grafting. The authors treated the patient with modified endoscopic sinus surgery to obtain OAF closure and provided dental implant placement procedures afterward. The authors also treated 8 other similar cases with favorable outcomes. In this study, the authors report the know-how of implant placement procedures in patients with OAF and maxillary sinusitis.

Predictors of peri-implant bone remodeling outcomes after the osteotome sinus floor elevation: a retrospective study

BACKGROUND

This study aimed to evaluate the radiographic outcomes of implants after osteotome sinus floor elevation (OSFE), and further identify the separate predictors for these radiographic outcomes.

METHODS

In this retrospective cohort study, a total of 187 implants were inserted into 138 patients using the OSFE technique. Seventy-four patients in the grafted group, and 64 patients in the non-grafted group completed this study. The vertical bone gain (VBG) and marginal bone loss (MBL) at 3 years following surgery were assessed as outcome variables. Based on extensive literature results, variables considered potential predictors of outcome variables included sex, age, tooth position, implant length, implant diameter, with or without grafting materials, residual bone height, sinus width, bone density, and sinus membrane thickness. Subsequently, the binary logistic regression analysis was applied with VBG and MBL as dependent variables, respectively. The receiver operating characteristic curve (ROC) with its area under the curve (AUC) was performed to further determine the predictive value of these predictors.

RESULTS

One hundred and six implants in grafted group and 81 implants in the non-grafted group were analyzed. The average VBG was 2.12 ± 1.94 mm for the grafted group and 0.44 ± 1.01 mm for the non-grafted group at 3 years (P < 0.05). The mean MBL was 1.54 ± 1.42 mm for the grafted group and 1.13 ± 1.69 mm for the non-grafted group at 3 years (P > 0.05). After the adjustment for confounders, logistic regression analysis demonstrated that implant length, grafting, residual bone height, and sinus membrane thickness were predictors of VBG. The odds ratio for VBG was 3.90, 4.04, 4.13 and 2.62, respectively. Furthermore, grafting exhibited the largest AUC at 0.80. While tooth position and implant length were predictors of MBL, the odds ratio for MBL was 3.27 and 7.85, respectively. Meanwhile, implant length exhibited the largest AUC at 0.72.

CONCLUSIONS

OSFE with or without simultaneous grafting materials both showed predictable clinical outcomes. Additionally, the present study is the first quantitative and significant verification that VBG has a significant association with sinus membrane thickness, as well as residual bone height, implant length and grafting. Whereas tooth position and implant length are markedly associated with MBL.

Healing Patterns of Non-Collagenated Bovine and Collagenated Porcine Xenografts Used for Sinus Floor Elevation: A Histological Study in Rabbits

Objective: To compare healing of collagenated and non-collagenated xenografts used for maxillary sinus floor elevation. Materials and Methods: Two different xenografts were used: deproteinized bovine bone (DBBM group) and collagenated corticocancellous porcine bone (collagenated group). Healing was studied after 2, 4, and 8 weeks. The loss of dimensions of the elevated area and the percentages of new bone, xenograft remnants, osteoclastic zones, vessels, inflammatory infiltrates, and soft tissues were analyzed. Three regions were evaluated: close to the bone walls (bone wall region), subjacent the sinus mucosa (submucosa region), and the center of the elevated area (middle region). The primary variables were the percentage of new bone and xenograft remnants. Results: Between 2 and 8 weeks, the elevated areas showed a reduction of 16.3% and 52.2% in the DBBM and collagenated groups, respectively (p < 0.01 between the two areas after 8 weeks). After 8 weeks, the highest content of new bone was observed in the bone wall region, which was higher in the collagenated group than in the DBBM group (41.6% and 28.6%, respectively; p < 0.01). A similar quantity of new bone was found between the two groups in other regions. A higher percentage of vessels in all regions evaluated (p < 0.01) and soft tissue in the sub-mucosa region (p < 0.05) was found in the collagenated group than in the DBBM group. Conclusions: The present study showed that both xenografts allowed new bone formation. In comparison with the non-collagenated xenograft, the collagenated xenograft underwent higher resorption, resulting in greater shrinkage of the elevated space after sinus lifting and a higher content of new bone in the regions close to the bone walls. Clinical relevance: In this study, the region adjacent to the bone wall showed the highest new bone content. This region resembles the base of the sinus, closest to the sinus floor and walls, and is the most important region from a clinical point of view because it is where the implant will be installed. Residues of the biomaterial remained after 8 weeks of healing. Other reports have shown that these biomaterial residues may interfere with the integration of implants.

Clinical, Histological, and Radiological Outcomes of Sinus Floor Elevation Using a New Approach before Extraction of Periodontally Hopeless Maxillary Molars: A Case Report with 3-year Follow-Up

Introduction. This report is the first to present a case with 3-year follow-up, in which sinus floor elevation was performed before extraction of periodontally hopeless teeth, in order to shorten the edentulous interval between extraction and loading of implants and improve the patient’s quality of life. Case Presentation. After a series of initial and supportive periodontal therapies, the lateral window was created at the apices of the hopeless teeth, followed by grafting of bone substitute and membrane material at the sinus floor. The tooth was preserved for 13 months prior to extraction followed by immediate implant placement. The patient is satisfied with the oral function partially retained during the treatment period. Predominance of new bone was detected by histologic analysis. The available bone height was augmented from 1–2 to 12–14 mm with little resorption (less than 2 mm of height) after 3 years of follow-up. The dental implant is in good condition without obvious signs of peri-implantitis or mobility after 3 years of loading. Discussion. The feasibility of modified sinus floor elevation (MSFE) could be seen in the current case. The potential benefit of MSFE may include shortening the edentulous interval, facilitating bone regeneration, and providing a chance for immediate implant placement. However, further clinical case evaluations and controlled studies are required to determine indications, effectiveness, and safety of such augmentation procedures.

Short and Ultra-Short Implants, in Association with Simultaneous Internal Sinus Lift in the Atrophic Posterior Maxilla: A Five-Year Retrospective Study

Recent short-term studies suggested the use of short and ultra-short implants in association with a modified osteotome sinus floor elevation (internal sinus lift) technique for the treatment of edentulous resorbed posterior maxilla. The aim of this retrospective study was to investigate this hypothesis in locking-taper implants with a mid-term follow-up of 5 years. Overall, 155 implants (32, 100, and 23 of, respectively, 5.0 mm, 6.0 mm, and 8.0 mm length) were positioned in the atrophic upper maxilla of 79 patients, and 151 implants were loaded with single crowns. Overall implant survival after 5 years was 94.84%. Implant survival for each length group was 93.75%, 94%, and 100% for 5.0, 6.0, and 8.0 mm length, respectively. Preoperative residual crestal bone height of 4.45 (1.3) mm increased to 9.25 (2.13) mm after implant placement and settled at 6.35 (1.73) mm after loading and at 5.25 (1.68) mm at follow-up. Elevation of the Schneiderian membrane was 4.8 (2.46) mm after implant placement, 3.06 (1.3) mm after loading, and 1.46 (1.06) mm at follow-up. Mean variations of peri-implant crestal bone loss and first bone-to-implant contact point were, respectively, -0.36 (1.3) mm and -0.62 (1.15) mm. It can be confirmed that internal sinus lift procedure revealed stable bone gain and negligible resorption at mid-term follow-up for atrophic upper crests with reduced height.

Simultaneous placement of short implants (≤ 8 mm) versus standard length implants (≥ 10 mm) after sinus floor elevation in atrophic posterior maxillae: a systematic review and meta-analysis

Purpose

The objective of this meta-analysis was to compare the clinical outcomes of using short implants (≤ 8 mm) inserted with osteotome sinus floor elevation (OSFE) and standard implants (≥ 10 mm) inserted with sinus floor elevation (SFE) in atrophic posterior maxillae with insufficient residual bone height (RBH).

Methods

An electronic search was performed on PubMed, EMBASE, and the Cochrane Library from 1994 to July 2022, in combination with a manual search of references in relevant articles. Randomized controlled trials (RCTs) that compared the clinical results between short and standard implant placement with SFE were included. The primary outcomes were implant survival rate and marginal bone loss (MBL); the secondary outcome was complication rate.

Results

Three RCTs were included, totaling 138 short and 156 standard implants. The results of the meta-analysis showed no significant differences between the short and standard implant groups in survival rate (RR = 1.02, 95% CI   0.96–1.08, p = 0.570), MBL (MD = − 0.13, 95% CI   − 0.32 to 0.07, p = 0.190) and complication rate (intra-surgical complication: RR = 1.14, 95% CI   0.46–2.83, p = 0.770; post-operative complication: RR = 1.34, 95% CI   0.71–2.55, p = 0.370).

Conclusions

Using short implants (≤ 8 mm) combined with OSFE might be an alternative to standard implants (≥ 10 mm) with SFE when the RBH of the posterior maxilla is insufficient. Based on a short-term clinical observation, short implants with OSFE show good results in terms of survival rate, MBL, and complication incidence.

Graphical Abstract

Primary stability of different implant macrodesigns in a sinus floor elevation simulated model: an ex vivo study

BACKGROUND

A novel type of implant (Straumann® BLX implant) has been developed for certain stability from the mechanical and biological aspects and is expected for the implant placement in atrophic maxilla with sinus floor elevation (SFE).

PURPOSE

The aim of this study was to evaluate the primary stability in the implants with different macrodesigns in an SFE simulated model. Primary stabilities defined as maximum insertion torque (MIT) and implant stability quotient (ISQ) were compared between this novel type of implant and other types.

MATERIALS AND METHODS

Five types of Straumann® 10 mm length implants (Standard Plus; SP, Tapered Effect; TE, Bone Level; BL, Bone Level Tapered; BLT and BLX) and two types of Straumann® 6 mm length implants (SP short, BLX short) were used in this study. Each implant was inserted through 5 mm-thick porcine iliac crest blocks (an SFE simulated model). Primary stability was evaluated by using MIT and ISQ.

RESULTS

The mean value of MIT for BLX group showed significantly higher values than SP, BL (p < 0.01), and TE (p < 0.05) groups. The mean value of ISQ for BLX group was significantly higher than the other groups (p < 0.01). The mean value of MIT and ISQ for BLX and BLX short group were significantly higher than those for SP and SP short group (p < 0.01).

CONCLUSIONS

In an SFE simulated ex vivo model, BLX group showed the highest values. These results suggest that implant selection can play a crucial role in the achievement of primary stability during SFE and simultaneous implant placement.

Tilted Implants and Sinus Floor Elevation Techniques Compared in Posterior Edentulous Maxilla: A Retrospective Clinical Study over Four Years of Follow-Up

The aim of this study was to evaluate the implant survival rate, marginal bone loss, and surgical and prosthetic complications of implants placed through sinus floor elevation and tilted implants engaged in basal bone to bypass the maxillary sinus. Sixty patients were enrolled for this study. According to the residual bone height of the posterior maxilla, the sample was divided into three groups of 20 patients: Group A (lateral sinus floor elevation), Group B (transcrestal sinus floor elevation), and Group C (tilted implants employed to bypass the sinus floor). Follow-up visits were performed one week after surgery, at three and six months, and then once a year for the next 4 years. The outcomes were the implant survival rate, marginal bone loss, and surgical and prosthetic complications. Although Groups A, B, and C demonstrated implant survival rates of 83.3%, 86.7%, and 98.3%, respectively, the statistical analysis showed no statistically significant difference between groups. Statistically significant differences between groups were also not found concerning marginal bone loss, as recorded by intra-oral X-ray measurements during follow-up examinations. Regarding complications, it was not possible to perform a statistical analysis. To reduce possible surgical risks, implant placement in basal bone could be preferred.

Repositioning of the bone window in lateral sinus floor elevation with simultaneous implant placement: A retrospective radiographic study

OBJECTIVES

To retrospectively evaluate whether repositioning the bone window leads to a better outcome of three-dimensional sinus augmentation in lateral sinus floor elevation (LSFE) with simultaneous implant placement.

METHODS

34 patients with a total of 40 implants (14: test group, 26: control group) receiving LSFE with simultaneous implant placement were included in this retrospective research. CBCT images were taken before surgery, immediately and 6 months after surgery. The two-dimensional augmentation parameters, including apical bone height (ABH), endo-sinus bone gain (ESBG), and palatal/buccal bone height (PBH/BBH), and three-dimensional parameters, including augmentation volume (AV) and palatal/buccal augmentation volume (PAV/BAV), were measured. The lateral defect length (LDL) and lateral window length (LWL) were also measured to evaluate the lateral antrostomy recovery.

RESULTS

At the 6-month follow-up, the reduction rates at ABH, ESBG, and BBH of the test group (ABH: 10.41% ± 30.30%, ESBG: 2.55% ± 8.91%, BBH: 2.50% ± 8.65%) were significantly lower than those of the control group (ABH: 25.10% ± 22.02%, ESBG: 11.47% ± 9.79%, BBH: 7.10% ± 5.37%; p < .05). In addition, the test group showed better three-dimensional augmentation stability on the buccal side (BAV reduction: 15.51% ± 10.86% vs. 27.15% ± 12.61%; p < .05). Moreover, the LDL/LWL ratio of the test group was significantly lower than that of the control group (p < .05).

CONCLUSION

Within the limitations of this study, repositioning of the bone window in LSFE with simultaneous implant placement could contribute to endo-sinus augmentation stability on the buccal side at the 6-month follow-up. Moreover, it would also facilitate recovery of the lateral antrostomy defect.

Patient-reported outcome measures following surgeries in implant dentistry and associated factors: a cross-sectional study

OBJECTIVES

We aimed to evaluate the patient-reported outcome measures (PROMs) of dental implant surgeries and analyse the associated indicators.

DESIGN

A cross-sectional study design was used.

SETTING

Department of Oral Implantology, Hospital of Stomatology, Wuhan University (May 2020-April 2021).

PARTICIPANTS

Participants with missing teeth in need of implant-supported rehabilitation.

INTERVENTIONS

Dental implant placement and/or bone augmentation procedures.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was discomfort on postoperative day 1, measured using a numerical rating scale (NRS). Secondary outcomes included pain and anxiety during surgery; discomfort on postoperative days 3, 7 and 14; and post-surgical complications.

RESULTS

A total of 366 participants were included, of which 288 (78.7%) and 328 (89.7%) reported no to mild pain and anxiety (NRS 0-3) during surgery, respectively. The proportion of patients reporting discomfort decreased from postoperative day 1 (57.7%) to day 3 (36.1%) and day 7 (17.5%). The most frequent postoperative adverse events were pain and swelling. Patient-related factors (age, sex, smoking, alcohol consumption, history of periodontitis, and pain and anxiety during surgery) and surgery-related factors (type and extent of surgical procedure) were analysed. The factors associated with the severity of discomfort after surgery included alcohol consumption, pain perception during surgery, bone augmentation procedures and age (p<0.05). Similarly, the factors associated with the duration of discomfort included alcohol consumption, pain perception during surgery and age (p<0.05).

CONCLUSIONS

PROMs related to dental implant surgeries can be predicted using certain risk indicators. Alcohol consumption, pain during surgery and age were associated with discomfort following dental implant surgery.

Maxillary sinus floor augmentation comparing bovine versus porcine bone xenografts mixed with autogenous bone graft. A split-mouth randomized controlled trial

Aim

To compare the effectiveness of two xenografts for maxillary sinus floor augmentation in terms of clinical, radiographical, histologic, and molecular outcomes.

Materials and methods

A split‐mouth randomized clinical trial was conducted at the University of Granada. Ten consecutive patients in need of bilateral two‐staged maxillary sinus floor augmentation were included. Each patient received both biomaterials (porcine bone mineral and anorganic bovine bone), which were randomly assigned for bilateral sinus augmentation. The maxillary autogenous bone scraped from the sinus access window was mixed with each xenograft at a 20:80 ratio. After a healing period of 6 months, bone biopsies were collected with a trephine during the implant placement in the regenerated area. Histologic, histomorphometrical, immunohistochemical, and molecular outcomes were analyzed. Clinical and radiographical data throughout the treatment phases were also evaluated.

Results

The resulting anatomic features were similar between both groups. After six months of graft consolidation, the graft resorption rates were similar between both biomaterials. The histologic, histomorphometrical, and immunohistochemical results showed no statistical differences between groups.

Conclusion

Anorganic bovine bone and porcine bone mineral combined with maxillary autogenous cortical bone show similar biologic and radiologic features in terms of biomaterial resorption, osteoconduction, and osteogenesis when used for maxillary sinus floor augmentation.

Radiographic assessment of deproteinized bovine bone mineral (DBBM) and collagen-stabilized DBBM for transalveolar sinus floor elevation: A 2-year retrospective cohort study

BACKGROUND

Theoretically, collagen-stabilized deproteinized bovine bone mineral (DBBM-C) has better operability compared with DBBM. DBBM-C avoids dispersing during the transalveolar sinus floor elevation (TSFE) because of its block shape.

PURPOSE

To evaluate radiological changes of using DBBM-C in TSFE.

MATERIALS AND METHODS

Patients who received TSFE using DBBM (Bio-Oss®) or DBBM-C (Bio-Oss® collagen) with simultaneous implantation were recruited. Graft bone height apically (aGH), endo-sinus bone gain (ESBG), and crest bone level (CBL) were assessed through panoramic radiograph and cone beam computed tomography (CBCT).

RESULTS

A total of 138 patients (138 implants) were retrospectively enrolled. After 2 years of implantation, the incidence of postoperative complications was 4.2% (95% CI: 0.9%-11.7%) and 4.5% (95% CI: 0.9%-12.7%) for DBBM and DBBM-C groups, respectively. Measured in panoramic radiograph, ΔaGH of DBBM-C (1.8 mm, SD: 1.4, 95% CI: 1.2-2.4, P = 0.044) group was significantly higher than that of DBBM (1.2 mm, SD: 1.4, 95% CI: 0.7-1.7) after 24 months. No significant differences for ΔCBL were noted during the entire observation period. Measured through CBCT, ESBG was 5.0 (SD: 1.8, 95% CI: 4.1-5.8) mm in DBBM group and 4.6 (SD: 1.6, 95% CI: 3.9-5.3) mm in DBBM-C group 24 months after implantation. The aGH value of DBBM-C group was significantly higher compared with DBBM in CBCT (OR = 1.4, 95% CI: 1.1-1.9, P = 0.020).

CONCLUSIONS

DBBM-C could achieve similar bone generation as DBBM in TSFE. Both materials could maintain aGH, ESBG, and CBL relatively stable 2 years after implantation.

Effectiveness of hydraulic pressure-assisted sinus augmentation in a rabbit sinus model: a preclinical study

OBJECTIVES

To investigate the effectiveness of hydraulic pressure-assisted sinus augmentation (SA) in a rabbit sinus model in terms of radiographical and histological healing.

MATERIALS AND METHODS

Bilateral SA was performed in 12 rabbits. Each sinus was randomly assigned to either a hydraulic pressure-assisted SA (test) or a conventional SA (control) group. Healing periods of 2 and 4 weeks were applied (n = 6 for each week). Healing pattern including newly formed bone (NB) and residual bone substitute material (RM) was analyzed with microcomputed tomographically, histologically, and histomorphometrically.

RESULTS

No sinus membrane perforation was detected in either group. In the microcomputed tomographic analysis, the test group exhibited higher apico-coronal spread of RM compared to the control group (p < 0.05). Particularly, the test group exhibited several masses of NB out of the cluster of RM. Histologically, the test group showed an elongated shape of the augmented space, whereas the control group generally presented a dome shape. Histomorphometrically, the total augmented area and the area of NB (1.32 ± 0.56 vs. 0.84 ± 0.40 mm2 at 2 weeks, 2.24 ± 1.09 vs. 2.22 ± 0.85 mm2 at 4 weeks) were not significantly different between the test and the control groups at both healing periods (p > 0.05).

CONCLUSION

Hydraulic pressure-assisted SA led to new bone formation in the distant areas from the bony access hole, but similar histological healing pattern to conventional SA.

CLINICAL RELEVANCE

Hydraulic pressure-assisted SA is a promising option for treating pneumatized posterior maxilla.

Osteotome-Induced Blood Clot and Subsequent Bone Formation with the Use of Collagen Sponge for Integration of Single Dental Implants into the Atrophied Posterior Maxilla: A Retrospective Follow-Up of 36 Implants after 5 to 13 years

Background

Atrophy of the posterior maxilla as a consequence of tooth loss and sinus pneumatization is a frequent condition encountered in the clinical practice. Prosthetic rehabilitation with implants in these patients often requires some kind of bone regeneration procedure to increase the bone volume.

Aim

The aim of the present retrospective study is to analyze the survival and success rates of a series of implants placed in the atrophic posterior maxilla with a transcrestal osteotome procedure, without placing a bone grafting material.

Materials and Methods

From 2006 to 2014, 36 dental implants (Neoss Ltd., Harrogate, UK) were inserted in 36 patients with at least 4 mm of bone below the maxillary sinus using transcrestal osteotome sinus floor elevation and placement of collagen sponge below the sinus membrane. ISQ measurements were made after implant placement and at abutment surgery after 4 to 6 months. The vertical bone height (VBH) was evaluated in intraoral radiographs taken prior to surgery and in radiographs from annual check-up appointments 5 to 13 years after implant placement. In addition, marginal bone loss (MBL) was evaluated.

Results

One implant was lost after four years of prosthetic loading. The remaining 35 implants showed no complications and were loaded with single crowns after 4–6 months of healing. All 35 implants showed clinical success after 8.5 ± 2.8 years of prosthetic loading (from 5 to 13 years). The vertical bone height was 5.9 ± 1.4 mm at surgery, 9.7 ± 1.1 mm at second surgery after 4–6 months, and 8.3 ± 1.8 at the follow-up at 8.5 ± 2.8 years (from 5 to 13 years). The implant stability registered was 73.2 ± 6.2 ISQ at the surgery and 75.8 ± 3.9 at the second surgery after 4–6 months.

Conclusions

The present long-term follow-up study showed that the crestal approach for sinus floor bone augmentation without additional bone grafting results in predicable bone formation and high implant survival. The osteotome technique is a valid alternative to the more invasive lateral window technique in single cases with a minimum of 4 mm of VBH below the maxillary sinus.