Long-Term Outcomes for the Treatment of Atrophic Posterior Maxilla: A Systematic Review of Literature

Pterygoid implant: extensometric and photoelastic analysis of a maxillary rehabilitation model

Pterygoid implants have been demonstrated to have a high success rate. Nevertheless, there are few biomechanical tests to evaluate the tensile forces induced by force dissipation in peri-implant tissues. This study employed photoelasticity and extensometry to demonstrate and compare the biomechanical behavior of non-axial implants in a pterygoid model and a conventional model of oral rehabilitation, thus allowing for qualitative and quantitative analysis. Two models received an implant measuring 3.75 x 13 mm in the canine pillar at a 90 ° angle to the Frankfurt plane. In the control group, an implant with a diameter of 3.75 mm and a length of 11 mm was placed in the maxillary tuberosity parallel the medial implant. In the study group, an implant with a diameter of 3.75 mm and a length of 11 mm was installed with an angulation of 45 degrees in the antero-posterior direction and 15 degrees in the buccal-palatal direction, with apical anchorage in the pterygoid process of the sphenoid bone. In the extensometric analysis, the models were subjected to five cycles of repeated axial tensile loading (100 N) at a rate of 0.5 mm/min. A computer was connected to the amplifier in order to record the output signal of the polyurethane surface, and the acquisition system software was employed to record the data. The data were analyzed in accordance with data distribution, as determined by the Shapiro-Wilk test and equality of variance. Subsequently, the data were classified according to the variables. The Student's t-test was employed when normal distribution of variances was identified, whereas the Mann-Whitney U test was utilized for data with non-normal distribution. A 5% significance level was employed. In the photoelastic analysis, replicas of both configurations were produced using photoelastic resin. The models were subjected to a single axial loading cycle, with a load of 100 N applied at a rate of 0.5 mm/min, and the resulting stress was observed under a circular polariscope. Photographs were taken at two time points: before and after loading. These images were then processed by the same operator using a computer graphics program, allowing for a more straightforward analysis of stress distribution. This was achieved by the formation of isochromatic fringes. The results of the strain gauge analysis revealed no statistically significant differences between the two groups (p = 0.37) or between the anterior (p = 0.08) and posterior (p = 0.74) implants. The photoelasticity analysis revealed the presence of high-intensity isochromatic fringes at the apex of the axial implant in the control model, as well as in the cervical-distal and apical regions of the pterygoid implant, where a high concentration was also observed. Although no statistically significant results were obtained from the quantitative analysis, our findings suggest that the favorable outcomes observed in the clinical studies are due to the high force dissipation observed in the pterygoid plate, which is composed of dense cortical bone.

Bone Regeneration After Sinus Floor Elevation in an Intact Sinus or a Sinus With Prior Large Membrane Perforation: A Preclinical Study Using a Rabbit Sinus Model

AIM

To determine bone regeneration following sinus floor elevation (SFE) at sites with or without prior sinus membrane perforation.

MATERIALS AND METHODS

The sinus membranes in the maxillary sinuses of 12 rabbits were intentionally perforated (≥ 5 mm) on one side, followed by application of a collagen matrix. SFE was performed on both sinuses after 8 weeks of healing, presenting two groups: SFE with a previous large sinus membrane perforation (group SFE_Perf), and in an intact sinus (group SFE). The animals were euthanized at 2 and 4 weeks after SFE. Micro-computed tomographic and histomorphometric analyses were performed.

RESULTS

The amount of newly formed bone within the augmented area did not differ significantly between the two groups at 2 weeks and 4 weeks (4.7 ± 1.0 mm2 vs. 5.3 ± 1.4 mm2 and 9.2 ± 1.7 mm2 vs. 10.8 ± 2.2 mm2, respectively, mean ± SD; p > 0.05). However, the amount of newly formed bone near the middle of the sinus membranes was significantly greater in group SFE than in group SFE_Perf (p < 0.05). There was no significant difference in the augmented volume. Fewer subepithelial glands and denser collagen fibres within the sinus membranes were observed in group SFE_Perf than in group SFE.

CONCLUSIONS

A large perforation of the sinus membrane followed by an 8-week healing period did not jeopardize new bone formation following SFE.

The Rehabilitation of Partially Edentulous Maxilla With Unilateral Zygomatic Implants: A Retrospective Study up to 23 Years Follow-Up

OBJECTIVES

This retrospective study aimed to evaluate the clinical outcomes associated with zygomatic implant (ZI) rehabilitation in partially atrophic edentulous maxillae over a mean follow-up period of more than 10.3 years.

METHODS

All consecutive patients underwent ZI rehabilitation between 1999 and 2020, with a minimum follow-up period of 3 years. The primary outcome was the implant survaival rate. Secondary outcomes included the prosthesis success rate, complications, and Oral Health-Related Quality of Life.

RESULTS

Of the 21 patients, treated with 27 ZIs and 48 conventional implants (CIs), 9 (42.9%) were females. The mean follow-up was 10.3 ± 5.7 years (range 3.2-23.4). ZI and CI survival rates were 100% and 97.9%, respectively, with one CI that failed. Eleven patients received 12 CIs placed in the pterygoid and tuberosity region. Most of the implants (81.33%) were immediately loaded, with 17 patients (80.9%) receiving 21 acrylic bridges. Of the total of 26 definitive prosthesis, the success rate was 96.1%. Local inflammation (n = 2) and soft tissue recession (n = 1) were reported as complications, occurring at a mean follow-up of 4.5 and 3.2 years, respectively. The mean score of the OHIP-14 questionnaire was 1.19 ± 1.99.

CONCLUSIONS

Unilateral ZI rehabilitation was a predictable option for patients with partially atrophic edentulous maxilla who have experienced previous graft or implant failures, or who require immediate loading. Splinting the ZI with CI for restoration appeared to be essential in unilateral ZI treatment. Complications were infrequent and could be managed effectively, with patient-reported outcomes indicating normalization in quality of life.

Osseodensification technique in crestal maxillary sinus elevation-A narrative review

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

Long-Term Clinical Outcomes of Transalveolar Maxillary Sinus Floor Elevation with Rotatory Instruments: An 8-Year Follow-Up Prospective Clinical Study

Background: Transalveolar sinus floor elevation (TSFE) is a surgical technique for the placement of dental implants in patients with reduced height of the maxillary posterior alveolar bone. This study aims to demonstrate the clinical outcomes of TSFE using the minimal invasive sinus elevation (MISE) technique in partially and totally edentulous maxillary patients. Methods: This prospective clinical study followed STROBE guidelines. TSFE was performed using the MISE technique with the simultaneous placement of implants. Dental implants were loaded at 6 months. Maxillary vertical bone gain was measured by CBCT, and marginal bone loss was assessed by periapical radiographs. Results: Ninety-one patients, with a mean age of 62.1 ± 11.8 years, were treated with TSFE and the placement of 107 implants, with a mean follow-up of 96.2 ± 11.7 months. An increase of 4.3 ± 0.4 mm in bone height was achieved, with a dental implant cumulative survival rate of 97.2%. Peri-implantitis was observed in 9.3% of implants, and membrane perforation occurred in 7.7% of cases. Technical complications were noted in 5.5% of patients. Conclusions: Within the limitations of this clinical study, it can be concluded that the MISE technique is a successful protocol for the placement of implants in the posterior maxilla with reduced height of the alveolar ridge, with a rate of biological and prosthetic complications below 10% over an average follow-up period of 8 years.

Mucosal cyst aspiration in conjunction with maxillary sinus elevation: A clinical cohort study

INTRODUCTION

Patients with mucosal cysts in the maxillary sinus require special consideration in patients who require implant therapy for the restoration when undergoing implant therapy for the restoration of the posterior maxillary dentition. Treatment strategies for these clinical situations remain controversial in the literature. Thus, this study seeks to describe a safe and effective therapeutic strategy for sinus augmentation in patients with pre-existing maxillary antral cysts.

METHODS

A total of 15 patients and 18 sinuses were consecutively enrolled in this cohort study and underwent maxillary antral cyst treatment by needle aspiration and simultaneous maxillary sinus augmentation (MSA). During surgical procedures, threeimplants (Zimmer Biomet, Indiana, USA) were positioned in 11 sinuses and two implants (Zimmer Biomet, Indiana, USA) were positioned in 5 sinuses.

RESULTS

Overall implant success and survival rates were 100% and 97.8%, respectively at 1 year and 5-year follow-ups. Crestal bone resorption averaged 0.3 ± 0.2 mm 5-year post-loading, showing bone stability. Implant survival rate at 5-year follow-up expressed predictability of the technique comparable to historical data when MSA was performed alone. Crestal bone resorption averaged 0.3 ± 0.2 mm 5 years post-loading and shows bone stability utilizing mucosal cyst aspiration with concomitant MSA procedures. Quality of life evaluation at 1-week post-op showed similar results to published historical data. In 81% (13 sinuses), the CBCT examination at 5-year follow-up showed no cyst reformation, in 19% (3 sinuses) cyst reformation was visible, but smaller in size when compared to the pre-op CBCT evaluation, and all the patients were asymptomatic.

CONCLUSIONS

Maxillary sinus mucosal cyst aspiration with concomitant MSA, may be a viable option to treat maxillary sinus cyst.

Osseodensification versus lateral window technique for sinus floor elevation with simultaneous implant placement: A randomized clinical trial on patient-reported outcome measures

OBJECTIVES

To compare patient-reported outcome measures and additional surgical outcomes after sinus floor elevation (SFE) with osseodensification (OD) versus lateral window (LW), both with simultaneous implant placement.

MATERIALS AND METHODS

Twenty participants requiring single-implant rehabilitation with residual bone height (RBH) ≤4 mm were enrolled. Pain experience, quality of life (QoL) via the Oral Health Impact Profile-14 (OHIP-14), analgesics intake, and other symptoms were self-reported for a week on a daily basis. Surgery duration, complications, and implant stability quotient at baseline (ISQ T0 ) and after 6 months (ISQ T6 ) were registered. Participants were followed up for 1 year.

RESULTS

From Day 0 (day of surgery) to Day 3, pain experience was significantly lower (p < 0.05) in the OD group. OHIP-14 score was significantly lower (p < 0.05) in the OD group on all postoperative days, except on Day 5. Average analgesics intake was significantly lower (p < 0.001) in the OD group. Surgery mean duration was significantly higher (p < 0.001) in LW compared to OD (71.1 ± 10.4 vs. 32.9 ± 5.3 min). After osseointegration period, all implants were successfully restored with screw-retained crowns.

CONCLUSIONS

Within the limitations of this study, it can be concluded that OD and LW techniques were similarly effective in SFE with simultaneous implant placement when RBH ≤ 4 mm. However, OD significantly outperformed LW in pain experience, impact on self-perceived QoL, surgery duration, postoperative edema, and analgesics intake.

Evaluation of two treatment concepts of four implants supporting fixed prosthesis in an atrophic maxilla: finite element analysis

BACKGROUND

Currently, oblique placement of long implants or the use of short implants to circumvent the maxillary sinus area and provide support for fixed prostheses are viable alternatives. The purpose of this study was to compare these two treatment concepts and ascertain which one exhibits superior biomechanical characteristics.

METHODS

Two different treatment concept models were constructed. The first one, LT4I, consisting of two mesial vertical implants positioned in lateral incisor regions and two distal tilted implants (45°) situated in second premolar regions of the maxilla. The second model, VS4I, includes two mesial vertical implants in lateral incisor regions and two vertically positioned short implants in second premolar regions. Numerical simulations were conducted under three loading types: firstly, oblique forces upon the molars; secondly, vertical forces upon the molars; thirdly, oblique forces upon the incisors. The maximum principal stress (σmax) and minimum principal stress (σmin) of the bone, as well as von Mises stress of the implants, were calcuated.

RESULTS

Under oblique loading on the molar, higher stress values in the bone were observed in LT4I group. Under vertical loading on molar, higher stress values in the bone were also observed in LT4I group. Furthermore, little difference was found between the two groups under oblique loading on the incisor.

CONCLUSION

Both treatment concepts can be applicable for edentulous individuals with moderate atrophic maxilla. Compared to tilted implants, short implants can transmit less occlusal force to the supporting tissues.

A Study of Two Novel Techniques for One-stage Closure of Chronic Oroantral Fistula and Sinus Floor Lift

PURPOSE

This study aimed to compare two novel techniques for chronic oroantral fistula (OAF) closure combined with maxillary sinus floor elevation.

MATERIALS AND METHODS

Ten patients who had implant installation needs but suffered from a chronic OAF were enrolled in the study from January 2016 to June 2021. The technique applied involved OAF closure and simultaneous sinus floor elevation by either a transalveolar or lateral window approach. Bone graft material evaluation results, postoperative clinical symptoms and complications were compared between the two groups. Student's t -test and χ 2 test were used to analyze the results.

RESULTS

In this study, 5 patients with a chronic OAF were treated with the transalveolar approach (group I), and 5 were treated with the lateral window approach (group II). The alveolar bone height was significantly higher in group II than in group I ( P ＜0.001). The pain at 1 day ( P =0.018) and 3 days ( P =0.029) postoperatively and facial swelling at 7 days ( P =0.016) postoperatively were obviously greater in group II than in group I. There were no severe complications in either group.

CONCLUSIONS

The techniques combined OAF closure with sinus lifting to reduce surgical frequency and risks. The transalveolar approach resulted in milder postoperative reactions, but the lateral approach could provide more bone volume.

Correlation between periodontal phenotype and sinus membrane thickness: A systematic review

AIM

To assess the correlation between the periodontal phenotype (PP) and sinus membrane thickness (SMT) in humans.

METHODS

This review was conducted according to the PRISMA guidelines. Two reviewers independently carried out electronic and manual literature searches of studies published in English, German, and Spanish, from 1970 to September 2022 in four electronic databases, PubMed/Medline, Scopus, Cochrane Library, and Web of Science, in addition to gray literature. Studies that assessed the correlation between PP and SMT in adults (aged 18 years) were included. Methodological quality was evaluated using the Appraisal Tool for Cross-Sectional Studies (AXIS) for articles that met the eligibility criteria.

RESULTS

Six studies, including 510 patients, were considered for qualitative analysis. All included studies were cross-sectional, and the correlation between the PP and SMT was evaluated, finding a positive and high correlation in 83.3% of them, based on a value of ≥0.7. All the included studies were assessed with a high overall risk of bias.

CONCLUSIONS

Periodontal phenotype and sinus membrane thickness are likely correlated. Nevertheless, further standardized studies are required to draw definitive conclusions.

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.

The use of autologous bone for augmentation procedures leads to low prevalence of peri-implantitis-a retrospective study over a 20-year period

The aim of this study was to compare the prevalence of peri-implantitis in implants inserted into pristine bone (control) to implants where autologous bone was used for grafting procedures (study). All patients who underwent implant surgery during a 20 years interval by one maxillofacial implant surgeon and received a prosthodontic rehabilitation afterwards were eligible for inclusion in the study. Periimplant bone resorption and periimplant disease were assessed. Of 421 patients 384 (91.2%) patients responded to a recall after having been treated over a 20-year period by one maxillofacial surgeon and several dentists. A total of 110 patients had 239 implants in pristine bone, and 274 patients had 607 implants placed in combination with autologous bone grafting procedures. Mean time in function was 74 months (range 15-236 months). In all, 342 implants (34.8%) were in function for longer than 7 years. A total of 64 implant sites (7.6%) in 39 patients (10.2%) showed signs of peri-implant mucositis. In addition, 17 implants (2.0%) in 14 patients (3.6%) revealed signs of peri-implantitis, of which five implants were in the control group (2.09%) whereas 12 implants were in the study group (1.98%), with no statistically significant difference (p = 0.8405). More than half of the patients with peri-implantitis had a history of periodontitis. Three implants were lost due to peri-implantitis and four implants failed for other reasons, resulting in an overall success rate of 99.2% in 846 implants. CONCLUSIONS: Within the limitations of the study it seems that the use of autologous bone still is a relevant option when performing augmentation procedures because of the low prevalence of peri-implantitis.

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

Clinical and radiographic outcomes of dental implant after maxillary sinus floor augmentation with rhBMP-2/hydroxyapatite compared to deproteinized bovine bone

Objectives

This study aimed to evaluate the clinical and radiographic outcomes of early implant placement and functional loading in maxillary sinus floor augmentation (MSFA) using recombinant human bone morphogenetic protein 2/hydroxyapatite (rhBMP-2/HA) and to compare these outcomes with those of the conventional protocol in MSFA using deproteinized bovine bone (DBB).

Materials and methods

The rhBMP-2/HA and DBB groups consisted of 14 and 13 patients who underwent MSFA with BMP and DBB, respectively. After placement of 22 implants and 21 implants in the rhBMP-2/HA and DBB groups, respectively, abutment connections were performed 3 months after implant placement for the rhBMP-2/HA group and 6 months after implant placement for the DBB group. Changes in grafted sinus height (GSH), marginal bone loss (MBL), and implant stability were evaluated up to one year after functional loading.

Results

Survival rates for the rhBMP-2/HA and DBB groups after one year of functional loading were 90.9% and 90.5%, respectively. Both groups exhibited no significant time-course changes in GSH until one year of functional loading (rhBMP-2/HA, p = 0.124; DBB, p = 0.075). Although significant MBL occurred after one year of functional loading for both groups (rhBMP-2/HA, p < 0.001; DBB, p < 0.001), there were no significant differences in time-course changes in MBL between the two groups (p = 0.450). The mean implant stability quotient values in the rhBMP-2/HA and DBB groups were 75.3 and 75.4 after one year of functional loading, respectively, and there were no significant differences between the two groups (p = 0.557).

Conclusions

MSFA using rhBMP-2/HA allowed implant rehabilitation with early implant placement and functional loading and led to a comparable survival rate and implant stability after 1 year of functional loading with acceptable MBL and stable maintenance of GSH compared to the MSFA using DBB with 6 months of healing after implant placement.

Evaluation of crestal sinus floor elevations using versah burs with simultaneous implant placement, at residual bone height ≥ 2.0 _ < 6.0 mm. A prospective clinical study

PURPOSE

To evaluate the efficacy of Versah drills in breaching the maxillary sinus floor while keeping the membrane intact, as well as measure the implant stability (primary stability at the time of implant placement by the osseous densification of the residual bone height (RBH) of ≥ 2.0 _ < 6.0 mm, and secondary stability after 6 months of osseous healing period).

METHODS

This prospective clinical study, which included twenty crestal sinus floor elevations, was conducted on 17 patients (10 males and 7 females, ages 29 to 70 years). The sinus membrane integrity was clinically checked at the time of osseodensification sinus lifting and confirmed by CBCT after sinus augmentation and implant insertion. Time of operation has been recorded from the first drill to implant installation. Primary implant stability was measured using an Osstell beacon at the time of implant placement, and secondary stability was measured after 6 months of osseous healing.

RESULTS

The mean of secondary stability in the current study is significantly higher than the mean of primary stability (P ≤ 0.011), which was 74.22 ± 8.11 and 69.85 ± 9.74, respectively, in RBH 3.81 mm as a mean. There was no clinical evidence of membrane perforation or complication reports, and the average operation time was 11.2 ± 1.85 min.

CONCLUSION

The current study found that at highly atrophic posterior maxilla with a residual bone height of ≥ 2.0 _ < 6.0 mm, osseodensification using Versah drills was effective in crestal sinus elevation with no membrane perforation, which was confirmed by cone-beam CT scan postoperatively, and showed higher primary and secondary implant stability.

Flapless osteotome-mediated sinus floor elevation using platelet-rich fibrin versus lateral approach using deproteinised bovine bone mineral for residual bone height of 2-6 mm: a randomised trial

OBJECTIVES

To evaluate patient-reported outcomes and radiographic results of simultaneous implant placement in severely atrophic maxilla using flapless endoscope-assisted osteotome sinus floor elevation with platelet-rich fibrin (PRF), also defined as PESS, and to compare the results with those of lateral sinus floor elevation (LSFE).

METHODS

Patients with a residual bone height (RBH) of 2-6 mm were included in a randomised controlled trial. PESS was performed with PRF as the sole grafting material. LSFE was performed using deproteinised bovine bone matrix. Patient-reported outcomes were recorded on a visual analogue scale (VAS-pain) and visual rating scale (VRS-swelling and VRS-willingness). Peri-implant bone height (PBH), bone mineral density (BMD), and sinus grafting remodelling index were measured using CBCT immediately postoperatively and 3^rd , 6^th and 18^th months post-surgery.

RESULTS

The study population consisted of 20 patients in each group. The RBH of two groups averaged 3.35±0.79 mm and 2.92±0.63 mm with no significant difference (p > 0.05). VAS-pain was 18.0 (IR 15.0-22.5) and 35.0 (IR 32.5-37.0) in the PESS and LSFE groups, respectively (p < 0.01). VAS-pain decreased with time in both groups. VRS-swelling was lower in the PESS group than LSFE group. VRS-willingness was higher in the PESS group than LSFE group (p < 0.01). At 18 months post-surgery, the marginal bone loss was 0.60±0.25 mm and 0.69±0.35 mm in the two groups with no significant difference (p = 0.52).

CONCLUSIONS

Within the limitations of this study, PESS was associated with lower postoperative morbidity and was more tolerable than LSFE. PESS could be a reliable procedure for sinus floor elevation in patients with insufficient RBH.

Retrospective Analysis of Clinical and Radiologic Data Regarding Zygomatic Implant Rehabilitation with a Long-Term Follow-Up

BACKGROUND

Zygomatic implants have been introduced to rehabilitate edentulous patients with severely atrophic maxillae. Their use has been reported by several studies, describing high overall survival rates at medium-long follow-up. The aim of this study was to retrospectively analyze if a few patient-related and implant-related features are correlated with implant success or the onset of complications.

MATERIALS AND METHODS

Data of patients treated with zygomatic implants between May 2005 and November 2012 at three private clinics were collected and retrospectively analyzed. For each implant, the following data were collected: implant length, insertion path, ridge atrophy and sinus characteristics (width, pneumatization, thickness of mucosae, patency of sinus ostium). General patient characteristics and health status data were also recorded. The outcomes evaluated were implant failure, infective complications, early neurologic complications and overall complications.

RESULTS

A total of 33 patients (14 men, 17 women, mean age 59.1) that received 67 zygomatic implants were included in the study. The mean duration of the follow-up was of 141.6 months (min 109; max 198). In this period, a total of 16 (23.88%) implants in 8 (24.24%) patients were removed and 17 (51.51%) patients with 36 (53.73%) implants reported complications. Immediate loading resulted in a significantly lower risk of complications compared with the two-stage prosthetic rehabilitation (OR: 0.04, p = 0.002). A thickness of the sinus mucosa > 3 mm emerged to be correlated with a greater occurrence of infective complications (OR: 3.39, p = 0.019). Severe and extreme pneumatization of the sinus was significantly correlated with the incidence of overall complications (p = 0.037) and implant failure (p = 0.044). A large sinus width was predisposed to a higher risk of neurologic complications, infective complications and implant failure (p = 0.036, p = 0.032, p = 0.04, respectively).

CONCLUSIONS

zygomatic implants are an alternative procedure for atrophic ridge rehabilitation when a conventional implant placement is not possible. Several clinical and anatomical factors can have a significant role in complication occurrence.

Influence of the Use of a Collagen Membrane Placed on the Bone Window after Sinus Floor Augmentation-An Experimental Study in Rabbits

BACKGROUND

We studied the influence on healing of a resorbable membrane covering the osteotomy site after maxillary sinus grafting, evaluated in different regions of the augmented area.

METHODS

Maxillary sinus augmentation was performed in 24 New Zealand rabbits. Osteotomy, 4 × 6 mm, were performed bilaterally. A collagenated cortico-cancellous porcine bone was used to fill the elevated region. A collagen membrane was randomly placed over the osteotomy site on one side (MG), and the other side was left uncovered (NMG). The animals were euthanized after 2, 4, and 8 weeks; and histomorphometric analysis was performed in eight different regions.

RESULTS

New bone percentages were similar in both groups. There were no statistically significant differences. In MG, the overall percentages were 15.6 ± 7.3%, 22.9 ± 6.1%, and 24.9 ± 12.0% after 2, 4, and 8 weeks, respectively. In NMG, the percentages were 11.2 ± 4.5%, 24.1 ± 5.7%, and 24.5 ± 15.7%, respectively. The proportions of new bone in the various regions after 8 weeks were 31 ± 8.9% and 29.9 ± 9.1% in the bone walls region, 25 ± 10.1% and 32.8 ± 9.1% in the submucosa region, 22.6 ± 21.6% and 10.9 ± 11.5 in the middle region, 17.3 ± 14% and 13.4 ± 9.8% in the close-to-window region, and 21.8 ± 11.6%, 19.1 ± 6.4% in the osteotomy region-for MG and NMG, respectively.

CONCLUSIONS

In both groups the greatest amounts of bone formation occurred near to the pre-existing bone walls, followed by the sub-mucosa region. The smallest amounts were found in the close-to-window region, followed by the central region. The placement of a collagen membrane to cover the osteotomy site did not influence the amount of new bone formation after sinus grafting.

Posterior jaws rehabilitation with < 7mm-short implants. A review

INTRODUCTION

The results with shorter and shorter implants have been revolutionizing the implantology scenario and are worthy of being well-analyzed and understood. This review aims to add further knowledge about the last 10-years observation period on < 7mm-short implants in the posterior atrophic jaws, better defining the indication of their use.

METHODS

From a Medline database research, systematic reviews, controlled and no- controlled trials (CT, n-CT) with ≥ 3years-follow-ups on <7 mm / ≥ 5mm-short implants (group A), and clinical studies with ≥ 1year-follow-up on 4mm-short implants (group B) were considered. The outcomes, in terms of implant survival rate (SR), marginal bone loss (MBL), and complications were analyzed according to the duration of follow-ups, implant site (maxilla and mandible), type of prosthesis (single crown or splinted units), vertically impaired or normal sites.

RESULTS

Thirty-four trials (28 for group A and six for group B) were selected. Group A: a mean follow up of 5,8 (3-10) years came out; pre-and post-loading SR range was 94.4- 100% and 89.6-100%, respectively; the range of MBL was 0.12-1.49; 50% of CT found less statistically significant surgical complications in comparison with standard implants (ST) in reconstructed sites, while major prosthetic problems were recorded with short -implants (SH) in 37.5% of CT; in no atrophied sites, a mean SR range of 86.7-100 % vs. 88-100 % and a total bone loss of 2 vs.1.6 for SH vs.ST emerged. Group B: the overall mean follow-up period was 2,3 years, and the pre-and post- SR ranges were 93-100 % and 87.5-100 %, respectively. The MBL range was 0.02- 0.63 mm. All RCT reported significantly fewer surgical complications with SH than with ST in reconstructed mandibles within one year. No prosthetic complications were reported for up to 5 years using no pontics or cantilevers fixed bridges.

CONCLUSIONS

Similar or even better results for SH than ST in terms of post-loading SR and MBL came out for < 7mm/ ≥ 5mm-short implants in atrophic bone regardless of the prosthetic solutions, with less surgical complications but a few more prosthetic problems; the good results up to 5 years for 4mm-short implants in mandibles are associated with splinted and no-risk prosthetic solutions.

Immediate Oral Rehabilitation With Quad Zygomatic Implants: Ultrasonic Technique vs Conventional Drilling

Inserting zygomatic implants is a challenging surgery and requires special care and great precision. Piezoelectric surgery offers several advantages: more precise bone cutting with improved intraoperative visibility and a low temperature increase. The aim of this case-control study was to evaluate whether ultrasonic instruments can be as effective as standard drilling instruments for zygomatic implant surgery in terms of clinical outcomes. Ninety-two patients with atrophic maxilla were included in the study. Implant sites were prepared with the ultrasonic technique (test group = 47 patients) or traditional drilling (control group = 45 patients). In total, 368 zygomatic implants were inserted (202 with the extrasinus technique, 77 with the sinus slot technique, and 89 with the Brånemark technique). Complete arch provisional prostheses were delivered 3 to 5 hours after the surgical operations. The mean follow-up after surgery was 24 months (range = 12-32 months). The primary outcome evaluations were based on implant survival rates and postoperative complications. Operative time and surgeon's stress were evaluated as secondary outcomes. Implant survival rate was 100% in the test and 98.89% in the control group. Postoperative complications were seen in 9 patients (4 in the test and 5 in the control group); the difference was not statistically significant. Operative time was longer in the test group; however, surgeons were more comfortable using ultrasonic instruments. Within the limitations of this preliminary study, the ultrasonic technique was a feasible alternative to traditional drilling for zygomatic implant surgery.

Five Years Follow-up of Short Implants Placed in Atrophic Maxilla with Simultaneous Sinus Floor Transcrestal Elevation

Objective

Many authors have tried to face the anatomical limitations resulting from maxillary bone atrophy. Up to five millimeters bone height, the lateral sinus floor elevation is the most commonly used and validated strategy to achieve the prosthetic rehabilitation. However, the disadvantages of this technique are its invasiveness and delayed rehabilitation. The aim of this paper was to assess 5 years clinical outcome of implants placed with a technique that allows the percrestal sinus floor elevation and the immediate implant placement.

Materials and Methods

30 transcrestal sinus floor elevations with immediate implant placement were performed in severely atrophic maxillae. Implant survival, marginal bone level variation, harvested bone height variation and periodontal indices were assessed.

Results

After a five year follow up none of the thirty implants were lost. The mean value of vertical harvested bone loss was 5%. The mean crestal bone loss was -0.33 mm (Standard Deviation (SD) 0.11 mm). The mean value of periodontal indices was respectively: PD 1.22 mm (SD 0.72 mm), PI 17.47% (SD 15.01 mm), BOP 9, 87%.,(SD 19.17 mm).

Conclusion

The results obtained are comparable with success criteria in implant rehabilitation. The reported technique proved to be successful in the population observed, with minimal trauma and reduced invasiveness.

Influence of different incision designs on bone increment of guided bone regeneration (Bio-Gide collagen membrane +Bio-OSS bone powder) during the same period of maxillary anterior tooth implantation

Exploring the influence of different incision designs on bone increment of guided bone regeneration [Bio-Gide collagen membrane +Bio-OSS bone powder (carbonate apatite crystal extracted from bovine bones), Bio-OSS bone meal was placed on the surface of the bone defect and then covered with a Bio-Gide membrane to close the wound] during the same period of maxillary anterior tooth implantation. The 99 patients from the stomatology department were divided into 3 groups: small incision (N = 30, group A), wide incision (N = 39, group B), internal gingival sulcus incision (N = 30, group C). At the different time (immediately after surgery, 6 months, 12 months and 24 months), the width and height of labial bone at different implant margin (2 mm, 4 mm, 6 mm) has no significant difference in comparison of any two of the three groups (p > 0.05). The score of esthetic feeling in group A was significant higher than group C (P < 0.05). The PPD, the incidence of SH, BOP in group A were all significant higher than group B (P < 0.05). The PISm, PISd, PPD, the incidence of SH and BOP in group A were all significant higher than group C (P < 0.05). The PISm, PISd, PPD, the incidence of SH and BOP in group B were all significant higher than group C (P < 0.05). The three groups has no significant different on the influence bone increment. The soft tissue condition around the implant after surgery was better in internal gingival crevicular incision than others two incisions, large-scale incision better than small incisions.

[Retrospective study on transcrestal sinus floor elevation with simultaneous implantation of short implants]

OBJECTIVE

To explore the changes in bone height of the maxillary sinus floor at different sinus ridge heights after transcrestal sinus floor elevation (tSFE) with the simultaneous implantation of short implants.

METHODS

A total of 74 Bicon short implants were implanted into 37 patients during the same period of maxillary sinus elevation. The residual bone height (RBH)<4 mm group has 43 sites, and the RBH≥4 mm group has 31 sites. After 5 years of follow-up observation, the implant survival rate and the change in bone height achieved in the maxillary sinus over time were measured and analyzed via clinical examination and X-ray imaging.

RESULTS

In the 74 implantation sites, the elevation height of the sinus floor was (6.64±1.32) mm and the bone height of the sinus floor was (3.35±1.29) mm 5 years after loading. No statistical difference was observed in the bone resorption of the implant neck between the RBH<4 mm and RBH≥4 mm groups. Meanwhile, a statistical difference was noted in the bone height obtained in the maxillary sinus between the two groups.

CONCLUSIONS

When RBH in the maxillary posterior tooth area was <4 mm, the simultaneous implantation of Bicon short implants with tSFE can achieve a high implant survival rate and bone gain in the maxillary sinus, but does not increase the absorption of the alveolar ridge bone.

Long-term crestal bone changes in implants placed in augmented sinuses with minimal or moderate remaining alveolar bone: A 10-year retrospective case-series study

OBJECTIVES

To evaluate long-term clinical and radiographic outcomes of dental implants placed after lateral window sinus augmentation utilizing the sagittal sandwich technique.

MATERIALS AND METHODS

Patients treated with sinus augmentation were included in this retrospective case-series study. The surgical procedure was performed with particulate autogenous bone- and anorganic bovine bone-derived mineral (3:7 ratio). Implants were grouped based on baseline residual alveolar ridge height: group S (residual alveolar ridge height of 0.1-3.5 mm), group M (height of 3.5-7mm), and group C (native bone). Radiographs were taken at baseline (abutment installation) and annually throughout the 10-year follow-up.

RESULTS

A total of 86 patients (92 sinus lifts) and 209 implants were included. Ten sinus membrane perforations were recorded (11% incidence), and graft infections occurred in 3 cases (3.2% incidence). During the 10-year follow-up, 3 implants (1.4%) failed. No significant differences in the mean implant marginal bone loss (MBL) between the three groups were found after 1-, 2-, and 5-year follow-up (p > .05). At 10 years, group C exhibited more MBL than group M with a mean difference of -0.53 mm (p = .01). After 10 years, MK III implants displayed significantly more bone loss in native bone than those in augmented bone with a mean difference of 0.48 mm (p = .02). Five patients and 7 implants developed peri-implantitis with no significant differences between the groups (p = .570).

CONCLUSION

Implant placement after two-stage sinus grafting utilizing the sagittal sandwich technique is a relatively safe and predictable procedure with minimal complications and MBL after 10-year follow-up.

Maxillary sinus augmentation with three different biomaterials: Histological, histomorphometric, clinical, and patient-reported outcomes from a randomized controlled trial

BACKGROUND

Lateral maxillary sinus augmentation (MSA) is a predictable bone regeneration technique in case of atrophy of the posterior-upper maxilla. Aimed at obtaining quantity and quality of bone suitable for receiving osseointegrated implants, its success is largely due to the skill of the surgeon, but also to the characteristics of the biomaterial used.

METHODS

Twenty-four patients needing MSA were included in the study. The patients were randomly allocated to three different groups: anorganic bovine bone mineral as control, tricalcium phosphate with or without hyaluronic acid (HA) as test groups. Nine months after MSA, bone biopsies were harvested for the histomorphometric analysis. Secondary outcomes were mean bone gain, intraoperative and postoperative complications, implant insertion torque, implant failure, and patient-reported outcome measures.

RESULTS

Although the percentage of new bone was not statistically different between the three groups (P = .191), the percentages of residual biomaterial was significantly higher (P < .000) and nonmineralized tissue significantly lower (P < .000) in the control than in the test groups. Test groups did not differ significantly from each other for all histomorphometric parameters. The implant insertion torque was significantly higher in the control group (P < .0005). The rest of the secondary outcomes were not significantly different between the groups.

CONCLUSION

MSA is a safe and predictable procedure in terms of histological, clinical, and PROAMs, regardless of the biomaterial used. The addition of HA did not influence the outcomes.

Factors influencing the prevalence of peri-implantitis in implants inserted in augmented maxillary sinuses: A multicenter cross-sectional study

BACKGROUND

Peri-implantitis is widely recognized as a major cause of late implant failure, both in pristine and regenerated bone. The present study aims to evaluate the prevalence of peri-implantitis in implants inserted in augmented maxillary sinuses and to analyze possible risk factors.

METHODS

A cross-sectional study was conducted in four centers including patients who underwent lateral or transcrestal sinus augmentation and received dental implants. Clinical and anamnestic data were collected using a standardized form. Univariate and multivariate logistic regression analyses have been performed for both implant-level and patient-level variables. Subsequently, a multilevel logistic mixed-effect model was built to analyze variables correlated with the occurrence of peri-implantitis.

RESULTS

A total of 156 patients (61 males and 95 females; mean age: 60.9 ± 11.6 years) with 315 implants inserted into augmented maxillary sinuses with a follow-up ranging from 1 to 18 years were evaluated. Seven implants in seven patients were previously lost for peri-implantitis (2.2% and 4.5% at implant- and patient-level, respectively); 250 implants showed no signs of peri-implant diseases (79.4%), 34 implants presented mucositis (10.8%), and 24 implants exhibited peri-implantitis (7.6%). Corresponding data evaluated at patient-level were 125 (80.1%), 17 (10.9%), and 14 (9.0%), respectively. At the multilevel analysis, history of periodontitis, sinus elevation with lateral approach, and one-stage sinus floor elevation significantly correlated with the occurrence of peri-implantitis (P <0.001).

CONCLUSIONS

History of periodontitis confirmed its well-known role as a risk factor for peri-implant pathologies. In addition, both lateral window technique and one-stage sinus floor elevation seemed to represent significant risk factors for peri-implantitis.

Soft Tissue Injury in Preparation for Implants

Diagnosis and treatment planning are critical in preparation for implant placement. Adequate evaluation, preoperative imaging, and surgical planning minimize early and late-stage soft tissue injuries. Correct placement of dental implants can be challenging with several contributing factors such as lack of proper preoperative soft tissue evaluation and surgical experience in dealing with soft tissue incisions and flap reflection, resulting in injury and complications involving the soft tissues.

Full Mouth Rehabilitation by Implant Supported Fixed Prosthesis

The purpose of this study is to report a case of full-mouth rehabilitation on six endosseous implants loaded following the standard procedure. It was decided to insert six implants in the maxillary and six implants in the mandibular arch in a patient with no systemic disease. The surgery was performed with the patient under local anesthesia with lignocaine and 1:100,000 adrenaline. Implant stability was sufficient (35 N/cm measured with a torque spring) for all 12 implants. An impression is taken in the open tray with a silicone impression material. Vertical dimension for rest and occlusion was checked with wax occlusal rims placed in the mouth. Interocclusal records were made with the metal framework in place. The final restoration was realized with ceramic layering completed. Good impressions and meticulous attention to detail are crucial for a successful implant-supported fixed prosthesis.

One-year implant survival following lateral window sinus augmentation using plasma rich in growth factors (PRGF): a retrospective study

Background

The aim of this study was to assess one-year implant survival after lateral window sinus augmentation using PRGF combined with various bone grafting materials.

Material and Methods

This was a retrospective chart review and radiographic analysis of patients that had undergone lateral window sinus augmentation with PRGF and had dental implants placed at least 6 months post augmentation. All implants included were followed up for at least one year after placement. Demographic, sinus and implant related characteristics (residual ridge height, sinus membrane perforation, type of graft material, implant length and width and ISQ at placement) were analyzed.

Results

A total of 31 patients with 39 sinus augmentations and 48 implants were included. The mean follow up was 22.8 ± 9.9 months. Implant survival was 95.8%, with 2 implants overall failing. Among all the variables assessed, the only one found to be associated with an increased risk for implant failure was the use of xenograft as bone grafting material in the sinus.

Conclusions

Within the limitations of this study, dental implants placed in maxillary sinuses grafted with PRGF in combination with bone grafting materials, exhibit high implant survival rates after at least one year follow up.

Key words:PRGF, sinus graft, growth factors, implant survival, platelet concentrates.

Quality assessment of systematic reviews regarding the effectiveness of zygomatic implants: an overview of systematic reviews

Background

Oral rehabilitation of atrophic maxillae features high complexity, for which there are several therapeutic modalities reported on scientific literature. Zygomatic implant placement is a viable option that features low morbidity and allows immediate prosthetic loading. The purpose of the present study was to determine the methodological quality of systematic reviews that assessed the effectiveness of zygomatic implants placed in atrophic maxillae.

Material and Methods

Searches were conducted on Medline via Pubmed, LILACS, Dare Cochrane, Scopus, and Sigle via Open Grey up to June 2019.

Results

Seven systematic reviews were eligible for Overview and comprised a total of 2313 patients, 4812 zygomatic implants, and a 96,72% success rate. Common surgical complications, in decreasing order, were: maxillary sinusitis, peri-implant mucositis, prosthetic fracture, and infections. Methodological quality was assessed using the AMSTAR 2 tool, which revealed that six systematic reviews showed critically low methodological quality and one review was assessed as of low methodological quality.

Conclusions

Zygomatic implants seem to be an adequate option for atrophic maxilla rehabilitation, however, new studies with a higher methodological rigor are needed to provide more reliable results to professionals and patients undergoing this modality of oral rehabilitation.

Key words:Zygomatic Implants, dental Implants, complications, oral rehabilitation.

The effect of residual bone height and membrane thickness on sinus membrane perforation in crestal sinus grafting: A prospective clinical study

This study sought to determine the rate of sinus membrane perforation in patients undergoing crestal sinus grafting, as well as the effect of Schneiderian membrane thickness and residual bone height (RBH) on membrane perforation, using cone beam computed tomography. The study included 25 patients undergoing 44 crestal sinus grafting procedures. The sites for crestal sinus grafting were divided into a control group (RBH≥5mm) and a test group (RBH<5mm). All sinus grafting procedures were also categorised based on membrane thickness: group A (<1mm), group B (1-2mm), and group C (≥2mm). The rate of membrane perforation was 18.2%. The median RBH measurement was 5.59mm. No statistically significant difference in membrane perforation rate was found between the test and control groups (P=0.262). The median thickness of the Schneiderian membrane was 1.35mm. There was no statistically significant difference in membrane perforation among the three membrane thickness groups (P=0.431). No significant correlation between RBH and membrane perforation was observed, although clinical observation indicated that there was a tendency for an increased membrane perforation rate in the presence of a RBH<5mm. The perforation rate was found to be at its highest when the membrane was thinner than 1mm.

Sequential healing of the elevated sinus floor with different size of antrostomy: a histomorphometric study in rabbits

PURPOSE

To study the influence of the access window dimensions on the healing at the antrostomy and within the augmented maxillary sinus.

MATERIAL AND METHODS

A maxillary sinus augmentation was performed in twenty-four albino New Zealand rabbits. Antrostomies of 3 × 6 mm (small) or 5 × 6 mm (large) in dimensions were randomly prepared in each animal. A collagenated cortico-cancellous porcine bone was used to fill the elevated region, and an equine collagen membrane was placed on the antrostomies. Three different groups were formed, based on the time of euthanasia, i.e., 2, 4, and 8 weeks from surgery.

RESULTS

No relevant changes of the height of the augmented sinus were detected over time. Mineralized bone increased between 2 and 4 weeks of healing while remained stable between 4 and 8 weeks. The highest amounts of new bone were found close to the sinus bone walls. No antrostomies were found healed with an even layer of corticalized bone, while large amounts of connective tissue were occupying the antrostomy in both groups.

CONCLUSION

Antrostomies of different dimensions resulted in similar outcome in bone formation both in the antrostomy regions and within the elevated sinus.

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

As the atrophic posterior maxilla often presents serious limitations for dental implant procedures, a minimally invasive technique was proposed. The study aimed to retrospectively evaluate the outcomes of short and ultra-short locking-taper implants, placed in combination with a modified osteotome sinus floor elevation procedure (internal sinus lift technique) in the posterior maxilla. A total of 31 patients received 51 locking-taper implants. Clinical and radiographic examinations were performed before treatment, at loading time, and after three years. Seven implants of 8.0 mm, 23 implants of 6.0 mm, and 21 implants 5.0 mm in length were rehabilitated with single-crown restorations. Implant survival at three-year follow-up was 96.08%. Pre-operative residual crestal bone height of 5.2 (1.41) (median (interquartile range)) mm increased to 7.59 (1.97) mm at the 36-month follow-up, with an average intra-sinus bone height gain of 3.17 ± 1.13 (mean ± standard deviation) mm. Mean peri-implant crestal bone loss was 0.29 (0.46) mm and mean first bone-to-implant contact point shifted apically to 0.12 (0.34) mm. It can be suggested with confidence that implants used in the study, placed in conjunction with an internal sinus floor elevation technique, can be restored with single crowns as a predictable treatment for the edentulous regions of the posterior maxilla.

Long-term outcomes of osteotome sinus floor elevation with or without bone grafting: The 10-year results of a randomized controlled trial

AIMS

To assess the long-term clinical and radiographic results of implants placed using osteotome sinus floor elevation (OSFE) with or without bone grafting.

MATERIALS AND METHODS

Forty-five patients were randomly assigned into two groups: Group 1 (OSFE with deproteinized bovine bone mineral) and Group 2 (OSFE without grafting). The patients were recalled at 1, 3, 5 and 10 years after surgery. The implant survival, endo-sinus bone gain (ESBG), marginal bone loss (MBL), peri-implant bone height (PBH, distance from the most coronal level to the most apical level of bone-to-implant contact), prosthesis survival and hardware complications, and peri-implant soft tissue conditions were assessed.

RESULTS

Forty patients attended the 10-year examination. Mean residual bone height was 4.58 ± 1.28 mm. The 10-year cumulative survival rate was 90.7% for Group 1 and 95.0% for Group 2. The PBH was 5.89 ± 1.24 mm for Group 1 and 5.74 ± 1.43 mm for Group 2 at 10 years. The ESBG of both groups remained stable after 3 years. Two-thirds of the implants were free of hardware complications. No significant differences in MBL and peri-implant tissue parameters were found.

CONCLUSION

OSFE with or without grafting both yielded predictable clinical outcomes with similar PBH (ClinicalTrials.gov. NCT01619956).

Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: an experimental study in rabbits

AIM

To study the influence on the healing of the placement of particulate autogenous bone in the antrostomy and in the subjacent region after maxillary sinus elevation.

MATERIAL AND METHODS

Sixteen New Zealand rabbits were undergone to bilateral maxillary sinus floor augmentation with 4 × 4 mm antrostomy dimension. The sinus mucosa was elevated, and the space obtained was filled with xenograft. In the test site (treated sites), autogenous bone was harvested from the tibia and was placed either in the antrostomy and the subjacent region while the control site was left untreated. Antrostomy was covered bilaterally with collagen membranes. Animals were euthanized after 1 and 8 weeks of healing, with 8 rabbits in each group. Histomorphometric evaluations were done. The Wilcoxon test is used for statistical analysis, for a 5% statistical significance.

RESULTS

After 1 week of healing, the new bone proportion in the antrostomy was 7.7 ± 11.2% and 6.1 ± 6.4% in the treated and untreated sites, respectively. In the subjacent region (close-to-window region), hardly any new bone was assessed. In the elevated region, 2.7-2.8% of total new bone was found in both sites. In the antrostomy region, after 8 weeks of healing, 35.5 ± 20.9% of new bone in the treated sites, and 28.6 ± 24.1% in the untreated sites was observed (p = 0.499). In the close-to-window region, the respective proportions were 25.8 ± 16.1% and 17.6 ± 16.3% (p = 0.018). In the elevated region, the total new bone reached fractions of 27.9 ± 12.9% and 23.6 ± 15.2% in the treated and untreated sites, respectively (p = 0.128).

CONCLUSIONS

The placement of autogenous bone in the antrostomy and the subjacent region after maxillary sinus elevation, slightly enhanced bone formation compared with sites only grafted with xenograft. Though, only the subjacent close-to-window region showed a statistical significance at 8 weeks of healing. Despite the limitations of the present study, due to its preclinical nature, findings should be extrapolated to humans with caution.

Virtual Implant Rehabilitation of the Severely Atrophic Maxilla: A Radiographic Study

BACKGROUND

Advanced maxillary atrophy is one of the most common clinical scenarios where implant placement could become difficult. Nevertheless, a volumetric evaluation using a suitable diagnostic software could facilitate the implant planning. The purpose of the present study is to suggest the potential application of the maxillary retro-canine area as the designated location for virtual tilted implants.

METHODS

A sample of Cone Beam Computed Tomography (CBCT) images from the Department of Dentistry (IRCSS San Raffaele, Milan, Italy) was evaluated. After a 3D anatomical evaluation, tilted implants were virtually positioned in the retro-canine regions. All the implants were inserted using the same procedure at 30° and 45° degrees of tilting. The length, palatal angulation and diameter of the placed implant were identified.

RESULTS

A total of 220 tilted implants were placed. An average implant measurement of 13.51 mm in length and 3.42 mm in diameter were calculated. Additionally, an average buccal-palatal angulation of 6° was identified. Upon statistical analysis, the implant length was found to be significantly higher at 45° degrees of mesio-distal angulation than at 30° degrees (<0.0001).

CONCLUSIONS

A considerable number of patients show a significant degree of bone atrophy. The implant-supported treatment plan can rely on three-dimensional imaging of the residual bone as a guiding tool to establish the most effective implant position for each specific case. In this study, it was found that an implant could have a greater length if its mesio-distal angulation was more accentuated. In addition, owing to the volumetric evaluation, it was possible to virtually insert tilted implants in almost all of the cases of atrophy. This could lead clinicians to consider the retro-canine area as a viable place to insert a longer tilted implant.

Long-Term Influence of Platelet-Rich Plasma (PRP) on Dental Implants after Maxillary Augmentation: Implant Survival and Success Rates

The atrophic maxilla often requires bone augmentation before implant placement to ensure long-term implant success. A previous prospective clinical trial examined the use of platelet-rich plasma (PRP) during maxillary augmentation. The short-term results showed no positive effect of PRP. The aim of this study was to evaluate the same patient collective of the previous study regarding the PRP long-term impact on the survival and success of dental implants. Fifty-three patients from the previous study diagnosed with maxillary atrophy and augmented with autologous bone grafts from the iliac crest and dental implants, were included in this study. Treatment was carried out on both sides in 34 patients with a split-mouth-design in which one randomly chosen side was treated additionally with PRP, the other side was the control-side. Nineteen patients were treated only on one side and were assigned to the PRP-or the control group randomly. Implant follow-up of the patients from the previous study was performed after an average time of 13 years. Implant success was evaluated using two different success criteria. Thitry-seven patients (25 women and 12 men) were investigated in this study. Seventeen patients (12 female, 5 male) were included in the PRP group, while 20 patients (13 female, 7 male) participated in the control group. A total of 210 implants were inserted. Of these, 102 implants (48.57%) were placed in the PRP group and 108 implants (51.42%) in the control group. Out of 102 investigated implants in the PRP group, 6 were removed (survival rate 94.1%). While two of the 108 implants in the control group were loss (survival rate 98.1%). In the PRP group, the cumulative probability of survival after 15.1 years was 94.1% and in the control group, was 98.1%, with no significant difference between the two groups. Higher significant difference for the control group was found in the cumulative success probability using Albrektson criteria (p = 0.05). Positive impact of PRP on long-term implant survival and success could not be found.

Long-term effectiveness of maxillary sinus floor augmentation: A systematic review and meta-analysis

AIM

To assess the long-term effectiveness (≥5 years) of maxillary sinus floor augmentation (MSFA) procedures applying the lateral window technique and to determine possible differences in outcome between simultaneous and delayed implant placement, partially and fully edentulous patients and grafting procedures.

MATERIALS AND METHODS

MEDLINE (1950-May 2018), EMBASE (1966-May 2018) and Cochrane Central Register of Controlled Trials (1800-May 2018) were searched. Inclusion criteria were prospective studies with follow-up ≥5 years and a residual bone height ≤6 mm. Outcome measures included implant loss, peri-implant bone level change, suprastructure survival, patient-reported outcome measures and overall complications. Data were pooled and analysed using a random effects model.

RESULTS

Out of 2,873 selected articles, 11 studies fulfilled all inclusion criteria. Meta-analysis revealed a weighted annual implant loss of 0.43% (95% CI: 0.37%-0.49%). Meta-regression analysis did not reveal significant differences in implant loss neither between edentulous and dentate patients nor implants placed simultaneously with or delayed after MSFA, nor implants placed in MSFA using solely autologous bone or bone substitutes. The results of the other outcome measures were favourable, and overall complications were low.

CONCLUSION

MSFA is a reliable procedure in the partially and fully edentulous maxilla for support of dental implants.

Indirect Sinus Augmentation With and Without the Addition of a Biomaterial: A Randomized Controlled Clinical Trial

PURPOSE

The aim of this study was to compare the results of indirect sinus augmentation with and without the addition of a biomaterial.

MATERIALS AND METHODS

Thirty patients aged 40 to 60 years participated in this randomized controlled clinical trial. After closed sinus lift operation, patients were randomly and equally divided into blood clot control and acemannan sponge graft groups. Simultaneous implant placement was then performed. Cone beam computed tomography was performed immediately and at 3 and 6 months postoperation. Bone formation was evaluated by the radiographic endo-sinus bone gain percentage around the implant.

RESULTS

Compared with the control group, the acemannan-treated group had a significantly greater radiographic endo-sinus bone gain percentage of approximately 2.4- and 2-fold at 3 and 6 months postsurgery, respectively (P < 0.05).

CONCLUSION

The addition of a biomaterial (Acemannan) with indirect sinus augmentation and simultaneous implant placement significantly enhances bone formation at 3 and 6 months postsurgery.

Short implants (5-8 mm) vs long implants (≥10 mm) with augmentation in atrophic posterior jaws: A meta-analysis of randomised controlled trials

The aim of this systematic review was to compare the survival rate, marginal bone loss changes and complications between short implants (5-8 mm) and long implants (≥10 mm) with a bone-augmented procedure in the posterior jaw. An electronic search of the MEDLINE (PubMed), Embase and Cochrane Library databases through September 2018 was done to identify randomised controlled trials (RCT) assessing short implants and long implants with at least a 1-year follow-up period after loading. A quantitative meta-analysis was conducted on the survival rate, marginal bone loss changes and complications. Ten RCTs met the inclusion criteria. There were no significant differences in the survival rate (RR: 1.01; 95% CI: [0.99, 1.03]; P = .32) and complications (RR: 0.48; 95% CI: [0.20, 1.17]; P = .11) between the two groups. Compared with the long implant group, the short implant group had a lower marginal bone loss change, and the effect measure was significant (mean difference: -0.13; 95% CI: [-0.20, -0.06]; P < .05). This systematic review showed no difference between the survival rates and complications of short implants (5-8 mm) and long implants (≥10 mm). The marginal bone loss changes in short implants are lower than those in long implants.

Maxillary Sinus Augmentation Using Hydraulic Pressure by Lateral Approach and Simultaneous Implant Placement: Clinicoradiographic Study

The purpose of this study was to assess clinically and radiographically efficacy of maxillary sinus augmentation using hydraulic pressure in a lateral approach with immediate implant placement. In a total of 10 patients having less than 4 to 6 mm of subantral bone height, lateral approach sinus membrane elevation procedure was performed using hydraulic pressure with the help of a specialized water lift kit followed by grafting and simultaneous implant placement. Cone beam computed tomography analysis was used to assess the change in subantral bone height from baseline to the 6 months postoperatively. Radiographically, subantral bone height increased from 3.86 ± 1.423 mm at baseline to 15.49 ± 2.73 mm at 6 months postoperatively with a gain of 11.63 + 2.63 mm (P < 0.001). Thus, it is concluded that hydraulic pressure may be efficiently used in lateral sinus augmentation procedures along with simultaneous implant placement.

The impact of graft remodeling on peri-implant bone support at implants placed concomitantly with transcrestal sinus floor elevation: A multicenter, retrospective case series

OBJECTIVES

To evaluate the impact on peri-implant bone support (as assessed on periapical radiographs) of the remodeling dynamics of varying graft biomaterials used for transcrestal sinus floor elevation (tSFE).

METHODS

The study is a multicenter, retrospective series of cases undergone tSFE (performed according to the Smart Lift technique) and concomitant implant placement. At operator's discretion, tSFE was performed with bone core (BC) alone or supplemented by deproteinized bovine or porcine bone mineral (DBBM and DPBM, respectively), synthetic hydroxyapatite in a collagen matrix (S-HA), or ß-tricalcium phosphate (ß-TCP). Immediately after surgery, at 6-12 months post-surgery, and at later (≥24 months) follow-up intervals, the percentage proportion of the implant surface in direct contact with the radiopaque area was calculated for the entire implant surface (totCON%). Also, the height of the graft apical to the implant apex (aGH) was assessed.

RESULTS

At 6-12 months following tSFE, median totCON% was 100%, with a median aGH of 1.4 mm. A tendency of aGH to decrease in height was observed at later follow-up intervals for sites treated with all grafting procedures. In all treatment groups, the majority of the implant surface was still surrounded by the radiopaque area at the longest follow-up visits.

CONCLUSIONS

Although the height of the peri-implant radiopaque area apical to the implant apex tends to reduce overtime at sites which have received tSFE, the peri-implant bone support seems to be maintained long term irrespective of the graft material used.

[Two-stage closed sinus lift for severe bone deficiency in the posterior maxilla imrpoves long-term clinical outcomes]

OBJECTIVE

To evaluate the long-term clinical outcomes of two-stage closed sinus lift for the maxillary sinus with residual bone height (RBH) of 1-3 mm in the posterior maxillary.

METHODS

Seventy-eight patients with maxillary posterior tooth loss (1 mm≤RBH≤3 mm and alveolar ridge width ≥5 mm) were treated with two-stage closed sinus lift at the Dental Implantation Center of our hospital between March, 2012 and December, 2014. Coral hydroxyapatite powder and 148 implants were implanted. The superstructure was fixed within 6 months after the operation and the patients were followed up for 1-5 years for assessing the patients' satisfaction, postoperative response, stability and survival rates of the implant, soft tissue condition, bone height of maxillary sinus floor elevation and the marginal bone loss.

RESULTS

Perforation of the maxillary sinus floor occurred in 3 (3.85%) of the cases. Twenty-three (30.67%) patients complained of mild pain, and 52 (69.33%) did not experience headache or fever or reported obvious pain or swelling after the operation. The overall response to the operation was favorable. The ISQ value was 58.39±1.39 immediately after the operation, and increased significantly to 81.88±1.22 at 6 months (P &lt; 0.05). During the healing period and the follow-up, none of the implants fell off, and the implant survival rate was 100%. The peri-implant probing depth and modified sulcus bleeding index at 1 year after sinus lifting were similar to those at 5 years after the operation (P &gt; 0.05), but the sinus floor elevation and marginal bone resorption at the two time points differed significantly (P &lt; 0.05).

CONCLUSIONS

Compared with lateral wall lifting, two-stage close lifting of the maxillary sinus floor is associated with less trauma and less discomfort, and effectively solves the problem of severe alveolar bone height deficiency in the maxillary posterior region to achieve favorable long-term clinical outcomes.

Maxillary Sinus Floor Augmentation With Autogenous Bone Graft From the Ascending Mandibular Ramus

PURPOSE

The objective of the present study was to assess patient satisfaction and esthetic implant outcome 10 years after maxillary sinus floor augmentation with autogenous bone graft from the mandibular ramus.

MATERIALS AND METHODS

Maxillary sinus floor augmentation with autogenous bone graft from the mandibular ramus was conducted in 48 consecutive patients from 2002 to 2006. Records and radiographs were retrospectively analyzed. Twenty-four patients including 34 sinus augmentation procedures and 37 implants were evaluated after 10 years. Subjective and professional evaluations of the final periimplant soft tissue, implant crown, and total implant treatment were conducted.

RESULTS

The 10-year survival of suprastructures and implants was 84% and 100%, respectively. The patients were highly satisfied with the esthetic and implant treatment outcome expressed by scores >90 on the visual analog scale. Most implants were characterized by scores of 1 or 2, resulting in a mean pink esthetic score of 9 (maximum 14) and a white esthetic score of 8 (maximum 10).

CONCLUSION

Maxillary sinus floor augmentation with autogenous bone graft is characterized by high long-term implant survival rate and patient satisfaction.

Bone Formed After Maxillary Sinus Floor Augmentation by Bone Autografting With Hydroxyapatite and Low-Level Laser Therapy: A Randomized Controlled Trial With Histomorphometrical and Immunohistochemical Analyses

PURPOSE

The aim of this study was to evaluate the bone formed after maxillary sinus floor augmentation (MSFA) by bone autografting combined with hydroxyapatite (HA) that had been either treated with low-level laser therapy (LLLT) or not.

MATERIALS AND METHODS

Twelve biopsies were obtained from patients 6 months after MSFA using a combination of 50% of autogenous bone (AB) and 50% of HA (AB/HA group, n = 6) followed by LLLT (AB/HA-LLLT group, n = 6). The laser used in this study was gallium-aluminium-arsenide laser with a wavelength of 830 nm (40 mW; 5.32 J/point; 0.57 W/cm). Samples obtained were subjected to histological, histometric, and immunohistochemical analysis for detection of tartrate-resistant acid phosphatase and runt-related transcription factor 2. The data were submitted to statistical analysis (Shapiro-Wilk and Student t tests; α = 5%).

RESULTS

Statistical analysis revealed no significant difference in vital bone presence and immunohistochemical analysis between the groups. There was no reduction in bone marrow or fibrous tissue in the AB/HA group and AB/HA-LLLT group. There was a decrease in the amount of remaining biomaterial between the groups (P = 0.0081).

CONCLUSION

LLLT did not increase the formation of new bone; instead, it accelerated the bone remodeling process.

Influence of exposing dental implants into the sinus cavity on survival and complications rate: a systematic review

BACKGROUND

After tooth loss, the posterior maxilla is usually characterized by limited bone height secondary to pneumatization of the maxillary sinus and/or collapse of the alveolar ridge that preclude in many instances the installation of dental implants. In order to compensate for the lack of bone height, several treatment options have been proposed. These treatment alternatives aimed at the installation of dental implants with or without the utilization of bone grafting materials avoiding the perforation of the Schneiderian membrane. Nevertheless, membrane perforations represent the most common complication among these procedures. Consequently, the present review aimed at the elucidation of the relevance of this phenomenon on implant survival and complications.

MATERIAL AND METHODS

Electronic and manual literature searches were performed by two independent reviewers in several databases, including MEDLINE, EMBASE, and Cochrane Oral Health Group Trials Register, for articles up to January 2018 reporting outcome of implant placement perforating the sinus floor without regenerative procedure (lateral sinus lift or transalveolar technique) and graft material. The intrusion of the implants can occur during drilling or implant placement, with and without punch out Schneiderian. Only studies with at least 6 months of follow-up were included in the qualitative assessment.

RESULTS

Eight studies provided information on the survival rate, with a global sample of 493 implants, being the weighted mean survival rate 95.6% (IC 95%), after 52.7 months of follow-up. The level of implant penetration (≤ 4 mm or > 4 mm) did not report statistically significant differences in survival rate (p = 0.403). Seven studies provided information on the rate of clinical complications, being the mean complication rate 3.4% (IC 95%). The most frequent clinical complication was epistaxis, without finding significant differences according to the level of penetration. Five studies provide information on the radiographic complication; the most common complication was thickening of the Schneiderian membrane. The weighted complication rate was 14.8% (IC 95%), and penetration level affects the rate of radiological complications, being these of 5.29% in implant penetrating ≤4 mm and 29.3% in implant penetrating > 4 mm, without reaching statistical significant difference (p = 0.301).

CONCLUSION

The overall survival rate of the implants into the sinus cavity was 95.6%, without statistical differences according to the level of penetration. The clinical and radiological complications were 3.4% and 14.8% respectively. The most frequent clinical complication was the epistaxis, and the radiological complication was thickening of the Schneiderian membrane, without reaching statistical significant difference according to the level of implant penetration inside the sinus.

Osteotome-Mediated Sinus Floor Elevation With or Without a Grafting Material: A Systematic Review and Meta-analysis of Long-term Studies (≥5-Years)

OBJECTIVE

To test the hypothesis of no difference in the long-term treatment outcome after osteotome-mediated sinus floor elevation with or without a grafting material.

MATERIALS AND METHODS

A MEDLINE/PubMed, Cochrane Library, and EMBASE search in combination with a hand-search of relevant journals was conducted, including human studies published in English from January 1, 1986 to December 1, 2017.

RESULTS

One comparative and 7 noncomparative studies fulfilled the inclusion criteria. Survival of suprastructures had never been compared within the same study. Meta-analysis demonstrated an overall estimated patient-based implant survival of 94%. Gain in vertical alveolar bone height was similar with the 2 treatment modalities. Noncomparative studies demonstrated high long-term survival rate of suprastructures and implants with the 2 treatment modalities, as well as limited periimplant marginal bone loss.

CONCLUSION

High long-term implant survival was demonstrated after osteotome-mediated sinus floor elevation with or without a grafting material. However, long-term randomized controlled trials comparing the 2 treatment modalities are sparse. Hence, conclusions drawn from this systematic review should be interpreted with caution.

Cappellin simplified sinus lift protocol for mini-invasive lateral approach - Preliminary study results

Purpose: The lateral approach in sinus lift allows to optimally manage severe bone resorption in posterior maxilla in order to place implant supported prosthesis; however, the conventional protocols requires bigger window and cannot determine in advance the precise position for bone incision, so in many cases the detachment of Schneider membrane is more difficult if the bone isn’t cut near the sinus floor or if there is a bone septum. The aim of Cappellin simplified sinus lift protocol is to minimize the surgical difficulties with a surgical guide realized from STL 3D printed model (conversion of DICOM cone-beam CT files). Case report: In our study (since 2013 to 2017) in 125 sinus lift cases (performed with Geistlich Bio-Oss® and a-PRF / PRGF) with 210 implants (Implant Direct® Legacy 2, 78 of which were placed at the same time as the sinus lift augmentation) we obtain a success of 100% for the sinus lift augmentation and 100% survival rate for the implants; we also drastically reduce the surgery time (average is about 25 minutes). CT scans were performed before the surgery and 4-6 months after the sinus lift; follow up for implant survival includes control and professional hygiene every 6 months. Conclusions: In regards of these preliminary results, Cappellin simplified sinus lift protocol offers advantages in terms of safety, simplicity, quickness, reliability and allows to reduce the economic costs of the procedure.