Sinus floor elevation utilizing the transalveolar approach

Prevention and management of intra-operative complications in maxillary sinus augmentation: A review

Maxillary sinus floor elevation is usually performed in two different ways: the lateral approach involves the creation of a bony window on the maxillary sinus lateral wall, providing direct access to the sinus cavity for membrane elevation and subsequent graft placement, and the transcrestal approach is considered less invasive. The aim of this article is to describe, based on the literature, how to anticipate, avoid, and manage the intraoperative complications that can occur with both approaches. For both approaches, the most common complication is the sinus membrane perforation. For the lateral approach, an average frequency ranging from 15.7% to 23.1% is reported, but because of the better visibility, their management will be easier compared to the transcrestal approach. Mean perforation rate reported for the transcrestal approach is lower (3.1%-6.4%), but it should be noted that a significant number of perforations cannot be detected and managed given the blind nature of this technique. Anatomical parameters such as sinus width and buccal wall thickness may be a risk factor for one approach and not the other. As it is impossible to assess the resistance of the Schneiderian membrane, the transcrestal approach is more likely to lead to infectious complications in the event of perforation. Others, such as the risk of vascular damage, are encountered only with the lateral approach, which can be prevented easily by dissecting the alveolo-antral artery. For both approaches, prevention is essential and consists in analyzing the anatomy, mastering the surgical technique, and collaborating with the ENT to manage the essentially infectious consequences of intraoperative complications.

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.

Three-dimensional changes and influencing factors of tent space following osteotome sinus floor elevation without grafting: A 48-month retrospective radiographic study

OBJECTIVES

To analyze the three-dimensional stability and morphologic changes of tent space after the osteotome sinus floor elevation (OSFE) procedures without bone grafts.

MATERIALS AND METHODS

Forty-six implants placed using the OSFE technique with simultaneous implant placement without bone grafts were included in this retrospective study. Cone-beam computed tomography (CBCT) scans of the augmented sinuses were obtained pre- and postoperatively up to 48 months of follow-up. The maxillary sinus cavity profiles were outlined using three-dimensional virtual reconstruction and superimposition of CBCT scans. The three-dimensional changes in the tent space were measured. A generalized estimating equation (GEE) was used to explore potential factors.

RESULTS

The implant survival rate was 97.8%. The mean volume of remaining tent space immediately after surgery was 96.8 ± 70.5 mm3, shrinking to 31.0 ± 24.9 mm3 after 48 months, while the mean percentage of remaining tent space volume decreased to 29.1 ± 20.7%. The tent space volume and the percentage of residual tent space volume only decreased significantly within 12 months after surgery (p = .008, .013). GEE results indicated positive correlations between the percentage of remaining tent space volume and implant protrusion length (p = .000) and apical height (p = .000), with a negative correlation between the sinus floor area immediately after surgery (p = .002) and the healing time (p = .022).

CONCLUSIONS

The volume of the tent space rapidly shrank after OSFE without bone grafts. Several factors might influence the tent space stability. Long-term clinical trials with larger sample sizes are necessary to further validate the results.

Risk Factors for Implant Failure Following Transcrestal Sinus-Floor Elevation: A Case Report and Literature Review

Although transcrestal sinus floor elevation (TSFE) is widely used for cases of insufficient residual bone height in the posterior maxilla, few studies focus on the risk factors of early implant failure associated with TSFE procedures. This study aimed to identify and summarize the possible risk factors of implant failure associated with TSFE to ensure a more predictable implant survival rate using TSFE. We report the treatment of a patient with implant failure following TSFE and discuss this case's possible associated risk factors. A standard implant with a diameter of 4.8 mm and length of 10 mm was used after the TSFE procedure. Implant loosening was suddenly observed 6 weeks after the initial surgery. Factors that could result in early implant failure included patient-related risk factors, anatomical factors of the operational area, and operation- and implant-related factors. Within the current study's limitations, the graft material particles between the implant surface and socket could be considered a direct risk factor resulting in implant failure. Therefore, more attention should be paid to socket cleaning during the TSFE procedure, and loose particulate grafting materials should be discouraged. Another significant consideration for implant loss is the possibility of fractures in the buccal or palatal cortical plates during the site preparation and implant insertion. Thus, these factors should be studied further and receive more clinical attention.

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.

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

OBJECTIVE

To date, it remains a challenge to conduct maxillary sinus floor elevation (MSFE) owing to heterogeneity of anatomical structures and limited operative visibility of the maxillary sinus. The aim of this study is to investigate the safety of MSFE and the accuracy of implant placement using dynamic navigation.

METHODS

Forty-two implants were placed in thirty-five patients requiring implantation in posterior maxilla with dynamic navigation. They were assigned to either lateral window sinus floor elevation (LWSFE) group (n = 22) or transcrestal sinus floor elevation (TSFE) group (n = 20) according to the residual alveolar bone height (RBH). Platform deviation, apex deviation and angular deviation between actual and planned implant placement were measured in precision evaluation software. Three deviations of two groups were compared via SPSS 22.0 software.

RESULTS

Neither accidental bleeding nor perforation of Schneiderian membrane occurred in any patients. The actual window position of LWSFE was consistent with the preoperative design. There were no significant differences in platform, apex and angular deviations between the two groups (P > 0.05).

CONCLUSION

In this study the dynamic navigation harvested clinically acceptable safety of MSFE and accuracy for implant placement in posterior maxillary region. The dynamic navigation would provide the clinician with assistance in achieving precise preoperative planning and reducing complications in surgical procedures. The granular bone grafts used in the LWSFE did not significantly affection on the accuracy of the simultaneous implant placement under the guidance of dynamic navigation.

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.

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.

Volumetric changes and graft stability after lateral window sinus floor augmentation: A randomized clinical trial

INTRODUCTION

The present investigation compared the stability and volumetric changes of two different grafting material used for lateral window sinus floor augmentation (LWSFA).

METHODS

Sixteen patients with a total 20 maxillary sinuses in need of LWSFA were included in the present study. The sinuses were grafted with either 100% anorganic bovine bone mineral (ABBM) alone (Group 1) or a mixture (0.8:1 ratio) of ABBM and mineralized cortical allograft (MCA) (Group 2). Cone beam computer tomography (CBCT) was obtained pre-operatively, and at 2-weeks, and 6-months after LWSFA to perform linear measurements including lateral window dimensions, sinus anatomy, residual bone height/thickness (RBH/RBT), and Schneiderian membrane thickness (SMT), among others. Three-dimensional segmentation analysis was used to evaluate changes of bone graft volume/height (GV/GH).

RESULTS

A total of 10 sinuses per group were included in the analysis. No statistically significant difference was found in between groups regarding mean reduction of GV (Group 1: 14.87% ± 16.60%, Group 2: 18.06% ± 9.81%, p = 0.33). Among the linear measurements, only SMT revealed a significant increase after 2-weeks more pronounce in Group 1 (8.70 mm) when compared with Group 2 (5.70 mm) with plausible effect upon LWSFA outcomes. Sinus width showed weak positive correlation with GH reduction after 6 months.

CONCLUSION

This study demonstrated that both ABBM alone and ABBM + MCA represent suitable alternatives for LWSFA with adequate graft stability as they revealed similar volumetric and linear dimensional changes 6 months postoperatively.

Combination of a surgical template and a collagen strip for guiding sinus floor elevation in the oblique sinus floor: A technical note

Sinus floor elevation (SFE) by transcrestal approach has been proven to be a predictable and minimally invasive treatment that augments posterior maxilla with insufficient bone height, allowing the prosthetic rehabilitation of this area with dental implants. However, precise and sufficient elevation of the Schneiderian membrane without perforation is challenging through this blind technique especially in the presence of anatomical restrictions. This note describes a novel technique combining a surgical template and an absorbable collagen sponge (ACS) strip for transcrestal SFE in the oblique sinus floor. A surgical template was used to locate the oblique sinus floor and a collagen strip was placed to orient membrane elevation, meanwhile, protect the sinus membrane. Within the limits of present observation, this technique may increase the manipuility while reducing the risk of complications.

Simultaneous implant placement and restoration with guided bone regeneration in the mandibular anterior region

BACKGROUND

Restoring the mandibular anterior teeth by implants can be difficult due to potential complications arising from using prosthetic implant connections that are larger than the incisors at the cementoenamel junction level.

METHODS

This retrospective study is aimed at determining the survival and esthetic outcomes of anterior mandible implants immediately placed and restored in patients diagnosed with stages 3-4 periodontitis. The study included 75 implants that were inserted along with guided bone regeneration in 42 patients. Over a follow-up period of 3 to 8 years (mean of 6.95 ± 1.78 years), the study evaluated esthetic, marginal bone loss (MBL), and biological and prosthetic complications.

RESULTS

No failures were recorded during the follow-up period; after eight years, the survival rate was 100%. Patient's age and gender did not have a statistically significant impact on MBL, but smokers had a greater MBL than non-smokers at the 8-year (2.98 mm vs. 1.23 mm, respectively, p = 0.016) time-point. At 3 years, only 13.3% of the implants had mesial papillae, 36.0% had distal papillae, and 16.0% had the cervical metallic part of the abutment exposed. Peri-implantitis was diagnosed in 20.7% of the patients at the 8-year follow-up time.

CONCLUSIONS

Based on the limitations of this study, immediate placement and restoration of the mandibular incisors can be a feasible procedure, but only a few implants achieved the complete restoration of the papillae.

Maxillary Sinus Lift Procedures: An Overview of Current Techniques, Presurgical Evaluation, and Complications

A maxillary sinus lift procedure is indicated if a dental implant needs to be placed in the posterior maxilla with limited bone available to accommodate a dental implant. Both open and closed sinus lifting procedures are reliable approaches for increasing the bone volume needed to support proper implant positioning. However, these methods can lead to several complications. In addition to the general complications commonly linked to oral surgery, such as swelling or hematoma, the primary complication in open sinus lifting is typically the perforation of the Schneiderian membrane during osteotomy. Detailed and extensive presurgical evaluation is crucial to minimize such complications. The objective of this study was to delineate contemporary trends in sinus lift surgery, with a specific emphasis on different techniques of sinus lift procedure, anatomical and surgical factors, presurgical evaluation, bone grafting, and the practical implications of these factors in implant dentistry cases involving a deficient posterior maxilla. In conclusion, while both osteotome and lateral window techniques can assist clinicians in addressing the complexities of implant placement in a deficient posterior maxilla, bone height before implantation remains a critical factor in determining the success and longevity of implants.

Endo-sinus bone gain following osteotome-mediated sinus floor elevation with Bio-Oss Collagen compared with no grafting material: a one-year single-blind randomized controlled trial

The objective of this study was to assess endo-sinus bone gain (ESBG) following osteotome-mediated sinus floor elevation with Bio-Oss Collagen (test) compared with no grafting material (control) using two- and three-dimensional radiographic methods, as part of a randomized controlled trial (ClinicalTrials.gov, NCT04618900). Forty healthy patients who met the necessary eligibility criteria were allocated by block randomization to either the test group (20 patients) or control group (20 patients). Cone beam computed tomography scans were obtained at enrolment (T0), immediately after surgery (T1), at delivery of the prosthetic rehabilitation (T2), and 1 year after functional implant loading (T3). Mean differences were expressed with the 95% confidence interval; significance was set at P < 0.05. ESBG was significantly increased with Bio-Oss Collagen compared with no grafting material at T1, T2, and T3 (P < 0.001). A gradual decrease in ESBG was observed over time with both treatment modalities (P < 0.001), which diminished the difference between the test and control groups at T2 and T3. ESBG was observed to be positively correlated with implant protrusion length and negatively correlated with the residual bone height. In osteotome-mediated sinus floor elevation, the application of Bio-Oss Collagen underneath the elevated Schneiderian membrane improved ESBG significantly when compared with no grafting material. However, the increased ESBG seems not to have positively improved the treatment outcomes in terms of the implant stability quotient or the survival of the implants or suprastructures.

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.

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

AIM

To evaluate the effectiveness and complications of the cushioned grind-out technique. The primary outcome was endo-sinus bone gain (ESBG), while secondary outcomes included the Schneiderian membrane perforation rate and mid- to long-term implant survival.

MATERIALS AND METHODS

In this retrospective study, we compared the cushioned grind-out technique with the classic osteotome technique, establishing statistical models to assess ESBG, membrane perforation rate and implant survival rate.

RESULTS

A total of 259 patients and 340 implants were included. The mean ESBG was 5.31 mm for the cushioned grind-out group and 4.64 mm for the osteotome group. Multivariable regression analysis revealed that the cushioned grind-out technique significantly facilitated ESBG (p = .028). Nineteen preparation sites experienced membrane perforation, with rates of 5.5% and 6.4% for the cushioned grind-out and osteotome groups, respectively. However, the difference was not statistically significant (p = .920). Additionally, the cumulative survival rate of the implants for 7 years was 95.2% and 91.4%, respectively, with the surgical technique not significantly influencing the results.

CONCLUSIONS

With 6 months to 7 years of post-prosthetic restoration review data, our findings show that the cushioned grind-out technique facilitates a higher ESBG, with no significant difference in membrane perforation or implant failure rate.

Evaluation of implant stability and increase in bone height in indirect sinus lift done with the osseodensification and osteotome technique: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Whether the use of osseodensification burs for indirect sinus lift improves primary implant stability and bone height as compared with the osteotome technique to overcome the challenges of the pneumatization of the maxillary sinus and vertical bone loss after extraction in the edentulous posterior maxilla is unclear.

PURPOSE

The purpose of this systematic review and meta-analysis was to evaluate the difference in primary implant stability and increase in bone height in indirect sinus lift using osseodensification and the osteotome technique.

MATERIAL AND METHODS

Two independent reviewers searched the MEDLINE/PubMed, EBSCO, and Cochrane Library databases and the Google Scholar Search engine for randomized clinical trials, nonrandomized clinical trials, and cross-sectional studies published from 2000 to 2022 to identify relevant studies evaluating the primary implant stability and increase in bone height in indirect sinus lift using osseodensification and the osteotome technique. A meta-analysis was performed to evaluate the cumulative data on primary implant stability and increase in bone height.

RESULTS

A total of 8521 titles were obtained by electronic database search, of which 75 were duplicates. A total of 8446 abstracts were screened, and 8411 that were not relevant to the topic were excluded. Thirty-five articles were eligible for full-text assessment. After the screening of full-text articles as per the selection criteria, 26 studies were excluded. For qualitative synthesis, 9 studies were included. For quantitative synthesis, 5 studies were included. For an increase in bone height, no statistically significant difference was observed (I² = 89%, P=.15, pooled mean difference=0.30 [-0.11, 0.70], CI=95%). For primary implant stability, the osseodensification group showed higher values than the osteotome group (I² = 20%, P<.001, pooled mean difference=10.61 [7.14, 14.08], CI=95%).

CONCLUSIONS

The evidence obtained from quantitative analysis of the studies determined that the osseodensification group showed higher primary implant stability than the osteotome group (P<.05). However, for mean increase in bone height, there was no statistically significant difference between the groups.

Effect of the implant apical exposure and coverage < or ≥ 2 mm bone graft on transcrestal sinus floor elevation: a 1- to 7-year retrospective cohort study

OBJECTIVES

This study aimed to analyze the effect of the apex coverage by the bone graft, including exposure and coverage less than or greater than 2 mm on implant survival rate and peri-implant bone and soft tissue remodeling.

MATERIALS AND METHODS

A total of 264 implants in 180 patients who had undergone transcrestal sinus floor elevation (TSFE) with simultaneous implant placement were included in this retrospective cohort study. Radiographic assessment was used to categorize the implants into three groups based on apical implant bone height (ABH): ≤ 0 mm, < 2 mm, or ≥ 2 mm. The implant survival rate, peri-implant marginal bone loss (MBL) during short-term (1-3 years) and mid- to long-term (4-7 years) follow-up, and clinical parameters were used to evaluate the effect of implant apex coverage after TSFE.

RESULTS

Group 1 had 56 implants (ABH ≤ 0 mm), group 2 had 123 implants (ABH > 0 mm, but < 2 mm), and group 3 had 85 implants (ABH ≥ 2 mm). There was no significant difference in the implant survival rate between groups 2 and 3 compared to group 1 (p = 0.646, p = 0.824, respectively). The MBL during short-term and mid- to long-term follow-up indicated that apex coverage could not be considered a risk factor. Furthermore, apex coverage did not have a significant effect on other clinical parameters.

CONCLUSIONS

Despite limitations, our study found that implant apex coverage by the bone graft, including exposure and coverage levels less than or greater than 2 mm, did not significantly affect implant survival, short-term or mid- to long-term MBL, or peri-implant soft tissue outcomes.

CLINICAL RELEVANCE

Based on 1- to 7-year data, the study suggests that implant apical exposure and coverage levels of less than or greater than 2 mm bone graft are both valid options for TSFE cases.

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.

Three-Dimensional Plotted Calcium Phosphate Scaffolds for Bone Defect Augmentation—A New Method for Regeneration

For sinus grafting, different methods and materials are available. One possible shortcoming of particulate bone grafts is either overfilling or augmenting the planned implant area insufficiently. To overcome this risk and to determine the implant position prior augmentation, we present an approach using three-dimensional printed scaffolds. A patient with a remaining anterior dentition and bilateral severely atrophied posterior maxilla was seeking oral rehabilitation. The cone beam computed tomography (CBCT) showed residual bone heights between one and two millimeters. Following the three-dimensional reconstruction of the CBCT data, the positions of the implants were determined in areas 16 and 26. Three-dimensional scaffolds adapted to the topography of the sinus were virtually designed and printed using a calcium phosphate cement paste. Bilateral sinus floor augmentation applying the printed scaffolds with an interconnecting porosity followed. After nine months, a satisfying integration of the scaffolds was obvious. At the re-entry, vital bone with sufficient blood supply was found. One implant could be placed in positions 16 and 26, respectively. After five months, the implants could be uncovered and were provided with a temporary denture. The application of three-dimensionally printed scaffolds from calcium phosphate cement paste seems to be a promising technique to graft the severely atrophied posterior maxilla for the placement of dental implants.

Biomechanical evaluation of custom-made short implants with wing retention applied in severe atrophic maxillary posterior region restoration: A three-dimensional finite element analysis

Severe bone atrophy in the maxillary posterior region poses a big challenge to implant restoration. Digitally designed and customized short implants with wing retention provide a safer and minimally invasive implant restoration scheme in such circumstances. Small titanium wings are integrated with the short implant supporting the prosthesis. Using digital designing and processing technology, the wings fixed by titanium screws can be flexibly designed, providing the main fixation. The design of the wings will influence the stress distribution and implant stability. This study analyzes the position, structure, and spread area of the wings fixture scientifically by means of three-dimensional finite element analysis. The design of the wings is set to linear, triangular, and planar styles. Under the simulated vertical and oblique occlusal forces, the implant displacement and stress between the implant and the bone surface are analyzed at different bone heights of 1 mm, 2 mm, and 3 mm. The finite element results show that the planar form can better disperse the stress. By adjusting the cusp slope to reduce the influence of lateral force, short implants with planar wing fixtures can be used safely even if the residual bone height is only 1 mm. The results of the study provide a scientific basis for the clinical application of this new customized implant.

Outcomes following osteotome-mediated sinus floor elevation with Bio-Oss Collagen or no grafting material: a one-year single-blind randomized controlled trial

The objective of this single-blind randomized controlled trial was to test the hypothesis of no difference in implant treatment outcome and patient-reported outcome measures (PROMs) following osteotome-mediated sinus floor elevation with Bio-Oss Collagen (test) compared with no grafting material (control) after 1 year of implant loading. Forty healthy patients (27 female, 13 male) with a mean age of 49 years (range 24-74 years) were randomly allocated to the test or control group. Outcome measures included survival of the suprastructures and implants, peri-implant marginal bone loss, complications, and PROMs; the latter included the Oral Health Impact Profile-14 and a self-administered questionnaire with visual analogue scales to assess the peri-implant tissue, implant crown, function of the implant, total implant treatment outcome, and oral health-related quality of life. Mean differences were expressed with the standard deviation and 95% confidence interval. The level of significance was 0.05. Survival of the suprastructures and implants was 100% with both treatment modalities. No significant difference in any of the outcome measures was observed between the test and control groups. High patient satisfaction and a significant improvement in quality of life were observed with both treatment modalities. Consequently, no significant difference in implant treatment outcome between the test and control groups was revealed after 1 year of implant loading. Neither of the treatment modalities can therefore be considered better than the other.

Comparison between Platelet-rich Fibrin and Saline Filling after Sinus Elevation without Adjunctive Bone Graft in Dental Implants Insertion Using CBCT

AIM

The goal of this research was to compare radiographically the outcomes of hydraulic transcrestal sinus lifting with platelet-rich fibrin (PRF) or normal saline filling on implant survival rates, negative outcomes, and variations in the height of residual alveolar ridge (HARB).

MATERIALS AND METHODS

There were 80 study participants included and 90 dental implants were placed. The study participants were divided into two categories: Category A and Category B. Each category consists of 40 study participants. Category A: Normal saline was placed in the maxillary sinus. Category B: PRF was placed in the maxillary sinus. Implant survival, complications, and HARB alterations were the outcome metrics. Radiographic images through Cone-beam computed tomography (CBCT) were retrieved and compared prior to surgery (T0), immediately following surgery (T1), three months later (T2), 6 months later (T3), and 12 months later (T4).

RESULTS

There are 90 implants having an average length of 10.5 ± 0.7 mm were inserted into the posterior portion of the maxilla of 80 patients with an average HARB of 6.9 ± 1.2 mm. At T1, elevation in HARB peaked, and the sinus membrane continued to droop but steadied while observed at T3. The steady increment of areas of radiopacities was noticed below the elevated membrane of the maxillary antrum. A radiographic intrasinus bone increase of 2.9 ± 1.4 mm was caused by the PRF filling, compared to 1.8 ± 1.1 mm by the saline filling at T4 (p < 0.05). Over the course of the one-year follow-up period, all of the implants were operating normally with no major issues.

CONCLUSION

Platelet-rich fibrin when used as a filling medium alone without bone graft can cause significant ascend in height of the residual alveolar bone (HRAB).

CLINICAL SIGNIFICANCE

The degradation of the alveolar bone under the maxillary sinus following tooth loss frequently restricts the placement of the implant in the edentulous region of posterior maxilla. Numerous sinus-lifting surgery procedures and tools have been developed to address these problems. It has been a topic of debate regarding the benefits of bone grafts placed at the apical region of the implant. The sharp protrusions of the granules of bone graft may also provide a danger of membrane puncture. Recently, it was shown that regular bone gain might occur inside the maxillary antrum without the use of any bone transplant material. Additionally, if there were substances that filled the gap between the floor of the sinus and the raised sinus membrane, then the membrane of the maxillary sinus could be raised greater and for a longer period of time during the phase of formation of new bone formation.

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.

Minimal invasiveness in the transcrestal elevation of the maxillary sinus floor: A systematic review

In the attempt to reduce the invasiveness of a transcrestal sinus floor elevation procedure, different aspects must be considered; that is, the minimization of intra- and postsurgery morbidity, the reduction of treatment time, and the simplification/elimination of the reconstructive technology. Within this context, a systematic literature search was performed for controlled clinical trials evaluating the impact of one or more of these aspects on transcrestal sinus floor elevation invasiveness. Nineteen articles (15 studies) were included. Overall, the results confirmed that transcrestal sinus floor elevation is a minimally invasive and effective option for bone augmentation in the edentulous, atrophic posterior maxilla. By using powered instruments rather than manual osteotomes and hand mallet, the invasiveness of transcrestal sinus floor elevation can be further reduced without affecting its clinical effectiveness. To impact effectively on morbidity, the key elements to consider when selecting instruments for transcrestal sinus floor elevation are (a) their availability as a standardized sequence, to be adapted on predetermined residual bone height, and (b) the possibility to control pressure (eg, with screwable osteotomes) and/or instrument excursion (eg, with stop devices) to fracture the maxillary sinus floor. Among powered instruments, a standardized sequence of drills incorporating a trephine drill seem to be particularly indicated, due to reduced chair time, high tolerability for the patient, and the possibility to isolate a bone core to implement histomorphometric outcomes. At molar extraction sites with an interradicular septum characterized by a height of at least 4 mm, immediate transcrestal sinus floor elevation and implant placement can be considered a valid option to shorten treatment time.

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.

Complications in sinus lifting procedures: Classification and management

Open and closed sinus lifting procedures are predictable methods to augment the bone needed for appropriate implant placement in the posterior maxilla in cases where available bone is limited. However, these techniques may give rise to complications and associated comorbidities. In the case of open sinus lifting, perforation of the Schneiderian membrane during osteotomy is the most common complication, with an incidence rate of around 20%-25%. Apart from those complications associated with oral surgery in general (such as swelling or hematoma), there are specific complications of open sinus lifting procedures that may arise less frequently (chronic rhinosinusitis, hemorrhage, or ostium blockage by overfilling) but which may nevertheless compromise the viability of the graft and/or the implants and cause substantial discomfort to the patient. Closed sinus lifting is a less invasive approach that allows transcrestal placement of the implants in cases where there is sufficient residual bone height. However, it may also be associated with specific complications, including membrane perforation, benign paroxysmal positional vertigo, and implant displacement to the sinus cavity. New technologies have been proposed to reduce these complications and comorbidities associated with conventional sinus lifting procedures, such as the use of piezoelectric devices and hydraulic sinus lift or reamer burs. The evidence supporting their effectiveness and safety, however, is still lacking. A detailed medical history together with a thorough radiographic and clinical examination are essential prior to any kind of bone regenerative augmentation involving the maxillary sinus. Moreover, it is recommended to employ the most appropriate surgical technique for the specific characteristics of the case and, at the same time, accommodating the experience and skills of the surgeon.

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.

Implant Placement Post Maxillary Sinus Lift Using Osseodensification Concept: A Case Report

Pneumatisation of the maxillary sinus is a roadblock to the successful placement of endosseous implants in the posterior maxilla. It is mandatory that the sinus has to be elevated to facilitate implant placement, for which the operating clinician should be well versed with the anatomy of the sinus to avoid intraoperative mishaps. Many techniques of sinus augmentation have been tried and tested with successful outcomes. This article presents a report of a 60-year-old female who had root stumps in relation to upper left first maxillary molar. She wanted an implant to replace the root stumps, however, on cone-beam computed tomography (CBCT) examination the sinus was pneumatised and required augmentation. The root stumps were extracted and after a six-month waiting window, she was treated with an indirect sinus augmentation procedure using Densah™ burs (Jackson, MI: Versah, LLC) after which an implant (5 mm x 8 mm) was placed with good osseointegration at three-month follow-up. The Densah™ bur facilitated sinus lift procedure is a good option for pneumatised sinuses with inadequate residual bone height.

The Modified Osseodensification Visco-Elastic (MOVE) Sinus Protocol: A Case Series to Illustrate the Combination of Osseodensification with Viscoelastic Bone Replacement Material

INTRODUCTION

The Modified Osseodensification Visco-Elastic (MOVE) protocol combines two established techniques for sinus lifting: osseodensification drills to elevate the Schneiderian membrane, and the use of a viscoelastic putty to distribute forces on the membrane, a combination first described by Neiva et al. (2019). This case series elucidates the technique for combining these materials, and its possible benefits, which include reduced procedure time, less traumatic sinus elevation, and more versatility for unusual sinus anatomy, such as sloped sinus floors and immediate implant sites.

CASE SERIES

The three cases, illustrating a single implant, adjacent implants, and an immediate implant, demonstrate various indications for using the MOVE protocol, documented with two- and three-dimensional radiography. The MOVE protocol is explained in detail with supplemental photos of the steps.

CONCLUSION

Applying the MOVE protocol has the potential to allow for same-day implant placement in sites that previously required preoperative bone augmentation or lateral wall sinus access, thereby reducing the extent of surgical invasiveness associated with implant placement in the posterior maxilla.

Long-term effects of sinus membrane perforation on dental implants placed with transcrestal sinus floor elevation: A case-control study

BACKGROUND

There is a little comparative data on implants placed transcrestally with/without sinus membrane (SM) perforation.

PURPOSE

To compare the clinical and radiological outcomes of implants with maxillary sinus perforation and those without SM perforation.

MATERIALS AND METHODS

Among 560 transcrestally placed implants in 324 patients, the patients who underwent cone-beam computed tomographic radiography (CBCT) were included. The following groups were established: implants with SM perforation (group P) and implants without SM perforation based on postoperative panoramic radiographs and patient records (group NP). Group NP was further divided into subgroups based on CBCT taken at the last patient visit: group NP1 consisting of implants with no protrusion or <1 mm of protrusion and group NP2 consisting of implants with ≥1 mm of protrusion. Mixed linear regression was performed for the factors affecting SM thickening and marginal bone loss. Mixed survival analysis was also performed.

RESULTS

A total of 379 implants in 221 patients were eligible. The mean follow-up period was 112.03 ± 54.2 months. Twenty-six implants failed (2 and 24 implants in groups P and NP, respectively), mainly due to peri-implant bone loss. No statistically significant difference was noted between the groups in SM thickness (2.4 ± 2.8 mm, 2.1 ± 3.4 mm, and 2.5 ± 3.5 mm in groups P, NP1, and NP2, respectively, p > 0.05). Marginal bone loss in group NP1 was significantly greater than that in the other groups. In the mixed model, SM perforation was not a determinant of sinus membrane thickening and implant survival in the mixed models and the survival analysis, respectively.

CONCLUSIONS

SM perforation in transcrestal sinus augmentation did not affect implant survival and SM thickening.

Implant-supported rehabilitation following transcrestal and lateral sinus floor elevation: analysis of costs and quality of life from a bi-center, parallel-arm randomized trial

AIM

to comparatively evaluate costs and specific aspects of oral-health related quality of life (OhRQoL) related to the period between the surgery phase of transcrestal and lateral sinus floor elevation (tSFE and lSFE, respectively) and 6 months after delivery of implant-supported prosthesis.

METHODS

A bi-center, parallel-arm, randomized trial comparatively evaluating tSFE and lSFE when applied concomitantly with implant placement was conducted. At 6 months after prosthesis delivery, data on cost-associated items related to the post-surgery period and selected aspects of OhRQoL were collected.

RESULTS

Analyses of costs and quality of life was conducted on 56 patients (tSFE: 28; lSFE: 28) and 54 patients (tSFE: 26; lSFE: 28), respectively. Significantly lower dose of anesthetic (2 vs 3 vials), amount of xenograft (420 mg vs 1975 mg), and duration of surgery (54' vs 86') were observed for tSFE compared to lSFE. No significant differences in the number of additional surgical sessions, postoperative exams, specialist consultations and drug consumption were found between groups. In a limited fraction of patients in both groups, improvements were observed for pain (tSFE: 3.8%; lSFE: 7.4%), comfort in eating any food (tSFE: 11.5%; lSFE: 3.6%), self-consciousness (tSFE: 19.2%; lSFE: 14.3%), and satisfaction about life (tSFE: 19.2%; lSFE: 10.7%).

CONCLUSIONS

The surgery phase of maxillary sinus floor elevation is characterized by more favorable cost-associated items for tSFE compared to lSFE. Differently, tSFE and lSFE do not differ for either costs related to the post-surgery phases or impact of the implant-supported rehabilitation on specific aspects of OhRQoL.

Clinical Outcome of Dental Implants after Maxillary Sinus Augmentation with and without Bone Grafting: A Retrospective Evaluation

(1) Background: The purpose of the present study was to retrospectively evaluate and compare the outcome of two sinus augmentation grafting protocols using a xenograft or blood clot alone over a 72-month follow-up. (2) Methods: Patients who received simultaneous lateral sinus floor augmentation and implant placement were included. Subjects were divided into two groups according to the grafting material, namely xenograft or blood clot, and into sub-groups based on the residual alveolar bone height (RABH) below the maxillary sinus, namely 4 to 6 mm or >6 mm. Kaplan-Meier survival estimates were calculated for each material group and for each sub-group at 1, 3, and 6 years. (3) Results: In total, 289 implants inserted in 136 patients with a one-stage procedure were considered. A total of 35 failures were registered. Overall survival rates were 94.2% for xenograft and 85.9% for blood clot alone at 1 year, 91.1% and 81.6% at 3 years, and 91.1% and 78.7% at 6 years. (4) Conclusions: In patients with 4-6 mm RABH, graftless interventions exploiting blood clot alone were not as successful as those using xenograft. When the RABH is low, sinus floor augmentation associated with grafting materials should be preferred whenever possible.

Long-Term Comparison of Survival and Marginal Bone of Implants with and without Sinus Augmentation in Maxillary Molars within the Same Patients: A 5.8- to 22-Year Retrospective Study

Maxillary sinus floor augmentation (MSFA) is widely used and considered a predictable procedure for implant placement. However, the influence of MSFA on implant survival and marginal bone loss (MBL) is still inconclusive. The purpose of this retrospective observational study is to evaluate the long-term genuine influence of MSFA on the survival and MBL of implants by comparing those with and without MSFA only in maxillary molars within the same patients. Thirty-eight patients (28 male and 10 female), with a total of 119 implants, received implants with and without MSFA, and were followed up for 5.8 to 22 years. Patient- and implant-related factors were assessed with a frailty model for implant survival and with generalized estimation equations (GEE) for MBL around the implant. No variables showed a statistical significance for implant failure in the frailty model. In GEE analysis for MBL, MSFA did not show any statistical significance. In conclusion, MSFA demonstrated no significant influence on implant failure and MBL in posterior maxilla in this study.

Patient's perception of recovery after osteotome-mediated sinus floor elevation with Bio-Oss collagen compared with no grafting material: a randomized single-blinded controlled trial

Background

Osteotome-mediated sinus floor elevation with or without a grafting material is associated with high implant survival, intrasinus bone gain, and low frequency of complications. However, patient’s perception of recovery and satisfaction with the surgical intervention are rarely reported. The objective of the present randomized controlled trial was to assess patient’s perception of recovery after osteotome-mediated sinus floor elevation with Bio-Oss collagen compared with no grafting material. Forty healthy patients were randomly allocated to Bio-Oss collagen or no grafting material. Oral health-related quality of life was assessed by Oral Health Impact Profile-14 at enrollment. Patient’s perception of recovery was assessed by self-administrated questionnaires and visual analog scale evaluating pain, social and working isolation, physical appearance, duration and quality of life alterations, eating and speaking ability, diet variations, and sleep impairment after 1 week and 1 month, respectively. Descriptive statistics was expressed as mean percentage with standard deviation. Correlation between impaired oral health-related quality of life, age, gender, and recovery were assessed by T test. Level of significance was 0.05.

Results

Osteotome-mediated sinus floor elevation is associated with high patient satisfaction, limited postoperative discomfort, and willingness to undergo similar surgery. Influence on patient’s daily life activities seems to be minimal and limited to the first postoperative days. Most patients managed to return to work and their routine daily activities after 0-2 days. Impaired preoperative oral health-related quality of life, gender, or younger age seems not to predispose for delayed recovery. However, number of days with pain, eating difficulties, and sleep disturbances were significantly increased with Bio-Oss collagen compared with no grafting material (P<0.05).

Conclusion

Patient’s discomfort seems to be minimal and limited to the first postoperative days following osteotome-mediated sinus floor elevation with or without a grafting material. Impaired preoperative oral health-related quality of life, gender, or younger age seems not to predispose for delayed recovery.

[Radiography study on osteotome sinus floor elevation with placed implant simultaneously with no graft augmentation]

OBJECTIVE

To investigate the change of endo-sinus bone height and bone volume in osteotome sinus floor elevation (OSFE) without bone graft but placing implants simultaneously by using cone beam computed tomography (CBCT) and three dimensional analysis, and to find the impacting factors on endo-sinus bone augmentation.

METHODS

OSFE was performed in 38 edentulous patients with missing teeth at posterior maxillary region, and 44 implants were placed and referred for OSFE using no graft materials. CBCT was performed pre-surgery and 9－68 months post-surgery when the patients encountered another implant surgery. The gained bone height at mesial, distal, buccal and palatal sites around the implant in sinus were measured, volumetric measurements of the endo-sinus gained bone volume (ESGBV) in the elevated region were calculated by Mimics software. Univariate analysis and multiple linear regression were performed to investigate the impacting factors on the gained bone height and ESGBV. Marginal bone loss was recorded according to the periapical radiography after implant restoration.

RESULTS

The mean residual bone height (RBH) pre-surgery was (3.41±1.23) mm, the mean protruded length (PL) into sinus of implant post-surgery was (3.41±1.28) mm, the mean endo-sinus gained bone height was (2.44±1.23) mm at distal sites, (2.88±1.20) mm at mesial sites, (2.83±1.22) mm at buccal sites and (2.96±1.16) mm at palatal sites, the mean endo-sinus gained bone height at distal sites was significantly lower than the other three sites (P < 0.05). The average endo-sinus gained bone height was (2.78±1.13) mm. The mean ESGBV was (122.15± 73.27) mm³. Univariate analysis showed the more RBH, the less bone height gained in sinus, which existed at buccal, lingual, mesial and distal sites (P < 0.001), and the more RBH, the smaller ESGBV gained (P=0.012). The ESGBV was significantly higher in the subjects whose bone generation period was more than 24 months than those whose bone generation period less than 24 months (P=0.034). The more PL, the more bone height and ESGBV gained (P=0.008). Multivariate analysis showed after adjusting factors of gender, age, smoking, width of sinus floor, thickness of sinus membrane pre-surgery, diameter and length of the implant, PL and bone generation period was positively correlated with mean endo-sinus gained bone height and ESGBV, while RBH negatively correlated with mean endo-sinus gained bone height. During the follow-up, the mean marginal bone loss was 0 (0－1.41) mm and all the implants loaded successfully.

CONCLUSION

OSFE without bone graft but with placed implant simultaneously can increase endo-sinus gained bone height and ESGBV. RBH, PL and bone generation period are the significant factors impacting endo-sinus bone augmentation.

The rehabilitation of posterior atrophic maxilla by using the graftless option of short implant versus conventional long implant with sinus graft: A systematic review and meta-analysis of randomized controlled clinical trial

Aim

The purpose of systematic review and meta-analysis was to compare the efficacy of short implant versus conventional long implant with sinus graft in patients rehabilitated for posterior atrophic maxilla.

Setting and Design

Systematic review and meta analysis.

Materials and Methods

Electronic searches were conducted in Pub Med, Embase, and Medline with supplemented by manual search up to December 2019. The randomized controlled trial (RCTs) comparing short implant (<8.5 mm) and long implant (>8.5 mm) with sinus graft were included. (Prospero CRD42020186972).

Statistical Analysis Used

Random-effect model, fixed-effect model, A funnel plot and the Egger's test.

Results

Twenty-two Randomized controlled trials (RCTs) were assessed with 667 patients and 1595 implants (short implant:767, Long implant:835). No significant difference of implant survival rate was recorded for short and long implant (at patient level: RR: 1.01, 95% CI = 0.52-2.0, P = 0.87, I2 = 0%, at implant level RR = 1.09, 95% CI = 0.6-2.0, P = 0.7, I2 = 0%). Similarly marginal bone resorption was reported no difference for short and long implant (MD = 0.16. 95% CI: -0.23 = -0.08, P = 0.00, I2 = 74.83%). Biological complications were marginally higher for long implant (RR = 0.48, 95% CI = 0.23-0.8, P = 0.13, I2 = 29.11%). and prosthetic complications were marginally higher for short implants (RR=1.56, 95% CI=0.85-3.15, P = 0.43, I2 = 0%).

Conclusion

There was no significance difference in implant survival rate and marginal bone resorption recorded for both the short implant and long implant with sinus graft, in the patients rehabilitated with posterior atrophic maxilla. Hence, short implant is a suitable alternative to long implant with sinus graft, for the rehabilitation posterior atrophic maxilla.

[Effect of anatomical parameters of maxillary sinus on the outcomes of transcrestal sinus lift]

OBJECTIVE

To investigate the effect of three anatomical parameters (maxillary sinus width, maxillary sinus angle, and residual bone height) on the outcomes of transcrestal sinus lift with simultaneous implant placement.

METHODS

A total of 60 maxillary sinuses in 42 patients were included in this study. All patients were treated with transcrestal sinus lift procedure associated with simultaneous implant placement using a composite graft material of autogenous bone and Bio-Oss. For each patient, beam computed tomography (CBCT) scans were performed preoperatively, immediately after surgery, and 6 months after surgery. The parameters were measured on the preoperative and postoperative CBCT images. The correlation of three anatomical parameters with graft resorption was analyzed using Pearson's correlation test.

RESULTS

The average residual bone height was (4.46±1.55) mm. The average width of maxillary sinus was (13.86±2.71) mm. The average sinus angle was 78.09°±10.27°. A significant positive correlation was observed between maxillary sinus width and graft resorption (P<0.01). A positive association was also found between sinus angle and graft resorption (P<0.01).

CONCLUSIONS

The findings show that graft bone resorption in elevated sinus has a positive correlation with the sinus width and sinus angle.

Minimally invasive maxillary sinus augmentation with simultaneous implantation on an elderly patient: A case report

BACKGROUND

In this case study, a minimally invasive transalveolar approach using platelet-rich fibrin and bone substitute with simultaneous implantation was carried out in an elderly patient. We analyzed the cone-beam computed tomography (CBCT) findings to evaluate bone regeneration.

CASE SUMMARY

A 65-year-old female with no contraindications for dental implants and loss of maxillary bilateral molars is described. Examination by CBCT showed the available vertical bone height in the bilateral posterior maxilla was 0.5-6.8 mm in the left and 2.8-6.5 mm in the right. The patient underwent a transalveolar approach using platelet-rich fibrin and bone substitute with simulataneous placement of an implant 10 mm in length. Six months post-surgery, the implant showed excellent osseointegration with the bone graft. Thereafter, full-ceramic crowns were fitted. Follow-up at 2 years demonstrated satisfactory prognosis.

CONCLUSION

Platelet-rich fibrin and bone substitute can be used to augment the maxillary sinus with a vertical bone height less than 4 mm.

Does sinus floor elevation in the presence of Schneiderian membrane pathology increase therisk of membrane perforation and implant failure rate?

Schneiderian membrane (SM) thickness >2mm is regarded to be a pathological mucosal change. The aim of the current study is to answer the question" Does presence of pathological changes in the SM increase the risk of sinus perforation during surgical sinus floor elevation (SFE)?" An electronic database (PubMed, Embase, Cochrane Library, and Chinese database) were systemically searched for the studies published until February 2020. Randomized and non-randomized studies that reported the incidence of SM perforation in patients with SM pathology (antral pseudocyst or mucosal thickening) during SFE. The outcome measures were the incidence of SM perforation and implant survival rate. The pooled odds ratio (OR) with 95% confidence intervals and the Fixed-effects model were calculated. P-value ≤ 0.05 was considered to be statistically significant. Eighteen studies with a total of 1542 patients and 1797 SFE were included. Statistically insignificant difference in the incidence of SM perforation was observed between the normal-appearing sinus and thickened sinus mucosa (Fixed; OR, 0.896; 95%CI, 0.504 - 1.59; P =0.707, I 2 =32%). The rate of SM perforation in the normal sinus, mucosal thickening, and antral pseudocysts was 14%, 6%, and 6% respectively. The Implant survival rate was 98% in the normal sinus, and 100% in antral pseudocyst and mucosal thickening. SM thickening or antral pseudocyst did not increase the risk of membrane perforation and implant failure rates. Future RCTs are needed to evaluate the risk of the presence of pathological changes in the SM on the failure of the bone augmentation and dental implant.

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.

Long-term outcomes of osteotome sinus floor elevation without grafting in severely atrophic maxilla: A 10-year prospective study

OBJECTIVE

The aim of the present study was to report 10-year results of osteotome sinus floor elevation (OSFE) without grafting severely atrophic maxilla (residual bone height ≤4 mm).

MATERIALS AND METHODS

Patients undergoing OSFE without grafting and implant placement were included for 10-year examinations. Implant survival, complication-free survival, modified bleeding index (mBI), modified plaque index (mPI), pocket probing depth (PPD), peri-implant marginal bone loss (MBL), endo-sinus bone gain (ESBG) and mean cost of recurrence were evaluated.

RESULTS

Overall, 23 patients with 35 implants attended 10-year examination. Cemented implant crowns or implant-supported fixed dental prostheses were delivered to the patients. Kaplan-Meier implant survival was 89.2% at implant level and 84.1% at patient level. Complication-free survival was 26.0% at patient level and 37.0% at implant level. The average complication-free survival time was 74.6 months (95% CI: 63.2-86.0 months) at implant level and 69.1 months (95% CI: 54.8-83.4 months) at patient level. The mBI, mPI, PPD, MBL and ESBG at 10-year follow-up were 0.91 ± 0.58, 0.48 ± 0.51, 2.94 ± 0.79 mm, 1.63 ± 0.83 mm and 2.72 ± 0.51 mm, respectively. The cost of managing recurrence was 43.6% of the initial cost of treatment.

CONCLUSION

The results of the present study indicate that OSFE without grafting is a reliable treatment option in severely atrophic maxilla. Acceptable survival rate, stable MBL and ESBG could be achieved within 10 years. Low complication-free survival and high costs of recurrence management need to be considered.

Radiologic comparative analysis between saline and platelet-rich fibrin filling after hydraulic transcrestal sinus lifting without adjunctive bone graft: A randomized controlled trial

OBJECTIVES

To evaluate implant survival rate, any complications, and changes in residual alveolar bone height (RABH) using saline or platelet-rich fibrin (PRF) filling after hydraulic transcrestal sinus lifting.

METHODS

Dental implants were placed after hydraulic transcrestal sinus lifting and the filling of saline (20 patients) or PRF (20 patients). Outcome measurements were implant survival, any complications, and RABH changes. Cone-beam computed tomography (CBCT) scans were taken and compared preoperatively (T0), immediately postoperatively (T1), at 3 months (T2), 6 months (T3), and 12 months postoperatively (T4), respectively.

RESULTS

In a total of 40 patients, 45 implants with a mean length of 10.4 ± 0.8 mm were placed in posterior maxilla of a mean RABH of 6.8 ± 1.1 mm. The increase in RABH peaked at T1, and continuous drooping of the sinus membrane was observed but stabilized at T3. Meanwhile, the gradual increase in the radiopacities was found below the lifted sinus membrane. The PRF filling induced the radiographic intrasinus bone gain of 2.6 ± 1.1 mm, which was significantly more than 1.7 ± 1.0 mm of saline filling at T4 (p < .05). All the implants were in function with no significant complications over the one-year follow-up period.

CONCLUSIONS

In this randomized case-control study, the feasibility of hydraulic transcrestal sinus lifting without bone graft was confirmed and PRF might be a better filler to support the elevated sinus membrane. However, adjunctive bone grafting should still be indicated for cases requiring more than 2-3 mm of intrasinus bone gain.

Dental Implants in Sjögren Syndrome

Sjögren's syndrome (SS) is a complex autoimmune disease that predominantly affects the exocrine glands, notably the salivary and lacrimal glands, resulting in dryness of the mucosa recognized as xerostomia. Chief oral complications reported by patients consist of high caries rate, burning sensation of the mucosa, early tooth loss, intensified tooth wear and repetitive failure of dental restorations. In particular, due to the decreased salivary flow, conventional removable prostheses might irritate the mucosa and lead to painful ulcerations at the borders of the denture. Implant-supported prostheses offer a unique solution to the difficulties experienced by edentulous patients with Sjögren's syndrome. This research showed no signs of peri-implantitis or peri-implant mucositis during 7-years following the placement of implants. The present study indicates that successful long-term maintenance of dental implants can be also achieved in SS patients.

Dental implants in Sjögren syndrome

Sjögren's syndrome (SS) is a complex autoimmune disease that predominantly affects the exocrine glands, notably the salivary and lacrimal glands, resulting in dryness of the mucosa recognized as xerostomia. Chief oral complications reported by patients consist of high caries rate, burning sensation of the mucosa, early tooth loss, intensified tooth wear and repetitive failure of dental restorations. In particular, due to the decreased salivary flow, conventional removable prostheses might irritate the mucosa and lead to painful ulcerations at the borders of the denture. Implant-supported prostheses offer a unique solution to the difficulties experienced by edentulous patients with Sjögren’s syndrome. This research showed no signs of peri-implantitis or peri-implant mucositis during 7-years following the placement of implants. The present study indicates that successful long-term maintenance of dental implants can be also achieved in SS patients.

Long-term outcomes of the implants accidentally protruding into nasal cavity extended to posterior maxilla due to inferior meatus pneumatization

BACKGROUND

There is limited information about inferior meatus pneumatization in terms of implant treatment for the posterior maxilla.

PURPOSE

To demonstrate the clinical, radiologic, and nasal endoscopic outcomes of implants accidentally protruding into the nasal cavities with inferior meatus pneumatization in the posterior maxilla.

MATERIALS AND METHODS

A total of 560 implants (324 patients) with transcrestal sinus augmentation in the posterior maxilla were screened. On panoramic radiographs, 132 implants (78 patients) appear to penetrate the sinus floor, but cone-beam computed tomography demonstrated that 26 implants (13 patients) penetrated the nasal floor due to inferior meatus pneumatization. Width of nasal and sinus cavities and extent of penetration were radiographically measured. Nasal endoscopy was performed.

RESULTS

Two implants were lost during 13.81 ± 5.40 years due to peri-implantitis. However, no nasosinusal problem occurred in any patient. The nasal cavity was significantly larger in patients with implants penetrating the pneumatized inferior meatus than in those with implants penetrating the sinus floor (P< .05). Nasal endoscopy demonstrated that the apical portion of the implants was covered with thin mucosa without inflammation.

CONCLUSION

Implants accidentally penetrating the pneumatized inferior meatus demonstrated high survival with no specific nasosinusal complications. Inferior meatus pneumatization should be considered for implant treatment in the posterior maxilla.

An alternative approach to transalveolar sinus elevation for the placement of multiple implants

Traditional approaches to sinus floor elevation for dental implant placement have limitations. This technical report describes a modified transalveolar method of elevating the sinus membrane when 2 or more implants are placed simultaneously in a maxillary posterior area where the residual bone height is insufficient. With a narrow osteotomy connecting drilled holes, the Schneiderian membrane can be directly elevated with curettes as with the lateral approach, resulting in a reduced risk of perforation.

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.

Biomaterial and biomechanical considerations to prevent risks in implant therapy

This paper is aimed to present a biomaterials perspective in implant therapy that fosters improved bone response and long-term biomechanical competence from surgical instrumentation to final prosthetic rehabilitation. Strategies to develop implant surface texturing will be presented and their role as an ad hoc treatment discussed in light of the interplay between surgical instrumentation and implant macrogeometric configuration. Evidence from human retrieved implants in service for several years and from in vivo studies will be used to show how the interplay between surgical instrumentation and implant macrogeometry design affect osseointegration healing pathways, and bone morphologic and long-term mechanical properties. Also, the planning of implant-supported prosthetic rehabilitations targeted at long-term performance will be appraised from a standpoint where personal preferences (eg, cementing or screwing a prosthesis) can very often fail to deliver the best patient care. Lastly, the acknowledgement that every rehabilitation will have its strength degraded over time once in function will be highlighted, since the potential occurrence of even minor failures is rarely presented to patients prior to treatment.

[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.

Linear measurements of sinus floor elevation based on voxel-based superimposition of cone beam computed tomography images

BACKGROUND

Postsurgical evaluation of sinus floor elevation regularly involves linear measurements of the elevated volumes in the cone beam computed tomography (CBCT) images. The accuracy of measurements could be compromised due to ill-defined sinus floor outline if implants are placed simultaneously.

PURPOSE

The aim was to examine a CBCT superimposition method to improve the measurement accuracy.

MATERIALS AND METHODS

Twenty patients who received transalveolar sinus floor elevation with immediate implantation were enrolled. CBCTs before and after surgery were transformed into digital imaging and communications in medicine format and imported into the Dolphin Imaging software. Voxel-based superimposition was automated to merge the files. In the superimposed image, parameters including alveolar bone height, protruded implant length, and total elevated height were measured. The superimposition and measurements were performed independently by two examiners and in two timepoints with 1-week time interval. We used intraclass correlation coefficient (ICC) to analyze the interexaminer and intraexaminer agreements.

RESULTS

Of measured parameters, the mean of difference between two timepoints ranged from 0.18 to 0.26 mm by examiner 1, and from 0.16 to 0.20 mm by examiner 2. ICCs were equal or greater than 0.98, indicating perfect intraexaminer agreement. For interexaminer reliability, the largest mean of difference was 0.27 mm in measuring alveolar bone height between two examiners. ICCs were greater than 0.98, showing perfect interexaminer agreement.

CONCLUSIONS

The voxel-based superimposition of pre- and post-surgical CBCT images with Dolphin Imaging is an effective and reliable way for linear measurements so as to assess the surgical outcome. There is minimal effect on reproducibility of measured data by different timepoints or performers.