Osteotome Sinus Floor Elevation without Grafting: A 10-Year Prospective Study

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.

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL RELEVANCE

Clinically, OSFE with grafting materials provides no additional benefit.

CLINICAL TRIAL REGISTRATION NUMBER

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

Radiographic Study of Transcrestal Sinus Floor Elevation Using Osseodensification Technique with Graft Material: A Pilot Study

This pilot study aimed to evaluate the level of implant success after transcrestal sinus floor elevation (tSFE) using the osseodensification technique (OD) combined with beta-tricalcium phosphate (β-TCP) by analyzing clinical and radiographic results. Moreover, the increase in bone height was analyzed immediately after surgery, 3 months after, and before loading by taking standardized radiographic measurements. Thirteen patients, four males and nine females, with a mean age of 54.69 ± 5.86 years, requiring the placement of one implant in the upper posterior maxilla, with a residual bone height of <8 mm and a minimum bone width of 5 mm, participated in the study. The bone gain data was obtained using cone-beam computed tomography (CBCT) immediately after surgery and twelve months after the placement. The correlation between initial and final bone height with implant stability was also assessed. The results were analyzed using SPSS 23 software (p < 0.05). The results of the study indicated a 100% implant success rate after a follow-up period of twelve months. Preoperative main bone height was 5.70 ± 0.95 mm. The osseodensification technique allowed a significant increase of 6.65 ± 1.06 mm immediately after surgery. After a twelve-month follow-up, a graft material contraction of 0.90 ± 0.49 mm was observed. No correlation was observed between the bone height at the different times of the study and the primary stability of the implant. Considering the limitations of the size sample of this study, the osseodensification technique used for transcrestal sinus lift with the additional bone graft material (β-TCP) may provide a predictable elevation of the maxillary sinus floor, allowing simultaneous implant insertion with adequate stability irrespective of bone height limitations.

APCs in sinus floor augmentation

After tooth loss in the posterior area of the maxilla, sinus floor elevation is often required to compensate the vertical bone loss due to sinus pneumatization. This narrative review reports on the potential benefits of autologous platelet concentrates (APCs) during this procedure. As for transcrestal approach, APCs have been used as "sole" substitute/graft. However, because of the low number of clinical trials available with PRGF, and even none for PRP, no definitive conclusions can be made regarding their efficacy. The number of studies on the use of L-PRF were outnumbered indicating good feasibility for vertical bone gain, with a high implant survival rate and a low degree of complications. PRP and PRGF have not been studied as a "single/sole" substitute for a one-stage lateral window approach, probably because of the weak physical characteristics of the membranes. L-PRF alone appears to be a predictable grafting material for lateral maxillary sinus grafting and a reduced RBH should not be considered as a risk factor. Compared to a "standard" bone substitute L-PRF shows slightly less vertical bone gain (consider enough membrane application and use of bony window as new sinus floor roof over the implant apices), enhanced early resorption (first 6 months after application), but a similar stable bone gain afterward. For a two-stage lateral window approach, APCs "alone" cannot be recommended, due to their weak withstand to the sinus pneumatization forces. APCs combined with bone substitutes seem to accelerate bone formation, without any additional benefits on the long-term new bone gain. The use of L-PRF membranes for the treatment of perforations appears to be an effective treatment option, but further clinical studies are needed to confirm this. Even though the abovementioned statements are based on large numbers of studies, additional RCTs comparing APCs with different types of grafting procedures for sinus elevation are needed.

Extra-short implants (≤ 6.5 mm in length) in atrophic and non-atrophic sites to support screw-retained full-arch restoration: a retrospective clinical study

PURPOSE

Increasing scientific evidence support extending the application of short dental implants to non-atrophic dental arches. The purpose of this study has been the evaluation of extra-short implants (≤ 6.5 mm in length) that were placed in atrophic and non-atrophic anatomical sites to support the same prosthesis.

METHODS

For that, a retrospective study was conducted by including complete dentures that were solely supported by extra-short implants in the maxilla and/or the mandible. Clinical data about patients, implants, anatomy, and prosthesis were obtained. Statistical analysis was performed to assess implant- and prosthesis-survival, changes in the marginal bone level and prosthetic complications.

RESULTS

A total of 87 implants in 15 screw-retained complete dentures were assessed. None of the prostheses nor the extra-short implant failed during the follow-up of 27.2 ± 15.4 months. The changes in the mesial and distal marginal bone level were + 0.15 ± 0.51 mm and + 0.11 ± 0.50 mm, respectively. Comparing the implants according to the availability of sufficient bone to place longer implants, indicated the absence of significant differences in the changes of the mesial marginal bone level. However, the changes in the distal marginal bone level showed a statistically significant difference in favor of implants that were placed in non-atrophic sites. Two events of screw loosening were reported that were resolved by retightening the screws.

CONCLUSIONS

Implant- and prosthesis-related outcomes support the use of extra-short implants in atrophic and non-atrophic site to support complete prosthesis.

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.

Radiographic results of osteotome-driven maxillary sinus floor elevation without grafting materials after 17.5 years radiographic evaluation of minimally-invasive sinus grafting

BACKGROUND

There is growing evidence that minimally invasive sinus augmentation works without the use of filler materials. This study assessed the bone integration and sinus projection of single-unit implants in the maxilla, which were placed approximately 18 years ago using a modified filler-free osteotome technique.

METHODS

Sixteen of the 24 treated patients of a former publication (treatment was performed between 2001 and 2004) were reassessed after a mean implant loading period of 17.5 years. The treated posterior areas were evaluated using cone-beam computed tomography (CBCT), and as a primary outcome parameter, sinus projection was determined in sectional views at the mesial, distal, buccal, and oral sites. Additionally, the percentage of alveolar bone contact was determined with respect to the implant length. Conventional radiographs were used to determine marginal bone levels. Additionally, plaque, bleeding on probing, and probing pocket depth were measured. The reconstructions were checked for chipping and other technical complications such as loss of retention, screw loosening, and screw fracture.

RESULTS

The mean age of the included patients was 72.8 ± 8.5 years. Two implants were lost. Therefore, fourteen implants were available for CBCT evaluation. The highest sinus projection of 2.1 ± 1.7 mm was observed in the distal aspect, while it was 1.1 ± 1.5, 0.9 ± 1.2, and 0.9 ± 1.1 mm at the mesial, buccal, and oral sites, respectively. The maximal sinus projection in one case was 6.7 mm. The percentage calculation of osseous implant integration (in mm ± standard deviations) with respect to the selected implant length at the mesial, distal, buccal, and oral sites showed values ranging from, 87.9 ± 16.0, 78.4 ± 20.3, 91.0 ± 12.5, and 90.5 ± 11.1%, respectively. Five implants displayed probing pocket depths of more than 4 mm with bleeding; all implants had less than 1 mm of bone loss in the observation period, that is, implants had mucositis. Six of 14 crowns showed small chippings within the ceramic veneering. One case of screw loosening was reported in medical history.

DISCUSSION

This study showed that implant placement in non-augmented sinuses resulted in good clinical results. The sinus projection, even if persistent and present, leads to no functional impairments. Given adequate maintenance, marginal bone levels remain constant and peri‑implant health can be observed. Moreover, these results represent only a small cohort; and therefore, should be interpreted with caution. However, in view of the existing literature, these highly promising results are in line with other findings.

CLINICAL SIGNIFICANCE

To the best of our knowledge, this dataset is the report with the longest follow-up. Overall, implants placed in the sinus without fillers represent a valuable alternative for tooth replacement in a minimally interventional manner.

Osteotome sinus floor elevation with concentrated growth factor and simultaneous implant placement with or without bone grafting: a retrospective study

The aim of this study was to compare the clinical effects of osteotome sinus floor elevation (OSFE) combined with concentrated growth factor (CGF) and simultaneous implant placement with or without bone grafting in the maxillary posterior region, where the residual bone height (RBH) was 4-6 mm. A total of 44 patients who underwent OSFE combined with CGF and the simultaneous placement of 60 implants (group A, 31 implants with bone grafting; group B, 29 implants without bone grafting) were included in this retrospective study. The clinical indicators of implants were observed for 24 months. Sinus floor lift height was 6.02 ± 0.99 mm in group A and 5.81 ± 0.72 mm in group B (P = 0.360) after surgery. There was no significant difference in the vertical bone resorption between the two groups at 24 months (P = 0.097). Postoperative pain at 14 days (visual analogue scale) was significantly greater in patients with bone grafting when compared to those without bone grafting (P < 0.001). There was no significant difference in marginal bone loss (MBL) between the two groups (P = 0.707 for MBL during the first 12 months, P = 0.922 for MBL during months 12-24). The implant success rate was 100% with or without bone grafting. The technique of OSFE with CGF, either with or without bone grafting, is safe and reliable in patients with RBH 4-6 mm.

Influence of anatomical factors related to maxillary sinus on outcomes of transcrestal sinus floor elevation

Background/purpose

Graft bone maturation and remodeling in the maxillary sinus require adequate angiogenesis and osteoprogenitor cells migration from the surrounding bony walls and Schneiderian membrane. This study aimed to evaluate the influence of anatomical factors related to maxillary sinus on the outcomes of transcrestal sinus floor elevation using cone-beam computed tomography (CBCT).

Materials and methods

Forty-five patients (63 elevated sites) were included in this study. CBCT were obtained preoperatively, immediately and 6 months after surgery. The anatomical features of residual bone height, maxillary sinus width, maxillary sinus angle and Schneiderian membrane thickness were measured on preoperative CBCT. Descriptive statistics and correlation analysis were conducted to evaluate the influence of anatomical factors on outcome parameters, including sinus lift height, graft bone resorption and marginal bone loss.

Results

The results showed that there was a positive correlation between sinus width and graft bone resorption. A significantly positive correlation between sinus angle and graft bone resorption was also found.

Conclusion

Our findings indicate that the anatomical factors of maxillary sinus (sinus width and sinus angle) have influence on the linear change of bone grafts after transcrestal sinus floor elevation.

Displacement of the full body of a dental implant into the sinus space without membrane perforation and subsequent osseointegration: a case report

An increasing number of studies have investigated the use of osteotome sinus floor elevation (OSFE) with simultaneous implant placement for maxillary sinus floor residual bone height (RBH) <4 mm. Many studies have reported good clinical results, but very few have reported complications related to this procedure. Here, the case of a 50-year-old female patient with an RBH in the left upper posterior region of 1–4 mm, who underwent OSFE with simultaneous placement of three Bicon short® implants, is described. One of the implants was found to be displaced during the second-stage surgery. The displaced implant was removed using piezosurgery, OSFE with simultaneous implant placement was repeated, and the missing tooth was reconstructed 6 months later. This case suggests that OSFE with simultaneous implant placement is feasible for severely atrophic maxillary sinus floor, but carries a risk of implant displacement.

Influence of maxillary antrolith on the clinical outcome of implants placed simultaneously with osteotome sinus floor elevation: A retrospective radiographic study

BACKGROUND

Large antroliths and those located adjacent to the sinus floor can affect clinical interventions and increase the difficulty of implant placement performed simultaneously with osteotome sinus floor elevation surgery.

PURPOSE

This retrospective study investigated the clinical outcomes of implants placed simultaneously with osteotome sinus floor elevation subjacent to maxillary antroliths.

MATERIAL AND METHODS

Twenty implants inserted subjacent to or intruding into the antrolith after sinus floor elevation were evaluated in 18 patients. Cone-beam computed tomography (CBCT) was used to measure antrolith size and membrane thickness at sites of osteotome sinus floor elevation. Periapical radiographs were used to assess the height of grafted bone. Generalized estimating equation (GEE) analysis was performed to correlate the occurrence of antroliths with patient background characteristics and dental outcomes, based on a sample population of 239, among whom 33 presented antroliths.

RESULTS

The 20 implants remained clinically stable over a mean follow-up period of 42.4 months. The mean thickness of the sinus membrane at osteotome sites was 5.4 ± 3.3 mm. None of the cases presented sinus membrane perforation or sinus symptoms following osteotome intervention. The mean gain in the height of grafted sinus bone was 4.0 ± 1.4 mm at the last follow-up. The occurrence of antroliths was higher among females and the elderly (>49 years old). The multivariable GEE analysis showed that the adjusted odds ratio for the occurrence of antroliths with root canal fillings was significantly lower than those without root canal fillings (odds ratio = 0.33; 95% confidence interval = 0.11-0.96).

CONCLUSION

Our findings indicate that osteotome sinus floor elevation is a surgical procedure with a risk <17%. Thorough planning based on CBCT and careful management during surgery can eliminate the negative effects of antroliths on implant performance.

Outcomes of implants placed after osteotome sinus floor elevation without bone grafts: a systematic review and meta-analysis of single-arm studies

Background

The aim of this study is to evaluate the implant survival/success rate, gain in alveolar bone height, crestal bone loss, and complications associated with implants placed in the posterior maxilla after osteotome sinus floor elevation without bone substitutes.

Methods

The electronic databases, such as MEDLINE, EMBASE, CENTRAL, and SCOPUS were systematically and manually searched for publications in peer-reviewed journals. The included articles were subjected to qualitative and quantitative analyses, and the meta-analysis was carried out for single-arm studies. Methodological quality assessment was made for all the included studies.

Results

The included studies were of moderate quality, with the overall implant success and survival rates of 98.3% and 97.9% respectively. The most frequent intra-surgical complication was sinus membrane perforation, accounting for 3.08% of the total implants with reported perforations. The overall crestal bone loss in patients with immediate implants placed with OSFE after a 5-year follow-up was 0.957 mm 95%CI (0.538, 1.377).

Conclusion

Within the limitations of this review, it can be concluded that the survival and success rates of implants placed immediately along with OSFE without any bone substitutes are acceptable and show adequate implant stability with less crestal bone loss over 5 years.

Scientometric Analysis of Dental Implant Research over the Past 10 Years and Future Research Trends

BACKGROUND

We conducted a bibliometrics analysis to explore the recent trends in dental implant research which could help researchers have a clear grasp of the relevant research hotspots and prospects. Material and Methods. Altogether, 15,770 articles on dental implants, from January 1, 2010, to October 31, 2019, were selected from the Web of Science Core Collection. We used BICOMB software to extract the high-frequency MeSH terms and construct binary and coword matrices. gCLUTO software was used for biclustering and visual analysis, Ucinet 6 software for social network analysis, SCIMAT software for strategic diagram building, Citespace 5.5 software to form timeline visualization, and VOSviewer software, eventually, for bibliometrics cocitation network.

RESULTS

Altogether, 72 high-frequency keywords were extracted from the selected articles and 4 clusters and 7 subcategories were identified through biclustering analysis in the dental implant research field. The use of the strategic diagram also enabled us to find the research hotspot and development trends.

CONCLUSIONS

The survival rate of dental implants and subsequent restoration have always been the core focus of research. Sinus floor elevation and guided bone regeneration are worthy of constant exploration owing to their reliability. With continuous improvement in technology, immediate loading could become a future research hot spot.

Different techniques in transalveolar maxillary sinus elevation: A literature review

Dental implant treatment in the posterior maxilla encounters bone quality and quantity problems. Sinus elevation is a predictable technique to overcome height deficiency in this area. Transalveolar sinus elevation is a technique that is less invasive and less time-consuming, first introduced for ridges with at least 5 mm of bone height. Many modifications and innovative equipment have been introduced for this technique. This review aimed to explain the modifications of this technique with their indications and benefits.

An exhaustive search in PubMed Central and Scopus electronic databases was performed until December 2020. Articles were selected that introduced new techniques for the transalveolar maxillary sinus approach that had clinical cases with full texts available in the English language. Finally, twenty-six articles were included. The data were categorized and discussed in five groups, including expansion-based techniques, drill-based techniques, hydraulic pressure techniques, piezoelectric surgery, and balloon techniques.

The operator’s choice for transalveolar approach techniques for sinus floor elevation can be based on the clinician’s skill, bone volume, and access to equipment. If possible, a technique with simultaneous implant placement should be preferred.

Influence of implant protrusion length on non-grafting osteotome sinus floor elevation with simultaneous implant: a 3- to 9-year retrospective study

BACKGROUND

This study analyzed the influence of implant protrusion length (IPL) on the possible factors that affect the long-term outcomes utilizing non-grafting osteotome sinus floor elevation (OSFE) with simultaneous implant placement, and to explore the optimal range of IPL.

MATERIALS AND METHODS

A retrospective study design was adopted. The clinical and radiographic data of 105 implants in 65 patients were collected after 3-9 (mean 5.04) years follow-up. IPL was divided into three groups (group1, IPL<2mm; group2, 2mm≤IPL<4mm; group3, IPL≥4mm). Endo-sinus bone gain (ESBG), peri-implant marginal bone loss (MBL), bone to implant contact length (BICL), and percentage of ESBG (%ESBG) were used to evaluate non-grafting OSFE. A Kaplan-Meier analysis was performed to assess the cumulative survival rate. Multiple linear regression model was used to explore the relationship between the possible influence factors and ESBG. Analysis of variance (ANOVA) was applied to explore the correlation of IPL with ESBG, MBL, BICL, and %ESBG.

RESULTS

A total of 102 implants in 62 patients fulfilled the survival criteria, giving the cumulative survival rates of 96.4% and 94.1% for implant-based analysis and patient-based analysis, respectively. The mean ESBG, MBL, and BICL at the latest follow-up were 1.95±0.88 mm, 0.58±0.68 mm, and 5.51±1.47 mm. ESBG was found to be positively correlated to IPL. A significant decreased bone formation efficiency was found when IPL was over 4 mm (P=0.02).

CONCLUSIONS

An optimal range of IPL within 4 mm was recommended for better long-term outcomes when applying non-grafting OSFE with simultaneous implant placement.

[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.

Sinus Floor Elevation via an Osteotome Technique without Biomaterials

According to classic Hirschfeld studies, the first teeth to be lost are the first and second maxillary molars. After the teeth are extracted and the alveolar process is developed, the maxillary sinus is reabsorbed and pneumatized with a decrease in bone availability in the posterior sector of the maxilla. This process often creates the need to perform regeneration techniques for the placement of implants in this area due to the low availability of bone. The most frequently used and documented technique for the elevation of the sinus maxillary floor is elevation by the side window, as proposed by Tatum. In 1994, Summers proposed a technique that allowed the elevation of the sinus floor from a crestal access using an instrument called an osteotome, as well as the placement of the implant in the same surgical act. The aimed of the study was to evaluate the survival of 32 implants placed in posterior maxilla with bone availability less than 5 mm performing a sinus lift augmentation technique with osteotome without biomaterials. The results of this study show a survival rate of 100% for 32 implants placed in situations with an initial bone availability of 2 to 5 mm without the use of graft material. The infra-drilling technique used offers an increase in the primary stability of implants that allows adequate osteointegration Implants placed were charged at 12 weeks. In all cases, spontaneous bone formation was observed, even in cases where a positive Valsalva maneuver was observed. This proposed technique reduces treatment time and the need for more invasive maxillary sinus augmentation techniques.

The comparative evaluation of transcrestal and lateral sinus floor elevation in sites with residual bone height ≤6 mm: A two-year prospective randomized study

OBJECTIVES

To compare clinical and radiographic outcomes between transcrestal sinus floor elevation (TSFE) and lateral sinus floor elevation (LSFE) approaches of simultaneous implant placement in atrophic maxilla.

MATERIALS AND METHODS

Patients with a residual bone height (RBH) ≤6 mm were enrolled and randomly assigned to TSFE and LSFE groups. Patients in both groups simultaneously underwent sinus floor elevation with bovine-derived xenograft and implant placement. Clinical and radiographic results were evaluated immediately after surgery and after 6, 12, 18, and 24 months. The endo-sinus bone gain (ESBG), apical implant bone height (ABH), endo-sinus bone-implant contact rate (EBICR), and crestal bone level (CBL) were assessed using panoramic radiographs.

RESULTS

Forty-one implants (TSFE: 21, LSFE: 20) were placed in cases with a mean RBH of 3.77 ± 1.16 mm. All implants obtained clinical success and satisfactory ESBG at 24 months. No significant differences were found in ESBG and ABH between two groups immediately after surgery, but LSFE group showed significantly higher values than TSFE group thereafter. Grafts in TSFE group reached stability 6 months earlier than that in LSFE group. In both groups, EBICR was almost 100%, and CBL showed no detectable changes.

CONCLUSIONS

LSFE can achieve higher ESBG 2 years after surgery. Otherwise, TSFE could be an alternative to LSFE, when the access for lateral window preparation is limited. Both approaches were highly predictable for RBH ≤6 mm during 24-month observation period for the implants placed simultaneously.

Navigated Antral Bone Expansion (NABE): a prospective study on 35 patients with 4 months of follow-up post implant loading

Background

The insertion of dental implants in the atrophic posterior maxilla can be a challenge. One option is to modify the residual native bone in preparation for proper, prosthetically-driven implant placement. The procedure presented in this study is called Navigated Antral Bone Expansion (N.A.B.E). This procedure employs the use of a navigation system to plan and guide the initial pilot drilling, bone expansion, final site preparation, and implant insertion. The aim of this study was to compare the distance between the alveolar ridge and the sinus floor measured before and after the surgery performed using the N.A.B.E. technique.

Methods

Thirty-seven partially edentulous patients who were candidates for implant supported restoration in the posterior maxilla, with a bone height ranging from 4 to 7 mm were enrolled. The N.A.B.E procedure was used to increase the bone height. Paired-samples t-test evaluated the distance between the alveolar ridge and the sinus floor measured before and after surgery. The occurrence of post-surgical complications, and the angular deviation between the planned osteotomy and the actual placed implant trajectories were evaluated.

Results

Out of the 37 consecutive patients enrolled in the study, 35 were considered in the data analyses. Patients’ bone height after surgery compared to the bone height before surgery showed a statistically significant increase (p < .0005) of 3.96 mm (95% CI, 3.62 mm to 4.30 mm). No post-operative complications were observed in the 35 patients. The mean angular deviation between the planned osteotomy trajectory and the placed implant trajectory ranged between 12.70⁰ to 34.90⁰ (mean 25.17⁰ ± 5.10⁰).

Conclusions

This study provides evidence that N.A.B.E. technique is able to provide a significant bone increase, and could be considered an alternative method to the management of the atrophic posterior maxilla with a minimally invasive approach.

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.

Distal Displacement of Maxillary Sinus Anterior Wall Versus Conventional Sinus Lift with Lateral Access: A 3-Year Retrospective Computerized Tomography Study

Background: The present study is designed to compare the outcomes of two sinus augmentation procedures: distal displacement of the anterior wall versus standard sinus lifting and grafting with a lateral window approach. Methods: In the displacement group, a localized surgical fracture of the sinus floor achieved through an electromagnetic device results in the distal displacement of the anterior wall. In the filling group, sinus lifting (with lateral access) and grafting with particulate xenogeneic bone substitute was performed. Bone volume beneath the maxillary sinus was investigated with computerized tomography after baseline and postoperative data superimposition. Clinical and radiological outcomes over three years had been evaluated. Results: Forty-three dental implants were selected. The two sinus lift procedures significantly increased the bone volume (p-value ≤ 0.0017) in the displacement group from 1.17 ± 0.34 to 1.53 ± 0.39 cc, with a final bone gain of +0.36 ± 0.17 cc, and in the filling group from 1.24 ± 0.41 to 1.94 ± 0.68 cc, with a bone augmentation of +0.71 ± 0.31 cc. No events of dental implant bulging into the maxillary sinus occurred. Two implants failed early on in the filling group, attesting the 3-year survival rate of 92.6% (CI95%: 82.7–100%). Marginal bone loss at the distal aspect was 1.66 ± 0.72 and 1.25 ± 0.78 mm, respectively, for the displacement and filling groups, with a significant difference (p-value = 0.0497). Conclusion: Results showed a significant and effective bone gain around dental implants at a 3-year survey for both sinus augmented by backward displacement of the anterior wall (+34%) and sinus lifting and grafting with a lateral window approach (+57%).

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.

Evaluation of maxillary sinus floor augmentation with the crestal approach and beta-tricalcium phosphate: a cone-beam computed tomography 3- to 9-year follow-up

Background

We performed maxillary sinus floor augmentation using the crestal approach and beta-tricalcium phosphate (β-TCP) and a long-term evaluation using cone-beam computed tomography (CBCT).

Methods

Twenty-three patients (30 implants) underwent sinus floor augmentation using the osteotome technique. Subjects underwent CBCT imaging before surgery, immediately after surgery, and at follow-up (≥ 3 years after surgery). We measured the changes in height of the augmented sinus floor (SL), the augmented bone above apex of the implant (BH), and the implant length that projected into the sinus (IL).

Results

The mean SL decreased from 6.54 ± 1.51 (immediately after surgery) to 3.11 ± 1.35 mm (follow-up). The mean BH decreased from 3.17 ± 0.97 to − 0.25 ± 1.19 mm; the maxillary sinus floor in many implants was near the apex at follow-up. The SL at follow-up showed a strong correlation with the IL (p = 0.0057).

Conclusions

Osteotome sinus floor elevation with beta-tricalcium phosphate was clinically effective. Cone-beam computed tomography analysis revealed that ≥ 3 years after surgery, the maxillary sinus floor was near the apex of the implant.

Long-term apical bone gain after implant placement combined with internal sinus-floor elevation without graft

BACKGROUND

To assess changes in apical bone height/bone gain over up to 8 years after implant placement combined with simultaneous internal sinus-floor elevation (ISFE) without use of graft.

METHODS

217 implants were placed in combination with graft-free ISFE and successfully healed in the posterior maxilla of 138 patients. Radiographs after surgery across an evaluation time of up to 8 years were analyzed. Changes in apical and marginal bone height related to the implants were measured. Differences in bone height over the study period were evaluated by use of Wilcoxon tests. To identify possible influencing factors on apical bone gain and marginal bone loss, backward linear regression variable selections and linear mixed regression models were performed.

RESULTS

At the apical aspects of the implants, significant mean vertical bone gain of 2.4 mm (mesial) and 2.6 mm (distal) was observed after 6 months (p < 0.05). Radiographic analysis yielded additional bone gain of up to approximately 3.5 mm over the study period. Small initial bone height was crossed with more pronounced apical bone gain (p < 0.05).

CONCLUSIONS

If implants are placed combined with graft-free ISFE, significant vertical bone gain, especially in the first year post-op, can be expected. Smaller initial bone height is associated with a higher likelihood for greater bone gain.

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).

Therapeutic outcomes of non-grafted and platelet concentrations-grafted transcrestal maxillary sinus elevation (TSFE): a systematic review and meta-analysis

To evaluate and compare the stability, quantity and quality of bone augmentation at maxillary sinus elevation sites by non-grafted transcrestal sinus floor elevation (TSFE) and platelet concentration grafted transcrestal sinus floor elevation (PC-TSFE). A complete literature search was performed up to April 2019. Clinical controlled trials, retrospective cohort studies, and prospective cohort studies were selected based on inclusion criteria. The clinical outcomes were implant survival rate (ISR), marginal/crestal bone loss (MBL/CBL) and endo-sinus bone gain (ESBG). Meta‐analysis was conducted on these 1-year based values. Furthermore, another meta-analysis on 1-year ISR value was conducted among studies with different residual bone heights (RBH) within the non-grafted TSFE group. A total of 18 studies were included: 13 in TSFE group and 5 in PC-TSFE group. No significant differences were displayed between the 1-year ISR of TSFE (97%, 95%CI = 0.96–0.99) and PC-TSFE group (99%, 95%CI = 0.97–1.00). Among the various studies with different RBH within TSFE group, no significant differences in 1-year ISR were displayed. The 1-year MBL/CBL value of PC-TSFE group (0.73 mm, 95%CI = 0.43–1.13 mm) did not show significant difference as compared to TSFE group (0.60 mm, 95%CI = 0.10–1.10 mm). Furthermore, no significant enhancement was observed on 1-year ESBG value on PC-TSFE group (3.51 mm, 95%CI = 2.31–4.71 mm) in comparison with the TSFE group (2.87 mm, 95%CI = 2.18m–3.55 mm). Grafting platelet concentrations around dental implants at TSFE sites did not significantly enhance the adjacent bone regeneration. Moreover, TSFE was shown to be a reliable therapeutic option for implant sites that need simultaneous maxillary sinus augmentation, even under limited RBH.

Assessment of the Simultaneous Use of Biomaterials in Transalveolar Sinus Floor Elevation: Prospective Randomized Clinical Trial in Humans

Implants inserted in the posterior maxilla frequently need additional surgery for successful bone augmentation. One of the most common procedures for this is transalveolar sinus floor elevation. There are different protocols for this procedure, and there is controversy over the simultaneous application of grafting material upon elevating. In this prospective randomized clinical study in humans, a total of 49 transalveolar sinus floor elevations were performed in 49 different patients, divided into a control group (without graft, 25 patients) and a test group (with graft, 24 patients). The analyzed variables were obtained through digital orthopantomography on day 0 (day of surgery) and 18 months after surgery. These measurements showed a tendency towards greater vertical bone gain in the test group, but this was not statistically significant. Therefore, considering that sinus elevation and implant placement without the application of grafts is a successful treatment with fewer complications, a critical assessment of the need for these biomaterials is necessary.

Evaluation of New Bone Formation in Sinus Floor Augmentation With Injectable Platelet-Rich Fibrin-Soaked Collagen Plug: A Pilot Study

INTRODUCTION

The objective of this study is to evaluate the new bone formation after sinus floor augmentation with collagen plugs used as carriers for injectable platelet-rich fibrin (i-PRF).

MATERIALS AND METHODS

Postoperative immediate and postoperative 6th month panoramic radiographies of patients treated between January 1, 2015, and February 1, 2018, with sinus floor augmentation using i-PRF-soaked collagen plugs were retrieved from the archives, and subantral bone heights of distal and mesial regions of simultaneously inserted implants were measured with a software program. Statistical analysis was performed to understand whether there is a significant change in new bone formation at 6th month follow-up control.

RESULTS

A total of 18 implants were inserted in 12 patients. There was significant new bone formation at 6th month follow-up radiography at mesial and distal regions of inserted implants (P < 0.05).

CONCLUSION

New bone was regenerated with i-PRF carried by collagen plugs in sinus floor augmentation.

Bone Levels Are Preserved After Simultaneous Sinus Elevation at Time of Implant Placement

PURPOSE

The purpose of this study was to confirm that after simultaneous implant placement and vertical bone augmentation in the posterior maxilla, the immediate postoperative bone height is maintained after 2 to 3 years of follow-up.

PATIENTS AND METHODS

Consecutive patients treated with implant placement in the posterior maxilla were evaluated. Cone-beam scans were taken preoperatively; immediately after implant placement; and for the sinus-grafted cases, 2 to 3 years after surgery. Crestal bone heights were measured. Patients were grouped according to the use of sinus augmentation or no sinus augmentation at the time of implant placement.

RESULTS

The increase in bone height was significant in the graft group when we compared immediate and 3-year follow-up measurements (P < .00001). In the graft group, there were no significant differences in bone height when we compared the immediate and 3-year follow-up periods (P = .31).

CONCLUSIONS

Simultaneous sinus floor elevation with grafting at implant placement results in stable bone levels after 2 to 3 years' follow-up.

How do peri-implant biologic parameters correspond with implant survival and peri-implantitis? A critical review

Objectives

The aim of this critical review was to evaluate whether commonly used biologic diagnostic parameters correspond to implant survival and peri‐implantitis prevalence.

Materials and methods

Publications from 2011 to 2017 were selected by an electronic search using the Pubmed database of the US National Library of Medicine. Prospective and retrospective studies with a mean follow‐up time of at least 5 years and reporting prevalence of peri‐implantitis as well as mean bone loss and standard deviation were selected. The correlation between reported prevalence of peri‐implantitis and reported implant survival, mean follow‐up time, mean bone loss, mean probing depth, and mean bleeding on probing was calculated. Mean bone loss and standard deviation were used for estimation of proportion of implants with bone loss exceeding 1, 2, and 3 mm.

Results

Full‐text analysis was performed for 255 papers from 4,173 available ones, and 41 met all the inclusion criteria. The overall mean weighted survival rate was 96.9% (89.9%–100%) and the reported prevalence of peri‐implantitis ranged between 0% and 39.7%, based on 15 different case definitions. The overall weighted bone loss was 1.1 mm based on 8,182 implants and an average mean loading time ranging from 5 to 20 years. No correlation was found between mean bone loss and the reported prevalence of peri‐implantitis. The estimated prevalence of implants with bone loss above 2 mm was 23%. The overall weighted mean probing depth was 3.3 mm, and mean weighted bleeding was 52.2%. Only a weak correlation was found between survival and function time (r = −0.49). There was no relation between the probing depth or bleeding and the mean bone loss, mean follow‐up time, and reported prevalence of peri‐implantitis.

Conclusion

Biologic parameters mean probing depth and mean bleeding on probing do not correlate with mean bone loss and this irrespective of follow‐up. Case definition for peri‐implantitis varied significantly between studies indicating that an unambiguous definition based on a specified threshold for bone loss is not agreed upon in the literature.

Modified Disk-Up Sinus Reamer for Sinus Floor Elevation and Simultaneous Implant Placement: An Animal Study with Miniature Pigs

Objective: The disk-up sinus reamer (DSR) is a modified instrument used to elevate the maxillary sinus floor. This study aimed to compare the effects of modified DSR sinus floor elevation (DSFE) with osteotome sinus floor elevation (OSFE), both with simultaneous implant placement. Methods: Twelve miniature pigs were treated with DSFE on one side and OSFE on the other. Implants 9 mm in length were placed in six pigs without grafting, while implants 11 mm in length were placed in the other six pigs with grafting. After submerged healing for 3 months, vertical bone gain (VBG), general and histological observation, and bone contact ratio (BCR) were analyzed. Results: The mean maxillary residual bone height (RBH) when implants were placed was 6.45 ± 0.36 mm. In the no-grafting group, DSFE and OSFE had a similar VBG after 3 months. The grafting group with DSFE recorded a significantly higher VBG (VBG0: 7.83 ± 0.44 mm, VBG1: 7.54 ± 0.40 mm) than the graft group with OSFE (VBG0: 5.45 ± 0.56 mm, VBG1: 4.34 ± 2.15 mm) (p < 0.05). One implant became loose and the sinus mucosa of three pigs appeared metallic in color on the control side (OSFE). Conclusions: The effect of OSFE and DSFE is similar when there is no need for grafting. DSFE seems a better alternative method for sinus floor elevation with grafting when more VBG is needed.

Osteotome Sinus Floor Elevation Without Grafting: A 10-Year Clinical and Cone-Beam Sinus Assessment

PURPOSE

To evaluate the thickness of the sinus membrane in contact with implants inserted 10 years before using an augmentation procedure without grafting material, and to identify adverse events correlated with implant protrusion in the sinus.

MATERIALS AND METHODS

Osteotome sinus floor elevations were performed without grafting material. The implants (Straumann AG, Basel, Switzerland) were placed simultaneously, all protruded into the sinus. After 10 years, implants were considered viable in the absence of mobility, pain, infection, or continued radiolucency. Sinus health was assessed using cone-beam computed tomography and by the way of a questionnaire in which patients reported symptoms of sinusitis they might have had.

RESULTS

Controlled implants (21 implants, 13 patients) were osseointegrated. The membrane thickness was <2 mm in 11 patients and 2 to 3 mm with flat thickening in 2 patients. No patients exhibited any clinical or radiographic signs of sinusitis.

CONCLUSIONS

No sinus complications were observed after 10 years. The initial protrusion of implants into the sinus did not influence long-term sinus health. The maintenance of successful integration is thus the key to avoiding sinus complication.

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.

Clinical research on a flapless surgical technique application of narrow implants

The aim of the present study was to investigate the role of Axiom (implant diameter) ø2.8 mm narrow body implant in the clinical effect of minimally invasive implants in edentulous space.This study included 10 patients with 10 edentulous spaces less than 5 mm and received minimally invasive surgery with 10 Axiom ø2.8 mm narrow implants. Re-stabilization of all implants began 6 months after surgery to fix the partial denture. All cases were followed up for clinical and panoramic X-ray examinations.Imaging examination on these 10 pieces of narrow implants after 6 months showed that implant alveolar bone crest average absorption amount was 0.20 mm and no implant peripheral inflammation mucositis and denture with adjacent teeth gingival papilla between the fillings. All patients felt strong mastication and the reparation effect was more than up to expectation. No implant loosening and shedding were observed.Hence, <5 mm edentulous space by Axiom ø2.8 mm implant minimally invasive reparation can be used for aesthetic purposes.

Clinical evaluation of modified transalveolar sinus floor elevation and osteotome sinus floor elevation in posterior maxillae: study protocol for a randomized controlled trial

BACKGROUND

Implant placement in the posterior maxilla is often complicated by the insufficient bone volume. While transalveolar sinus floor elevation (TSFE) has been proven as a predictable surgical procedure to increase the bone height in the posterior maxilla, questions in regard to the necessity of the bone grafting during the sinus lift and the question of whether TSFE could be performed when the residual bone height is below 5 mm are still debated. Furthermore, high-quality evidence comparing the clinical outcome of transalveolar sinus floor elevation with osteotome and modified sinus floor elevation with crestal non-cutting drills is limited.

METHODS/DESIGN

One hundred twenty adult patients who fit the inclusion criteria are being recruited from the Peking University Hospital of Stomatology First Clinical Division (Beijing, China). All patients are assigned to one of four groups according to a table of random numbers. Participants will receive (1) TSFE using osteotomes with bone grafting, (2) TSFE using osteotomes without bone grafting, (3) modified TSFE with bone grafting, or (4) modified TSFE without bone grafting. In a one-year follow-up period, implant survival rates, complications, implant stability, bone remodeling around the implant, and patient-reported outcome (visual analog scale for intraoperative discomfort and postoperative pain) will be observed and documented. The implant stability will be gauged by the resonance frequency analysis six times (at baseline and weeks 6, 8, 12, 16, and 26), and the bone remodeling will be observed and compared via radiographic examinations.

DISCUSSION

The result of the trial will potentially contribute to better decision making in atrophic posterior maxilla when implant placement is needed. Therefore, if the outcome is deemed favorable, the use of the modified TSFE would achieve an outcome equivalent to that of the traditional TSFE while introducing less trauma and postoperative discomforts. Separately, whether the bone graft procedure is necessary for the TSFE will also be discussed.

TRIAL REGISTRATION

The study has been registered in ClinicalTrials.gov under the identifier number NCT03445039 . Registered on 26 February 2018.

Nonlinear Biomechanical Characteristics of the Schneiderian Membrane: Experimental Study and Numerical Modeling

Objective

The aim of this study is to quantify the nonlinear mechanical behavior of the Schneiderian membrane.

Methods

Thirty cadaveric maxillary sinus membrane specimens were divided into the elongation testing group and the perforation testing group. Mechanical experimental measurements were taken via ex vivo experiments. Theoretical curves were compared with experimental findings to assess the effectiveness of the nonlinear mechanical properties. The FE model with nonlinear mechanical properties was used to simulate the detachment of the Schneiderian membrane under loading.

Results

The mean thickness of the membrane samples was 1.005 mm. The mean tensile strength obtained by testing was 6.81 N/mm². In membrane perforation testing, the mean tensile strength and the linear elastic modulus were significantly higher than those in membrane elongation testing (P < 0.05). The mean adhesion force between the Schneiderian membrane and the bone was 0.052 N/mm. By FE modeling, the squared correlation coefficients of theoretical stress-strain curves for the nonlinear and linear models were 0.99065 and 0.94656 compared with the experimental data.

Conclusions

The biomechanical properties of the Schneiderian membrane were implemented into the FE model, which was applied to simulate the mechanical responses of the Schneiderian membrane in sinus floor elevation.

Maxillary Sinus Floor Augmentation: a Review of Selected Treatment Modalities

Objectives

The objective of the present study is to present the current best evidence for enhancement of the vertical alveolar bone height and oral rehabilitation of the atrophic posterior maxilla with dental implants and propose some evidence-based treatment guidelines.

Material and Methods

A comprehensive review of the English literature including MEDLINE (PubMed), Embase and Cochrane Library search was conducted assessing the final implant treatment outcome after oral rehabilitation of the atrophic posterior maxilla with dental implants. No year of publication restriction was applied. The clinical, radiological and histomorphometric outcome as well as complications are presented after maxillary sinus floor augmentation applying the lateral window technique with a graft material, maxillary sinus membrane elevation without a graft material and osteotome-mediated sinus floor elevation with or without the use of a graft material.

Results

High implant survival rate and new bone formation was reported with the three treatment modalities. Perforation of the Schneiderian membrane was the most common complication, but the final implant treatment outcome was not influenced by a Schneiderian membrane perforation.

Conclusions

The different surgical techniques for enhancement of the vertical alveolar bone height in the posterior part of the maxilla revealed high implant survival with a low incidence of complications. However, the indication for the various surgical techniques is not strictly equivalent and the treatment choice should be based on a careful evaluation of the individual case. Moreover, further high evidence-based and well reported long-term studies are needed before one treatment modality might be considered superior to another.

Long-term stable vertical bone regeneration after sinus floor elevation and simultaneous implant placement with and without grafting

BACKGROUND

Less invasive surgical approaches to regenerate bone intra-sinus and allow long-term functional implant stability are needed.

PURPOSE

To evaluate long-term vertical bone regeneration after sinus floor elevation and simultaneous implant placement with and without bone grafting.

METHODS

Vertical bone gains (VBG) post-sinus elevation, with and without grafting, were evaluated in thirty individuals presenting an average residual bone height (RBH) of 4.2 mm using a standardized digital technique. Measurements were taken preoperatively, and at an average of 64.6 months follow-up. Clinically, peri-implant tissues were assessed for pocket formation and presence of inflammation to evaluate established success criteria.

RESULTS

Overall, RBH averaged 4.2 ± 1.1 mm (range: 1.8-5.8) and VBG 7.7 ± 1.6 mm (range: 6.0-12.9). Mean difference of 7.6 mm between vertical bone heights (VBH) at augmented implants sites and initial RBH, 11.8 versus 4.2 mm, (P < .0001, CI95%: 6.9-8.2) was statistically significant. RBH averaged 4.5 ± 0.8 mm and 3.8 ± 1.2 (P = .07) and VBG 6.8 ± 0.5 and 8.5 ± 1.9 mm (P = .003, CI95%: 0.6-2.7), for nongrafted and grafted individuals, respectively. The grafting group received an average graft volume of 0.35 ± 0.1 cc (range: 0.25-0.5) per implant site. Long-term follow-ups average 64.6 months (range: 36-144) and all implants met the success criteria. VBG ≥ 7 mm were 7.3 times more likely to develop on grafted sites (OR = 7.3, P = 0.02, CI95%: 1.2-46.2).

CONCLUSION

None to negligible amounts of grafting material are required to regenerate substantial amounts of autogenous bone into atrophic sinus cavities after simultaneous implant placement. The regenerated VBH seems stable for functional implant stability long-term. Implant success rates were 100% at an average of 64.6 months.

Long-term evaluation of osteotome sinus floor elevation and simultaneous placement of implants without bone grafts: 10-Year radiographic and clinical follow-up

BACKGROUND

Insertion of an implant in the edentulous posterior maxilla is a challenging procedure because of poor bone quality and increased pneumatization of the maxillary sinus after tooth extraction. To increase the amount of bone, several surgical bone grafting techniques have been used-with considerable morbidity for patients. Osteotome sinus floor elevation (OSFE) is a less invasive technique. The clinical and radiographic outcome of 53 implants placed with this technique without bone graft has been reported previously.

PURPOSE

Here we report the clinical and radiographic findings after 10 years of implant load bearing.

MATERIAL AND METHODS

In a retrospective study, 34 Astra implants in 25 patients were subjected to 10-year follow-up radiologically and clinically. Each patient received 1 or 2 conical Astra implants. The level of the marginal bone and the height of the residual peri-implant alveolar bone (RPAB) for each implant were measured from digital intra-oral radiographs.

RESULTS

Two implants in edentulous patients were lost at the 1-year follow-up, and 1 more at the 3-year examination. There was no loss between 3-year and 10-year follow-up. At 10-year follow-up 36 implants were included. Implants used in single-tooth replacements and in partially edentulous cases had a 100% survival rate. The mean marginal bone loss was 0.6 ± 0.8 mm. The bone height at the time of implant insertion ranged from 1.8 to 6.9 mm, with a mean value of 4.3 ± 1.0 mm. At 10-year follow-up the mean gain in bone at the implant sites for all implants was 2.6 ± 1.2 mm.

CONCLUSIONS

The OSFE technique is a reliable method for rehabilitation of patients with atrophied posterior maxilla. However, the success of this method is associated with the amount of the residual bone. In the present study, this surgical approach without bone graft showed reliable long-term results with Astra implants.

Graft-Free Maxillary Sinus Floor Elevation: A Systematic Review and Meta-Analysis

BACKGROUND

This systematic review and meta-analysis aims to investigate survival rates of dental implants placed simultaneously with graft-free maxillary sinus floor elevation (GFSFE). Factors influencing amount of vertical bone gain (VBG), protruded implant length (PIL) in sinus at follow-up (PILf), and peri-implant marginal bone loss (MBL) are also evaluated.

METHODS

Electronic and manual searches for human clinical studies on simultaneous implant placement and GFSFE using the lateral window or transcrestal approach, published in the English language from January 1976 to March 2016, were conducted. The random-effects model and mixed-effect meta-regression were used to analyze weighted mean values of clinical parameters and evaluate factors that influenced amount of VBG.

RESULTS

Of 740 studies, 22 clinical studies were included in this systematic review. A total of 864 implants were placed simultaneously with GFSFE at edentulous sites having mean residual bone height of 5.7 ± 1.7 mm. Mean implant survival rate (ISR) was 97.9% ± 0.02% (range: 93.5% to 100%). Weighted mean MBL was 0.91 ± 0.11 mm, and it was significantly associated with the postoperative follow-up period (r = 0.02; R2 = 43.75%). Weighted mean VBG was 3.8 ± 0.34 mm, and this parameter was affected significantly by surgical approach, implant length, and PIL immediately after surgery (PILi) (r = 2.82, 0.57, 0.80; R2 = 19.10%, 39.27%, 83.92%, respectively). Weighted mean PILf was 1.26 ± 0.33 mm (range: 0.3 to 2.1 mm).

CONCLUSION

Within limitations of the present systematic review, GFSFE with simultaneous implant placement can achieve satisfactory mean ISR of 97.9% ± 0.02%.

Maxillary sinus floor elevation with simultaneous implant placement without grafting materials: a systematic review and meta-analysis

The present study aimed to conduct a systematic review and meta-analysis on the effectiveness of maxillary sinus floor elevation and immediate implant installation without the use of grafting material. An electronic search without date or language restriction ​​was performed in PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, Web of Science, Embase, and the grey literature, to May 2016. Eligibility criteria encompassed prospective and retrospective cohort studies, controlled clinical trials, and randomized clinical trials. The search and selection process yielded 18 studies, published between 2005 and 2016. A meta-analysis was conducted only for experimental studies comparing sinus floor elevation with and without grafting material; results were expressed as the standardized mean difference (SMD) or risk ratio (RR) with the 95% confidence interval (CI). An average gain in bone height of 4.7mm over an average 39.4 month period was observed in the sinus elevated without grafting material. Regarding implants, there was a cumulative average survival rate of 97%. On meta-analysis, bone gain (P=0.98) and implant survival (P=0.13) did not differ significantly between sinuses lifted with or without grafting material, with a SMD of 0.01 (95% CI -0.42 to 0.44) and with a RR of 0.55 (95% CI 0.26 to 1.19), respectively.

Long-Term Effect of Surface Roughness and Patients' Factors on Crestal Bone Loss at Dental Implants. A Systematic Review and Meta-Analysis

Publications from 2011 to 2015 were selected to evaluate effect of implant surface roughness on long-term bone loss as surrogate for peri-implantitis risk. 87 out of 2,566 papers reported the mean bone loss after at least 5 years of function. Estimation of the proportion of implants with bone loss above 1, 2, and 3 mm as well as analysis the effect of implant surface roughness, smoking, and history of periodontitis was performed. By means of the provided statistical information of bone loss (mean and standard deviation) the prevalence of implants with bone loss ranging from 1 to 3 mm was estimated. The bone loss was used as a surrogate parameter for "peri-implantitis" given the fact that "peri-implantitis" prevalence was not reported in most studies or when reported, the diagnostic criteria were unclear or of dubious quality. The outcome of this review suggests that peri-implant bone loss around minimally rough implant systems was statistically significant less in comparison to the moderately rough and rough implant systems. No statistically significant difference was observed between moderately rough and rough implant systems. The studies that compared implants with comparable design and different surface roughness, showed less average peri-implant bone loss around the less rough surfaces in the meta-analysis. However, due to the heterogeneity of the papers and the multifactorial cause for bone loss, the impact of surface roughness alone seems rather limited and of minimal clinical importance. Irrespective of surface topography or implant brand, the average weighted implant survival rate was 97.3% after 5 years or more of loading. If considering 3 mm bone loss after at least 5 years to represent the presence of "peri-implantitis," less than 5% of the implants were affected. The meta-analysis indicated that periodontal history and smoking habits yielded more bone loss.

Influences of Schneiderian membrane conditions on the early outcomes of osteotome sinus floor elevation technique: a prospective cohort study in the healing period

OBJECTIVES

To radiographically investigate early outcomes of osteotome sinus floor elevation in the healing phase utilizing cone beam computed tomography and evaluate influences of Schneiderian membrane conditions.

MATERIAL AND METHODS

One hundred patients were consecutively recruited for osteotome sinus floor elevation (OSFE) surgery using deproteinized bone mineral. CBCT was taken prior to (T0), immediately post-operatively (T1), and after the healing period (T2). Linear and volumetric measurements of the elevated region from T0 to T1 were performed for evaluation on computed tomography (CT).

RESULTS

Osteotome sinus floor elevation were performed in 100 patients. One implant of each patient was selected. Mean residual bone height (RH) was 7.21 ± 1.12 mm. Mean sinus floor elevation height (SE) was 4.81 ± 0.75 mm. The mean endo-sinus bone gain after the healing period was 3.25 ± 0.83 mm. Pre-opterative CBCT scans revealed that 72 patients had a normal sinus membrane in osteotome region, 13 patients presented with flat thickened mucosa and 15 patients with antral pseudocysts. There is no significant difference in sinus mucosa elevation height, bone graft volume and new bone formation in group of Thickening membrane and Antral pseudocysts compared with normal.

CONCLUSIONS

The radiographical results show that OSFE is a safe and predictable surgical procedure in residual bone height of 7.21 ± 1.12 mm. Mild flat thickening (>2 and <5 mm) and antral pseudocysts in a small size without clinical symptoms may not be contraindications to OSFE surgery.

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

PURPOSE

The aim of the present study was to systematically assess the current evidence on the effect of nongrafted compared to graft-assisted maxillary sinus floor elevation on implant survival/failure, endosinus bone gain, crestal bone loss, and bone density around dental implants.

MATERIALS AND METHODS

MEDLINE-PubMed, Cochrane-CENTRAL, and EMBASE databases were searched up to November 2015 for randomized controlled trials (RCTs) and controlled clinical trials-(CCTs), evaluating dental implants placed in combination with maxillary sinus elevation without and with bone grafting. Implant survival/failure served as the primary outcome, whereas endosinus bone gain, crestal bone loss, and bone density around dental implants were secondary outcomes. To assess possible bias, the Cochrane risk of bias tool was used. Data were extracted and a meta-analysis performed where appropriate.

RESULTS

Independent screening of 3180 papers resulted in six eligible experiments. Heterogeneity was observed among experiments. One experiment showed low, three unclear, and two a high risk of bias. The assessed outcomes showed no significant long-term differences between groups.

CONCLUSION

Within the limit of the current systematic review, nongrafted maxillary sinus floor elevation seems to be characterized by new bone formation and high implant survival rate comparable to bone-graft-assisted maxillary sinus floor augmentation. Further long-term studies are needed before definitive conclusions can be made.