The International Journal of Oral & Maxillofacial Implants, 04/2023

One of the most important parts of any research project is the statistical analysis through which results are described and deemed significant or otherwise. Given this role of statistical analyses, it is imperative to understand what statistical tests are available and, most importantly, when they are appropriate. This is because choosing an improper statistical test can lead to inaccurate results and meaningless conclusions. We have written this data analysis guide to assist dental researchers with carrying out a proper analysis plan in consultation with a statistician. In this first part, we detail common types of outcome and predictor variables and include some common tests that can be used for each scenario. Using different simulated datasets, we also provide examples of common data visualization techniques and how a proper statistical test can be applied. We hope this guide provides some general background knowledge on common statistical techniques and allows for easier and more effective conversations with your statistician. Schlagwörter: statistical methods, data visualization, tutorial

Purpose: To study the effect of BMP-2 on the volumetric and histometric changes in peri-implant defect treatments in animal models. Materials and Methods: An electronic search of four databases and a manual search of peer-reviewed journals for relevant articles were performed. Animal studies with data that compared the volumetric and/or histometric outcomes of peri-implant defect treatment with and without the use of BMP-2 were included. Meta-analyses were performed to analyze the weighted mean difference (WMD) and confidence interval (CI) for the recorded variables. Results: After completing the search process, 21 randomized controlled trials were included. The results of the meta-analyses showed that the WMD of bone-to-implant contact (%BIC) with 4 to 8 weeks and 12 to 24 weeks of follow-up was 15.50% (95% CI = 3.28% to 27.72%, P = .01) and 16.17% (95% CI = 11.17% to 21.16%, P < .00001), respectively, favoring the BMP-2 group. The WMD for the percentage of defect fill with 4 to 8 weeks and 12 to 24 weeks of follow-up was 15.88% (95% CI = 3.90% to 27.86%, P = .009) and 10.48% (95% CI = 0.95% to 20.02%, P = .03), respectively, favoring the BMP-2 group. The WMD for the vertical bone gain with 8 to 16 weeks of follow-up was 1.63 mm (95% CI = 0.58 to 2.67 mm, P = .002), also favoring the BMP-2 group. Conclusion: This review demonstrated that the use of BMP-2 in treating peri-implant defects showed better clinical and histometric outcomes than defects not treated with BMP-2 in animal models. Schlagwörter: growth substances, bone morphogenetic proteins, dental implants, peri-implantitis, systematic review, meta-analysis

Purpose: To assess the literature comparing histologic levels of osseointegration for titanium vs zirconia dental implants. Materials and Methods: This systematic review was conducted following the PRISMA guidelines and was registered in PROSPERO (CRD42021236781). Electronic and manual searches were carried out through the PubMed/MEDLINE, PubMed Central, and Embase databases with a platform-specific search strategy combining controlled terms (MeSH and Emtree) and text words. The articles were selected by two independent investigators who evaluated the articles based on the criteria for eligibility. Results: A total of 17 articles were included. All were preclinical studies. The populations included dogs (27.55%), minipigs (14.28%), rats (14.28%), and rabbits (43.89%); and the implantation site varied among the mandible (36.82%), maxilla (9.04%), tibia (17.64%), skull (10.70%), and femur (25.80%). A total of 370 titanium (Ti) implants and 537 zirconia (Zr) implants were evaluated. The average osseointegration (% bone-to-implant contact) for Zr was 55.51% (17.6% to 89.09%), and for Ti was 58.50% (23.2% to 87.85%). There was no statistical difference between studies at the 2-month follow-up (P = .672), but this difference was significant at 1 and 3 months (P < .001). Conclusions: Within the limitations of this review, Zr implants had a similar level of osseointegration compared to Ti implants. Nonetheless, because these findings are based on preclinical research, all data must be carefully examined. Schlagwörter: meta-analysis, histology, titanium, zirconia, osseointegration, dental implants

Purpose: To compare the risk of sinus membrane perforation (SMP) among lateral window sinus floor elevation (LSFE) and transcrestal sinus floor elevation (TSFE) techniques in prospective and retrospective studies for patients who underwent sinus augmentation for dental implant placement. Materials and Methods: A database search was conducted to screen the literature published from January 1960 to August 2021. The associations between SMP and surgical techniques as well as other clinical factors were evaluated via network meta-analysis. The impact of SMP on vertical ridge gain and implant survival was also evaluated. Results: Eighty-five studies with 5,551 SFE procedures were included. In LSFE techniques, using rotary burs showed the highest risk of SMP (surface under the cumulative ranking area [SUCRA] = 0.0745). In TSFE techniques, using reamers had the lowest risk of SMP (SUCRA = 0.9444). Increased SMP prevalence was significantly associated with reduced implant survival rate (odds ratio [OR] = 0.45 per 10% increase of SMP rate [95% credible interval (CreI): 0.21, 0.71], P < .001). Conclusions: With the inherent limitations, this network meta-analysis suggested that some techniques within either the LSFE or TSFE group may reduce SMP risk. Additional randomized controlled trials and better assessment of SMP are required to directly compare the risk of SMP between LSFE and TSFE. Schlagwörter: meta-analysis, oral and maxillofacial surgery, dental implants, systematic reviews and evidence-based medicine, oral implants, implantologu, sinus floor elevation, complication, sinus lifting, sinus augmentation

Purpose: To evaluate the survival rate and marginal bone level (MBL) of calcium phosphate–blasted acid-etched titanium implants placed in a cohort of patients with different ridges after a follow-up period of at least 10 years. Materials and Methods: A total of 61 patients with a minimum implant follow-up of 10 years were selected for this historical prospective, best clinical practice cohort study. Between 2009 and 2012, 121 titanium implants were placed using a flap, flapless, or postextractive technique. The implant placement timing was performed according to pre-extractive diagnosis and divided into immediate (immediately after tooth extraction with an absence of infection), early (within 2 to 3 months with an acute periapical lesion), delayed (6 to 12 months from extraction with a large periapical infection), or late (> 12 months from extraction with healed edentulous ridges). All implants were loaded after 3 months with provisional and definitive cemented restorations. Periapical radiographs were taken before implant insertion and at 3, 6, 12, 24, 36, 48, 96, and 120 months (T3, T6, T12, T24, T36, T48, T96, and T120, respectively). The MBL was calculated in single blind by an additional examiner. Linear logistic regression was performed to analyze statistically significant differences in relation to different operative variables at all evaluation times. Multilevel mixed logistic regression was made to evaluate the factors associated to MBL at 10 years (T120). Results: After 10 years, 47 patients and 92 implant restorations were analyzed, showing that 88 implants (95.6%) survived and 4 implants (4.4%) failed. The cumulative drop-out rate was 22.1%. Loosening and/or mobility was observed in a total of 9 abutments (9.7%) during the observational time. No other complications were reported. Implants placed with a flapless technique revealed a similar MBL to those placed with a flap technique. No significant differences were observed between the surgical techniques at T96 and T120. Immediate and early implants revealed a more stable MBL than both delayed and late implants up to T48. At longer evaluation times (T96 and T120), the MBL values were not statistically significant (P > .05). Narrower diameter implants (3.5 mm) revealed a higher bone loss when compared to the 4.1-mm– and 5.0-mm–diameters, especially in the first year from implant insertion (from T3 to T12) and at longer follow-up (T36 and T48). After that, the difference was reduced. Multilevel analysis showed that none of these variables appear to significantly influence MBL at 120 months. Conclusions: MBL was not influenced by surgical technique or implant placement timing after 10 years. Maintaining a strict occlusal and hygiene control created the conditions to preserve bone integrity and achieve a high implant survival rate. Schlagwörter: historical prospective study, flapless technique, flap technique, immediate implant insertion

Purpose: To evaluate the gain in peri-implant keratinized mucosa (KM) using a combination of a free gingival graft (FGG) strip with a xenogeneic collagen matrix (XCM) and compare it to that of an FGG alone. Materials and Methods: This randomized controlled clinical study included a total of 30 patients with a minimal amount of peri-implant KM (≤ 1 mm) in the maxillary and mandibular anterior regions (including the premolars). The study population was divided into two groups using a randomization protocol; group A (n = 15) received a combination of FGG strip and XCM, and group B (n = 15) received FGG only to augment the KM. Clinical parameters included width of KM (WKM) measured at baseline, 1 month, and 6 months; a customized pink esthetic score (PES) measured at baseline and 6 months; and patient morbidity using visual analog scale (VAS) at days 1, 7, and 14 postoperatively. Results: After 1 month, both groups showed statistically significant gain in KM that reduced slightly by the 6-month follow-up but remained statistically significant when compared to baseline. When the gain was compared between the two groups, the difference was not statistically significant. Better esthetic outcomes and lower morbidity were reported in group A compared to group B, and this difference was statistically significant. Conclusions: Within the limitations of the study, it can be concluded that the combination of FGG strip with XCM is a viable alternative to the use of FGG in augmenting peri-implant KM. Schlagwörter: dental implants, free gingival grafts, keratinized mucosa, peri-implant health, strip technique, xenogeneic collagen matrix

Purpose: To evaluate the efficacy of split-thickness labial eversion periosteoplasty (EPP) for soft tissue closure in horizontal ridge augmentation of posterior mandibular regions using a bone shell onlay grafting technique. Materials and Methods: Sixteen patients (12 female and 4 male; mean age: 46.2 ± 8.7 years) with 18 horizontal bone defects in posterior mandibular regions were included for lateral onlay bone grafting using the bone shell technique. After lateral bone augmentation, the EPP was used for soft tissue closure and was prospectively followed up for wound healing efficacy using a modified scoring index. The scoring index included dichotomous (yes: 0 / no: 1) evaluation of the following items: (1) bleeding on palpation or spontaneously, (2) tissue color difference, (3) presence of hematoma, (4) presence of granulation tissue, (5) incomplete incision margin closure, (6) dehiscence with visible augmentation material, (7) presence of exudation, and (8) presence of suppuration. In addition, a visual analog scale (VAS) was used to quantify and record the amount of pain and swelling (0 = no pain/swelling and 5 = severe pain/swelling); VAS scores of 0, 1, and 2 were rated as 1 in the dichotomous scoring index, and VAS scores of 3, 4, and 5 were rated as 0. A summarized wound healing score consisting of all 10 items was assessed at days 2, 7, and 14 and at months 1 and 4 postoperatively, including a comparison of the follow-up evaluations. Results: The summarized healing score increased significantly (P < .01) between day 2 (score: 6.6 ± 1.1) and day 7 (score: 8.9 ± 1.0) but showed little difference between day 14 (score: 9.6 ± 0.6) and the 1- and 4-month follow-ups (score: 10.0 ± 0). There was no wound dehiscence and no incomplete incision margin adaptation. For the individual parameters evaluated, bleeding on palpation, hematoma, and exudation were the most frequent side effects at day 2 at 50%, 100%, and 22.2%, respectively, and at day 7 at 16.7%, 55.6%, and 22.2%, respectively. The average pain score and the swelling/edema score were initially 4.0 ± 0 and 3.0 ± 0.77 on day 2, with a significant decrease (P < .001) by day 7 (pain: 2.0 ± 0; edema/swelling: 2.0 ± 0.59) and day 14 (pain: 1.0 ± 0.42; edema/swelling: 2.0 ± 0.79) and complete absence (score: 0) at months 1 and 4. Conclusions: Labial split-thickness EPP facilitates flap advancement and enables tight soft tissue coverage in large horizontal posterior mandibular bone augmentations as a result of offset double-layer wound closure. Although this procedure is shown to be surgically demanding, the postoperative complication rate may be reduced significantly. Schlagwörter: soft tissue closure, lateral bone augmentation, posterior mandible

Objective: To verify the effect of fiducial marker number and configuration on target registration error (TRE) for dynamic computer-aided zygomatic implant surgery. Material and Methods: All patients who underwent zygomatic implant surgery with navigation from January 2018 to December 2021 were enrolled. For each patient, 6 to 8 miniscrews were placed intraorally as fiducial markers before the surgery. After the registration procedure, the TRE, which represents the distance between the target of the image space and the real position of the fiducial markers, was calculated. SPSS (22.0) was used for statistical analysis. Results: A total of 325 titanium miniscrews were placed in 47 patients who underwent zygomatic implant placement by navigation. The lowest TRE was 0.2 mm, compared to the highest TRE of 1.9 mm. There was no significant difference in the mean TRE value among the different titanium miniscrew groups (P = .07). A total of 8 miniscrews in 7 patients were lost in the maxillary tuberosity area prior to and during navigation surgery, which resulted in an irregular polygonal distribution of fiducial markers. However, there was no statistically significant difference in TRE between a polygonal distribution (0.62 ± 0.35 mm) and an irregular polygonal distribution (0.68 ± 0.33 mm) (P = .35). Conclusion: A scattered, polygonal distribution with of a minimum of five fiducial markers in an edentulous maxilla could achieve acceptable TRE values in registration. It seems that the registration error was not influenced by the absence of one corner in a polygon distribution. Schlagwörter: registration, navigation surgery, zygomatic implant, edentulous maxilla

Purpose: To compare the stability of short vs standard (ie, regular-length) implants in the edentulous mandible. Materials and Methods: In this prospective clinical study, 20 patients with edentulous mandibles received four implants each—two short implants (4 mm) in the region of the first molar and two standard implants (≥ 10 mm) in the interforaminal region. Implant stability was assessed using resonance frequency analysis immediately after implant placement and at the day of the abutment connection after 3 months of healing in order to provide an implant stability quotient (ISQ). Results: Implant stability in the two implant groups at placement (ISQ: short 66.2; standard 68.2) and at abutment connection (ISQ: short 74.9; standard 75.7) did not differ substantially or statistically significantly (both P > .05). Findings did not change after statistically controlling for potential confounders such as bone quality and bone crest width. At abutment connection, 95% of the short and 97.5% of the standard implants demonstrated sufficient stability for conventional loading (P > .05). Conclusions: Short dental implants demonstrate similar primary and secondary stability compared to standard implants and seem to be a promising treatment option for rehabilitation of patients with edentulous mandibles. Schlagwörter: dental implants, short implants, implant stability, resonance frequency analysis

Purpose: To determine which clinical factors might affect the postimplantoplasty presence of residual threads, platform alterations, and level of surface roughness. Materials and Methods: A total of 60 implants were placed in 20 resin models (10 edentulous maxillary models and 10 partially dentate mandibular models), and 5-mm peri-implant bone defects were created. These models were then placed in simulation mannequins. A single researcher performed the implantoplasties, which were divided into the following groups: favorable situation (FS; maxillary incisors without adjacent teeth), unfavorable situation (US; mandibular molars with adjacent teeth), crown (C; mandibular premolars with a prosthetic crown and adjacent teeth), and noncrown (NC; mandibular premolars with adjacent teeth and without a prosthetic crown). The presence of residual threads, gaps in the implant-abutment interface, and silicone debris was assessed using a scanning electron microscope (SEM), and the surface roughness (Sa and Sz) was analyzed with a confocal optical microscope. A descriptive and bivariate analysis was conducted. Results: The postimplantoplasty surfaces were significantly smoother than the original implant surfaces. The surface roughness was significantly higher in the US group than in the FS group. Gaps in the implant-abutment interface were infrequent (6.67%; 95% CI = 2.62 to 15.93) and only appeared in the posterior zone. The odds ratio for the presence of residual threads and silicone debris (US group vs FS group) was 7.1 (95% CI = 4.15 to 12.14; P < .001) and 5.53 (95% CI = 3.21 to 9.53; P < .001), respectively. When a prosthetic crown was present, residual threads were 7 times more likely to be found (OR = 7.0; 95% CI = 3.5 to 13.99; P < .001). Conclusions: Implantoplasty leads to a significant reduction in the surface roughness of implants but is affected by several variables. Performing implantoplasty on posterior mandibular implants with adjacent teeth seems to be more challenging compared to implants placed in the anterior region of a fully edentulous maxilla. The presence of a prosthetic crown should also be considered as a relevant factor. Furthermore, implantoplasty can sometimes cause gaps in the implant-abutment interface and an accumulation of silicone debris, especially in areas with limited access. Schlagwörter: implantoplasty, dental implants, surface roughness, peri-implantitis

Purpose: To validate guided surgery for zygomatic implants (ZIs) by analyzing the final position of the implants relative to the preoperatively planned position. Material and Methods: Five patients with fully edentulous atrophic maxillae treated with four ZIs through a fully guided implant surgical approach were evaluated. The preoperative phase included digital planning, through which the surgical guide was designed and created. Analysis of the guided surgery accuracy was carried out by superimposing the digital planning over the final position of the implants using preoperative and postoperative CBCT. The radiologic evaluation included implant angular deviation, entrance deviation, exit deviation, platform deviation, and apex apicocoronal and mesiodistal deviation. Results: All five patients (two men and three women; mean age: 61.8 ± 3 years) were each treated with four ZIs using a fully guided approach with an extrasinusal path, obtaining ideal emergence of the implants. Superimposition comparison found a mean axial angular implant deviation of 0.79 ± 0.41 degrees and a mean implant entrance deviation of 0.95 ± 0.26 degrees. The platform deviation was 0.62 ± 0.19 mm buccopalatally and 0.76 ± 0.14 mm mesiodistally, while the apical deviation was 0.42 ± 0.13 mm buccopalatally and 1.06 ± 0.37 mm mesiodistally. Conclusions: Guided surgery in zygomatic implants appears to be sufficiently accurate to make it a safe and predictable technique. Schlagwörter: computer-guided surgery, oral and maxillofacial, zygomatic implants

Purpose: To determine the optimal implant diameter under limited bone width by comparing the effects of implants with different diameters on implant stability, peri-implant bone stability, and osseointegration. In addition, to evaluate the reliability of resonance frequency analysis (RFA) in detecting osseointegration and marginal bone level (MBL). Materials and Methods: Mandibular premolars and first molars of seven beagle dogs were extracted. After 8 weeks, their mandibular models and radiographic information were collected to fabricate implant templates. Implant sites were randomly divided into three groups according to diameter: Ø3.3, Ø4.1, and Ø4.8 mm. Implant stability quotient (ISQ) measurement and radiographic evaluation were performed after surgery (baseline) and at 4, 8, and 12 weeks. Three dogs were euthanized at 4 weeks to observe osteogenesis and implant-tissue interface biology. Four dogs were euthanized at 12 weeks to observe osseointegration. Hard tissue sections were prepared to analyze osteogenesis (fluorescence double labeling) and osseointegration (methylene blue–acid fuchsin staining). Results: At baseline and at 4, 8, and 12 weeks, the ISQ values of Ø4.1- and Ø4.8-mm implants did not differ (P > .05), but both had higher values than the Ø3.3-mm implants (P < .05). The mean marginal bone resorption (MBR) associated with Ø3.3-, Ø4.1-, and Ø4.8-mm implants was 0.65 ± 0.58 mm, 0.37 ± 0.28 mm, and 0.73 ± 0.37 mm, respectively. The buccal MBR of Ø4.8-mm implants was significantly higher than that of Ø4.1-mm implants (P < .05). The bone-to-implant contact (BIC) percentage at 12 weeks did not differ for any group (P > .05). The correlation coefficients between the ISQ and MBL of the Ø3.3-, Ø4.1-, and Ø4.8-mm implants were –0.84 (P < .01), –0.90 (P < .001), and –0.93 (P < .001), respectively, while that between the ISQ and BIC was 0.15 (P > .05). Conclusions: During the early healing stage, the performance of Ø4.1- and Ø4.8-mm implants in terms of implant stability was better than that of Ø3.3-mm implants. Implant diameter may not influence BIC percentage. RFA can be used to evaluate implant stability and MBL but is not suitable to assess the degree of osseointegration. Schlagwörter: dental implants, diameter, implant stability, osseointegration, resonance frequency analysis

Purpose: To evaluate the incorporation of liquid platelet-rich fibrin in different collagen matrices in vitro. Materials and Methods: Collagen matrices with liquid platelet-rich fibrin were used and divided into the following test groups (n = 5): Mucoderm (MD), Mucograft (MG), and Fibro-Gide (FG). After incubating the collagen matrices in liquid platelet-rich fibrin, histologicl and fluid absorption capacity analysis were performed. Intergroup comparisons of cell count, blood plasma penetration area, and fluid absorption capacity were performed using one-way ANOVA and Tukey tests. Intragroup comparisons of fluid absorption capacity were made using the independent t test with a 5% significance level. Results: Descriptive qualitative analysis showed total incorporation of liquid platelet-rich fibrin in the FG group, while the MG and MD groups showed only partial and shallow incorporation, respectively. There was a statistically significant difference among the three groups regarding inflammatory cell infiltration (P = .000), with the FG group presenting the highest number of cells in the matrices (577.15 ± 54.88). The FG group showed an area of total blood plasma penetration into the matrix, followed by the MG group with partial penetration, and the MD group with minor penetration area (P = .000). Considering the fluid absorption capacity analysis, only groups FG and MG were statistically different when comparing the liquid platelet-rich fibrin absorption coefficient (P = .017), with higher absorption in group FG (14.30 ± 3.35). Conclusions: The FG collagen matrix showed a good capacity for liquid platelet-rich fibrin incorporation in vitro. Schlagwörter: platelet-rich fibrin, biomaterials, collagen

Objective: To assess the effect of topically applied hyaluronic acid (HA) on the stability of immediately loaded implants in the posterior maxilla. Materials and Methods: For the clinical study, a total of 20 implants were placed in 14 patients seeking the replacement of missing single or multiple posterior maxillary teeth. The patients were randomly divided into two groups. In the clinical control group (CC group), 10 implants were placed and immediately loaded, while in the clinical study group (CS group), 10 implants were coated with HA immediately before placement and immediately loaded. All patients had implant stability clinically evaluated at implant placement time (T0) and 1 (T1), 3 (T3), and 6 (T6) months after loading. Peri-implant pocket depth and modified sulcus bleeding index were evaluated clinically at 6 months in all patients. Bone density was evaluated radiographically after 3 months. All the clinical and radiographic data were subjected to statistical analysis. For the animal study, a total of 12 implants were placed in the tibiae of six rabbits. For each rabbit, 1 implant without any applied HA was placed in the left tibia (AC group), and 1 implant coated with HA was placed in the right tibia (AS group). The rabbits were euthanized at 21 and 45 days after implant insertion. Results: There were no significant statistical differences between the two groups regarding implant stability, peri-implant pocket depth, modified sulcus bleeding index, or bone density from the palatal and apical aspects. However, there was a significant statistical difference in the bone density from the buccal aspect in favor of the study group. The animal study showed that the newly formed bone in the right tibiae showed improved quantity and quality of bone, as it had denser bone trabeculae and smaller marrow spaces compared to the left tibiae. Conclusion: In the clinical study, the application of hyaluronic acid had a superior effect on the buccal bone density around immediately loaded implants. In the animal study, hyaluronic acid had a synergistic effect on the quality and quantity of bone formation around dental implants. Schlagwörter: hyaluronic acid, implant, posterior maxilla, stability

Purpose: To evaluate differences in the temperature rise at the cervical area of one-piece vs two-piece implants during the setting of relined provisional crowns. Materials and Methods: A K-type thermocouple was fixed to the coronal thread of 15 one-piece implants and 15 two-piece implants that were mounted on a plexiglass apparatus. Baseline temperature (Bl Temp) was recorded before starting the curing process. The maximum temperature (Max Temp) reached during the process in both implant groups was also recorded. Total heat flux (THF) was calculated as well as the thermal amplitude (Temp-Amp) at the implant surface. Finally, the differences between the implant types were compared using unpaired t test. Results: The increase in temperature from baseline was statistically significantly greater in the one-piece implants than in the two-piece implants (P < .01). Similarly, the THF and Temp-Amp were significantly greater in the one-piece implants compared to two-piece implants (P < .01). Conclusions: The polymerization of PMMA-based resin temporary crowns produces a significant temperature rise in both one-piece and two-piece implants. It is advisable to use two-piece implants to restore immediately loaded implants to reduce the risk to implant surroundings that may occur due to the temperature rise at the implant neck. Schlagwörter: implant, temperature, immediate restoration, one-piece, two-piece

Purpose: To assess, using CBCT, the volume and height of bone formation after open maxillary sinus elevation without the use of grafts. Materials and Methods: The study was retrospective and included 24 patients with a total of 67 implants. CBCT examinations were conducted at baseline (0 to 43 days postsurgery) and after an average healing period of 6.2 months (range: 5.1 to 7.8 months). The image analysis included metal artifact reduction, registration, and a standardized protocol for segmenting the anatomical structures of the maxillary sinus, including calculating the 3D volumetric changes after bone formation. Conventional manual 2D measurement of vertical bone formation was executed for comparison. Clinical factors assumed to be relevant for bone formation were obtained from patient medical records. Results: One implant was lost before prosthetic loading, representing an early implant loss rate of 1.5%. Differences in intra- and interexaminer reproducibility were registered for the conventional 2D method (P < .05). The average vertical bone formation measured with the 2D method was 4.8 mm (4.6 to 5.0 mm), covering 60.2% of the implant height within the sinus. The average volumetric bone formation measured with the developed 3D image-analysis method was 801 mm3 in total and 195 mm3 in a restricted region around each implant. Bone formation was registered in 62% of the volume of the restricted region. A correlation regarding bone formation was found between the two methods (R2 = 0.705). Clinical factors such as age, smoking, general health, and postoperative complications did not correlate with the amount of bone formed. Conclusion: CBCT image analysis is a promising method for objective 3D evaluation of bone formation after sinus elevation. A correlation was seen between the manually measured bone height (2D) and the bone volume in a restricted region around each implant using the developed method (3D). Reducing visual interpretation minimizes errors related to examiner reliability. Clinical factors did not significantly affect the volumetric bone formation. Schlagwörter: 3D, bone volume, CBCT, graftless, sinus elevation

Purpose: To compare glycated multilayered membranes (OV) to a commercially available thin-layer membrane (OP) in a lateral ridge augmentation model in dogs. Materials and Methods: This was designed as a three-arm study, where one negative control (empty defect) was compared to two test arms: alveolar bone defects grafted with a mixture of 90% deproteinized bovine bone mineral and 10% porcine collagen, then covered with either a thick- (OV) or thin-layered (OP) membrane. Animals were randomly divided into three groups corresponding to the final sacrifice times of 4 weeks, 12 weeks, and 24 weeks. Sections underwent microCT, histology, histopathology, and histomorphometry. Results: No statistical differences were observed for OV compared to OP regarding the percentage of mineral volume and mean mineral density, amount of bone maturation, percentage of bone graft and membrane remaining in the grafted area, alveolar ridge width measurements, membrane mineralization, or ossification. Test groups presented significantly higher values compared to the empty control for all the endpoints. Conclusions: Within its limitations, this in vivo study highlighted that multilayered thick glycated membranes can serve as effective occlusive barriers for up to 6 months. Schlagwörter: bone grafting, collagen membrane, ridge augmentation

Purpose: To analyze the effects of age on the sinus graft remodeling of transalveolar sinus floor elevation (SFE) with simultaneous placement of dental implants. Materials and Methods: A retrospective study design was adopted. A total of 222 sites in 216 patients who underwent transalveolar SFE with immediate implant placement were included. The clinical and radiographic data were collected at preoperative, postoperative, and postloading time points. Age was divided into three groups: < 30 years, 30 to 50 years, and > 50 years. The ratio of sinus graft resorption (Ratio) was used to evaluate the outcomes of the surgery and loading. ANOVA was applied to explore the correlation of total elevation height (TEH) with implant loading. The Ridge regression model was used to explore the relationship between Ratio and age and other possible factors. Results: A total of 222 implants in 216 patients were included for implant-based analysis. The TEH averaged 6.983 ± 2.251 mm on the day after surgery (T1), and sinus graft resorption was found during the healing period and after implant loading (P < .01). Age was found to be a reliable correlation with the Ratio (P < .01). A significantly decreased bone formation efficiency was found with aging. Conclusion: According to the results of this retrospective chart review, age was the main factor affecting the outcomes when applying transalveolar SFE with simultaneous implant placement. This finding could be a guide for clinical treatment. Schlagwörter: sinus floor elevation, bone formation, age, implant loading