The International Journal of Oral & Maxillofacial Implants, 05/2023

It is important for dental researchers to have a general idea of the different types of data that can be collected from a study and the available statistical tools that can be used with such data. By knowing about what is available, researchers will have an informed idea of the types of studies that should be conducted, the data that should be collected, and the proper statistical methods for analyzing collected data. In the first part of this general overview of statistical methods, we walked through the various types of data that traditional statistical techniques, such as t tests and linear regression, can handle. In this second part, we explore more complex types of data that traditional statistical techniques are unable to handle. Specifically, we discuss longitudinal and time-to-event data because both occur frequently in dental studies and require special modeling techniques in order to analyze correctly. Using two different simulated dental datasets, the proper application of techniques such as repeated measures ANOVA, linear mixed modeling, generalized estimating equations, log-rank test, and Cox proportional hazards models are discussed and illustrated in depth. Keywords: statistics, tutorial, longitudinal, survival

Purpose: To assess the survival rate (SR) and probability of postoperative complications at both the implant and patient level for each of the four surgical techniques for zygomatic implant (ZI) placement: Brånemark, sinus slot, extrasinus, and extramaxillary. Materials and Methods: A systematic literature review and meta-analysis of clinical studies that reported the survival rate and postoperative ZI complications for the rehabilitation of atrophic edentulous maxillae was conducted based on PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) recommendations. Two independent reviewers consulted four databases during the literature search: MEDLINE (PubMed), Google Scholar, Clinicaltrials.gov, and LILACS. Duplicate articles were eliminated. Results: A total of 35 studies were included in the meta-analysis. Subgroup analysis showed that study design (prospective vs retrospective) had no significant impact (P = .10) on the outcomes. The SR was highest for the Brånemark and extrasinus techniques (100%) and lowest for the sinus slot technique (94%; 95% CI = 86% to 102%). The extramaxillary (38%; 95% CI = 1% to 3%) and the Brånemark (29%; 95% CI = 15% to 44%) techniques resulted in the highest occurrence of patient-level complications. Moreover, the extramaxillary technique showed the highest percentage of prothesis-related complications (44%; 95% CI = 27% to 62%). Conclusions: ZI placement was demonstrated to be a reliable technique for the rehabilitation of severely atrophic maxillae, irrespective of the surgical technique evaluated. Accurate case and surgical protocol selection is of paramount importance to reduce technique-related postoperative complications. Keywords: dental implants, maxillary atrophy, surgical technique, survival rate, zygomatic implants

Purpose: To compare the linear and angular deviations of sites prepared for implants with the proposed 3D-printed sliding guide vs a 3D-printed conventional sleeveless static guide. Materials and Methods: This study consisted of two groups: a control group of 14 3D-printed conventional sleeveless static guides, and a test group of 37 3D-printed sliding guides. The guides were designed to drill 37 implant sites in each group. Linear and angular deviations were determined after scanning the drilled casts. Linear deviations were measured at the coronal and apical aspects of the drilled implant sites at 5-, 10-, 15-, and 20-mm distances. Results: There were no significant differences between the control and study groups regarding the coronal and 5-mm apical linear deviations. The angular and 10-, 15-, and 20-mm linear deviations of the 3D-printed sliding guide were significantly smaller than the control group. Conclusions: The proposed 3D-printed sliding guide could reduce the angular deviation of drilled implant sites from the planned positions, which is reflected in reducing the linear apical deviation of prepared implant sites longer than 5 mm. Keywords: 3D-printed implant sliding guide, linear deviation, angular deviation, dental implant surgical guide, in-office 3D printing

Purpose: To evaluate via CBCT the anatomical variations of the maxillary teeth and associated major anatomical cavities, the maxillary sinus and nasal fossa. Material and Methods: CBCT scans of 221 patients were used to examine maxillary sinus variations, the posterior superior alveolar artery (PSAA) course, nasal septum variations, middle and inferior concha-meatus variations, canalis sinuosus, infraorbital ethmoid cell, infraorbital canal, anterior nasal spina, and nasopalatine canal. Results: The incidence of anatomical variations was 32.6% for maxillary sinus septa, 50.9% for PSAA, 23.1% for nasal septum deviation, 6.3% for nasal septum spur and pneumatization, 3.6% for paradoxical middle concha, 14.9% for middle concha hypertrophy, 39.6% for middle concha bullosa, 0.45% for bifid inferior concha, 0.9% for paradoxical inferior concha, 60.1% for inferior conch hypertrophy, 1.8% for inferior concha bullosa, and 40.3% for the infraorbital ethmoid cell. The study mainly observed group 2 anterior nasal spina with a rate of 35.7%, group 1 nasopalatine canal with a rate of 37.1%, and infraorbital duct type 2 with a rate of 70%. In 20.4% and 47% of cases, canalis sinuosus was located in the right and left sides of the maxilla, respectively. Conclusions: Maxillary sinus variations, PSAA prevalence and localization, nasal septum and concha variations, anterior nasal spina subgroups, nasopalatine canal subgroups, canalis sinuosus prevalence, and localization and infraorbital ethmoid cell prevalence were found to be consistent with the literature. Moreover, a rare case of the lower bifid concha was identified. The nasomaxillary complex and related dental structures, which are a multidisciplinary study area, should be carefully examined in the presence of pain of unknown origin and the planning of surgical procedures. Keywords: anatomical variation, CBCT, cone beam computed tomography, dentoalveolar region, nasal cavity, maxillary sinus

Purpose: To examine whether patient-level disease diagnoses, drug treatments, and dental clinical factors are correlates of early implant failure. Materials and Methods: This historical, nested case-control study used electronic medical records to retrieve patient-level data on individuals with implant failure occurring up to 6 months after implantation, including demographics, clinical information (number, location, and complicated status of implants), underlying diseases (osteoporosis, diabetes, hypertension, inflammatory bowel disease [IBD], myocardial infarction [MI]), and drug purchases (chemotherapy, bisphosphonates, selective serotonin inhibitors, antihypertensive medications, proton pump inhibitors [PPIs], disease-modifying antirheumatic drugs, corticosteroids, and nonsteroidal anti-inflammatory drugs) among adult members of a large, state-mandated health provider in Israel between 2015 and 2020. Individuals with implant extraction occurring up to 6 months after implantation were matched 1:1 to controls. Univariate and adjusted multivariate conditional logistic regression models were used to examine the odds ratios (ORs) of all dental implant risk factors among the patients. Results: A total of 585 individuals with implant failure (mean age, 53 years [42,62], 51.3% females and 49.7% males) were identified among 29,378 eligible patients. Compared to controls, patients who experienced implant failure (ie, cases) were more likely to have smoked in their lifetime (18% vs 11.5%, P = .009), experienced IBD (1.5% vs 0.02%, P = .059), and consumed PPIs within 6 months of the implant surgery (40.0% vs 32.5%, P = .028). Clinical factors, including the number of implants per person (individuals with two implants, OR = 1.53; individuals with at least four implants, OR = 3.33; P < .01), location of implant (maxilla; OR = 1.59; 95% CI: 1.2–2.04), and smoking (OR = 1.57; 95% CI: 1.09–2.26) were significant correlates of early implant failure among the included cases. Crohn’s disease, MI, and osteoporosis were found to be borderline significant correlates of early dental implant failure. Conclusions: Among the factors examined, the number of implants, the location of implants, and smoking history were significant correlates of early implant failure, while Crohn’s disease, MI, and osteoporosis were found to not be significant. Larger patient-level studies are needed to examine the individual and combined effects of diseases, medications, and clinical factors on early implant failure. Keywords: dental implant failure, smoking, Crohn’s disease, myocardial infarction, osteoporosis, maxillary implants

Purpose: To evaluate the 3-year success and survival rates of fixed prostheses supported by 4-mm extra-short implants splinted to 10-mm implants in patients with shortened maxillary arches and low maxillary sinus floors. Methods: A total of 11 patients with reduced alveolar bone heights due to low maxillary sinus floors received two or three titanium-zirconium tissue-level implants: one or two extra-short (4 mm) implants, and one implant 10 mm in length. After 6 months, prosthetic rehabilitation with splinted crowns connecting the 4- and 10-mm implants was performed. Follow-up visits and maintenance protocols were implemented every 4 to 6 months. Results: The 11 patients were treated with 11 10-mm implants and 17 4-mm implants. One extra-short implant failed and was removed before loading, and its planned design was modified from three splinted crowns to a bridge between the 10- and 4-mm implants. After 36 months, all (11/11) prosthetic rehabilitations connecting the 10-mm (11/11) and 4-mm (16/16) implants were functional. At the 10-mm implant sites, the median (interquartile range [IQR]) probing depth and marginal bone loss measured 2.9 mm (2.3 to 3.2) and 1.3 mm (1.0 to 1.5), respectively. At the 4-mm implant sites, the median (IQR) probing depth and marginal bone loss measured 2.9 mm (2.4 to 3.1) and 0.3 mm (0.1 to 0.5), respectively. Conclusion: Prosthetic rehabilitation with splinted crowns connecting 4-mm and 10-mm implants showed promising outcomes in shortened maxillary dental arches after 3 years. Additional studies are needed to further validate these findings. Keywords: alveolar bone loss, dental implants, short dental implants, maxilla, survival rate

Purpose: To evaluate the survival and success rates of short (> 6 mm and ≤ 8.5 mm) implants after at least 2 years of functional loading. Implants were assessed using clinical parameters such as marginal bone loss (MBL), pocket depth (PD), keratinized mucosa width (KMW), bleeding on probing (BoP), and the peri-implant condition (mucositis or peri-implantitis). Any correlations between clinical parameters were analyzed. Materials and Methods: This observational and retrospective study included 114 posterior maxillary and mandibular implants placed in 27 women and 38 men with a mean age of 68.04 ± 9.07 years. Patients included in the study had received at least one short implant between 2001 and 2013, such that each implant was in occlusal function for at least 2 years by 2015. Patients with only long (≥ 10 mm) implants, patients with any systemic condition, and smokers were excluded from the study. PD, KMW, peri-implant condition, BoP, and MBL were the clinical parameters assessed in the study. Data on prosthesis type (single or splinted) and implant features were also obtained. All data were submitted to analysis via Mann-Whitney unpaired test, with a significance level of P < .05. Spearman correlation coefficient was also measured to verify the negative or positive correlation. Results: The mean follow-up time was 74.08 months, and mean implant success and survival rates were 87.63% and 94.74%, respectively. There were 6 implant failures (5.26%). A total of 66 (59.46%) prostheses were screw-retained implant-supported restorations, and 45 (40.54%) were cemented. A total of 93 (86.49%) short implants were splinted to another implant, and 15 out of 111 (13.51%) restorations were single implants. Keratinized mucosa was missing around 43 (39%) implants, whereas PD was measured to be between 0 and 3 mm in 64.86% of implants and ≥ 4 mm in 31.53% of implants. MBL was ≤ 1.5 mm in 71.17% of cases and > two-thirds the length of the implant in 2.71% of cases. Mucositis and peri-implantitis were found in 22.52% and 7.21% of implants, respectively. The correlation coefficient showed a positive result for PD and MBL (0.11; P = .368) and negative results for PD and KMW (–0.42; P = .002) and KMW and MBL (–0.19; P = .183). Conclusions: Within the limitations of this study, it is possible to conclude that short implants are a feasible treatment option for dental rehabilitation. They are considered an excellent alternative to complex procedures and have high survival rates after at least 2 years of follow-up, with compatible peri-implant local tissue response. Moreover, a significant negative correlation between KMW and PD was observed. Keywords: short implant, oral rehabilitation, edentulism, dental implant, peri-implantitis

Purpose: To compare bone substitutes composed of glycated collagen with synthetic micro-sized (1 to 10 μm) hydroxyapatite (OB) vs non–cross-linked collagen matrix with large-particle (250 to 1,000 μm) bovine-derived hydroxyapatite (BOC). Materials and Methods: The P1 to P4 premolars were bilaterally extracted from the mandibles of 19 Beagle dogs. After 21 days, osteotomies were created in each dog that received OB or BOC and were covered with a collagen membrane or were left untreated. The animals were randomly divided into three groups based on sacrifice time (4, 12, or 24 weeks). The right and left hemimandibles were trimmed to facilitate imaging and histology, and all tissues were placed in 10% neutral-buffered formalin. Microcomputed tomography (MicroCT 40 Scanner, Scanco) was used to analyze bone sections. Bone volume, residual material volume, and bone mineral density were determined for each treatment site (OB and BOC) based on a volume of interest that encompassed the original defect. Additionally, blinded histopathologic assessment (based on the ISO 10993-6 scoring system) and histomorphometry were performed on sections ground to < 100 μm thick and stained with Stevenel’s blue. Results: No clinical side effects were noted. No statistical differences were observed for OB vs BOC regarding the mineral volume percentage. Compared to OB, BOC had significantly higher mean mineralization densities at 12 weeks (P < .01), but this difference did not extend to 24 weeks. For residual grafting material, bone maturation, alveolar ridge restoration, and inflammatory response, OB showed a residual amount of bone graft and no statistical differences compared to BOC. Conclusion: Both OB and BOC represent valid treatment options for critically sized bone defects. Both bone fillers outperformed the sham-operated, ungrafted (empty) control, demonstrating statistically improved bone growth and ridge restoration. Keywords: bone grafting, collagen membrane, ridge augmentation, collagen scaffold

Purpose: To examine the remodeling process of both the soft and hard tissue components of the postextraction socket around immediately loaded dental implants after tooth extraction in maxillary esthetic areas. Materials and Methods: Subjects underwent immediate placement of single implants in postextraction sockets without bone grafting, and their immediate provisionalization with custom tooth-like interim crowns were fabricated using digital diagnostic impressions and a dental milling machine. Intraoperative and 1-year follow-up layered scans of the postextraction sockets after implantation were acquired using a 3D optical system. In the short term, subjects underwent computed tomographic scans. Digital impressions for gingival contours, originally stored as STL (standard tessellation language) files, were converted to DICOM (Digital Imaging and Communications in Medicine) files with the implant shoulder working as a referral point, which were then superimposed to 3D radiologic images. The observed volumetric and linear outcomes were measured using a program known as DentaScan. The width of the alveolar crest at the level of the implant shoulder and marginal bone levels were acquired. Nonparametric tests were applied with a level of significance set at P < .01. Results: No failure was reported after a follow-up of 1 year. Little or no inflammation of the treated areas was registered, and there were practically no signs of suppuration. The areas showed a significant reduction in the overall volumes for both soft and bone tissue, with a P value < .0001 from the baseline (0.983 ± 0.172 cm3) to the 1-year survey (0.865 ± 0.156 cm3). If the soft and bone tissue changes were separately evaluated, a significant loss (with a P value < .0001) was registered for only the bone tissues (from 0.434 ± 0.075 to 0.355 ± 0.061 cm3). Moreover, changes in gingival tissue from baseline to the 1-year survey (–0.040 ± 0.067) appeared to be significantly different from the overall volume loss (–0.118 ± 0.083 cm3). A shrinkage in width (–0.5 ± 0.7 mm) was found from baseline (12.6 ± 0.6 mm) to the 1-year follow-up (12.1 ± 0.9 mm). Marginal bone levels were 0.97 ± 0.70 mm and 0.39 ± 0.78 mm, respectively, at the mesial and distal aspects of the implants. Conclusions: The present analysis suggested that immediately customized provisionalization was effective enough to prevent both volume loss and linear shrinkage at the layers of the treated areas. Moreover, the buccal aspects seemed to be the areas most affected by the loss of volume. The mean loss in width, which amounted to roughly 0.5 mm, appeared to be negligible when compared to the overall width measured before surgery. Keywords: alveolar remodeling, immediate implant, intraoral digital scanning, imaging superimposition, immediate provisionalization, computerized tomography

Purpose: To evaluate the bone level changes in a new implant design (fully tapered with platform switching) with the one-abutment one-time protocol after 1 year of loading. Materials and Methods: Thirty patients received 1 or 2 implants (6-, 8-, or 10-mm length and 3.5-, 3.75-, or 4.5-mm diameter, bone-level design) to replace one or multiple edentulous sites. Only the mesial implant was assessed. Radiographic, clinical, and esthetic results and the survival and success rates were evaluated 1 year after final loading. Results: At 1 year, no peri-implant bone loss was seen in any of the cases. Mean marginal crestal bone loss between surgery and crown placement was 0.19 ± 0.17 mm (P < .0001). Between surgery and the 1-year follow-up, the mean marginal crestal bone loss was 0.25 ± 0.24 mm (P < .0001). The difference in the modified Plaque Index between 1 year of follow-up and crown placement was significant for in the mesial (0.33 ± 0.54 mm; P = .003) and distal surfaces (0.5 ± 0.73 mm; P = .001). The probing pocket depth was statistically significantly deeper at 1 year than at crown placement at the mesial and distal aspects (average depth = 0.75 mm; P < .0005). No statistically significant differences were found for any other clinical or esthetic parameters. The overall survival and success rates after 1 year were 100%. Conclusions: The fully tapered, deep-thread, platform-switched implant design placed with the one-abutment one-time protocol demonstrated minimal marginal crestal bone loss and crestal bone stability at 1 year of follow-up. Keywords: crestal bone loss, fully tapered implants, one-time one-abutment, platform switching

Purpose: Τo evaluate and compare the marginal bone loss (MBL), survival rates, and periodontal parameters of immediately loaded implants with either Dolder bar or Locator attachments placed in the interforaminal region of edentulous mandibles. Materials and Methods: A total of included 19 patients with edentulous mandibles each received two implants in the interforaminal area of the symphysis. Randomly allocated Dolder bar or Locator attachments were then attached immediately, and both clips and a framework were fastened to the denture by the dental laboratory within 24 hours. Results: A total of 28 subjects with 56 implants were treated in accordance with the immediate-loading study protocol. Of these, 9 patients were lost to follow-up; 1 patient reported a serious illness and 8 patients moved and couldn’t be reached. The 19 subjects not lost to follow-up (11 women and 8 men; average age: 68 years) were included. Every patient received either two Locator abutments and were assigned to group A (7 patients; 36.8%) or two multiunit abutments and were assigned to group B (12 patients; 63.2%). No implant failure was detected for either group, and therefore the survival rate for both groups was 100% after 5 years. After 5 years without any symptoms, 2 implants from group A and 7 implants from group B showed > 2 mm of MBL, which makes the group A success rate 85.7% and the group B success rate 70.8%. Modified sulcular bleeding index (mSBI) did not differ significantly at any of the measurement intervals. However, the modified plaque index (mPI) of group B was significantly higher than group A at the 60-month follow-up. Conclusion: It can be concluded that either splinting or not splinting the immediately loaded interforaminal implants to retain mandibular overdentures (OVDs) does not affect marginal bone levels after 5 years and immediate loading of nonsplinted implants with Locator attachments can be safely preferred to retain mandibular OVDs. Keywords: immediate loading, overdenture, MBL, nonsplinted implants

Purpose: To evaluate the survival rate (primary outcome) and the marginal bone loss (secondary outcome) of the OsseoSpeed EV Implants (Astra Tech Implant System, Dentsply Sirona Implants; hereinafter EV implants) used in a wide range of clinical scenarios and followed up to 8 years in a nonuniversity setting. Materials and Methods: All EV implants consecutively placed from 2013 to 2021 in a private dental clinic were included, and medical and radiologic records were retrospectively investigated. Independent reviewers collected 11 data types as potential influencing variables and measured the mesial and distal marginal bone levels to the nearest 0.5 mm on available radiographs, either panoramic or periapical. Tables of descriptive statistics were made at implant and patient levels. Univariate and multiple Cox regression models were adjusted for clustering effects and determined the hazard ratio (HR) and odds ratio (OR) for each independent variable collected. Results: The study sample consisted of 597 EV implants and 235 patients. During a mean follow-up of 42.1 ± 23 months (range: 10 to 94 months), 44 implants were lost (7.4%)—34 early (5.7%) and 10 late (1.7%)—in 38 patients (16.1%). The overall survival rate (SR) was 92.6% (CI: 90.5% to 94.7%), and the proportion of patients with all their implants surviving was 83.8% (CI: 79.1% to 88.5%). At the end of the study, the probability of survival of an implant that did not fail early was 98.2% (CI: 97.1% to 99.3%). Implant-level analysis identified two significant variables: implant diameter (HR 0.37, P = .009**) and immediate postextraction placement (HR 2.35, P = .025*). At the patient level, bruxism (OR = 3.29; P = .009**), history of periodontitis (OR = 2.18, P = .030*), and the number of implants placed (OR = 1.43; P = .001**) were found to be statistically significant. After removing dropouts and early failures from a sample of 528 implants, 412 (78%) had a marginal bone loss (MBL) ≤ 0 mm at the end of the observation time, and 106 surviving implants (22%) showed a mean MBL of 1.42 ± 1.08 mm (range: 0.25 to 6.75 mm). Conclusions: An overall medium-term SR of the EV implants was 92.6%. Four of five EV implants showed a mid-term MBL ≤ 0 mm, and 91.86% of implants completed the observation period with an MBL < 2 mm. Thus, the EV implant system was shown to be a valid alternative for routine use in a nonuniversity setting. Clinicians should remember that there is no 100% implant survival in everyday practice and that bruxism, periodontitis, narrow-diameter implants, and immediate placement are risk factors for a higher failure rate. Keywords: implant survival, implant failure, OsseoSpeed EV Implant, marginal bone loss, risk factors

Purpose: To assess the implant survival rate in mandibles reconstructed with free fibula flap after oral tumor resection after 1 year of prosthetic loading. A secondary objective was to compare immediate or delayed implant placement protocols in this population. Materials and Methods: Electronic and manual searches were performed on different databases for controlled and prospective trials that indicated implant survival rate. This systematic review followed PRISMA guidelines. Risk of bias was evaluated using Cochrane Collaboration tools. Meta-analyses heterogeneity source assessment and GRADE evaluation were performed among studies with identical follow-ups. Results: Among 305 primarily selected articles, 109 were eligible after reading the title and abstract, and 8 were included after full-text reading: 2 randomized controlled trials and 6 prospective studies comprising 140 patients and 507 implants. Meta-analyses estimated an overall survival rate of 97% (95% CI: 94% to 99%) after 1 year of prosthetic loading. The survival rate was 98% (95% CI: 94% to 100%) with immediate implantation and 97% (95% CI: 90% to 99%) with delayed implantation. Only 3 studies reported radiotherapy treatment, with no real impact on implant survival rate. Overall, 69% of tumors were benign. Conclusions: Implant placement in vascularized fibula flaps in the mandible is recommended for patients undergoing segmental mandibular reconstruction after tumor resection. Within the limitations of this study, no significant difference in survival rates was found between immediate and delayed implant placement. Keywords: dental implants, fibula, mandible, oral tumors, survival rate, systematic review, meta-analysis

Purpose: To evaluate the peri-implant outcomes of customized healing abutments (CstHA) placed on dental implants inserted in fresh tooth extraction sockets. Materials and Methods: The study was registered on PROSPERO: CRD42022304320. A systematic search in PubMed, Scopus, and Web of Science was conducted between April 2022 and October 2022 to identify clinical studies involving immediate implant surgery associated with CstHA placement. The Joanna Briggs Institute Critical Appraisal and RoB2 tool were performed for the risk of bias analysis. Results: A total of 12 studies were included, most of them with low risk of bias. Four studies compared CstHA vs conventional healing abutments (CnvtHA), two compared CstHA vs cover screw and collagen matrix (CMa), and six were clinical case series. For the CstHA vs CnvtHA comparison, favorable results were observed for CstHA considering papilla maintenance and probing depth, yet the mean marginal bone level was statistically similar between CstHA and CnvtHA. CstHA showed advantages when compared to CMa for total bone volume, papilla height, and midfacial mucosa maintenance. Significantly less horizonal bone loss was reported when using CstHA compared with CMa. Horizontal and vertical bone loss was observed in a few (or no) sites in the case series using CstHA. Conclusions: CstHA provides favorable peri-implant response because in general it does not result in a significant loss of soft and hard tissues. Keywords: soft tissue–implant interactions, prosthodontics, wound healing

The traditional configuration of four maxillary implants to restore full-arch maxillary fixed implant prostheses is not without pitfalls. Intraoperative variability, such as bone quality and quantity, may lead to unexpected intraoperative challenges that may not allow for execution of the original treatment plan. Additionally, extensive maxillary sinus pneumatization may inhibit posterior spread and lead to a shortened dental arch or excessive cantilever forces. The PATZi protocol is a systematized algorithm for maxillary full-arch implant treatment planning that addresses such intraoperative surprises and achieves full arch length in the planned prosthesis. PATZi also assigns a numbering classification to each implant configuration, which leads to uniform communication and grading of surgical difficulty, as well as predictable planning for developing future salvage plans. By using the PATZi protocol as a guideline, the surgeon may improve composite torque value and anteroposterior (AP) spread, eliminate distal cantilever forces, and ultimately improve the predictability of the prosthetic treatment plan. Keywords: full-arch implants, all-on-x, fixed hybrid prosthesis, implant protocol

Maxillary sinus augmentation with a lateral approach is known to present more postoperative complications than other atrophic posterior maxilla treatment modalities because it is more invasive. These complications include infections that occur in the form of chronic or acute sinusitis. According to the literature, the frequency of these complications ranges from 3% to 5%. They can result from an inadequate management of intraoperative complications or from a poor evaluation of maxillary sinus particularities and pathology before the surgery. Therefore, the prevention of postoperative complications lies in the selection of cases that will allow for the identification and evaluation of infectious risk. Only a multidisciplinary approach that includes an implantologist, a rhinologist, and the treating physician will allow this. On the other hand, in infectious complication cases, the intervention of the otorhinolaryngologist (ENT) specialist is necessary. Based on the available literature and the author’s experience, the methodology described in this article will allow for the prevention and management of postoperative complications related to this surgical technique. Keywords: barotrauma, maxillary sinus augmentation, osteomeatal complex patency, penicillin allergy, peri-implantitis, postoperative complications, sinusitis

Purpose: To compare the fit of 3D-printed titanium (Ti) and cobalt-chromium (Co-Cr) abutments with implants to computer numerical control (CNC)–milled, ready-made abutment-implant assemblies. Their clinical applicability was also evaluated by measuring removal torque values (RTVs) and percentage torque loss of abutment screws. Materials and Methods: A total of 138 abutments were included in the study: 92 abutments were fabricated with Ti and Co-Cr alloys using computer-assisted design (CAD) through selective laser melting, and 46 ready-made abutments were prepared. The fit of interfaces between 90 abutments from the three groups (30 ready-made, 30 3D-printed Ti, and 30 3D-printed Co-Cr abutments) and implant assemblies was demonstrated by scanning electron microscopy (SEM) and confocal scanning laser microscopy (CSLM). After 30-Ncm torque tightening of Ti abutment screws twice within 10 minutes, the RTVs and percentage torque loss of screws of 48 abutments (16 ready-made, 16 3D-printed Ti, and 16 3D-printed Co-Cr) were evaluated after 10 minutes of thermocycling and cyclic loading. Results: The fits of 3D-printed Co-Cr abutments were not statistically different from those of ready-made abutments (P = .383), while the fit of 3D-printed Ti abutments was inadequate (P < .001). The RTVs of 3D-printed abutments after cyclic loading were significantly decreased compared with those of CNC-milled abutments (P < .001). Conclusion: The fit of interfaces between 3D-printed Co-Cr abutments and implants was adequate. The RTVs of 3D-printed Co-Cr abutments were not significantly different from those of CNC-milled abutments after 10 minutes of 30-Ncm torque tightening and thermocycling. Keywords: 3D-printed abutment, fit, implant abutment, removal torque values (RTVs)

Purpose: To evaluate the effect of ultraviolet-C light (UVC) photofunctionalization treatment time on the biologic activity of airborne particle–abraded and acid-etched (SLA) titanium surfaces and to analyze its physical and chemical mechanisms. Materials and Methods: SLA titanium was treated with UVC light for different lengths of time (10 minutes, 20 minutes, 30 minutes, 1 hour, 2 hours, 4 hours, and 24 hours), and then changes to its surface characteristics were evaluated via electron microscope scanning, X-ray photoelectron spectroscopy (XPS), water contact angle measurement, and zeta potential measurement. The effect of UVC photofunctionalization on the biologic processes of SLA titanium surfaces was assessed by analyzing the bovine serum albumin adsorption, adhesion, proliferation, morphology, and alkaline phosphatase activity of MG-63 cells. Results: UVC irradiation did not change the topography of SLA titanium surfaces. As treatment times increased, the water contact angle decreased from 120 degrees to 0 degrees, and the hydrocarbon content decreased. Zeta potential testing showed increased surface potential of photofunctionalized titanium. In vitro testing showed that cell adhesion, proliferation, morphology, and alkaline phosphate (ALP) activity on titanium surfaces were significantly improved by UVC photofunctionalization. Conclusions: UVC photofunctionalization can improve the biologic activity of SLA titanium surfaces by removing hydrocarbons and increasing the surface potential of titanium. Keywords: UVC photofunctionalization, zeta potential, biologic activity, SLA titanium, surface modification