Oral Maxillofac Research Articles

An indirect method of verifying passive fit of complete arch implant-supported frameworks fabricated from photogrammetry scans

The passive fit of frameworks on multi-unit abutments has been considered crucial for the long-term success of complete arch, implant-supported, fixed prostheses. 1 Jokstad A. Shokati B. New 3D technologies applied to assess the long-term clinical effects of misfit of the full jaw fixed prosthesis on dental implants. Clin Oral Implants Res. 2015; 26: 1129-1134 Crossref PubMed Google Scholar Photogrammetry has demonstrated better accuracy than intraoral scanning and conventional impression techniques to record the position of implants. 2 Sallorenzo A. Gómez-Polo M. Comparative study of the accuracy of an implant intraoral scanner and that of a conventional intraoral scanner for complete-arch fixed dental prostheses. J Prosthet Dent. 2022; 128: 1009-1016 Abstract Full Text Full Text PDF PubMed Scopus (13) Google Scholar However, errors introduced during fabrication may still compromise the passive fit of the definitive prosthesis, even with accurate scanning using the photogrammetry technique. 3 Al-Meraikhi H. Yilmaz B. McGlumphy E. Brantley W. Johnston W.M. In vitro fit of CAD-CAM complete arch screw-retained titanium and zirconia implant prostheses fabricated on 4 implants. J Prosthet Dent. 2018; 119: 409-416 Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar The current intraoral methods of verifying passive fit, including visual inspection, tactile sensation, radiography, disclosing materials, screw resistance test, and the Sheffield test, are subjective and not capable of detecting lingual or subgingival misfit. 4 Abduo J. Bennani V. Waddell N. Lyons K. Swain M. Assessing the fit of implant fixed prostheses: a critical review. Int J Oral Maxillofac Implants. 2010; 25: 506-515 PubMed Google Scholar In the conventional protocol, the definitive cast made from a custom tray elastomeric impression can be verified with a dental gypsum device. 5 Manzella C. Burello V. Bignardi C. Carossa S. Schierano G. A method to improve passive fit of frameworks on implant-supported prostheses: an in vivo study. Int J Prosthodont. 2013; 26: 577-579 Crossref PubMed Google Scholar However, since the frameworks made from photogrammetry are manufactured without a definitive cast, verifying the passive fit of the frameworks is challenging. 6 Rutkunas V. Larsson C. Vult von Steyern P. Mangano F. Gedrimiene A. Clinical and laboratory passive fit assessment of implant-supported zirconia restorations fabricated using conventional and digital workflow. Clin Implant Dent Relat Res. 2020; 22: 237-245 Crossref PubMed Scopus (11) Google Scholar In the treatment of the first patient, misfits were found between the frameworks and the 3-dimensional printed cast; therefore, the accuracy of the frameworks needed to be verified to determine whether the distortion was introduced during printing of the cast (Fig. 1A-C). An inexpensive and user-friendly method of verifying the passive fit of frameworks is described. Figure 1A, Intraoral view after removal of interim prosthesis. B, Impression scanning using photogrammetry technology. C, Misfits between framework and printed cast. D, Placement of abutment replicas. E, Fixture of replicas with dental gypsum. F, Evaluating fit of framework. View Large Image Figure Viewer Download Hi-res image

Effects of Combining Plasma Rich in Growth Factors with Different Bone Grafts on Early Bone Healing: An Experimental Study.

To histologically and radiographically investigate the effect of plasma rich in growth factor (PRGF) mixed with bone grafts on ossification in the early period. A total of 12 New Zealand male rabbits (weighing between approximately 2.5 to 3 kg) were included in this study. Subjects were randomly divided into two sets of groups: control and experiment. Autograft, DFDBA (demineralized freeze-dried bone allograft), and DBBM (deproteinized bovine bone mineral) were applied to different defects in the control groups, and autograft + PRGF, DFDBA + PRGF, and DBBM + PRGF were applied in the experimental groups. All subjects were euthanized 28 days after surgery. The volumes of the bone, new connective tissue, and new capillaries were evaluated stereologically, and the bone density in the defects was investigated radiographically. Regarding the stereologic evaluation, the volumes of the bone and capillaries were significantly higher in the experimental groups than in the control groups. In contrast, the connective tissue volume was considerably lower (P < .001, in all groups). Similarly, radiographic examinations showed that the bone density measurements in the experimental groups were higher than in the control groups. However, these differences were statistically significant only between the DFDBA + PRGF and DFDBA groups (P < .011). The present study provides evidence that the addition of PRGF to autograft, DFDBA, and DBBM enhances osteogenesis in the early period compared to using these grafts alone. It also accelerates the remodeling of connective tissue to bone in defects. Int J Oral Maxillofac Implants 2023;38:569-575. doi: 10.11607/jomi.9858.

Splinting or Nonsplinting Adjacent Implants? A Retrospective Study Up to 15 Years: Part II-Success and Survival Rate Analysis.

To analyze the success and survival of splinted and nonsplinted implants. A total of 423 patients (n = implants: 888) were included in the study. The success and survival of implants for 15 years were analyzed using a multivariable Cox regression model, and the significant effect of the splinting of prostheses and other risk factors were evaluated. The cumulative success rate was 34.2%: 33.2% in nonsplinted (NS) and 34.8% in splinted implants (SP). The cumulative survival rate was 92.9% (94.1%, NS; 92.3%, SP). Whether to splint was not related to the success and survival of implants. The smaller the implant diameter, the lower the survival rate. The crown length and implant length were significantly associated only with NS implants: The longer the crown length and the shorter the implant length, the greater the risk of implant failure. The emergence angle (EA) and the emergence profile (EP) had a significant effect on only the SP implants: EA3 showed a higher risk than EA1, and EP2 and EP3 had a higher risk of implant failure. Crown length and implant length affected only the nonsplinted implants: The higher the crown length and the shorter the implant length, the greater the risk of implant failure. A significant effect for emergence contour was found only in SP implants: the implants restored with prostheses with EA ≥ 30 degrees on both the mesial and distal sides, and convex EP on at least one side had higher risks of failure. Int J Oral Maxillofac Implants 2023;38:443-450. doi: 10.11607/jomi.10054.

Splinting or Nonsplinting Adjacent Implants? A Retrospective Study Up to 15 Years: Part I-Biologic and Mechanical Complication Analysis.

To analyze the biologic and mechanical complications of splinted and nonsplinted implant restorations. A total of 423 patients (n = implants: 888) were included in the study. Biologic and mechanical complications that occurred for 15 years were analyzed using the multivariable Cox regression model, and the significant effect of the splinting of prostheses and other risk factors were evaluated. Biologic complications occurred in 38.7% of implants: 26.4% of nonsplinted implants (NS) and 45.4% of splinted implants (SP). Mechanical complications occurred in 49.2% of implants: 59.3% NS and 43.9% SP. Implants splinted with both mesial and distal adjacent implants (SP-mid) had the highest risk of peri-implant diseases. As the number of implants splinted increased, the risk of mechanical complications decreased. Long crown lengths increased the risk of both biologic and mechanical complications. Splinted implants had a higher risk of biologic complications and lower risk of mechanical complications. The implant splinted to both adjacent implants (SP-mid) had the highest risk of biologic complications. The greater the number of implants splinted, the lower the risk of mechanical complications. Long crown lengths increased the risk of both biologic and mechanical complications. Int J Oral Maxillofac Implants 2023;38:435-442. doi: 10.11607/jomi.10053.

Hard and Soft Tissue Alterations After Immediate Implant Placement and Provisionalization with Customized Definite Abutment in Esthetic Zone: A Retrospective Study.

To evaluate the hard and soft tissue alterations of immediate implant placement and provisionalization with customized definitive abutments in the esthetic zone. Single unsalvageable maxillary anterior teeth were replaced with immediate implant placement and provisionalization with definitive abutments in 22 participants. Digital impressions and CBCT images were obtained presurgery, immediately after surgery, and 6 months after surgery. Horizontal and vertical buccal bone changes in thickness and height (HBBT, VBBH), vertical changes for the gingiva margin, mesial and distal papilla height, and horizontal changes for soft tissue (HCST) were analyzed using a 3D superimposition method. Twenty-two participants completed the study. No implant failed, and there were no mechanical or biologic complications for any patients. At 6 months after surgery, the mean HBBT changes at 0, 1, 2, 3, 5, 7, 10, 11.5, and 13 mm were -0.92 ± 0.73, -0.83 ± 0.53, -0.82 ± 0.49, -0.70 ± 0.64, -0.65 ± 0.47, -0.50 ± 0.51, -0.15 ± 0.45, -0.10 ± 0.57, and -0.00 ± 0.64 mm, respectively. The mean VBBH change was -0.61 ± 0.76 mm. The mean HCSTs at -3, -2, -1, 0, 1, 2, and 3 mm sub- and supra-implant shoulder were -0.65 ± 0.54, -0.70 ± 0.56, -0.65 ± 0.51, -0.61 ± 0.56, -0.47 ± 0.54, -0.47 ± 0.59, and -0.46 ± 0.59 mm, respectively. The mean gingiva margin recession was -0.38 ± 0.67 mm. The mean mesial papilla height recession was -0.03 ± 0.50 mm. The mean distal papilla height recession was -0.12 ± 0.56 mm. The definitive abutment used with immediate implant placement and provisionalization could potentially maintain the buccal bone thickness and height. For the facial soft tissue, it also benefited the maintenance of the midfacial gingival margin position and papilla height during the 6-month follow-up. Int J Oral Maxillofac Implants 2023;38:479-488. doi: 10.11607/jomi.9914.

Evaluation of Implant Location on Fiber-Reinforced Maxillary Overdentures with Finite Element Method.

To examine and compare stress values of implants, highest tensile and compressive values, and their distribution in cortical and trabecular bone near and around the implant region using different materials (aramid fiber, glass fiber, polyethylene fiber, carbon fiber, and cobalt-chromium [Co-Cr] alloy). Four dental implants were placed in the maxillary crest with two different location scenarios, and the 3D finite element analysis method was used to evaluate stress characteristics. Two maxillary models were created in which the implants were placed in different locations (lateral and first premolar, canine and second premolar). Four implant-supported overdenture prostheses were reinforced, applying Co-Cr alloy, glass fiber, aramid fiber, and carbon fiber. Static loads of 200 N were applied on the first molar region using the food stuff method. Stresses around the implants and denture-bearing areas and compression and tensile stresses on the cortical and trabecular bone were evaluated. In all tested models, the highest von Mises stresses on implants and prostheses were observed in aramid fiber-reinforced overdentures. This was followed by glass fiber, Co-Cr alloy, and carbon fiber groups, respectively. It was observed that the lowest tensile and highest compression stress values in cortical and trabecular bone occurred in prostheses supported with carbon fiber. In all infrastructure materials, the design in which the implants were placed bilaterally in the lateral teeth and the first premolar region was found to be advantageous in terms of stress levels and distribution. High elastic modulus fiber-reinforced overdenture prostheses transmitted less stress to implants and surrounding tissues than Co-Cr alloy. Anteriorly placed implant design illustrated lower stress values in the prosthesis, implant, and cortical and trabecular bone, and this placement design may increase the survival rates of both dental implants and overdentures. In light of this study, fibers can be recommended for clinical use and securely applied as an alternative material to metal support. Int J Oral Maxillofac Implants 2023;38:523-532. doi: 10.11607/jomi.9946.

Effect of Drilling Preparation on Immediately Loaded Implants: An In Vivo Study in Sheep.

To determine the biologic and biomechanical effects of two implant drilling protocols on the cortical bone around implants subjected to immediate loading. A total of 48 implants were inserted into the mandibles of six sheep following one of two drilling protocols: undersized preparation (US; n = 24) and nonundersized preparation (NUS; n = 24). Immediately after implant insertion, an abutment was placed on each implant and 36 implants were subjected to 10 sessions of dynamic vertical loads (1,500 cycles, 1 Hz) of 25 N or 50 N. Insertion torque value (ITV) was recorded at implant installation. Resonance frequency analysis (RFA) was measured at implant insertion and at each loading session. Fluorochrome was administered at day 17, and the animals were euthanized after 5 weeks. The removal torque values (RTVs) were measured, and samples underwent histomorphometric, μCT (microcomputed tomography), and fluorescence image acquisition analyses. The bone volume density (BV/TV), bone-to-implant contact (BIC), bone area fraction occupancy (BAFO), and fluorochrome stained bone surface (MS) were calculated. A linear mixed model analysis was performed, and Pearson paired correlation was calculated. Five implants from the NUS group failed, with a mean ITV of 8.8 Ncm and an RFA value of 57. The mean ITVs for US group and NUS group were 80.5 (± 14) Ncm and 45.9 (± 25) Ncm, respectively (P < .001). No differences were noted in the RFA values from the time of implant insertion until the end of the study. No differences in RTV, BV/TV, BAFO, or MS were observed between the groups. Intense new bone formation took place in the NUS group implants that were subjected to load. Undersized preparation of cortical bone ensured a greater BIC compared to a nonundersized preparation. Moreover, this study demonstrated that immediate loading did not interfere with the osseointegration process, but loading induced intense new bone formation in the NUS group. It is not recommended to immediately load the implants when the clinically perceived primary stability is lower than an ITV of 10 Ncm and an RFA value of 60. Int J Oral Maxillofac Implants 2023;38:607-618. doi: 10.11607/jomi.9949.

5- to 15-Year Survival of Immediately Loaded Implants in Fully Edentulous Maxillae: A Multilevel Analysis in a Retrospective Cohort Study.

Although immediate-loading implant (ILI) treatment is a general treatment strategy for fully edentulous maxillae, long-term evidence is required. The purpose of this study was to evaluate the long-term clinical results of, and risk factors for, ILI treatment in fully edentulous maxillae. ILI treatments of maxillae using 526 implants in 117 patients were reviewed retrospectively. The longest and mean observation periods were 15 years and 9.2 years, respectively. Kaplan-Meier survival curve analysis, log-rank tests, and multilevel mixed-effects parametric survival analysis were used for statistical analyses. Overall, 38 of 526 implants failed in 23 patients, and the estimated 15-year cumulative implant-level and patient-level survival rates were 90.7% and 73.7%, respectively. The cumulative implant survival rate was significantly higher in female patients than in male patients. Sex, implant length, and implant diameter were significantly associated with implant survival. ILI treatment of completely edentulous maxillae demonstrated viable long-term clinical outcomes. Male sex, shorter implant length, and narrow implant diameter negatively affected implant survival. Int J Oral Maxillofac Implants 2023;38:516-522. doi: 10.11607/jomi.10310.

National population-based analysis of demographics and outcomes of patients diagnosed with extranodal NK/T-cell nasal type lymphoma in the US: Does ethnicity play a role?

e18772 Background: Extranodal Natural Killer/T-cell Lymphoma Nasal Type (ENKTL-NT) in an uncommon malignancy with rising incidence in the United States (US) despite previously being described only in Asia and Latin America (J Oral Maxillofac Pathol PMC3125667 Crit Rev Oncol Hematol PMID33493634). Although primarily occupying the nasal cavity, other locations may be affected, which makes its presentation ambiguous. Diagnosis is important as omitting radiation has been associated with detrimental survival (J Oncol Pract PMID31600462). This is the first national population-based analysis evaluating ethnic differences for Hispanics (HI) diagnosed with ENKTL-NT. Methods: Data were analyzed on ENKTL-NT patients in the US reported to the Surveillance, Epidemiology, and End Results (SEER) database between 2000-2018. Demographic, clinical and survival patterns were analyzed. Kaplan-Meier and Cox regression analyses were used when appropriate. Multivariate analysis and propensity score matching were performed with adjustment for age, stage and B-symptoms. Results: 1,205 patients (HI=409, Non HI (NH)=796) were diagnosed with ENKTL-NT. Male sex predominated in both. HI were diagnosed at younger median age, 43 years (y) vs 59y in NH [p &lt;0.001]. Most of HI and NH were whites 98% vs 58%; however, for NH other races were noted. Most of the patients were diagnosed between 2010-2014. For both, the presence of B symptoms was predominantly unknown. At diagnosis stage I was mainly for HI while unknown stage was most likely noted for NH [p = 0.013]. HI were less likely than NH to receive radiation as part of their treatment, 47% vs 57% respectively [p = 0.003]. Median survival for HI was 1.7y vs 1.2y for NH; survival probability at 2, 5 and 10y for HI corresponded to 0.467, 0.413 and 0.355, while for NH it was 0.444, 0.352 and 0.292, respectively. OS probability at 10y had no statistically significant difference [p = 0.06]. On multivariate analysis, those who were older than 80y and between 60-80y, had worse OS compared to those younger than 60y (HR 2.3 - 95% CI: 1.7 – 3 and 1.2 - 95% CI: 1 – 1.5). Regarding stage, those who were at stage III/IV had worse OS than those at early stage I/II (HR 2.4 -95% CI: 1.7 - 3.2 and HR 3.4 -95% CI: 2.7 - 4.30). Conclusions: This national population-based study identified statistical differences in HI diagnosed with ENKTL-NT. Interestingly, HI were less likely to receive radiation therapy which is the mainstay treatment and key determinant for survival. The fact that there was no statistical difference in survival for HI and NH may underrepresent the improved survival from HI as they are not optimally treated and still living as longer as the NH. Additional research with biological variables should be carried out to better understand this oncological outcome and potentially offer improved targeted treatments for this ethnic minority.

Immediate Implant Placement With or Without Immediate Provisionalization in the Maxillary Esthetic Zone: A Systematic Review and Meta-analysis.

To determine whether immediate implant placement and loading renders different outcomes from delayed loading with respect to midfacial mucosal level in the maxillary esthetic area. A literature search was conducted in four electronic databases (PubMed, Web of Science, Embase, and Cochrane), identifying eligible clinical studies published prior to December 2021. Only randomized controlled trials (RCTs) comparing immediate implant placement with or without immediate loading in the maxillary esthetic zone with a mean follow-up of at least 12 months were selected for qualitative analysis and meta-analysis. The Cochrane Risk of Bias tool was adopted to assess the quality of the evidence. The heterogeneity between the pooled literature was analyzed through the chi-square test (P < .05) and quantified by the I2 index. A mixed-effects model was applied if it appeared that there was noteworthy heterogeneity; otherwise, a random-effects model was chosen. For continuous outcomes, the estimate of relative effect was presented to display the standardized mean differences (SMDs) and 95% CIs. For dichotomous variables, the Mantel-Haenszel statistical method was applied with effect sizes expressed as risk ratios (RRs) and 95% CIs. This study is registered on PROSPERO with number CRD42017078611. Out of 5,553 records, 8 RCTs were involved, providing data for 324 immediately placed implants (immediate implants subjected to immediate loading [IPIL]: 163; immediate implants subjected to delayed loading [IPDL]: 161) that had been in function within 12 to 60 months. Meta-analyses revealed significantly lower midfacial mucosal level changes for IPIL compared with IPDL, pointing to 0.48 mm (95% CI: -0.84 to -0.12; P = .01), as well as more significant papillary recession after IPDL (SMD -0.16; 95% CI: -0.31 to 0.00; P = .04). The differences regarding implant survival and marginal bone loss between the two loading groups showed no statistical significance. The result of metaanalyses revealed similar plaque score (SMD 0.03; 95% CI: -0.22 to 0.29; P = .79) and probing depth (SMD -0.09; 95% CI: -0.23 to 0.05; P = .21) for IPIL and IPDL. On the other hand, IPIL induced a trend toward more bleeding on probing (SMD 0.22; 95% CI: 0.01 to 0.42; P = .04) and less change in facial ridge dimension (SMD 0.94; 95% CI: -1.49 to -0.39; P < .01). After a follow-up ranging from 12 to 60 months, midfacial mucosa level change was 0.48 mm lower following IPIL compared with IPDL. Immediate implant placement and loading is conducive to the preservation of physiologic soft and hard tissue architecture, appearing to offer considerable benefits in the anterior zone. In summary, IPIL should be considered in the esthetic zone if the primary implant stability permits. Int J Oral Maxillofac Implants 2023;38:422-434. doi: 10.11607/jomi.10112.

Influence of Keratinized Tissue on Short Dental Implants: A Parallel Cohort Retrospective Study on 217 Implants with a Mean Follow-up of 4.1 Years.

To assess whether the presence or absence of keratinized tissue height (KTh) may have an influence on marginal bone levels, complications, and implant survival for short implants. The study was designed as parallel cohort retrospective research. Short implants with an implant length < 7 mm were considered. One cohort was composed of patients with short implants surrounded by ≥ 2 mm of KTh (adequate KTh); the other cohort included implants with < 2 mm of KTh (not-adequate KTh). Outcome measures were marginal bone level (MBL) changes, failures, and complications. One hundred ten patients treated with 217 short and extrashort implants (4 to 6.6 mm long) were retrospectively included. The mean follow-up was 4.1 years after prosthetic loading (range: 1 to 8 years). The differences between KTh groups in MBL were not statistically significant at every follow-up considered: 0.05 mm at 1 year (P = .48), 0.06 mm at 3 years (P = .34), 0.04 mm at 5 years (P = .64), and 0.03 at 8 years (P = .82). A total of nine complications were reported: three in the not-adequate KTh group and six in the adequate group; the difference was not statistically significant (OR: 3.03, 95% CI: 0.68 to 13.46, P = .14). Five implants failed due to peri-implantitis, two in the not-adequate KTh group and three in the adequate group, without a statistically significant difference (OR: 2.76, 95% CI: 0.42-17.99, P = .29). This study showed no statistically significant differences in MBL, complications, and implant failure rates between short implants with adequate or not-adequate KThs. However, given the importance of patient comfort while brushing and plaque accumulation, keratinized tissue grafts could be important in selected patients, especially for those who are severely atrophic, also taking into consideration all the limitations of this study and the mediumterm follow-up. Nevertheless, longer follow-ups, larger numbers of patients, and randomized controlled clinical trials are needed before making more reliable clinical recommendations. Int J Oral Maxillofac Implants 2023;38:462-467. doi: 10.11607/jomi.9918.

Evaluation of Implant Body Diameter, Platform Diameter, and the Use of a Transepithelial Component on Implant-Abutment Connection Microgap: An In Vitro Study with In Situ Hard X-Ray Radiography.

To evaluate the effect of implant body diameter, platform diameter, and the use of transepithelial components on implant-abutment connection (IAC) microgap width. In total, 16 tests were performed on four commercial dental restoration models (BTI Biotechnology Institute). Different static loads were applied to the embedded implants according to the International Organization for Standardization (ISO) 14801, using a customized loading device. Measurements of the microgap were taken by means of highly magnified x-ray projection in situ in a micro-CT scanner. Regression models were obtained and compared through an analysis of covariance (ANCOVA). To quantify the effect of each variable, t tests (α = .05) of experimental results were performed. Under 400 N, using a transepithelial component for the dental restoration, the microgap width was reduced by 20% (P = .044). Meanwhile, a 22% microgap reduction was observed when the implant body diameter was increased by 1 mm (P = .024). Finally, increasing the platform diameter by 1.4 mm led to a microgap reduction of 54% (P = .001). The use of a transepithelial component in dental restorations reduces the microgap width in IACs. Furthermore, given sufficient space for the implantation, larger implant bodies and platform diameters can also be used for this purpose. Int J Oral Maxillofac Implants 2023;38:489-495. doi: 10.11607/jomi.9855.

Influence of Dentist-Related Risk Factors on Implant Survival Provided by Dentists Without Structured Training: Results of a Retrospective Cross-Sectional Study.

To evaluate the cumulative survival rate (CSR) of implants placed by Chinese dentists who lacked structured training and to identify the dentist-related risk factors associated with implant failure. Data from 2,036 patients who underwent implant-supported restoration at a university-affiliated stomatology hospital were collected. CSR was regarded as the dependent variable. Patient-related characteristics (age, sex, insertion site, and surgical complexity) and dentist-related factors (experience, number of implant brands used, education level, sex, and specialty) were collected as independent variables. The chi-square test was used to identify dentist-related factors for implant failure after addressing patient-related potential confounders using propensity score matching (PSM). Dentist- and patient-related risk factors were further analyzed using multivariable logistic regression within the subgroups. The CSRs were 98.48% for patients (with single or multiple implants) and 98.86% for implants after 48 to 60 months of observation. Dentists with < 5 years of experience and specialists in implant dentistry were significantly associated with implant failure after addressing potential patient-related confounders. Within the group of dentists with < 5 years of experience, complicated cases were the major risk factor. For the group of specialists in implant dentistry, < 5 years of experience and male patient were the major risk factors. New dentists (< 5 years of experience) and specialists in implant dentistry are considered to be dentist-related risk factors for implant failure. This confirms that a learning curve exists for new specialists to reach the level of proficiency and expertise. Int J Oral Maxillofac Implants 2023;38:553-561. doi: 10.11607/jomi.9969.

Biomechanical and Histologic Evaluation of Osseointegration of Titanium Dental Implants Modified by Various Combinations of Sandblasting, Acid-Etching, Hydroxyapatite, and Hyaluronic Acid Coating Techniques.

To compare the osseointegration process of the titanium dental implants with five different surface characteristics-sandblasted, sandblasted and acid-etched, hyaluronic acid-coated (HYA), hydroxyapatite-coated (HA), and machined-in an experimental sheep model at 1- and 3-month examinations. One hundred sixty dental implants were placed in the left and right tibias of 16 sheep. Five experimental groups were designed. Eight animals (80 implants) were used for biomechanical tests of reverse torque analysis and resonance frequency analysis (RFA). Eight of them (80 implants) were used for the evaluation of bone-to-implant contact (BIC) percentage in histomorphometric analysis. Forty of 80 implants (8 implants for each group) were used at 1-month examinations, and the remaining 40 (8 implants for each group) implants were used at 3-month examinations in the biomechanical test group and histomorphometric examination group, separately. Intergroup analysis at the 3-month followup showed that the increase in the implant stability quotient (ISQ) value was statistically significant for only the HYA group (P < .05). According to ISQ values at 1 and 3 months, group HYA showed statistically higher values at the 1 and 3-month examinations (P < .05). Groups HYA and HA had statistically higher reverse torque values than other groups at the 1-month examination (P < .05). At the 3-month evaluation, the HYA group showed significantly higher reverse torque values compared to other groups (P < .05). The BIC values of the sandblasted and acid-etched, HYA, and HA groups were significantly higher than the sandblasted and machined groups at the 1- and 3-month examinations (P < .05). The BIC value for the HA group showed decreased value at the 3-month examination compared to the 1-month examination (P < .05). The RFA, reverse torque, and histomorphometric analysis at 1- and 3-month examinations show that dental implants coated with HYA may have increased potential for osseointegration compared to dental implants with sandblasted, sandblasted and acid-etched, machined, and HA-coated surfaces. Int J Oral Maxillofac Implants 2023;38:583-590. doi: 10.11607/jomi.9935.

Diffuse Sclerosing Osteomyelitis: A Potential Risk Indicator for Peri-implantitis? A Case Series.

To propose diffuse osteomyelitis as risk indicator for peri-implantitis following the loss of several dental implants in patients that present with highly sclerotic bone areas. A total of six "nightmare cases"-three of which were treated at the Department of Periodontology of the University Hospitals of the Catholic University Leuven and three of which were referred there for a second opinion-were retrospectively analyzed using radiographs obtained via contact with referring clinicians in order to fully reconstruct the treatment pathway and dental history for each of these patients. All patients suffered from early implant failures and/or severe peri-implantitis with bone loss and crater formation up to the apical level, as well as the loss of all or nearly all implants. Re-examination of their preand postoperative CBCTs, in combination with several bone biopsies, confirmed the diagnosis of a diffuse sclerosing osteomyelitis in the treated area. Osteomyelitis could be linked to a longstanding history of chronic and/or therapyresistant periodontal/endodontic pathology. The current retrospective case series seems to suggest that diffuse osteomyelitis should be considered as a risk indicator for severe peri-implantitis. Int J Oral Maxillofac Implants 2023;38:503-515. doi: 10.11607/jomi.9773.

Implant Placement with Simultaneous Guided Bone Regeneration in the Anterior Region Close to the Periapical Lesion of Adjacent Teeth: A Combined Treatment Strategy to Prevent Complications.

To evaluate the safety and performance of a potential novel strategy to resolve the above scenario by simultaneously performing implant-related surgery and endodontic microsurgery (EMS). A total of 25 subjects requiring GBR during implant placement in anterior areas were allocated into two groups. In the experimental group (adjacent teeth with periapical lesions) with 10 subjects, implantation and GBR were performed for edentulous areas with simultaneous EMS for adjacent teeth. In the control group (adjacent teeth without periapical lesions) with 15 subjects, implantation and GBR were performed for edentulous areas. The clinical outcomes, radiographic bone remodeling, and patient-reported outcomes were assessed. Within a 1-year follow-up, the implant survival rate was 100% in both groups, with no significant difference regarding complications. All teeth achieved complete healing following EMS. Repeated analysis of variance (ANOVA) measurements revealed a significant change over time in horizontal bone widths and postoperative patient-reported outcomes, but no intergroup statistically significant differences (P > .05) in horizontal bone widths and visual analog scale scores of pain, swelling, and bleeding were observed. Likewise, the bone volumetric decrease (7.4% ± 4.5% in the experimental group and 7.1% ± 5.2% in the control group) from T1 (suture removal) to T2 (6 months after implantation) revealed no intergroup differences. The horizontal bone width gain at the implant platform was slightly lower in the experimental group (P < .05). Interestingly, the color-coded figures of both groups showed a facial reduction of grafted material in edentulous areas. However, the apical regions following EMS exhibited stable bone remodeling in the experimental group. This novel approach to address the problem involving implant-related surgery close to the periapical lesion of adjacent teeth appeared safe and reliable (no.: ChiCTR2000041153). Int J Oral Maxillofac Implants 2023;38:533-544. doi: 10.11607/jomi.9839.

Keratinocyte Proliferation and Hemidesmosome Formation on Surfaces for Dental Implants: In Vitro Study.

To demonstrate the likelihood of the polyetheretherketone (PEEK), zirconia (ZrO2), and titanium (Ti) disks to support proliferation and hemidesmosome formation of gingival cells. Water contact angle was performed on each material, and surface roughness (Ra) was measured. Scanning electron microscopy and x-ray photoelectron spectroscopy were used. Later, oral keratinocyte cells were cultured on disks, and metabolic activity and expression of hemidesmosome markers, integrin α6 and β4, in relation to the biomaterial disks at 1, 3, and 5 days of cell culture were quantified. Tissue culture polystyrene was used as the control. Statistical analysis was performed with analysis of variance (ANOVA) with Tukey post hoc comparison test. A P value of < .05 was considered statistically significant. The water contact angle ranged from 70.2 degrees (Ti) to a maximum of hydrophobicity of 93.3 degrees (PEEK). Ra was highest on ZrO2, followed by PEEK. Ti showed the most keratinocyte metabolic activity at 1, 3, and 5 culture periods. Contrarily, ZrO2 and PEEK disks had lower keratinocyte metabolic activity at all observation times, with no statistical differences between both groups. Integrin α6 and β4 expression was highest on TCPS and ZrO2 compared to Ti and PEEK. Keratinocytes proliferated faster on Ti than on ZrO2 and PEEK substrates, and expression of hemidesmosome formation markers, integrin α6 and β4, were higher on ZrO2 than either Ti or PEEK. Int J Oral Maxillofac Implants 2023;38:496-502. doi: 10.11607/jomi.9894.

Micro/Nanostructured Bioactive Titanium Implant Surface with Sol-Gel Silicate Glass Nanoparticles.

To develop a surface coating of sol-gel 70S30C bioactive glass (BAG) nanoparticles on titanium disks and dental implants and characterize the BAG coating from the standpoint of average surface roughness, adhesion strength, and coating stability upon implant insertion under clinical settings. BAG was prepared using a modified sol-gel technique, then milled into nanoparticles. The resultant powder was characterized in terms of phase structure, composition, and particle size. Titanium disks and dental implants were coated with BAG nanoparticles via electrophoretic deposition. Surface characterization of coated implants was conducted. Uncoated and BAGcoated implants were examined for average surface roughness using a confocal laser scanning microscope. Pull-off tests were conducted to measure the adhesion strength of the BAG coating to the underlying disks. To measure the amount of coating loss and evaluate the effect of insertion on coating thickness, coated implants were inserted under clinical settings into artificial and natural bones. BAG nanoparticles had an amorphous structure with particle sizes < 20 nm in diameter. Electrophoresis resulted in a continuous coating that covered the whole implant surface. Microscopic analysis confirmed the porous nanostructure of the BAG coating, which formed a homogenous surface with microcracks. The BAG coating had a uniform thickness of 35.38 ± 4.67 μm. The average surface roughness was significantly lower for BAG-coated implants, with less surface irregularities (3.34 ± 0.45 μm for uncoated implants, 1.45 ± 0.23 μm for BAG-coated implants). An adhesion strength of 18.51 ± 3.37 MPa was recorded for the BAG coating. After insertion into artificial bone, 66.23 ± 10.23% of the coating weight remained on the implant surface. A reduction in the thickness of the BAG coating only occurred in sites of high friction with bone after implant insertion into bovine bone. Coating titanium implants with 70S30C BAG nanoparticles is attainable through electrophoretic deposition and results in a homogenous coating layer with a moderately rough surface, considerable adhesion strength, and high coating stability during implant insertion. Int J Oral Maxillofac Implants 2023;38:591-606. doi: 10.11607/jomi.10272.

Could Fixed Implants Be a Viable Treatment Option in Disabled Patients? A Clinical Retrospective Study.

To verify the survival rates and marginal bone loss (MBL) of implants in patients with different disability types. Clinical and radiographic assessments were performed in a total of 189 implants for fixed implant prostheses in 72 patients. Data were collected on loaded implants at least 1 year in function, and the mean observation time was 37.3 months. Implant survival was examined, and MBL was observed around the implants of two groups (mental disability vs physical disability) based on age, sex, implant location (anterior vs posterior), and prosthetic connection (internal vs external). Of the 189 implants, 4 failed; the total implant survival rate was 97.8% across a mean of 37.3 months. The cumulative survival rate at 85 months in a Kaplan-Meier survival curve analysis was 94.3% ± 3% in patients with mental disability and 50% ± 35.4% in patients with physical disability, which was a statistically significant difference between the disability groups (P = .006). Fisher exact test showed significant differences in MBL only with age (P < .001). The implant MBL by disability type-adjusted for age and observation period-showed significant differences in multiple linear regression analyses (P = .003). The implant survival rates in patients with disability were in line with those reported for nondisabled patients. The MBL of the implants was within the physiologic bone loss after implant loading. Implants in patients with mental disability showed higher cumulative survival rates than in patients with physical disability, but also a higher amount of MBL. Within the limitations of this study, dental implants for patients with disability are viable. These results can establish future implant treatment plans for this population. Int J Oral Maxillofac Implants 2023;38:562-568. doi: 10.11607/jomi.9880.

Machine Learning and Artificial Intelligence: A Web-Based Implant Failure and Peri-implantitis Prediction Model for Clinicians.

To develop a machine learning model that can predict dental implant failure and peri-implantitis as a tool for maximizing implant success. This study used a supervised learning model to retrospectively analyze 398 unique patients receiving a total of 942 dental implants presenting at the Philadelphia Veterans Affairs Medical Center from 2006 to 2013. Logistic regression, random forest classifiers, support vector machines, and ensemble techniques were employed to analyze this dataset. The random forest model possessed the highest predictive performance on test sets, with receiver operating characteristic area under curves (ROC AUC) of 0.872 and 0.840 for dental implant failures and peri-implantitis, respectively. The five most important features correlating with implant failure were amount of local anesthetic, implant length, implant diameter, use of preoperative antibiotics, and frequency of hygiene visits. The five most important features correlating with peri-implantitis were implant length, implant diameter, use of preoperative antibiotics, frequency of hygiene visits, and presence of diabetes mellitus. This study demonstrated the ability of machine learning models to assess demographics, medical history, and surgical plans, as well as the influence of these factors on dental implant failure and peri-implantitis. This model may serve as a resource for clinicians in the treatment of dental implants. Int J Oral Maxillofac Implants 2023;38:576-582. doi: 10.11607/jomi.9852.