The International journal of oral & maxillofacial implants最新文献

{"title":"Influence of Titanium versus Temporary Peek Abutments on Peri- Implant Tissue Contouring in Single Crowns in the Esthetic Area: A Controlled Clinical Trial.","authors":"Lidya Nara Marques de Araújo, Aliane da Silva Bezerra, Wagner Ranier Maciel Dantas, Patrícia Dos Santos Calderon, Bruno César de Vasconcelos Gurgel","doi":"10.11607/jomi.11904","DOIUrl":"https://doi.org/10.11607/jomi.11904","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the effect of titanium abutment versus a temporary PEEK abutment on the peri-implant tissue contouring of implant-supported temporary single crowns in the esthetic area.</p><p><strong>Materials and methods: </strong>Thirty single implants were sequentially allocated, 15 in the prefabricated titanium abutment group (TA) and 15 in the temporary PEEK abutment group (PA). Clinical parameters were assessed at T1 (time of provisional crown installation) and T2 (end of tissue contouring). Outcomes included Visible Plaque Index (VPI), Mucosal Bleeding Index (MBI), Probing Depth (PD), Keratinized Mucosa Width (KTM), Mucosal Thickness (MT), Bleeding on Probing (BoP), papilla height/width ratio (PH/PW), Crown Height to Width Ratio (CH/CW), and Pink Esthetic Score (PES). Mann-Whitney, Pearson's chi-square/ Fisher's exact and Spanova tests were used to analyze the results.</p><p><strong>Results: </strong>The sample consisted of 19 female patients (67.9%) and 9 male patients (32.1%), with a significant age difference between the groups (P= 0.036). Both groups showed significant improvement in PES following peri-implant tissue contouring (P < 0.001), with no significant group × time interaction. Clinical parameters, including VPI, MBI, PD, BoP, MT, and KTW, remained comparable between groups throughout the study period. The VPI increased slightly in both groups, without a significant time effect (P = 0.086) or group × time interaction (P = 0.364).</p><p><strong>Conclusions: </strong>Temporary PEEK and titanium abutments are equivalent in terms of peri-implant tissue stability and esthetic outcomes during crown conditioning.</p>","PeriodicalId":94230,"journal":{"name":"The International journal of oral & maxillofacial implants","volume":"0 0","pages":"1-29"},"PeriodicalIF":1.7,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148889896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Screw Loosening and Torque Loss of Zirconia-Based Implant- Supported Dental Prostheses: A Retrospective Clinical Study.","authors":"Saman Savabi, Farahnaz Nejatidanesh, Ghazal Savabi, Maryam Gheisarifar, Melika Janghorban, Omid Savabi","doi":"10.11607/jomi.11511","DOIUrl":"https://doi.org/10.11607/jomi.11511","url":null,"abstract":"<p><strong>Purpose: </strong>Dental implants are a widely used and effective method for tooth replacement, yet complications such as abutment screw loosening remain a challenge. The aim of this study was to investigate the effect of different abutments, connection types and restoration types on abutment screw loosening.</p><p><strong>Materials and methods: </strong>A retrospective analysis was conducted on 161 patients (85 women, 76 men; mean age 53 ± 6.3 years) with 308 abutments in zirconia-based implant-supported fixed dental prostheses (FDPs). Kaplan-Meier analysis and the log-rank test were used to analyze and compare the screw loosening probabilities and mean estimation time to torque loss after loading of implant supported restorations with different implant systems, abutments and restorations type, and tissue vs bone level implants. The torque value of studied abutments was analyzed by Kruskal-Wallis test and Mann-Whitney Test. One way analysis of variance and independent sample t test were used to compare torque loss value of abutment's type, single vs multiple FDPs, and tissue Vs bone level implants. The level of significance was set at 0.05.</p><p><strong>Results: </strong>The overall survival rate of implant-supported FDPs was 99.2%. Complete loosening occurred in 2.1% of abutments. Torque loss values were significantly different between implant systems (p < 0.001), restoration types (p < 0.001), and tissue-level versus bone-level implants (p < 0.05). Tissue-level implants and multi-unit FDPs demonstrated more removal torque. No significant differences in torque loss were found between angled, straight, and solid abutments (p = 0.19).</p><p><strong>Conclusion: </strong>Torque loss and probability of screw loosening of different implant systems were significantly different. Multi-unit FDPs and bone level implants showed significantly less torque loss while abutment type did not influence the screw loosening.</p>","PeriodicalId":94230,"journal":{"name":"The International journal of oral & maxillofacial implants","volume":"0 0","pages":"1-24"},"PeriodicalIF":1.7,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148890019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-Piece Zirconia Implants: An Office-Based Retrospective Study with up to 7 Years and Mean 3 Years of Follow-up.","authors":"Jens Tartsch, Bruno Chrcanovic, Ann Wennerberg, Ralf-Joachim Kohal, Tomas Albrektsson","doi":"10.11607/jomi.11469","DOIUrl":"10.11607/jomi.11469","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the clinical outcomes of two different but identically designed two-piece zirconia implants (NobelPearl and Zeramex XT) in a private dental practice.</p><p><strong>Materials and methods: </strong>Between 2017 and 2024, 167 implants were placed in 106 patients and followed up to 88 months (mean: 39.1 months). In addition to the implant survival rate, marginal bone loss (MBL), clinical parameters, and surface properties were examined using 3D profilometry. The statistical analysis included descriptive evaluations and a survival analysis using the life-table method.</p><p><strong>Results: </strong>Three implants were lost (two fractures, one failed osseointegration), corresponding to an effective survival rate of 98.2%. The mean MBL varied between -0.14 mm and -0.58 mm. The surface roughness was minimal (Sa ~0.5 μm). No risk factor showed a significant association with implant loss in the univariate analysis.</p><p><strong>Conclusions: </strong>Two-piece screw-retained zirconia implants showed a high survival rate and stable peri-implant tissue conditions over a period of up to 7 years. They represent a promising metal-free alternative to titanium implants. Further prospective long-term studies are needed to validate these results and to better understand potential risk factors.</p>","PeriodicalId":94230,"journal":{"name":"The International journal of oral & maxillofacial implants","volume":"0 0","pages":"1-16"},"PeriodicalIF":1.7,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144746624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of Narrow-Diameter Implants Placed in the Posterior Region for Rehabilitation with a Single Crown: A Retrospective Cross-Sectional Clinical Study.","authors":"Mirela Bergmann Carlucci, Gustavo Vicentis Oliveira Fernandes, Mohamed Rahhal, Mona Samir Gaber, Juliana Campos Hasse Fernandes, Julio Cesar Joly","doi":"10.11607/jomi.11710","DOIUrl":"10.11607/jomi.11710","url":null,"abstract":"<p><strong>Objective: </strong>Alveolar ridge atrophy is the result of extensive bone resorption. In cases where the available bone does not allow placement of standard-diameter implants without grafting, short and extra-short implants or narrow-diameter implants (NDI) may be used. NDIs exhibit high survival rates, reaching 95.5% after a nine-year follow-up. Thus, the goal of the present study was to evaluate outcomes of NDIs rehabilitated with a single crown in the posterior regions of the maxilla and the mandible.</p><p><strong>Materials and methods: </strong>Patients treated with Ti-Zr NDIs in the posterior region with single crowns were screened. Radiographic and clinical examinations were performed to evaluate marginal bone loss (MBL), peri-implant probing depth (PPD), bleeding on probing (BoP), mobility, palpation, and percussion. Digital images were analyzed to measure and evaluate proximal bone loss. The implants were divided into groups: Group I (Success), II (Satisfactory), III (Compromised), and IV (Failure). The Kruskal-Wallis test was used (p=0.05).</p><p><strong>Results: </strong>A total of 25 patients (56 Ti-Zr NDIs) were evaluated (mean follow-up: 3.3±1.1 years), with 100% survival rate; no mobility or pain was observed. The mean PPD was 2.11±0.65 mm, and BoP was present in 79.2% of cases. Radiographic analysis showed a mean mesial MBL of 0.83 ± 0.64 mm and a distal MBL of 0.91±0.78 mm. No significant correlation was found between MBL and PPD (p=0.45) or BoP (p=0.26). According to the success criteria, 91% (n=49) of implants were classified as successful (Group I), 7% (n=4) as satisfactory (Group II), and 2% (n=1) as compromised (Group III), with no failures recorded.</p><p><strong>Conclusion: </strong>NDIs in the posterior regions rehabilitated with a single-unit crown are a reasonable, reliable, and feasible option for oral rehabilitation.</p>","PeriodicalId":94230,"journal":{"name":"The International journal of oral & maxillofacial implants","volume":"0 0","pages":"1-23"},"PeriodicalIF":1.7,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148835876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Early Stability of Short vs. Standard Dental Implants with Identical Shallow-Thread in the Posterior Region of the Mandible: A Prospective Pilot Study.","authors":"Mohammad Abdulwahab Abdullah Al-Jonaid, Ali Hussain Ali Al-Hudaid, Abdulwahab Al-Dailmy, Wael Ahmed Telha, Mohammed Sultan Al-Ak'hali","doi":"10.11607/jomi.11698","DOIUrl":"10.11607/jomi.11698","url":null,"abstract":"<p><strong>Background: </strong>Short dental implants are a less invasive alternative for the limited posterior mandible, but their early stability dynamics remain unclear compared to standard implants.</p><p><strong>Purpose: </strong>This prospective, non-randomized observational pilot study aimed to explore and descriptively compare early stability patterns (primary stability, stability dip, and recovery) between 7 mm short implants and 11 mm standard shallow-thread implants in the posterior mandible, treating implant length as the only design variable.</p><p><strong>Materials and methods: </strong>Ten patients received 20 implants (10 short, 10 standard) based on anatomical feasibility. Implant stability quotient (ISQ) was measured immediately post-implant placement (T0) and at the end weeks 1, 2, 3, and 5 (T1-T4). Insertion torque (ITV) was recorded. Linear mixed models (LMM) with patient random intercepts were the primary analysis. Bonferroni correction (α=0.005) was applied for 10 post-hoc comparisons. Bone density (D2/D3) by calibrated CBCT-HU.</p><p><strong>Results: </strong>Primary stability (ITV and ISQ at T0) was similar between groups. Short implants showed nominal trends toward a larger dip magnitude (9.2±4.4 vs 5.9±2.3 ISQ units) and greater recovery (4.8±2.4 vs 2.6±2.2), but after Bonferroni correction none of the between-group comparisons at individual time points or intervals remained statistically significant (all p > 0.005). Bone density (D2 vs D3) had a statistically significant and clinically dominant effect on absolute ISQ at all times (LMM p<0.001). In the short-implant group, a moderate negative correlation between baseline ISQ and dip magnitude (r≈0.54) had wide confidence intervals that crossed zero and did not reach conventional statistical significance, and is therefore considered exploratory.</p><p><strong>Conclusions: </strong>Within the constraints of this small, nonrandomized pilot, 7-mm shallow-thread implants in D2-D3 bone demonstrated primary stability that was descriptively similar to 11-mm implants. Apparent differences in dip and recovery did not remain statistically significant after correction for multiple comparisons and should be interpreted as hypothesis-generating only. However, bone density exerted a greater influence on early ISQ than implant length. These observations provide effect-size estimates and testable hypotheses for future adequately powered randomized trials rather than practice-changing guidance.</p>","PeriodicalId":94230,"journal":{"name":"The International journal of oral & maxillofacial implants","volume":"0 0","pages":"1-36"},"PeriodicalIF":1.7,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148835888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Prognostic Accuracy of Bone Density and Alveolar Ridge Width Estimated by CBCT in Predicting Primary Implant Stability: A Clinical Study.","authors":"Soaad Tolba Badawy, Asmaa Saleh Elmahdy, Amal T Badawi","doi":"10.11607/jomi.11843","DOIUrl":"https://doi.org/10.11607/jomi.11843","url":null,"abstract":"<p><strong>Background: </strong>Preoperative prediction of primary implant stability may improve treatment planning in the esthetic maxilla. This prospective clinical study in female patients evaluated whether CBCT-based bone density, alveolar ridge width, and histomorphometric trabecular bone content are associated with primary implant stability, and assessed the feasibility of preoperative prediction using CBCT-derived variables.</p><p><strong>Materials and methods: </strong>Thirty-five implant sites in the maxillary esthetic zone were included. Preoperative CBCT was used to record bone density as mean gray value (GV) at the planned implant site, and ridge width was measured at 1, 3, and 6 mm apical to the crestal level. Histomorphometry quantified percent area of bone trabeculae (%BT) from biopsy sections obtained prior to implant placement. Primary stability was recorded as implant stability quotient (ISQ). Associations were analyzed using Pearson correlation. A multivariable regression model was constructed to explore a purely preoperative prediction approach for ISQ using CBCT-derived variables.</p><p><strong>Results: </strong>ISQ demonstrated significant positive correlations with % BT (r = 0.609, p < 0.001), ridge width at 1 mm (r = 0.423, p = 0.011), 3 mm (r = 0.572, p < 0.001), and 6 mm (r = 0.480, p = 0.003), and CBCT bone density (GV) (r = 0.483, p = 0.003). The final regression model was significant (F(2,32) = 16.240, p < 0.001) and explained 50.4% of ISQ variance (R² = 0.504; adjusted R² = 0.473; residual standard error = 8.156). Both predictors were independently associated with ISQ (GV: B = 0.019, p = 0.002; Width3mm: B = 4.539, p < 0.001). Cross-validation showed stable performance (CV R² = 0.541; root mean square error (RMSE) = 8.18).</p><p><strong>Conclusion: </strong>CBCT-derived bone density and ridge width are significantly associated with primary implant stability and can preoperatively predict ISQ with moderate explanatory power. The proposed prediction equation (ISQ = 23.770 + 0.019 × GV + 4.539 × Ridge width at 3 mm) may assist clinicians in estimating primary implant stability before implant placement in female patients.</p>","PeriodicalId":94230,"journal":{"name":"The International journal of oral & maxillofacial implants","volume":"0 0","pages":"1-29"},"PeriodicalIF":1.7,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148835824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Platelet-Rich Fibrin Low-Speed Centrifugation Protocols in Dental Implants Osseointegration: A Preclinical Study in Rats.","authors":"Thaisa Macedo Iunes Carrera, Lélio Fernando Ferreira Soares, Marcela Claudino, Noé Vital Ribeiro Junior, Suzane Cristina Pigossi, Priscilla Barbosa Ferreira Soares","doi":"10.11607/jomi.11562","DOIUrl":"https://doi.org/10.11607/jomi.11562","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluated osseointegration in areas grafted with either PRF membranes alone or injectable PRF (i-PRF) with deproteinized bovine bone mineral (DBBM) in rat tibias.</p><p><strong>Materials and methods: </strong>Non-critical bone defects were created in 64 rats, divided into four groups: CO (blood clot), PRF (PRF membranes), BO (DBBM), and SB (i‑PRF with DBBM). Implants (1.4 mm x 2.7 mm) were placed after 60 days. Euthanized at 15 and 45 days, the right tibias underwent micro-computed tomography (μCT) and histomorphometry, while the left tibias were used for biomechanical analysis.</p><p><strong>Results: </strong>No significant differences were observed between the groups in the removal torque analysis after 15 and 45 days. At 15 days, no significant differences were found between the groups in the μCT analysis. However, a greater volume of mineralized tissues and bone trabeculae was observed in the SB group compared to the PRF and CO groups after 45 days (p<0.05). At 15 days, the PRF group showed the highest bone-to-implant contact (BIC), while the BO group led at 45 days. Significant differences were found between PRF and BO at 15 days (p=0.005) and between BO vs. SB and BO vs. PRF at 45 days. For bone area fraction occupancy (BAFO), PRF had the highest value at 15 days, but BO led at 45 days, with significant changes over time in both BO and CO groups (p<0.05).</p><p><strong>Conclusion: </strong>PRF appears to enhance early healing, but DBBM provided more stable long-term support for bone regeneration around dental implants placed in grafted areas in this study.</p>","PeriodicalId":94230,"journal":{"name":"The International journal of oral & maxillofacial implants","volume":"0 0","pages":"1-25"},"PeriodicalIF":1.7,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148835863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Implant Restoration Combined with Kangfuxin Liquid on Periodontal Health Indicators and Masticatory Function in Patients with Chronic Periodontitis and Dentition Defects.","authors":"Xuming Wang, Xiaoli Ji","doi":"10.11607/jomi.11842","DOIUrl":"https://doi.org/10.11607/jomi.11842","url":null,"abstract":"<p><strong>Objective: </strong>This work was designed to reveal the effects of implant restoration combined with Kangfuxin Liquid (KFXL) gargling on periodontal health indicators, systemic inflammatory markers, and masticatory function in patients with chronic periodontitis (CP) and dentition defects.</p><p><strong>Methods: </strong>One hundred and twenty patients with CP and dentition defects were randomized into a control group or an observation group (n = 60 each). Both groups underwent implant restoration therapy, while the observation group additionally received KFXL gargling. Following 6 weeks of continuous treatment, clinical efficacy, periodontal indices-including periodontal probing depth (PD), sulcus bleeding index (SBI), and plaque index (PLI)-serum inflammatory markers [lactoferrin (LF), interleukin-6 (IL-6), and visfatin (VF)], quality of life (SF-36), masticatory function, and adverse events were assessed and compared between groups.</p><p><strong>Results: </strong>Following treatment, the observation group achieved better results, with a total effective rate of 91.67% versus 78.33% in the control group. Significant advantages were also noted in periodontal health, systemic inflammation reduction, masticatory function, and quality of life (SF-36 score) in the observation group (P < 0.001). In terms of safety, the total incidence of adverse reactions was 6.67% in the observation group and 8.33% in the control group (P > 0.05).</p><p><strong>Conclusion: </strong>Implant restoration combined with KFXL gargling considerably improves periodontal health, reduces systemic inflammation, and enhances quality of life and masticatory function in patients with CP and dentition defects, with a favorable safety profile.</p>","PeriodicalId":94230,"journal":{"name":"The International journal of oral & maxillofacial implants","volume":"0 0","pages":"1-29"},"PeriodicalIF":1.7,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148835826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Titanium versus Temporary Peek Abutments on Peri- Implant Tissue Conditioning in Single Crowns in the Esthetic Area: A Controlled Clinical Trial.","authors":"Lidya Nara Marques de Araújo, Aliane da Silva Bezerra, Wagner Ranier Maciel Dantas, Patrícia Dos Santos Calderon, Bruno César de Vasconcelos Gurgel","doi":"10.11607/jomi.11904","DOIUrl":"https://doi.org/10.11607/jomi.11904","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the effect of titanium abutment versus a temporary PEEK abutment on the peri-implant tissue conditioning of implant-supported temporary single crowns in the esthetic area.</p><p><strong>Materials and methods: </strong>Thirty single implants were sequentially allocated, 15 in the prefabricated titanium abutment group (TA) and 15 in the temporary PEEK abutment group (PA). Clinical parameters were assessed at T1 (time of provisional crown installation) and T2 (end of tissue conditioning). Outcomes included Visible Plaque Index (VPI), Gingival Bleeding Index (GBI), Probing Depth (PD), Keratinized Mucosa Width (KTM), Gingival Thickness (GT), Bleeding on Probing (BoP), papilla height/width ratio (PH/PW), Crown Height to Width Ratio (CH/CW), and Pink Esthetic Score (PES). Mann-Whitney, Pearson's chi-square/ Fisher's exact and Spanova tests were used to analyze the results.</p><p><strong>Results: </strong>The sample consisted of 19 female patients (67.9%) and 9 male patients (32.1%), with a significant age difference between the groups (P= 0.036). Both groups showed significant improvement in PES after conditioning (P< 0.001), with no significant group × time interaction. Clinical parameters, including VPI, GBI, PD, BoP, GT, and KTW, remained comparable between groups throughout the conditioning period. The VPI increased slightly in both groups, without a significant time effect (P=0.086) or group × time interaction (P=0.364).</p><p><strong>Conclusions: </strong>Temporary PEEK and titanium abutments showed comparable peri-implant tissue stability and esthetic outcomes during crown conditioning.</p>","PeriodicalId":94230,"journal":{"name":"The International journal of oral & maxillofacial implants","volume":"0 0","pages":"1-25"},"PeriodicalIF":1.7,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148835908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adjustment Efficiency and Internal Fit of Screw-Retained Zirconia Crowns on Additively Manufactured Dental Casts: An In Vitro Study on the Effect of Printing Layer Thickness and Digital Implant Analog Design.","authors":"Mohamed El Gedaily, Mustafa Borga Donmez, Münir Demirel, Gülce Çakmak, Çiğdem Kahveci, Burak Yilmaz","doi":"10.11607/jomi.11686","DOIUrl":"10.11607/jomi.11686","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate how the layer thickness of additively manufactured casts and implant analog design influence the adjustment efficiency and internal fit of screw-retained zirconia crowns, compared with those adjusted on conventional stone casts.</p><p><strong>Materials and methods: </strong>A master mandibular model with an implant and its antagonist were digitized to additively manufacture implant casts with 50 µm or 100 µm layer thicknesses and either proprietary friction-retained (S) or third-party screw-retained (N) analogs (S-50, S-100, N-50, N-100), along with their corresponding maxillary casts. Conventional stone casts (CNV) served as the control (n = 10). Screw-retained zirconia crowns were fabricated for each cast, and the duration of interproximal and occlusal contact adjustments was recorded. Crown fit on the master model was evaluated using the triple-scan protocol, followed by a qualitative assessment of interproximal and occlusal contacts. Crowns with heavy contacts were readjusted and timed, then reevaluated to determine whether interproximal adjustments affected the fit. Comparisons among resin casts were performed using a generalized linear model with Bonferroni-adjusted post hoc tests, while comparisons with CNV casts were made with 1-way analysis of variance and Dunnett's tests. Qualitative contact data were analyzed using the chi-square test (α = .05).</p><p><strong>Results: </strong>Crowns on 50 µm-layer casts needed less adjustment and exhibited smaller gaps than those on 100 µm-layer casts; S analogs led to smaller gaps (P ≤ .010). Compared to CNV, 50 µm-layer casts led to lower adjustment duration and S-50 led to lower internal gaps (P ≤ .020). Only mesial interproximal contacts differed significantly on the master model (P = .001); crowns from S analog casts showed normal contacts, while at least 50% those from other casts had light contacts. At least 50% of the crowns exhibited normal distal contacts, and those with heavy contacts (3 on the mesial and 16 on the distal side) showed improved fit after adjustment. No occlusal adjustments were required on the master model.</p><p><strong>Conclusions: </strong>Reduced printing layer thickness and the use of proprietary friction-retained analogs improved the adjustment efficiency and internal adaptation of screw-retained zirconia crowns.</p>","PeriodicalId":94230,"journal":{"name":"The International journal of oral & maxillofacial implants","volume":"0 0","pages":"1-26"},"PeriodicalIF":1.7,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148835828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}