International Journal of Implant Dentistry最新文献

Purpose: There are no clear quantitative criteria for the prosthetic labial emergence profile in maxillary anterior implant treatment. We evaluated the impact of the prosthetic labial emergence profile on labial tissue alterations.

Materials and methods: We retrospectively analyzed 49 patients with 75 implants in the maxillary anterior region. Cone-beam computed tomography images were obtained at superstructure placement and 1 year later. Two parameters quantified the prosthetic labial emergence profile: (1) emergence angle (EA), defined as the angle between the tangent line from the implant-abutment junction to the superstructure and the implant axis; and (2) subgingival contour distance (SCD), the distance from the deepest concavity of the profile to the tangent line. Labial transmucosal tissue was evaluated by changes in gingival height (ΔGH) and bone height (BH) from the platform. Associations were analyzed using nonlinear least squares regression with robust estimators.

Results: A larger EA (≥ 30°) was associated with smaller ΔGH (overall Wald test p = .025). However, the pointwise 95% CI for the contrast between 21.2° and 30.95° included zero (- 0.57 to 0.08). A larger SCD (≥ 0.5 mm) was associated with significantly smaller ΔGH (p = .026; 95% CI, - 0.64 to - 0.10). Neither EA nor SCD showed significant associations with ΔBH.

Conclusions: EA ≥ 30° and SCD ≥ 0.5 mm may help suppress labial soft tissue recession within an esthetically acceptable range. These quantitative indicators provide guidance for prosthetic design in maxillary anterior implants and may contribute to improving esthetic outcomes.

Purpose: This systematic review evaluated the implant survival rate and prosthetic complications of single implant-supported mandibular overdentures (1-IOD) and compared them with those of traditionally recommended two implant-supported mandibular overdentures (2-IOD).

Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used as a reference for reporting this systematic review. The study protocol was prospectively registered in the PROSPERO database (registration number: CRD420250644169). This review included 17 randomized controlled trials that compared 1-IOD and 2-IOD, with a follow-up period of at least 12 months after denture placement. The assessed outcomes included implant survival rate, denture fractures, denture relining, O-ring replacement, and metal housing reattachment. The risk of bias in the included studies was assessed using the Cochrane Risk-of-Bias 2 tool.

Results: This meta-analysis revealed no difference in implant survival rates between the 1- and 2-IOD groups over a 5-year period. In the subgroup analysis, overdenture fractures, denture remakes, and metal housing reattachments were more frequently observed in the 1-IOD group, whereas no statistically significant differences were found in the need for relining or O-ring replacement.

Conclusions: Although 1-IOD may be a less invasive alternative to 2-IOD, careful consideration is necessary because of its increased incidence of prosthetic complications.

Background: Guided bone regeneration (GBR) relies on biocompatible membranes to support osteogenesis. 1,4-butanediol diglycidyl ether (BDDE)-crosslinked hyaluronic acid (xHyA) has shown promise in enhancing bone regeneration, yet its mechanisms remain unclear.

Objective: This study evaluates the osteogenic effects of xHyA-functionalized native pericardium collagen membrane (NPCM) and ribose-crosslinked collagen membrane (RCCM) using an airlift culture model with SaOS-2 cells. Transcriptomic changes following xHyA treatment were also investigated.

Methods: SaOS-2 cells were cultured on NPCM and RCCM, with or without xHyA functionalization. Cytocompatibility, alkaline phosphatase (ALP) activity, mineralization (Von Kossa staining), and RNA sequencing were assessed. Differential gene expression and pathway enrichment analyses were conducted on cells exposed to two xHyA concentrations.

Results: Both membrane types supported cell viability, though NPCM allowed cellular infiltration while RCCM maintained barrier integrity. xHyA significantly enhanced ALP activity and mineral deposition across both substrates. RNA sequencing revealed minimal upregulation of classical osteogenic genes but identified differential expression in pathways related to focal adhesion, VEGF signaling, and stem cell differentiation. IGF1R, FYN, and MAPK14 were consistently upregulated regardless of xHyA concentration.

Conclusion: xHyA functionalization enhances osteogenic activity, evidenced by increased ALP and mineralization, likely via modulation of cell-matrix interactions rather than classical osteogenic gene activation. These findings support using xHyA-functionalized membranes in GBR and warrant further investigation in vivo.

Introduction: Peri-implantitis (PI) is a biofilm-related condition driven by bacterial colonization on dental implant surfaces, leading to inflammation of the peri-implant connective tissue and progressive bone loss. Despite advancements, effective strategies for eradicating these biofilms remain elusive. While high-intensity focused ultrasound (HIFU) has been popularized in medicine, its effects on dental implant-attached biofilms remain unclear. This study presents in vitro findings on the effects of HIFU treatment on titanium (Ti)-attached Streptococcus mutans (S. mutans) biofilms and evaluates its impacts on the surface roughness and chemical composition of the Ti disc substrates.

Methods: To optimise the HIFU parameters, four quadrants of a pair of Ti discs [machined (M) and alumina grit blasted (AB)] were marked using laser etching (MD Waterlase, US). HIFU beams, generated by a 254 kHz transducer and operated at intensities of 0 W, 10 W, 20 W, and 30 W, were applied to each quadrant for 2 min (min) in a water medium. The roughness of the treated surfaces was measured using Atomic Force Microscopy (AFM), and the surface composition was analyzed using Scanning Electron Microscope-Energy Dispersive Spectrometry (SEM-EDS). To investigate the biofilm debridement, 10-day-old S. mutans cultures were grown on 20 pairs of similar Ti discs, and then the optimized HIFU intensity of 20W was applied to five test pairs. Qualitative analyses were performed using a Dual Fluorescence/Reflection Confocal Laser Scanning Microscope (FRCLSM) and SEM imaging. Quantitative data on cell viability were collected using crystal violet (CV), (3-[4,5-dimethylthiazol-2-yl]-2,5 2,5-diphenyl tetrazolium bromide) (MTT), and flow cytometry (FCM) assays. Data from these test conditions were analyzed alongside cultures on biofilms that were untreated (control). Statistical data were calculated using ANOVA and appropriate t-tests for repeated measures.

Results: The surface roughness of AB Ti discs showed a highest and significant increase (p < 0.05) following HIFU exposure at 20 W through three roughness parameters (Sa, Sq, and Sdr), compared to the controls (1207 nm, 1455 nm, 62% compared to 842 nm, 1042 nm and 30% respectively). This optimized HIFU treatment not only significantly reduced the bacterial counts of the biofilms (76% of total bacteria from M discs, 59% on AB discs in FCM assays) but also created areas of complete biofilm removal in SEM images.

Conclusion: This study provides preliminary in vitro evidence that HIFU can remove bacterial biofilms. Further research is required to determine its feasibility as a potential non-surgical approach for the prevention and management of peri-implantitis.

Background: Implant placement is a critical step for achieving primary stability. During this process, a compressive force, referred to as an "insertion load," is applied through a handpiece or manual driver. However, the influence of the insertion load has not been quantitatively investigated. Since primary stability is essential for predicting successful osseointegration, clarifying the effects of the insertion load may contribute to improving the safety and success of implant treatment.

Methods: Straight single-thread implants with pitches of 0.6 mm (S06) and 1.2 mm (S12) and double-thread implants with a 0.6 mm pitch (D06) were used (10 each). Insertion loads of the minimum required load, 5 N, 10 N, and 15 N were applied. Insertion torque values (ITVs), removal torque values (RTVs), and insertion times were measured (p = 0.05). The interface between the implants and the simulated bone was observed with a digital microscope under each load.

Results: The minimum insertion load was greatest in the order of S12 < S06 < D06. Variation in the insertion load did not affect the ITV or RTV, but lower loads extended the insertion time. Increased insertion loads led to more voids caused by bone fragment loss, especially in the double-thread designs.

Conclusions: While the insertion load did not directly influence the ITV or RTV, it varied by implant design. Higher loads potentially damage the surrounding bone, indicating the importance of careful load management.

Background: Vertical bone defects remain a challenge in implant dentistry. Titanium mesh (TM) is widely used in guided bone regeneration due to its ability to stabilize grafts, but it requires intraoperative adaptation, increasing surgical time and the risk of complications like mesh exposure. Customized titanium mesh (CTM), designed using CAD/CAM or 3D printing, offers a precise fit and may reduce surgical risks. This systematic review and meta-analysis aims to compare CTM and TM in terms of bone gain and complication rates in vertical ridge augmentation procedures.

Materials and methods: A systematic search was carried out in four electronic databases (PubMed, Cochrane Central, Web of Science, and Google Scholar) up to January 2025, with no time restrictions applied. Studies comparing customized titanium mesh (CTM) and conventional titanium mesh (TM) for vertical ridge augmentation were considered eligible if they included at least 10 patients and a minimum follow-up period of 6 months. The primary outcomes were vertical and horizontal bone gain, as well as membrane exposure. Meta-analyses and meta-regressions were performed using R software.

Results: A total of 22 studies were included in the analysis (3 randomized controlled trials, 6 prospective studies, 12 retrospective studies, and 1 cohort study), comprising 608 patients and 1,318 implants. The mean vertical bone gain was 6.24 mm for the TM group and 5.14 mm for the CTM group, with no statistically significant difference between them (P = 0.628). In contrast, CTM achieved significantly greater horizontal bone gain (6.38 mm vs. 3.85 mm; P = 0.004). Membrane exposure occurred more frequently in the TM group (30.9%) than in the CTM group (20.3%), although the difference was not statistically significant (P = 0.721). Other complications, such as infections, were also more common in the TM group but did not show statistical significance.

Conclusion: Within the limitations of the included studies, CTM appears to offer comparable bone gain to TM, with superior horizontal bone gain and a tendency to fewer complications. The results support the potential advantages of customized mesh in clinical practice. Further randomized trials with standardized protocols and long-term follow-up are recommended to confirm these findings.

Purpose: Implant dentistry is an established therapy option with sufficient long-term success for the replacement of missing teeth. Education in implant dentistry should not only focus on theory but also on practical courses. The purpose of the current examination was to assess the accuracy of fully guided and pilot-drill guided implant insertion applying plotted static guides in a cohort of undergraduate dental students.

Methods: Matching a three-dimensional set of radiographic data and surface scans of 51 artificial mandibular models, 51 surgical templates were produced by plotting. Metal sleeves allowing either a pilot-drill or fully guided implant insertion were inserted alternatively in region 36 and 46. A total of 102 implants were inserted by 51 undergraduates. Subsequently, the positions of the implants were analyzed radiographically considering the accuracy. Additionally, the time required for implant insertion was recorded and a questionnaire was completed. Statistical analysis followed.

Results: In general, the accuracy of fully guided implant insertion was higher compared to pilot-drill guided. Mean three-dimensional deviation was 2.24 ± 0.38 degrees for fully guided vs. 4.51 ± 2.20 degrees for pilot-drill guided implant insertion. Time required for fully guided implant insertion was statistically significant higher compared to pilot-drill guided (15:22 ± 5:22 vs. 9:35 ± 3:58 min, p < 0.01). The returned questionnaires reported a high interest but a self-assessed minor previous knowledge in implant dentistry.

Conclusion: The examination could show that inexperienced undergraduates benefited from fully guided implant insertion in a laboratory set-up. Based on the questionnaires there is a distinct demand for an extended education in implant dentistry among undergraduate students.

Purpose: With increasing demand for aesthetic, metal-free restorations, all-ceramic materials have gained popularity in implant prosthodontics. However, questions regarding their long-term performance, material selection, and design features remain unresolved. This guideline, developed by the German Association of Oral Implantology (DGI) in collaboration with the German Society of Dentistry and Oral Medicine (DGZMK), aims to enhance treatment safety, guide clinical decision-making, and improve patient education concerning all-ceramic implant-supported restorations.

Methods: A systematic literature review was conducted to evaluate the clinical performance of all-ceramic restorations in three main indications: implant-supported single crowns, short-span fixed dental prostheses, and full-arch restorations. Recommendations were developed based on the quality of evidence or expert consensus.

Results: For single crowns, lithium disilicate, silicate ceramics, and all generations of zirconia demonstrated favorable 3-year survival rates (~ 96-97%). In contrast, polymer-infiltrated ceramics showed inferior performance and were not recommended. For short-span FDPs and full-arch reconstructions, only 3Y-TZP zirconia is supported by clinical evidence. Micro-veneering and monolithic designs reduce chipping risks. Patient education is emphasized due to limited evidence for newer materials and full-arch restorations.

Conclusions: All-ceramic implant restorations can be successfully implemented with careful material selection, adherence to bonding protocols, and appropriate prosthetic design. However, clinical limitations persist, especially in full-arch indications. Interdisciplinary collaboration is essential to optimize outcomes and minimize complications.

Background: The rising global demand for dental implant highlights the necessity for precise imaging techniques that minimise patient risk of radiation exposure. While the cone -beam Computed Tomography (CBCT) remains the gold standard, its ionizing radiation exposure raises safety concerns. This systematic review and meta-analysis aim to evaluate the accuracy of non-ionizing alternatives, Magnetic Resonance Imaging (MRI) and Ultrasonography (US), in dental implantology.

Methods: Databases (MEDLINE, Scopus, Cochrane) were searched for studies (2014-2024) using predefined PICO criteria. Risk of bias was assessed via QUADAS-2. Meta-analysis employed fixed/random-effects models to synthesize quantitative data on geometric deviations and soft-tissue accuracy.

Results: Twelve studies were included in this study. While MRI generally exhibited greater deviation in implant tip placement at 0.3 mm (95% CI -0.08, 0.68), its overall accuracy remained comparable to CBCT. MRI showed a higher mean deviation at the implant entry level of 0.38 mm (95% CI 0.04, 0.71) and for implant angulation with a mean difference of 0.81 degree (95% CI -0.50, 2.12), indicating less precision under specific conditions. Conversely, Ultrasonography demonstrated superior performance in soft tissue accuracy with a smaller deviation compared to CBCT, at just 0.04 mm (95% CI -0.04, 0.13).

Conclusion: MRI and ultrasonography offer reliable non-ionizing alternatives for dental implant planning, with MRI matching CBCT in hard-tissue accuracy and ultrasonography excelling in soft tissue assessment. Further standardisation of protocols is needed to address variability in clinical workflows.

Clinical trial number: The Clinical Trial Number is not applicable in this systematic review. This study was prospectively registered on the International Prospective Register of Systematic Reviews (PROSPERO) online with the identification number CRD42024610741.