Purpose: To evaluate the trueness of denture bases fabricated using digital light processing (DLP) and milling methods using three-dimensional (3D) models with varying residual ridge morphologies.

Methods: Edentulous mandibular 3D models representing a well-rounded ridge (WR), knife-edge ridge (KR), and flat ridge (FR) were designed using computer-aided design (CAD) software. Denture bases for these models were created using dental CAD software and fabricated via DLP 3D printing at build angles of 0 and 45 degrees (DLP0 and DLP45) and by milling (MIL). A total of 90 denture bases were fabricated, with 10 bases per model–method combination. These bases were digitized and compared to their original CAD data to assess the adaptation across three regions: denture border, alveolar ridge, and retromolar pad. Measurements were performed at three time points: before water storage, after 1 day of water storage, and after 7 days of water storage.

Results: The MIL bases exhibited significantly lower 3D surface deviations than the DLP0 and DLP45 bases. The KR models generally exhibited greater 3D surface deviations than the WR and FR models. Temporal changes in the denture bases were significant across almost all ridge types and manufacturing methods.

Conclusions: The trueness of digitally fabricated denture bases is influenced by the residual ridge morphology and manufacturing method. Milling demonstrated superior trueness compared to DLP. Temporal dimensional changes were observed in almost all the bases.

Purpose: This systematic review aimed to investigate and compare peri-implant soft-tissue responses to tooth-colored abutment materials frequently used in implant dentistry.

Study selection: A comprehensive electronic search was performed in three databases (MEDLINE via PubMed, Google Scholar, and Scopus) to identify relevant literature. The study-selection criteria included original research articles written in English that investigated the effects of various tooth-colored abutment materials on peri-implant soft-tissue responses.

Results: In total, 136 articles were included in this systematic review. Tooth-colored abutment materials, particularly zirconia and polyetheretherketone (PEEK), facilitated favorable soft-tissue adaptation, enhanced esthetics, and contributed to long-term implant success. Zirconia demonstrated excellent biocompatibility, enhanced cell viability and attachment, and lower inflammatory responses compared to titanium, suggesting improved soft-tissue integration and reduced biofilm-related risks. PEEK exhibited favorable mechanical properties and biocompatibility but limited cell attachment due to its hydrophobicity, indicating the need for surface modification. Titanium remains the clinical standard for integration but is associated with greater inflammation and biofilm formation than tooth-colored materials.

Conclusions: This review highlights the effects of tooth-colored abutment materials on peri-implant soft-tissue responses and emphasizes the importance of selecting appropriate materials for successful dental implants. Zirconia represents a promising biological alternative to titanium, promoting a stable soft-tissue barrier that contributes to minimizing inflammation and maintaining long-term tissue health. Conversely, while PEEK offers strong mechanical properties, it faces challenges regarding cell proliferation and matrix production, limiting its optimal biological performance. Further research will provide deeper insights into the best options for enhancing patient and esthetic outcomes.

Purpose: This review examined clinical and technological factors that influence implant placement accuracy in computer-assisted implant surgery (CAIS) systems.

Study selection: A systematic search of PubMed, Scopus, and Embase identified English-language studies published between January 2015 and January 2025. The eligible studies included randomized controlled trials, observational studies, systematic reviews, in vitro investigations, and case reports. Data extraction focused on the coronal, apical, and angular deviations. Methodological quality was appraised using the Oxford Centre for Evidence-Based Medicine (CEBM) framework and validated bias assessment tools.

Results: Fifty-three studies were included. Accuracy was influenced by patient-related factors (arch type, bone density, and edentulous span), surgical variables (flap design, operator experience, and guide protocol), and technological parameters (imaging modality, fiducial markers, and calibration). Static systems achieved high accuracy in dentate cases with stable guide support, but were less reliable in posterior or edentulous jaws. Dynamic navigation provided intraoperative flexibility and consistent performance across arches, although outcomes depended on calibration precision and operator learning curves. Robotic-assisted systems achieved the lowest mean deviations through trajectory control and haptic feedback, although evidence remains limited to early clinical and in vitro studies.

Conclusions: Although all CAIS systems achieve high accuracy, their performance varies according to the design of the system and clinical context. Static systems are effective when stabilization is ensured, while dynamic navigation offers adaptable accuracy across scenarios, and robotics exhibit the greatest consistency by reducing operator variability. Further multicenter randomized trials and standardized reporting are needed to strengthen the available evidence and guide clinical selection.

Purpose: This systematic review evaluated the clinical performance, physical-mechanical properties, and accuracy of removable partial denture (RPD) frameworks fabricated using three-dimensional (3D) printing technologies—specifically, selective laser sintering (SLS), selective laser melting (SLM), and direct metal laser sintering (DMLS)—compared to those produced by conventional casting or methods using a partial digital workflow.

Study selection: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines, a literature search was conducted in the PubMed, Scopus, Web of Science, and Cochrane databases in October 2024. Studies were included if they compared the fit, accuracy, mechanical and physical properties, and clinical outcomes of metal RPD frameworks made using 3D printing technologies with those produced using conventional casting or partial digital methods. The risk of bias was assessed using appropriate tools (modified CONSORT, ROB2, and ROBINS-I) based on the study design and a qualitative analysis was conducted. This study received no funding and was registered with PROSPERO (#CRD42024597225).

Results: Thirty studies were included: 12 compared 3D printing technologies with conventional casting, eight with partial digital methods, and 10 with both. Clinically, 3D-printed frameworks could improve retention and patient satisfaction. The laboratory results showed higher density, better mechanical properties (yield strength, surface roughness, and microhardness), and varied accuracy by component and method, with SLM and DMLS often outperforming conventional casting. The evidence was limited by methodological variability, a moderate risk of bias in many studies, and inconsistencies across the study designs and parameters.

Conclusions: 3D-printed RPD metal frameworks demonstrated clinical accuracy and mechanical-physical performance comparable or superior to those of conventional and partially digital methods for RPD frameworks, with ongoing advances expected to further enhance their precision and clinical applicability.

Purpose: This systematic review evaluates the effectiveness of artificial intelligence (AI) models in dental implant treatment planning, focusing on: 1) identification, detection, and segmentation of anatomical structures; 2) technical assistance during treatment planning; and 3) additional relevant applications.

Study selection: A literature search of PubMed/MEDLINE, Scopus, and Web of Science was conducted for studies published in English until July 31, 2024. The included studies explored AI applications in implant treatment planning, excluding expert opinions, guidelines, and protocols. Three reviewers independently assessed study quality using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Quasi-Experimental Studies, resolving disagreements by consensus.

Results: Of the 28 included studies, four were high, four were medium, and 20 were low quality according to the JBI scale. Eighteen studies on anatomical segmentation have demonstrated AI models with accuracy rates ranging from 66.4% to 99.1%. Eight studies examined AI’s role in technical assistance for surgical planning, demonstrating its potential in predicting jawbone mineral density, optimizing drilling protocols, and classifying plans for maxillary sinus augmentation. One study indicated a learning curve for AI in implant planning, recommending at least 50 images for over 70% predictive accuracy. Another study reported 83% accuracy in localizing stent markers for implant sites, suggesting additional imaging planes to address a 17% miss rate and 2.8% false positives.

Conclusions: AI models exhibit potential for automating dental implant planning with high accuracy in anatomical segmentation and insightful technical assistance. However, further well-designed studies with standardized evaluation parameters are required for pragmatic integration into clinical settings.

Purpose: To evaluate the effects of various cleaning methods on the bond strength between lithium disilicate (LS₂) ceramics and resin cement under short- and long-term aging conditions using network meta-analysis (NMA) and pairwise meta-analysis (PMA).

Study selection: An electronic search of seven databases (PubMed, Scopus, Embase, Web of Science, Google Scholar, Defense Technical Information Center, and LILACS) with a manual search of the reference lists was conducted for articles published up to March 10, 2025. Eligible studies included those that assessed the bond strength of LS₂, either uncontaminated or contaminated with human saliva, fit-checking materials, try-in paste, or their combinations, using different cleaning methods. Risk of bias was evaluated using the RoBDEMAT tool. A frequentist multivariable random-effects model was used to calculate the effect sizes.

Results: Fifteen studies met the inclusion criteria. Under short-term aging conditions, NMA showed higher bond strengths in the uncontaminated LS₂ group and the contaminated groups cleaned with hydrofluoric acid etching, commercial ceramic cleaning agents, or phosphoric acid etching than those uncleaned or cleaned with water or alcohol. In long-term aging, PMA and NMA exhibited higher bond strengths in the uncontaminated LS₂ group and contaminated group cleaned with phosphoric acid etching than those contaminated groups cleaned with water or alcohol.

Conclusions: Phosphoric acid etching effectively eliminates contaminants, whereas the application of water or alcohol is ineffective. Although ceramic cleaning agents effectively decontaminate surfaces under short-term aging conditions, their performance deteriorates over time, potentially compromising long-term bond durability.

Purpose: This study compared the scanned data obtained from four conventional silicone impressions using a laboratory scanner to investigate the effects of impression materials on accuracy and precision.

Methods: The master model was a gauge with four small height increments constructed from an assembly of ceramic gauge blocks. Impressions of the master model were made using four silicone impression materials (Imprinsis Regular: blue; Fusion II: pink; Fit Checker: white, Imprint3: yellow). The impressions were scanned under blue light using a laboratory scanner. The points of inquiry were 1) advisability of three-dimensional (3D) reconstruction, 2) reproducibility at the surface level, and 3) microstep detectability. Data were analyzed using a one-way analysis of variance and Tukey’s multiple comparison test.

Results: 3D reconstruction was achieved for all impressions except Imprint3. The scanning performance of the impression material affected the spectral reflection factor. There was no significant difference in surface reproducibility among the three impression materials, and the detectability of small step height in Imprinsis Regular was significantly better than that in other impression materials (P < 0.05).

Conclusions: The color of the impression material affected digitization when a blue-light scanner was used. The digitization accuracy of Imprinsis Regular was higher than that of the other impression materials. However, the digitization accuracy of the three impression materials that could be 3D-reconstructed was within clinical tolerance. These findings can broaden the clinical applications of digital dentistry and mitigate the errors associated with dental materials.

Purpose: To investigate the association of removable partial denture (RPD)/complete denture (CD) and fixed partial denture (FPD) use with health-related quality of life (HRQoL), evaluated using the EuroQol 5-dimension, 5-level instrument (EQ-5D-5L) among older adults with tooth loss.

Methods: Cross-sectional data from the 2022 Japan Gerontological Evaluation Study. Participants were classified as RPD/CD users, FPD users, or nonusers. Generalized linear regression models stratified by the number of teeth were used to explore the association of RPD/CD and FPD use with the HRQoL evaluated using the EQ-5D-5L. The interactions among the number of teeth, RPD/CD, and FPD use were examined.

Results: After adjusting for all covariates, RPD/CD and FPD users with 5–19 teeth had higher predicted HRQoL utility scores than nonusers (RPD/CD [n=14,297]: 0.837 vs. 0.850; FPD [n=7,476]: 0.858 vs. 0.861 [nonusers vs. users]). The interaction between number of teeth and RPD/CD and FPD use revealed that differences in HRQoL between users and nonusers were greater among those with 1–14 teeth for RPD/CD use and among those with 10–14 teeth for FPD use (RPD/CD: β = −0.008, P < 0.01; FPD: β = −0.008, P = 0.183).

Conclusions: RPD/CD and FPD users with 5–19 teeth had a higher HRQoL than nonusers, with differences appearing to depend on the number of teeth. The World Health Organization has promoted the incorporation of oral health into universal health coverage (UHC). Given the minimal HRQoL difference between CD users and nonusers among edentulous individuals, unconventional dentures may merit inclusion in UHC.

Purpose: This review critically examined the impact of various whitening toothpaste formulations on color stability, surface roughness, gloss, and microhardness of dental restorative materials.

Study selection: A comprehensive literature search yielded 101 articles from PubMed, 159 from Embase, and 617 from SCOPUS, spanning 1983–2024, of which 33 met the inclusion criteria.

Results: Studies have shown that whitening toothpastes influence color change and surface characteristics. Hydrogen peroxide (HP) formulations are generally effective in achieving color alteration, although their impact on microhardness and roughness varies. Charcoal-based toothpastes tend to increase surface roughness because of their abrasive nature, whereas blue covarine toothpaste provide some brightening effects but are also associated with higher roughness. Results regarding nanohybrid and microhybrid composites were mixed; some studies found nanohybrids to be superior in color stability, whereas others favored microhybrids. However, nanohybrids are more susceptible to roughness changes due to whitening agents, whereas nanofilled composites consistently demonstrate better surface integrity under abrasive conditions.

Conclusions: These findings highlight the importance of selecting toothpaste formulations that align with restorative material properties to optimize esthetic results without compromising durability. Although HP formulations show promise in balancing whitening efficacy with surface preservation, their long-term effects require further study. Additionally, continued research is needed to refine the formulations, particularly for charcoal and blue covarine, to reduce abrasiveness and extend restoration longevity.

Purpose: This systematic review evaluated the effect of different printing orientations on the physical-mechanical properties and accuracy of resin denture bases and related specimens.

Study selection: Utilizing PRISMA 2020 guidelines, a comprehensive search of PubMed, Web of Science, Cochrane, and Scopus databases was conducted until June 2024. Included studies examined the accuracy, volumetric changes, and mechanical or physical properties of 3D-printed denture bases in various orientations. Studies without relevant data were excluded. Bias risk was assessed using a modified CONSORT checklist.

Results: This review included 24 studies on 3D-printed denture base resins, mainly based on stereolithography and digital light processing. Horizontal orientation (0°) generally enhanced flexural strength, while tilted and vertical orientations (90°) reduced it. Microhardness results varied due to differences in materials, layer thicknesses, and post-curing. Surface roughness was highest at 45°. Vertical orientation uses less material but is less time-efficient. Microbial adhesion, influenced by surface roughness, varied with printing orientation without a clear consensus on the optimal direction.

Conclusions: Printing orientation significantly impacts the physical and mechanical properties and accuracy of 3D-printed resin dentures. A horizontal orientation (0°) improved flexural strength, while accuracy and adaptability were better at 45° and 90°. Surface roughness, translucency, and chemical stability are also affected by orientation, post-curing, and material choice. Although a 90° orientation reduces material use, it increases printing time. Standardized study designs are recommended for drawing definitive conclusions in future research.

Patients: Three residents of a long-term care home volunteered to participate in a rehabilitation program involving a virtual reality blowgun game. The participants played the game 5 days a week as a new exercise routine. After 4 weeks of intervention, tongue pressure and forced expiratory volume in 1 s improved in all participants. In addition, the jaw-opening force and forced expiratory volume in 6 s improved in two participants. All three participants rated the virtual reality blowgun game as more enjoyable than their regular rehabilitation programs.

Discussion: Previous studies have shown that gamification can be useful in dysphagia rehabilitation. However, there are no previous reports describing the use of virtual reality in rehabilitation programs aimed at improving swallowing and respiratory functions in older adults while investigating participant motivation. The outcomes of the cases described herein suggest that such programs can be as effective as conventional expiratory training. Furthermore, gamification can enhance enjoyment, even in exercises designed to improve physical function.

Conclusions: These cases indicate that the virtual reality blowgun game may effectively improve swallowing and respiratory functions in older adults while being enjoyable.

Purpose: Excessive occlusal forces resulting from inadequate dental prosthesis, along with periodontal infection (PI), lead to severe periodontitis; however, the roles of senescent cells and their involvement in the mechanisms underlying this process remain unclear. Therefore, this study aimed to elucidate the roles of senescent cells and their cell types in severe periodontitis with excessive force (occlusal trauma [OT]).

Methods: To determine whether senescent cells exacerbate alveolar bone resorption, we developed a severe periodontitis rat model by inducing PI and OT and assessed the presence of senescent cells and bone resorption. Senolytics (dasatinib + quercetin [DQ]) were administered to evaluate the changes in the appearance of senescent cells and bone resorption.

Results: PI and OT + PI increased senescent cells as well as osteoclasts. Furthermore, p21 and receptor activator of nuclear factor-kappa B ligand (RANKL) co-expressing cells were observed in the OT + PI group rats, suggesting a correlation between bone resorption and senescent cells. Cell type analysis identified osteoblasts and Th17 cells as RANKL⁺ cells expressing p21 or p16. DQ administration reduced senescent cells and osteoclasts, thereby preventing alveolar bone resorption.

Conclusions: RANKL⁺ senescent osteoblasts and Th17 cells are involved in osteoclastogenesis and bone resorption. Our findings highlight a new target for the prosthetic treatment of severe periodontitis.

Purpose: This study evaluated biomechanical behavior of endocrown and post-core restorations produced from computer aided design/computer aided manufacturing (CAD/CAM) and traditional materials in severely damaged teeth that lack a ferrule and assessed the associated failure risk of resin cement.

Methods: A phantom maxillary central incisor and mandibular second premolar were trimmed 1 mm coronally to the cemento-enamel junction, the root canals were enlarged, and the teeth were scanned. Data were transferred to a solid modeling software. Twenty-two models were constructed, including endocrowns (hybrid ceramic, lithium disilicate, and polyetheretherketone [PEEK]) and post-cores (glass-fiber post/composite core; glass-fiber single-piece post-core; PEEK single-piece post-core; gold single-piece post-core). Hybrid ceramic and lithium disilicate crowns were modeled on the post-cores. Loads of 100 N for the central incisor and 300 N for the premolar were applied in a 45° oblique direction. von Mises stresses were analyzed on both root dentin and restorations, and the failure risks for the resin cement were calculated.

Results: The highest stresses were found at the roots of the PEEK endocrown (37.6 MPa) for the central incisor and of the lithium disilicate endocrown for the premolar (40.0 MPa) among endocrown groups. PEEK endocrowns had the lowest stress within the restoration and presented a higher risk of cement failure. The glass-fiber post/composite core groups demonstrated the highest adhesive and cohesive failure risks for post cement.

Conclusions: For the central incisor and mandibular premolar, lithium disilicate and PEEK endocrowns, respectively, generated less stress at the root. However, PEEK endocrowns had a higher risk of cement failure.

Purpose: Psoriasis is a complex, chronic inflammatory keratosis of unclear origin that is challenging to treat. In patients with psoriasis suspected of having metal allergies, the removal of oral metallic prostheses contributes to the alleviation of psoriasis symptoms. However, the relationship and mechanism of the metal removal effect and improvement in psoriasis symptoms in patients with metal allergies are unknown. This study aimed to investigate the relationship between metal allergies and psoriasis using an animal model.

Methods: In the metal allergy model, 4-week-old rats were sensitized and treated with nickel (II) chloride (NiCl₂) solution (provocation model). In the psoriasis model, imiquimod (IMQ) cream was applied to the shaved dorsal skin of rats (IMQ model). To create a psoriasis/metal-allergy composite rat model, we combined the provocation and IMQ models (provocation + IMQ model). Macroscopic observation, histological analysis, and quantitative gene expression analyses were performed to evaluate outcomes.

Results: In the IMQ model, psoriasis-like symptoms were visually observed from day 2 to day 9. In the provocation + IMQ model, psoriasis-like symptoms persisted for at least 11 days. Histological analysis revealed epidermal thickening and an increase in the number of interleukin (IL)-17-positive cells in the provocation + IMQ model on days 7 and 9. The gene expression of IL-17 in the submandibular lymph nodes and spleen increased in the provocation + IMQ model.

Conclusions: The induced state of Ni allergy may contribute to the maintenance of psoriasis pathology through IL-17 activity.

Purpose: This study aimed to investigate the association between denture restoration and cognitive impairment through a meta-analysis and to assess the correlation between different degrees of tooth loss.

Study selection: Observational studies exploring the association between denture restoration and cognitive function were systematically searched across six databases from January 2000 to January 2024. Two researchers independently searched electronic databases and extracted relevant studies from all articles.

Results: This study included 24,252 participants from six observational studies. The risk ratio and 95% confidence interval (CI) were used to compare the risk of cognitive impairment. Participants who experienced tooth loss without dentures had a 1.27-fold (95% CI: 1.20–1.38) higher risk of cognitive impairment, whereas those with dentures had only a 1.01-fold (95% CI: 0.92–1.12) higher risk. In the dose-response analysis, the risk of cognitive impairment in the non-denture group increased by 1.009 times (95% CI: 1.006–1.012) for each tooth lost, whereas the denture restoration group showed a 1.003 times (95% CI: 1.000–1.006) increased risk. The years of follow-up and clinical measurement tools simultaneously explained this heterogeneity.

Conclusions: This study provides detailed evidence of a potential association between denture restoration and a reduced risk of cognitive impairment. Furthermore, there was a correlation between denture restoration and a reduced impact of the number of teeth lost on the risk of cognitive impairment. Therefore, timely and reasonable denture restoration may contribute to prevent cognitive impairment.

Purpose: Fixed restorations and dental enamel have different structures that produce different wear on opposing teeth, resulting in clinical problems. Therefore, it is necessary to determine the type of restoration that causes less wear on naturally opposing teeth to make recommendations. The objective of this study was to systematically analyze the evidence from observational studies and clinical trials on enamel wear in different ceramic restorations.

Study selection: The designs of the included studies were randomized clinical trials (RTCs), non-randomized clinical trials (non-RTCs), and observational studies (OS). The studies must answer the research question, be available in full text, be written in English or Spanish, and have had at least six months of follow-up. Protocol number: CRD42023397759.

Results: After screening 499 records, 20 RTCs were subjected to data extraction, 10 were excluded, 10 were included in the systematic review, and only 5 were included in the network meta-analysis. The risk of bias assessment reported moderate to high risk of bias, quality, and certainty of evidence was evaluated and rated as moderate. Network meta-analysis showed higher enamel wear was observed in natural dental enamel against metal-ceramic antagonists.

Conclusions: Enamel wear occurs in all teeth, even when the antagonist is a natural tooth. The wear is larger on surfaces with the ceramic crown antagonists studied (metal-ceramic, glazed zirconia, and polished zirconia). It is necessary to conduct additional clinical trials with larger follow-up periods and sample sizes.

Purpose: This network meta-analysis (NMA) of randomized controlled trials (RCTs) aimed to identify effective initial conservative treatment strategies for patients with temporomandibular joint disorders (TMD).

Study selection: RCTs comparing treatment options for TMD published between January 2000 and July 2021 were retrieved from the databases of PubMed and Embase via a comprehensive electronic search. Patients diagnosed with myalgia (muscle pain) or arthralgia (joint pain) according to pain-related Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) were eligible for inclusion. Twelve treatment options and a placebo were included in the mutual comparisons. The risk of bias was assessed using Risk of Bias 2.0. Forest plots of direct comparisons between individual studies were created using MetaInsight. NMA was performed using R statistical software (netmeta).

Results: Twenty-four RCTs involving 1336 patients assessing pain and 12 RCTs involving 614 patients assessing maximal mouth opening were identified. Low-level laser therapy (standard mean difference [SMD]: -2.12, 95% confidence interval [CI]: -3.18, -1.06), self-exercise (SMD: -1.51, 95% CI: -2.82, -0.2), and stabilization splints (SMD: -1.16, 95% CI: -2.02, -0.29) were effective in improving pain; however, the certainty of evidence was very low. Self-exercise (SMD: 0.71, 95% CI: -0.58, 2.01), stabilization splints (SMD: 0.65, 95% CI: -0.09, 1.39), and low-level laser therapy (SMD: 0.63, 95% CI: -0.34, 1.6) were effective in improving maximal mouth opening; however, the certainty of evidence was very low.

Conclusions: Stabilization splints, self-exercise, and low-level laser therapy may be effective in the initial treatment of TMD.

Purpose: This study aimed to compare the deviation of hypermobile teeth in partially edentulous dental arches during impression taking using digital and conventional techniques.

Methods: A partially edentulous mandibular model with three target hypermobile teeth (including the left first premolar, #34; left second molar, #37; and right first premolar, #44), was used as the simulation model. After reference data were acquired using a desktop scanner, impressions of the simulation model were obtained using a digital intraoral scanner (IOS) and two conventional techniques (hydrocolloid material with a stock tray and silicone material with a custom tray as impression data (n=12/group). The three-dimensional accuracy (root mean square value) and two-dimensional accuracy (mesiodistal and buccolingual displacements) of the target teeth in each impression dataset were calculated based on the reference data. The comparison among three impression techniques was statistically performed using the Kruskal–Wallis test (α=0.05).

Results: For #34 and #44, the three- and two-dimensional accuracies of the impressions fabricated through data acquired through digital scanning (digital impression) were significantly superior to those of the hydrocolloid impression (P < 0.05), whereas no significant difference was found between the digital and silicone impressions. For #37, no significant difference in the accuracy of the impression data for the target teeth was observed among the three impression techniques.

Conclusions: Digital impression acquiring using an IOS is recommended over using a conventional hydrocolloid impression to prevent the deviation of hypermobile teeth in partially edentulous dental arches. Hypermobile tooth deviation in digital impression data depends on the tooth location.

Purpose: This study aimed to evaluate the risk of bone loss around single short molar crown-supporting implants in an atrophic mandible.

Methods: Implants of different lengths (L = 4 or 6 mm) and diameters (Ø = 4.1 or 4.8 mm) were placed in the molar area of an atrophic mandible. Additional control mandible models were simulated for 4.1 mm diameter implants (L = 4, 6, 8, and 10 mm). A vertical masticatory load of 200 N was applied to three or six occlusal contact areas (3ca or 6ca) of the prosthetic crown. The bone strain energy density (SED) of 109.6 µJ/mm³ was assumed to be the pathological threshold for cortical bone. The peri-implant bone resorption risk index (PIBRri) was calculated by dividing the maximum SED of the crestal cortical bone by the SED pathological threshold.

Results: Increasing the implant length from 4 to 6 mm, implant diameter from 4.1 to 4.8 mm, and number of contact areas from 3 to 6 reduced the SED and PIBRri values by approximately 20%, 35%, and 40%, respectively, when comparing pairs of models that isolated a specific variable. All models with 6ca had a low bone resorption risk (PIBRri<0.8), while the Ø4.1 short implant with 3ca had a medium (0.8≤PIBRri≤1.0) or high (PIBRri>1.0) resorption risk.

Conclusions: Increasing the diameter or occlusal contact area of a 4 mm short implant in an atrophic mandible resulted in reduced bone resorption risks, similar to or lower than those observed in a regular mandible with standard-length implants.

Purpose: Marginal bone loss (MBL) occurs in the periapical cervical bone after dental implant placement and abutment connection. MBL may not result in peri-implantitis; however, it is always accompanied by MBL. Recent studies have demonstrated that early MBL is a predictor of peri-implantitis. In this narrative review, we aimed to provide an evidence base for recommended treatment strategies for clinicians to prevent MBL.

Study Selection: We reviewed the recent literature and performed a narrative synthesis of the evidence, focusing on available systematic reviews and meta-analyses of implant marginal bone resorption.

Results: The available evidence indicates that certain biological, material, and technical factors can influence MBL and consequently dictate the risk of developing peri-implant disease in later years. The order of the impact of the strength of each factor is unknown. Current recommendations to prevent MBL include controlling patients’ smoking and hemoglobin A1c levels to sufficiently low levels before surgery and throughout their lifetime. Regarding the material, a platform-switching, conical-connecting implant system, and an abutment with a height of at least 2 mm should be selected. Placement should be performed using techniques that ensure sufficient soft tissue (keratinized gingival width > 2 mm, supracrestal tissue height > 3 mm), and non-undersized preparations in the cortical bone should be made with connected concave abutments during primary or secondary surgery. Patients should receive supportive peri-implant therapy during maintenance.

Conclusions: MBL development is multifactorial and can be reduced by considering the biological, material, and technical factors.