Search Results (119)

Background: Limited data are available regarding the mechanical performance of 3D-printed fixed partial dentures (FPDs) fabricated from different materials and connector geometries. The purpose of this in vitro study was to evaluate the influence of connector size and material type on the fracture resistance of three-unit posterior FPDs fabricated with two commercially available 3D-printable dental resins. Methods: A standardized metal model with two cylindrical abutments was used to design three-unit FPDs. A total of sixty samples were produced, considering three connector sizes (3 × 3 mm, 4 × 4 mm, and 5 × 5 mm) and two different resins: Temp Print (GC Corp., Tokyo, Japan) and V-Print c&b temp (Voco GmbH, Cuxhaven, Germany) (n = 10). Specimens were fabricated with a DLP printer (Asiga MAX UV), post-processed per manufacturer recommendations, and tested for fracture resistance under occlusal loading using a universal testing machine. Data were analyzed using nonparametric tests (Mann–Whitney U and Kruskal–Wallis; α = 0.05). Results: Significant differences were found between material and connector size groups (p < 0.001). Temp Print (GC Corp., Tokyo, Japan) demonstrated higher mean fracture loads (792.34 ± 578.36 N) compared to V-Print c&b temp (Voco GmbH, Cuxhaven, Germany) (359.74 ± 131.64 N), with statistically significant differences at 4 × 4 and 5 × 5 mm connectors. Fracture strength proportionally increased with connector size. FPDs with 5 × 5 mm connectors showed the highest resistance, reaching values above 1500 N. Conclusions: Both connector geometry and material composition significantly affected the fracture resistance of 3D-printed FPDs. Larger connector dimensions and the use of Temp Print (GC Corp., Tokyo, Japan) resin enhanced mechanical performance. Full article

Background/Objectives: Digital prosthodontics increasingly utilize both additive (3D printing) and subtractive Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM), yet comprehensive comparisons remain limited. This scoping review evaluates their relative performance across prosthodontic applications. Methods: Systematic searches (PubMed, Scopus, Web of Science, Embase, 2015–2025) identified 28 studies (27 in vitro, 1 retrospective). Data were extracted on accuracy, efficiency, materials, and outcomes. Results: CAD/CAM milling demonstrated superior accuracy for fixed prostheses, with marginal gaps for milled zirconia (123.89 ± 56.89 µm), comparable to optimized 3D-printed interim crowns (123.87 ± 67.42 µm, p = 0.760). For removable prostheses, milled denture bases achieved a trueness of 65 ± 6 µm, while SLA-printed dentures post-processed at 40 °C for 30 min showed the lowest root mean square error (RMSE) (30 min/40 °C group). Three-dimensional printing excelled in material efficiency (<5% waste vs. milling > 30–40%) and complex geometries, such as hollow-pontic fixed dental prostheses (FDPs) (2.0 mm wall thickness reduced gaps by 33%). Build orientation (45° for crowns, 30–45° for veneers) and post-processing protocols significantly influenced accuracy. Milled resins exhibited superior color stability (ΔE00: 1.2 ± 0.3 vs. 3D-printed: 4.5 ± 1.1, p < 0.05), while 3D-printed Co-Cr frameworks (SLM) showed marginal fits of 8.4 ± 3.2 µm, surpassing milling (130.3 ± 13.8 µm). Digital workflows reduced chairside time by 29% (154.31 ± 13.19 min vs. 218.00 ± 20.75 min). All methods met clinical thresholds (<120 µm gaps). Conclusions: Milling remains preferred for high-precision fixed prostheses, while 3D printing offers advantages in material efficiency, complex designs, and removable applications. Critical gaps include long-term clinical data and standardized protocols. Future research should prioritize hybrid workflows, advanced materials, and AI-driven optimization to bridge technical and clinical gaps. Full article

Aim: This in vitro study aimed to evaluate the adhesive performance of zirconia and lithium disilicate Maryland cantilever restorations on prepared and non-prepared anterior abutment teeth. While conventional clinical protocols involve abutment tooth preparation, no-preparation (no-prep) restorations have emerged as a viable, minimally invasive alternative. This study compared the adhesion fracture resistance (N) of zirconia restorations on non-prepared enamel surfaces with those on prepared surfaces exposing the dentin. Additionally, the zirconia restorations were compared with lithium disilicate Maryland cantilever restorations, a more common yet costly alternative. Materials and Methods: Forty extracted anterior teeth were allocated into four groups based on preparation type (prepared vs. non-prepared) and material (zirconia vs. lithium disilicate). Each group received cantilevered single-unit FPDs fabricated via CAD/CAM and adhesively cemented using Variolink^® Esthetic DC. Standardized loading was applied using a universal testing machine, and the fracture resistance was recorded. Results: The fracture resistance ranged from 190 to 447 N in the zirconia groups and from 219 to 412 N in the lithium disilicate groups. When comparing all the zirconia versus all the lithium disilicate ceramic restorations, regardless of tooth preparation, no statistically significant difference was found (p = 0.752). However, the non-prepared restorations exhibited significantly higher fracture resistance than their prepared counterparts (p = 0.004 for zirconia; p = 0.012 for lithium disilicate ceramic). All the failures were attributed to tooth fracture, except one zirconia restoration, with no debonding observed. Conclusions: Both zirconia and lithium disilicate Maryland cantilever restorations demonstrated reliable adhesive performance when bonded using appropriate surface conditioning and adhesive protocols. Interestingly, the non-prepared designs exhibited higher fracture resistance than the prepared abutments, highlighting their potential advantage in minimally invasive restorative dentistry. Zirconia Maryland bridges, in particular, represent a cost-effective and mechanically resilient option for anterior single-tooth replacement. Full article

Background: The potential impact of the number of implants (four vs. six) on the implant survival of implant-supported fixed complete dentures (IFCDs) remains inconclusive and subject to ongoing debate. This study compared the implant survival of immediately loaded four vs. six IFCDs, delivered using a patient-centered systematic treatment plan, in a large patient cohort assessed with consistent diagnostic methodology and comprehensive longitudinal follow-up. Methods: This retrospective study included records of 943 patients receiving 5989 implants with an average follow-up of 5.0 ± 3.2 (range 0–17) years delivered using a systematic clinical decision support system (CDSS) based on a defined alveolar atrophy classification (CC). Implant survival was analyzed considering predictor variables comprising treatment and anatomic and systemic health-related factors at the overall, maxillary, and mandibular levels using Kaplan–Meier analysis, log-rank tests, and single-predictor and multilevel Cox proportional hazard analysis derived from causal direct acyclic graph methodologies. Results: The 2- and 5-year cumulative survival rates (CSRs) of four and six IFCDs were comparable (2-year: 98.6% vs. 98.4%, p = 0.362; 5-year: 98.8%, 98.7% p = 0.346). The differences between four and six IFCDs were more pronounced at the maxillary levels, specifically after 2 years (97.7% vs. 98.6% p = 0.084), and at the mandibular level after 5 years (98.6% vs. 99.4%, p = 0.136.). Multilevel Cox proportional hazard models at overall and jaw levels adjusted for confounding factors indicated that implant loss was correlated to jaw type and age at overall and age alone at the mandibular level. Alveolar atrophy (CC) defined within the adopted CDSS was not robustly associated with implant loss. Conclusions: Under the guidance of a systematically applied patient-centered CDSS, four and six IFCDs demonstrated high and comparable mid-to-long-term implant survival rates irrespective of the level of analysis or statistical model used to adjust for confounding factors. Prosthetic and technical complications were not evaluated and were, therefore, beyond the scope of this study. Full article

This study aimed to evaluate the effect of different manufacturing techniques and thermal aging on the fracture resistance of provisional crowns and fixed partial dentures. Methods: A total of 60 provisional crowns and 60 provisional fixed partial dentures were fabricated using three manufacturing techniques: conventional manufacturing (CM), subtractive manufacturing (SM), and additive manufacturing (AM). An index created from SM-manufactured restorations was used to produce the CM group. Artificial abutments were created by duplicating scanned phantom teeth using model resin. Half of the restorations (n = 10 per group) were subjected to thermal aging (5–55 °C, 5000 cycles). The fracture resistance values of the specimens were tested using a universal testing machine. Data were analyzed using a two-way ANOVA and Tukey’s post hoc tests (α = 0.05). The highest mean fracture resistance was observed in the SM group without aging, both for crowns (1645.4 ± 346.8 N) and fixed partial dentures (1291.13 ± 564.15 N). The two-way ANOVA revealed statistically significant differences among the groups, and thermal aging significantly reduced the fracture resistance (p < 0.05). Both the manufacturing method and thermal aging significantly influenced the fracture resistance of provisional crowns and fixed partial dentures. In fixed partial dentures, a significant effect of aging was associated with the reduced durability of restorations fabricated using the subtractive manufacturing method. Full article

This study aimed to evaluate prosthetic complications, implant survival rates, and marginal bone loss in implant-supported monolithic restorations compared to metal-ceramic restorations. The study was registered in PROSPERO (CRD420251022336) and conducted following the Cochrane Handbook for Systematic Reviews of Interventions and PRISMA guidelines. A systematic search was conducted in the electronic databases MEDLINE/PubMed, Web of Science, Scopus, Embase, and ProQuest for articles published up to December 2024. The inclusion criteria comprised studies evaluating only randomized clinical trials that evaluated implant-supported monolithic restorations directly compared to metal-ceramic restorations, considering any type of ceramic material and regardless of the fixation system (screw-retained or cemented), with a minimum follow-up of one year. A meta-analysis was performed using RevMan 5.4 software, and the risk of bias and certainty of evidence were assessed using the RoB 2.0 and GRADE tools, respectively. A total of six studies were included, all of which exclusively evaluated monolithic zirconia single crowns over follow-up periods ranging from 1 to 3 years. None of the included studies evaluated fixed partial dentures or restorative materials other than monolithic zirconia. In total, 267 patients (mean age range: 18–57 years) were analyzed, with a total of 174 implant-supported monolithic zirconia crowns and 165 metal-ceramic single crowns in the posterior region (premolars and molars). The meta-analysis revealed that implant-supported monolithic zirconia single crowns exhibited significantly fewer prosthetic complications compared to metal-ceramic single crowns (p < 0.0001; Risk Ratio [RR]: 0.26; Confidence Interval [CI]: 0.14–0.47). However, no statistically significant differences were observed between implant-supported monolithic zirconia and metal-ceramic single crowns regarding implant survival rates (p = 0.36; RR: 1.66; CI: 0.56–4.94) or marginal bone loss (p = 0.15; Mean Difference [MD]: −0.05; CI: −0.11–0.02). The risk of bias assessment indicated that four studies had a low risk of bias. However, the certainty of evidence was classified as low for prosthetic complications and implant survival rates and very low for marginal bone loss. Within the limitations of this review, it can be concluded that implant-supported monolithic zirconia single crowns can be considered a favorable treatment option as they show comparable implant survival and bone stability to metal-ceramic crowns, with a potential reduction in short-term prosthetic complications such as screw loosening and ceramic chipping. However, due to the limited number of studies included and low certainty of evidence, further long-term research is still needed to confirm their clinical performance over time. Full article

Background/Objectives: Conservative options for single-tooth replacements in the anterior region include all-ceramic one-retainer resin-bonded fixed dental prostheses (RBFDPs) and three-unit fixed partial dentures (FPDs). Methods: This systematic review assessed their clinical outcomes. Following the PRISMA 2020 guidelines, an electronic search of MEDLINE/PubMed was conducted from November 1991 to March 2025 for randomized clinical trials (RCTs), prospective cohort studies (PCSs), and retrospective cohort studies (RCSs). Keywords included dental prosthesis, fixed prosthesis, resin-bonded prosthesis, single-tooth replacement, anterior teeth, all-ceramic, lithium disilicate, monolithic, zirconia, survival rate, and success rate. Failures and complications were analyzed to determine long-term outcomes. Results: The search identified 990 articles, and the full-text review of 54 articles was performed, resulting in 23 studies meeting the inclusion criteria. This review revealed that one-retainer RBFDPs and three-unit FPDs in the anterior region demonstrated high survival and success rates. However, debonding was a common complication in RBFDPs, while framework design issues were noted in FPDs. Conclusions: These outcomes highlight the reliability of both approaches as conservative, all-ceramic, prosthodontic interventions for anterior single-tooth replacements. The consideration of one-retainer RBFDPs and three-unit FPDs is advisable due to their favorable clinical performance and minimal invasiveness. Full article

Objectives: This study aimed to establish reference values for bite force in individuals with various prosthetic restorations and to examine the relationship between prosthetic treatment groups (PTGs) and bite force as an indicator of masticatory muscle function. Materials and Methods: In a cross-sectional study from November 2021 to March 2023, 198 participants aged 18 to 95 years were recruited from multiple dental and geriatric centers. The participants were assigned to seven PTGs based on their dental and prosthetic statuses. Bite force was measured using the Occlusal Force Meter GM10, with three recordings on each side of the jaw, and analyzed using ANOVA. Results: The bite force decreased with fewer teeth and the transition from fixed to removable dentures. Fully dentate participants exhibited the highest bite forces, differing significantly from the other groups (p < 0.001). For the fully dentate individuals (547 ± 240 N), the bite force decreased progressively with the extent of prosthetic restoration, reaching 55 ± 45 N in edentulous individuals with complete dentures in both jaws. However, edentulous participants with two interforaminal implants demonstrated higher bite forces than those with partial dentures. Conclusions: Bite force is significantly impacted by prosthetic restoration type. Fully dentate individuals have the highest bite forces, while edentulous patients with implant-supported dentures also show considerable bite forces, similar to those with partial dentures. Full article

Background: Resin-bonded fixed dental prostheses (RBFDPs) have become an increasingly popular minimally invasive solution for replacing missing anterior teeth. However, their long-term success is influenced by factors such as bridge design and material selection. Methods: This systematic review and meta-analysis aimed to assess the impact of different bridge designs on the clinical performance and failure risks of anterior ceramic RBFDPs. A comprehensive search of electronic databases was conducted to identify clinical studies published in English up to January 2025. Nine studies, including randomized controlled trials, cohort studies, and clinical trials, met the inclusion criteria. Results: The analysis revealed that single-retainer RBFDPs demonstrated lower failure rates than two-retainer models (RR: 0.36, 95% CI: 0.17–0.75). Among failure types, fractures were significantly less common in cantilever designs compared to two-retainer designs (RR: 0.25, 95% CI: 0.09–0.73), while no significant differences were observed in debonding rates (OR: 0.40, 95% CI: 0.015–1.10). Conclusions: In terms of material selection, all-ceramic RBFDPs in cantilever designs exhibited significantly lower failure rates (RR: 0.12, 95% CI: 0.03–0.43), whereas metal-ceramic RBFDPs showed no significant difference in failure rates based on bridge design (RR: 0.56, 95% CI: 0.21–1.53). These findings suggest that all-ceramic cantilever RBFDPs may offer superior long-term outcomes, highlighting the importance of precise preparation and cementation protocols for clinical success. Full article

Background: A considerable percentage of people in the population have lost their teeth. According to the Word Health Organization (WHO), 40% have lost teeth for multiple reasons. The lack of restorative treatments and the lack of fixed options could impact the quality of life of patients. Objective: To determine the quality of life of patients treated with dental implants at the School of Dentistry, University of the Americas, Quito, Ecuador, by the Medical Specialty in Oral Rehabilitation from 2017–2022. Materials: The inclusion criterion was patients treated with dental implants age 20 to 70 years old, who agreed to participate in this study, in Quito/Ecuador. The Oral Health Impact Profile (OHIP-14) survey was used. The patients’ clinical history, psychological status, and social status were also recorded. Complementary tests (clinic analysis) were conducted to evaluate the general health status of each patient. Results: After the corresponding analysis, the total number of patients who wished to participate in this study in compliance with the inclusion criteria was n = 1303. The seven questions included patient sex, age, and type of prosthesis used in their rehabilitation (single implant, fixed prosthesis on an implant, overdentures, or hybrid prostheses). The obtained results indicated that single implants and overdentures (two jaw implants) improved quality of life, and no statistically significant difference was noted between the sexes. Conclusions: The quality of life of patients with total dentures who received dental implants improved substantially, and more fixed dentures helped them to recover their masticatory function appropriately. Single implants were not excluded. In the investigated population, the results were unanimous in how implants improved their comfort and even helped in the recovery of their self-esteem. Full article

Objective: This study aims to evaluate the influence of pontic length and design on the fracture resistance of zirconia fixed dental prostheses (FDPs). By assessing different span lengths under controlled mechanical loading conditions, the research seeks to provide insights into optimizing the structural integrity of zirconia dental bridges. Materials and Methods: A total of 20 zirconia bridges were fabricated and tested in vitro. Ten bridges were designed to replace a single missing molar (tooth 46), with a pontic span of 11 mm, while the remaining ten were crafted for two missing teeth (35 and 36), featuring a longer pontic span of 17 mm. The zirconia frameworks were milled using the Wieland Zenotec^® Select Hybrid system and cemented onto metal abutments with Voco Meron Plus QM resin-reinforced glass ionomer cement. The specimens were subjected to occlusal loading using a ZwickRoell ProLine Z005 testing machine at a crosshead speed of 1 mm/min until fracture occurred. Results: The mechanical testing revealed a significant correlation between pontic length and fracture resistance. The mean fracture resistance for three-unit bridges (single pontic) was 3703 N, whereas four-unit bridges (double pontic) exhibited a significantly lower resistance of 1713 N. These findings indicate that increased span length reduces the fracture resistance of zirconia restorations due to higher stress accumulation and reduced rigidity. Conclusions: This study underscores the importance of pontic length and design in determining the fracture resistance of zirconia restorations. Shorter spans exhibit greater structural stability, reinforcing the need for careful treatment planning when designing multi-unit zirconia bridges. By optimizing bridge parameters, clinicians can improve clinical outcomes and extend the longevity of zirconia prostheses in restorative dentistry. Full article

Background: Various types of dentures are applied in the treatment of missing teeth. The research carried out so far has proven that both the absence of teeth and the replacement of missing teeth with dentures affect the functional condition of masseter muscles. The purpose is, thus, to find out how the tone, elasticity, and stiffness of masseter muscles change after prosthetic treatment. Material and methods: The material for the study consisted of 137 individuals, who were divided into group 1, with dentures (n = 87) and undergoing prosthetic treatment, and group 2, without dentures (n = 50) with teeth preserved, and not undergoing prosthetic treatment. Additionally, group 1 was divided into subgroups, in accordance with the type of prosthetic treatment applied: group 1a—removable complete dentures (n = 14), group 1b—removable partial dentures (n = 48), group 1c—fixed partial dentures (n = 22), group 1d—fixed complete dentures (n = 3). The biomechanical properties of masseter muscles, namely: tone, stiffness, and elasticity were assessed by means of myotonometry. The measurements were taken under muscle relaxation and under maximum muscle contraction. Results: The values of the parameters of tone, stiffness, and elasticity were higher in group 2, without dentures, in comparison with group 1, with dentures, yet they did not differ with statistical significance. The type of prosthesis used affected the results obtained. Masseter muscles demonstrated the best biomechanical parameters in the case of applying fixed partial dentures. Conclusions: Prosthetic replacement of missing teeth contributes to maintaining the good condition of masseter muscles, which has been confirmed by the results of myotonometric measurements taken. Full article

Background/Objectives: Recent research has indicated that placing dental implants in patients diagnosed with bruxism has led to higher rates of implant failure. This study aimed to provide more accurate knowledge about the relationship between bruxism and implant loss in patients (number, age, gender) with different numbers of implants and prosthetic restorations, considering the follow-up time, compared to non-bruxers. Methods: A systematic search was conducted in PubMed and Cochrane Library using the keyword combination “dental implant”, “bruxism”, and “implant failure”. This search had no language or time restrictions. Results: The review included 15 papers, which were divided into four groups. The first group focused on studies regarding implant loss regardless of the superstructure. In the second group, research on implant-supported removable prostheses was examined. The third group consisted of a single study specifically addressing implant-supported single crowns. Lastly, the fourth group comprised two studies investigating implant-supported single crowns and fixed partial dentures. Only three out of the fifteen studies failed to find a correlation between bruxism and implant failure. The meta-analysis shows a significant pooled effect across the included studies, with an odds ratio of 4.68. Conclusions: Bruxism is a probable risk factor for mechanical issues in implant-supported prostheses and implant-supported crowns. Additionally, elevated failure rates have been documented in patients with bruxism. Full article

Background: The present article describes a step-by-step maximally digitalized workflow protocol with computer-aided design and computer-aided manufacturing (CAD/CAM) in partial-arch edentulous patients rehabilitated with fixed dental prostheses and removable partial dentures (FDPs and RPDs). Methods: Facial digitalization, intraoral scans, and functional mandibular movement recordings were used to create a 4D virtual patient on commercially available CAD software. The fixed components including post-and-cores, both metal–ceramic with extra-coronal attachment and monolithic zirconia crowns, and the RPDs were manufactured by computer numerical controlled direct milling. Results: This innovative digital approach using the virtual patient and the superimposition of interim RPDs fitted in the mouth has been used to provide fixed and removable rehabilitation to the patient without clinical complications with 2 years of follow-up. Conclusions: Within the limitations of this report, the developed combined prosthesis fabrication technique allowed optimization of the production by decreasing the clinical steps and laboratory procedures in partial-arch edentulous rehabilitated with FDPs and RPDs. Full article

Objective: In everyday dentistry, lithium disilicate is a valid option for single-fix partial dentures, and this material crystallization process is available with two protocols: long and short. This study’s aim was to assess the effects of these two different crystallization protocols, long and short, on the marginal gap of lithium disilicate single crowns. Methods: A total of 24 abutment plastic teeth were scanned using an intra-oral scanner. For each plastic tooth, an identical pair of lithium disilicate crowns was milled (a total of 48 crowns) by a four-axis machine. Each paired sample was categorized into two groups: long crystallization (24 crowns) and short crystallization (24 crowns). To assess precision, each unit’s marginal gap (including abutments and crowns) was meticulously measured at four specified regions using a scanning electron microscope. A Kolmogorov–Smirnov test performed on the study variables indicated a normal distribution (p > 0.05), and it was followed by independent t-tests (α = 0.05). Results: For the long crystallization group, the mean total marginal gap values were 42.91 ± 9.67 μm, and for the short crystallization group, the values were 43.25 ± 8.14 μm, with no significant difference between the groups (p = 0.894). In addition, no significant differences were found between the groups regarding the mean marginal gap measurements for all four surfaces (distal (p = 0.310), mesial (p = 0.732), palatal (p = 0.655), and buccal (p = 0.535)). Conclusions: Both the long and short crystallization methods used for lithium disilicate single crowns demonstrated marginal gap values of less than 120 μm, which are within the clinically acceptable range, with no significant differences across any parameters between the two groups. Regarding the marginal gap value, it is recommended to use the short crystallization protocol as it is more time-efficient. Full article