Dental Prostheses Research Articles

A retrospective single cohort study on the 5-13 year clinical outcomes of implant-supported cross-arch fixed dental prostheses with monolithic zirconia-based frameworks.

To investigate the mid-to-long term clinical outcomes of the implant-supported cross-arch fixed dental prostheses (IFCDPs) with monolithic zirconia-based frameworks and related risk factors of success and survival. This retrospective study encompassed individuals exhibiting terminal dentition or edentulism in the maxilla and/or mandible who underwent treatment involving IFCDPs with monolithic zirconia frameworks. Inclusion criteria required a documented follow-up period of at least five years post-definitive prosthesis delivery. Evaluation of outcomes focused on the survival rates of implant and prosthesis, along with the incidence of biological and technical complications. The mixed-effects Cox regression model was employed to analyze the risk factors associated with prosthesis failure and peri-implantitis. A cohort of 47 patients, consisting of 14 women and 33 men with a mean age of 55.2 ± 12.5 years (range: 25-83), was included in this study. The mean follow-up period was 71.6 ±13.2 months (mean ± SD, range: 60-147). A total of 51 cross-arch prostheses supported by 302 implants, distributed between the maxilla (27 prostheses) and mandible (24 prostheses), were assessed. By the end of the follow-up period, 289 (97.64%) of the 302 implants remained functional. Peri-implantitis was observed in 27 implants (24 in mandible), yielding an overall implant-related success rate of 91.06%. Nine frameworks experienced fractures (eight in mandible), resulting in an overall prosthesis-related survival rate of 82.35%. Subsequent analysis revealed the mandible to be a significant risk factor for framework fracture (HR = 11.64, p = 0.024) and peri-implantitis (HR = 10.88, p = 0.003). The implant-supported cross-arch fixed dental prostheses featuring monolithic zirconia-based frameworks demonstrated favorable clinical outcomes throughout a 5-13-year observation period. Notably, in the design of monolithic zirconia-based framework prostheses, the mandible emerged as a significant risk factor for framework fractures and an independent risk factor for peri-implantitis.

Effect of Fiber Reinforcement on the Flexural Strength of Long-Span, 3D-Printed, Interim Fixed Dental Prosthesis.

To inspect the impact of polyethylene fiber (Ribbond) on the long-span, 3D-printed, interim fixed dental prosthesis regarding fracture strength. A stainless steel platform was fabricated to replicate the partial edentulism for a maxillary four-unit fixed dental prosthesis. The prosthesis was fabricated by a Formlabs SLA 3D printer. The specimens were allocated into four groups of 20 each: experimental reinforced Group A (prosthesis with a slot reinforced with fiber); experimental Group B (prosthesis with a slot filled with 3D-printed material), negative control Group C (prosthesis with a slot); and control Group D (full-contour prosthesis). Fracture strength exams were performed with a universal tester. The fracture patterns were examined. A statistical analysis was conducted using one-way ANOVA and Tukey HSD test. The control group exhibited a significantly higher mean flexural load (D: 306.32 ± 50.76 N) compared to the other groups (A: 194.37 ± 68.02 N; B: 178.25 ± 42.67 N; and C: 156.68 ± 29.73 N; [P < .001]). No differences were identified among Groups A, B, and C. The fracture pattern differed between the nonreinforced Groups B, C, and D and reinforced Group A, with catastrophic failure observed in the nonreinforced group and unseparated failure observed in the reinforced group. The study findings demonstrate that the incorporation of Ribbond in 3D-printed, interim fixed dental prostheses does not significantly enhance their fracture strength. However, it does lead to a noticeable change in the fracture behavior, shifting from a complete failure to an incomplete fracture pattern.

The Accuracy of 3D-Printed Fixed Dental Restorations.

The aim of this invitro study was to evaluate the accuracy of resin-based fixed dental restorations, namely veneers, single crowns, and four-unit fixed partial dental prosthesis (FPDs), using two different 3D printing technologies and polymer-based materials. A standard maxillary polyurethane jaw model containing prepared teeth was scanned using an intraoral scanner. The generated STL data were used to design the restorations virtually using CAD software. Two 3D printers were utilized for the provisional digital light processing and stereolithography for the castable resin patterns. Each printer produced 10 specimens of each type of restoration, for a total of 80 restorations. The 3D-printed restorations were then 3D scanned using the same intraoral scanner and evaluated for external and internal dimensional accuracy in terms of trueness and precision. A one-way ANOVA and two-sample T-test were implemented to compute the precision (variability between groups) and trueness (with the designed CAD model). A level of statistical significance of p-value < 0.05 was set. Statistical differences in the external dimensional analysis of the incisors, molars, and four-unit FPD with p-values < 0.001, 0.002, and 0.004, respectively. For the internal dimensional analysis, the overall mean values of trueness ranged between 17 and 52 μm, and the variability was significant. The external and internal dimensional accuracy values of the 3D-printed fixed dental restorations in this invitro study in terms of trueness can be clinically accepted after chairside modifications. However, significant variability between the 3D-printed restorations was observed. Further investigations are needed to improve the accuracy of the 3D-printed fixed dental restorations. In terms of clinical applications, 3D-printed fixed dental restorations produced by both 3D-printing technologies and polymer-based materials achieved acceptable levels of trueness, although some variability was observed. Significant deviations from the CAD model may require further chairside adjustments. Future integration of AI with 3D-printing may further improve the accuracy and efficiency of fixed dental restoration production.

Association between oral health and physical performance in Brazilian older adults: SABE cohort study

BackgroundOral health is recognized as integral to general health and impaired dentition status may affect physical performance among older adults. This study evaluated the longitudinal association between clinical and self-reported oral health measures and physical performance (outcome) in Brazilian older adults.MethodsThis was a longitudinal study that used data from the second (year 2006), third (year 2010) and fourth (year 2015) waves of the Health Well-being and Aging Study conducted in Brazil. Physical performance, evaluated using the Short Physical Performance Battery (SPPB), was the dependent variable. Independent variables of interest were the number of teeth, presence of periodontal pocket, use of dental prostheses, and poor perceived oral health. The association between oral health measures and physical function was analyzed using generalized estimating equations with an ordinal regression model.ResultsIn the total sample, every additional tooth was associated with a greater chance of achieving a higher score on the SPPB test. Individuals wearing dental prostheses had higher chances of having higher scores than those not wearing them. In the analyses for the dentate sample, the presence of a periodontal pocket was not associated with SPPB and the increase in the number of teeth increased the chance of achieving a higher score.ConclusionA greater number of teeth, and using dentures, were associated with higher physical performance. Periodontal disease was not associated with the outcome.

The effect of osteoclasts on epigenetic regulation by long non-coding RNAs in osteoblasts grown on titanium with nanotopography

Titanium (Ti) implant osseointegration is regulated by the crosstalk among bone cells that are affected by epigenetic machinery, including the regulation of long non-coding RNAs (lncRNAs). Nanotopography Ti (Ti Nano) induces the differentiation of osteoblasts that are inhibited by osteoclasts through epigenetic mechanisms. Thus, we hypothesize that osteoclasts affect lncRNA expression in Ti Nano-cultivated osteoblasts. Osteoblasts were grown on Ti Nano and Ti Control that were then co-cultured with osteoclasts for 48 h. Using RNAseq, we identified 252 modulated lncRNAs in osteoblasts regulated by both surfaces of Ti, but mainly in Ti Nano-cultivated osteoblasts. A negative correlation was observed between Kcnq1ot1 and the mRNAs of Alpl, Bglap, Bmp8a, Col1a1, and Vim in Ti Nano-cultivated osteoblasts with osteoclasts. The pull-down indicated that Bglap mRNA is a direct target of Kcnq1ot1, with enhanced physical interaction in Ti Nano-cultivated osteoblasts, and greater osteoclast inhibition than the Ti Control. The bone marker expression at the levels of mRNA and protein were downregulated by the Kcnq1ot1 silencing, indicating its pivotal role in osteoblast differentiation. These results showed that nanostructured Ti surface modulates the osteoblast–osteoclast crosstalk, at least in part, through the regulation of lncRNA expression in osteoblasts. We demonstrate that the lncRNA Kcnq1ot1 directly interacts with Bglap mRNA, and this interaction is enhanced by nanotopography and reduced by osteoclasts with greater intensity in Ti Nano-cultivated osteoblasts. These findings confirm the molecular mechanisms associated with the high osteogenic potential of nanotopography and can potentially support osteointegration of dental and skeletal prostheses.

Numerical–Experimental Analysis to Optimize the Geometry of a Prosthetic Abutment

This paper aims to identify methods for optimizing the geometry of dental prosthesis preparation, through both an analytical study and a numerical investigation. Assuming a 10° inclined load with respect to the median sagittal plane, a double algorithm was developed that was capable of calculating the axial resistance area and the cusp resistance area (if present) of a prosthetic abutment as the main geometric parameters vary. In particular, a coupling model with a pseudo-elliptical base was proposed, which is better than the circular shape representing the real shape assumed by the abutment following the dental intervention. The model also allows the presence of a cusp. This model was first analyzed using FEA, also simulating the presence of coupling cement between the abutment and the crown, and then physically made with a 10:1 scale prototype. The convergence of the experimental results found with the numerical–theoretical studies is an indication of the validity of the proposed model. A key contribution of this research using the proposed algorithm allowed to demonstrate that a superior limit of 0.25 for the ratio (HR) between the heights of the cusp sulcus (h-hc) and the abutment (h) is required to achieve good stability of the coupling. The methodology developed in this study is applicable to a variety of teeth, making it versatile and highly adaptable for broader clinical applications.

Effect of dental implant neck profile switching on crestal bone healing

Introduction: The majority of dental implants and prostheses rely on the association with the soft tissues that may be vulnerable to future requirements. There are two main requirements for osseointegration: first, the bone must be healthy; second, the implant must be stable and able to withstand the functional load. Methods and Results: Using both the computer12 model and finite element analysis technique to assess the bone space volume in implants with narrow-neck hybrid design compared with butt platform and bevel design at an inter-implant distance of 1 mm, the result showed approximately 56.7 mm in the butt joint platform design implant and between two bevel platforms (+2.74% or more), while it showed 78.42 mm (+38.32%) between two narrow-neck hybrid designs. Discussion and Conclusion: The implant platform switching technique is used to decrease the stress on the crestal bone and allow for better load distribution. This can be done at two levels: one is at the fixture–abutment interface, and the second within the bone at the fixture itself in the body–neck area. The narrow-neck hybrid design seems to be superior in lowering the stress on crestal bone and to provide more room for bone healing potential with less negative effect on soft tissue healing.

Impact of aging on the fracture strength of 3D-printed fixed implant prostheses: A comparative analysis of monolithic and bi-layer with or without fiber-reinforced composite frameworks.

This study aims to evaluate the fracture strength of three-unit, implant-supported fixed dental prostheses (FDPs) constructed from 3D-printed resin. It compares structures with and without fiber-reinforced composite (FRC) frameworks under conditions that mimic artificial aging. Forty FDPs were fabricated and divided into two groups: monolithic (n=20) and bi-layer (n=20). The monolithic group (MG) consisted entirely of FDPs made from 3D-printed resin for permanent restorations, while the bi-layer group (BG) featured FDPs with an FRC framework veneered with the same 3D-printed resin. Each group was subdivided into two subgroups: one subjected to artificial aging (MTG, n=10; BTG, n=10), and the other served as the baseline control (n=10). All subgroups underwent a mechanical bending test, applying a single load to failure using a universal testing machine. There was a statistically significant difference in fracture strength due to the presence of the FRC framework (p<0.01). The framework became the FDP more resistant to load. The mean load to failure and standard deviations were as follows: MG 406.59N (±33.84), MTG 286.20N (±152.15), BG 1142N (±162.88), and BTG 945N (±211.52). Although no statistical differences in strength were observed between aged and nonaged subgroups, variations in failure patterns emerged, with the BG and BTG groups showing a predominance of failures compared to the MG. The inclusion of an FRC framework significantly enhanced the fracture strength of the FDPs. While the aging protocol did not alter thestrength, failures predominantly occurred in the 3D-printed resin superstructure at the connectors. The highest rate of fractures occurred in the premolar connector.

CANDIDÍASE ORAL EM USUÁRIO DE PRÓTESE DENTÁRIA: UMA REVISÃO DE LITERATURA SOBRE ETIOLOGIA, DIAGNÓSTICO E TRATAMENTO

Oral candidiasis is a common condition primarily caused by the yeast-like fungus Candida albicans, an opportunistic microorganism that is part of the normal oral microbiota. The clinical presentations of oral candidiasis can be divided into primary or secondary forms. The primary form can manifest in the following subtypes: pseudomembranous, erythematous, and hyperplastic. Another category, known as 'denture stomatitis,' is associated with the use of removable dental prostheses. Based on this relationship between disease development and the use of dental prostheses, the present study aims to conduct a literature review on the topic. Searches were conducted in the PubMed and SciELO databases using Health Sciences Descriptors (DeCS/MeSH): "Oral Candidiasis," "Dental Prosthesis," "Oral Pathology," "Oral Hygiene," and "Oral Rehabilitation," combined with the boolean operators "AND" and "OR." A total of 167 articles were identified. After an initial review, articles that did not meet the inclusion criteria of this study were excluded, resulting in only 13 articles being included. It was concluded that poor hygiene of dental prostheses is identified as the main predisposing factor for the development of this condition, emphasizing the importance of preventive interventions and the adoption of regular maintenance routines.

Surface properties and biofilm formation on resins for subtractively and additively manufactured fixed dental prostheses aged in artificial saliva: Effect of material type and surface finishing

Statement of problemAdditive manufacturing (AM) and subtractive manufacturing (SM) have been widely used for fabricating resin-based fixed dental prostheses. However, studies on the effects of material type (AM or SM resin) and surface finishing (polishing or glazing) on the surface properties and biofilm formation are lacking. PurposeThe purpose of this in vitro study was to investigate the effects of material type and surface finishing on the surface roughness, wettability, protein adsorption, and microbial adhesion of the AM and SM resins marketed for fixed restorations under artificial saliva-aged conditions. Material and methodsDisk-shaped specimens (∅10×2 mm) were fabricated using 3 types of resins: AM composite resin with fillers (AMC), AM resin without fillers (AMU), and SM composite resin with fillers (SMC). Each resin group was divided into 2 subgroups based on surface finishing: polished (P) and glazed (G). Therefore, 3 polished surface groups (AMCP, AMUP, and SMCP) and 3 glazed surface groups (AMCG, AMUG, and SMCG) were prepared. Specimens were then categorized according to aging condition in artificial saliva. Surface roughness (Ra and Sa), contact angle, surface free energy (SFE), protein adsorption, and microbial adhesion were measured. The data were analyzed using a nonparametric factorial analysis of variances and post hoc tests with Bonferroni correction (α=.05). ResultsWhen nonaged, significant interactions between material type and surface finishing were detected for Ra, contact angle, SFE, protein adsorption, and microbial adhesion (P≤.008). AMCP showed higher Ra and microbial adhesion than AMUP and SMCP, and higher contact angle and protein adsorption than SMCP (P<.001). AMCG had lower SFE than AMUG (P=.005) and higher bacterial adhesion than SMCG (P<.001). AMC had higher Sa than AMU and SMC (P≤.006). When aged, significant interactions between material type and surface finishing were detected for Ra, Sa, protein adsorption, and microbial adhesion (P≤.026). The contact angle and SFE were significantly affected only by the material type (P≤.001), as AMC exhibited higher wettability than SMC (P≤.004). AMCP had higher Ra and microbial adhesion than AMUP and SMCP (P≤.003). AMCP had higher Sa and protein adsorption than SMCP (P≤.004). AMCG showed lower Ra and higher protein adsorption than AMUG (P≤.001). ConclusionsBoth material type and surface finishing significantly affected surface properties and biofilm formation. AMCP exhibited higher surface roughness, protein adsorption, and microbial adhesion compared with SMCP. Glazing may reduce the differences in surface-biofilm interactions between AMC and SMC.

A comparative study of strength and surface properties of permanent 3D-printed resins with CAD-CAM milled fixed dental prostheses.

To compare the strength, surface roughness, and hardness of newly introduced permanent three-dimensional (3D)-printed resin in comparison with computer-aided design and computer-aided manufacturing (CAD-CAM) milled materials. Three 3D-printed resins (NextDent C&B, Formlabs Permanent Crown, and VarseoSmile Crownplus) and two CAD-CAM milled (IPS e.max ZirCAD LT and VITA Enamic) resins were used to fabricate discs specimens. A total of 200 disc specimens were fabricated according to manufacturer recommendations. Within each group, half of the specimens were subjected to thermal cycling (5°C-55°C, the 30s, 5000 cycles). Aged and nonaged specimens were evaluated for biaxial flexural strength (BFS), surface roughness, and hardness. Results were statistically analyzed using analysis of variance (ANOVA) and t-tests (α=0.05). Significant differences (p<0.05) were observed in the BFS, surface roughness, and hardness between the 3D-printed and milled groups, before and after thermal aging. Overall, the CAD-CAM milled ceramic group had superior strength, surface roughness, and hardness when compared to all other groups (p<0.001), except for surface roughness after thermal aging, which was similar in all groups (p=0.063). Within each group, there was no significant difference (p>0.05) in surface roughness after thermal aging. BFS values of 3D-printed materials were statistically similar. In terms of surface roughness, Formlabs specimens displayed the highest value before and after thermal cycling, when compared to other 3D-printed materials. Regarding hardness, the VarseoSmile Crown plus group demonstrated the highest values compared to other 3D-printed materials, before and after thermal cycling. Permanent 3D-printed resins have lower strength than CAD-CAM milled materials. 3D-printed permanent resin materials exhibited high roughness and comparable hardness to CAD-CAM materials. Thermal aging negatively affected the properties of 3D-printed permanent crowns. Owing to the low strength of 3D-printed permanent resins, they may not be recommended for clinical practice until further improvements in flexural strength are made to meet clinical standards.

A CBCT study of changes in temporomandibular joint morphology with immediate implant placement and immediate loaded full-arch fixed dental prostheses

BackgroundDental implants are becoming a popular treatment of choice. Immediate implant placement with immediate loaded full-arch fixed dental prostheses (IPILFFDP) presents an attractive solution for edentulous and partially edentulous patients because of its high success rate, reduction in overall treatment time, and improved esthetics. However, whether it can minimize the risk of temporomandibular disorder (TMD) has not been previously studied.ObjectiveTo quantitatively evaluate the temporomandibular joint (TMJ) morphology changes before and after IPILFFDP, using cone beam computed tomography (CBCT).MethodsTwelve participants without TMJ symptoms undergoing IPILFFDP were included in the study. Preoperative and 1-year postoperative assessment of CBCT scans were performed on 18 items related to TMJ and vertical dimensions. Mimics software was used for data analysis. T-test, Pearson, and Spearman correlation analyses were performed.ResultsThere were no significant differences in bilateral joints between pre and post IPILFFDP. Compared with pre-treatment CBCT, post-treatment CBCT showed a significant increase in posterior joint space. There was an approximately 2 mm increase in the vertical dimension after IPILFFDP, which is correlated with an increase in the medial joint space.ConclusionsFor patients without TMJ-related signs and symptoms, the IPILFFDP could keep the neuromuscular memory of patient’s facial muscles and occlusion, and use adapted centric posture as a guide, which led to more precise restoration of the original jaw position and may shed light in future related clinical studies.

Dental Implant Artifacts in MRI: Compatibility and Considerations

This review investigated dental implant artifacts in magnetic resonance imaging (MRI) and their safety in clinical practice. Dental prostheses, including implants, crowns, and orthodontic appliances, cause artifacts due to their high magnetic susceptibility, particularly in materials like iron, stainless steel, and cobalt-chromium. Titanium implants are considered safe under MRI environments according to the American Society for Testing and Material (ASTM) standards, with no reported thermal injury or dislodgement during examinations. Despite limited artifacts from titanium's paramagnetic nature, minute ferromagnetic components can still affect visualization. Thus, reducing artifacts in oral and maxillofacial MRI scans is crucial. Two main categories of artifact reduction techniques are identified: improved porous titanium or alternative materials like zirconia and adjusting MR parameters with advanced sequences. Recommendations include increasing the readout bandwidth, reducing slice thickness, using spin-echo sequences instead of gradient-echo, and employing short tau inversion recovery or DIXON techniques for fat suppression. Additional methods like VAT, VAT-SEMAC combination, and MAVRIC show promise, although applicability may be restricted in specific MRI scanners. Continuous advancements in dental implant materials and MRI sequences are needed to improve imaging quality and reduce artifacts. Collaboration among dental practitioners, radiologists, and MRI technologists is essential for refining techniques and ensuring patient safety. Although overall dental implant artifacts pose challenges, safety in MRI is well-established. Ongoing developments hold significant potential to enhance MRI imaging quality in patients with dental devices

Acoustic resonance frequency analysis for evaluating prosthetic screw stability in splinted implant-supported fixed dental prostheses: An in vitro study

Prosthetic screw loosening is a common mechanical complication of implant-supported fixed dental prostheses. Although techniques for detecting screw loosening in single implant-supported fixed dental prostheses have been reported, studies on the screw stability for splinted implant-supported fixed dental prostheses are lacking. The purpose of this in vitro study was to determine whether acoustic resonance frequency analysis using a newly developed system could detect prosthetic screw loosening in splinted implant-supported fixed dental prostheses. Maxillary and mandibular edentulous gypsum casts with screw-retained definitive fixed dental prostheses supported by 6 implants were used. A tapping simulation (0.2N, 50Hz) was directly applied to the buccal side of the tested screw, and a pickup device was used to collect the acoustic signals. The resonance peak frequencies of these signals were extracted by using time-frequency-domain analysis based on short-time Fourier transform. A 2-way mixed analysis of variance was performed to evaluate how jaw position and insertion torque affect resonance peak frequency. The Pearson correlation analysis was used to assess the relationship between the insertion torque and resonance peak frequency for each screw (α=.05). Deviation from the insertion torque resulted in significant changes in the resonance peak frequency within 6 to 9kHz. Additionally, significant positive correlation between the insertion torques and resonance peak frequencies was observed for all screws (P<.05). This correlation was affected by the position of the screw within the prosthesis. Specifically, screw loosening in the posterior and anterior regions had a greater influence on the resonance peak frequency than that in the central region. The acoustic resonance peak frequency shifted leftward as the screw preload torque decreased, indicating a significant correlation with screw stability. These results suggest that acoustic resonance frequency analysis can be used to detect the stability status of a single prosthetic screw in a splinted implant-supported fixed dental prosthesis conveniently and with high sensitivity.

Comprehensive Image Quality Evaluation and Motion Phantom Studies of an Ultra-Fast (6-Second) Cone-Beam Computed Tomography Imaging System on a Ring Gantry Linear Accelerator

PurposeTo evaluate the image quality of an ultra-fast CBCT system - Varian HyperSight. MethodsIn this evaluation, five-studies were performed to assess the image quality of HyperSight CBCT. First, a HyperSight CBCT image quality evaluation was performed and compared with Siemens simulation-CT and Varian TrueBeam CBCT. Second, a visual comparison of image quality among simulation-CTs, HyperSight CBCT and TrueBeam CBCT was performed for a head-and-neck patient, and patients with metal dental fillings and prosthesis. Third, the HU vs electron density curve of HyperSight CBCT was compared with GE and Siemens simulation-CTs. Fourth, Siemens simulation-CT and HyperSight CBCT scans were acquired on the Catphan setting-up at different locations inside the bore (±10cm in all three principal directions from the center), and the HU variations for different materials were evaluated. Fifth, a 4D lung tumor phantom study was performed to assess moving tumor alignment during image registration. ResultsSignificant improvement of image contrast, HU constancy, and noise level on HyperSight CBCT was observed compared to TrueBeam CBCT. Significant image quality improvement was observed on HyperSight CBCT for patients with dental fillings and prosthesis compared to simulation-CT without metal artifact reduction. The linear fit trend-line of HU vs electron density curves for GE simulation-CT, Siemens simulation-CT and HyperSight CBCT showed 0.6% difference for HU value below 2000. The maximum HU difference for HyperSight CBCT when Catphan positioned within ±10cm in all three principal directions was ≤98 on bone 50%, and ≤29 other than bone, and was ≤31 on bone 50%, and ≤17 other than bone for Siemens simulation-CT. Both tumor shape and tumor alignment discrepancies on CBCT scans were observed in 4D phantom study. ConclusionsThis evaluation shows significant image improvement of HyperSight CBCT over conventional CBCT on image contrast, HU constancy, and noise level with scatter correction and metal artifact reduction reconstruction methods. HyperSight CBCT has similar image quality to simulation-CTs, and shows the potential application for treatment planning. The rapid acquisition of HyperSight CBCT showed both tumor shape and tumor alignment discrepancies of moving target. Careful considerations of patient respiratory motion monitoring and target matching are highly recommended.

Changes in facial soft tissue support with and without a maxillary labial flange.

To quantify facial esthetic outcomes of prosthetic upper lip support in both full animation and repose for patients with an existing implant-supported fixed complete dental prosthesis (ISFCDP). Twenty patients had a removable prosthetic labial flange fabricated for their existing maxillary prosthesis. The 3dMDface system was used to capture video sets of each patient going from repose to high smile with and without the labial flange. A single frame representing high smile and repose was selected from each video. Five facial anatomic markers and 21 individual points on the upper lip were evaluated for both image sets using quantitative photometric analysis. To provide a qualitative assessment, the same images were shown to dentists, laypeople, and the research subjects (patients) to determine which they found to be more esthetically pleasing, or if there was no difference. Quantitative data was evaluated using paired t-tests. The two-dimensional analysis showed a difference with and without a labial flange for lip projection and lip thickness. Additionally, 13 out of 21 landmarks in the three-dimensional analysis showed differences when comparing the superimposed labial flange and no flange linear difference values between high smile and repose. Survey results showed that research subjects (54.41%), dentists (51.50%), and laypeople (44.50%), all preferred labial flange versus no flange photos or were not able to tell a difference. Qualitative and quantitative results suggest that a prosthetic labial flange has an impact on upper lip support. Clinicians should consider lip support both in full animation and repose when treatment planning for the maxillary ISFCDP.

Clinical Performance of 3D Printed Resin Composite Posterior Fixed Dental Prosthesis: A Permanent Solution?

This clinical trial aimed to evaluate the clinical outcomes of 3D-printed resin composite posterior fixed dental prosthesis (FDP) restorations. Between October 2020 and August 2022, 49 patients (33 females, 16 males, aged 19-60) received 68 3-unit 3D-printed resin composite posterior FDPs (ELS Even Stronger, Saremco, Switzerland). Follow-ups were conducted at baseline (2 weeks) by independent observers using modified FDI criteria, assessing anatomical form, marginal adaptation, surface roughness, color match, fracture, retention, and patient feedback. Fifty FDPs completed a 1-year follow-up, and 18 reached 2 years. The mean observation period was 14.15 months. Failures were categorized as mechanical or biological, with 19 FDPs failing: 14 mechanical (12 cohesive fractures) and 5 biological (3 needing endodontic treatment, 2 periodontal issues). Two FDPs were recemented. Three FDPs showed surface luster loss, color mismatches, and staining. The survival rate based on mechanical failures was 69.5%, dropping to 61.0% when including biological complications. After 2 years, 3D-printed resin composite FDPs demonstrated acceptable performance, with most failures due to fractures in the connector region, suggesting the need for design revisions.

Prosthetic Soft Tissue Management in Esthetic Implant Restorations, Part I: Presurgical Planning, Implant Placement, and Restoration Timing. A Narrative Review.

This two-part review article delineates various techniques to enhance esthetic outcomes in anterior implant treatments. Part I concentrates on presurgical measures, case selection, implant placement, and restoration timing. Part II discusses post-surgical steps, the temporary restoration phase, the emergence profile contour, abutment types, and impression techniques. A comprehensive search was conducted using Medline/PubMed, Embase, Scopus, and the Cochrane Library. The primary keywords included were "Dental Implants," "Dental Prosthesis, Implant-Supported," "Esthetics, Dental," "Dental Impression Techniques," and "Tissue Management." Initially, 1472 studies were identified, from which 187 were selected based on publication year and title relevance. After removing duplicates, 84 abstracts were reviewed in full text, culminating in 59 studies being thoroughly analyzed. Optimal esthetics in implant restorations are attainable through meticulous treatment planning, precise surgical execution, and systematic restorative steps, ensuring predictable outcomes. Factors such as a thick gingival biotype, an intact facial bone wall, and atraumatic extraction significantly contribute to superior esthetic results. Immediate implant placement combined with immediate provisionalization provides the most predictable outcomes by supporting and maintaining soft tissue architecture. Conversely, delayed implant placement and provisionalization often require extensive manipulation of collapsed soft tissues to achieve desired esthetics.

Maryland Bridges: A Conservative Approach to Aesthetic Tooth Replacement – A Case Report

Restoring missing central incisors in the mandibular jaw is a challenging esthetic challenge in dentistry, especially for younger patients. Maryland bridges are a highly effective treatment option, restoring oral function and aesthetics, and resulting in high patient satisfaction. These bridges have advantages over conventional fixed dental prosthesis, such as minimal removal of the tooth structure, minimal pulpal trauma risk, and reduced time and cost. Provisional restorations are usually not required. Maryland bridges are cemented to the abutment tooth using electrolytic etching to retain the metal framework. The bond is strengthened after etching, and the development of resin cements has enhanced bridge retention. A missing anterior tooth poses an esthetic, functional, and rehabilitative problem, especially for younger patients. Resin bonded bridges are minimally invasive, offering advantages such as minimal removal of the tooth structure, minimal pulpal trauma risk, and reduced time and cost. This case report describes the fabrication technique for a single missing lower anterior tooth, focusing on conservative, economical, and esthetic treatment outcomes.

Zirconia in fixed prosthodontics: a review ofthe literature.

The purpose of this narrative review is to organize information and knowledge about the properties of the clinical evidence of zirconia-applied dental restorations and to provide relevant information to establish application methods to obtain long-term clinical prognosis of zirconia-applied dental prostheses. From PubMed and manual searches, found "zirconia," "crown," "survival," and "success" keywords were searched. Case reports, case series, reviews, abstracts, in vitro studies, and observational studies were excluded. Additionally, implant superstructures not supported by the periodontal ligament and partially covered crowns were excluded. A total of 42 studies were identified. According to the studies in this review, the most common complication of porcelain-layered zirconia restorations is porcelain fracture, but the long-term prognosis is stable. However, complications of monolithic zirconia restorations include crown fractures and fractures of the abutment tooth and root, and long-term clinical evidence is not available yet. Additionally, bruxism can be a complication factor with both types of restorations, so it is important to carefully examine the oral habits, including bruxism, before treatment. Therefore, the success of zirconia-based restorations in clinical practice requires a careful approach in addition to accurate knowledge of the zirconia material and identification of applicable cases.