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Hua Xi Kou Qiang Yi Xue Za Zhi = Huaxi... Feb 2024Noncarious lesions, a multifactorial condition encompassing tooth attrition, abrasion, and erosion, have a surge in prevalence and required increased attention in...
Noncarious lesions, a multifactorial condition encompassing tooth attrition, abrasion, and erosion, have a surge in prevalence and required increased attention in clinical practice. These nonbacterial-associated tooth defects can compromise aesthetics, phonetics, and masticatory functions. When providing full-arch fixed occlusal rehabilitation for such cases, the treatment strategy should extend beyond by restoring dentition morphology and aesthetics. This report details a complex case of erosive dental wear addressed through a fully digital, full-arch fixed occlusal rehabilitation. A 4D virtual patient was created using multiple digital data sources, including intraoral scanning, 3D facial scanning, digital facebow registration, and mandibular movement tracing. With a comprehensive understanding of the masticatory system, various types of microinvasive prostheses were customized for each tooth, including labial veneers, buccal-occlusal veneers, occlusal veneers, overlays, inlays, and full crowns, were customized for each tooth. The reported digital workflow offered a predictable diagnostic and treatment strategy, which was facilitated by virtual visualization and comprehensive quality control throughout the process.
Topics: Humans; Tooth Erosion; Digital Technology; Esthetics, Dental; Tooth Attrition; Inlays
PubMed: 38475959
DOI: 10.7518/hxkq.2023.2023130 -
The Journal of Advanced Prosthodontics Feb 2024The aim of this stuldy was to compare the clinical marginal fit of CAD-CAM inlays obtained from intraoral digital impression or addition silicone impression techniques.
PURPOSE
The aim of this stuldy was to compare the clinical marginal fit of CAD-CAM inlays obtained from intraoral digital impression or addition silicone impression techniques.
MATERIALS AND METHODS
The study included 31 inlays for prosthodontics purposes of 31 patients: 15 based on intraoral digital impressions (DI group); and 16 based on a conventional impression technique (CI group). Inlays included occlusal and a non-occlusal surface. Inlays were milled in ceramic. The inlay-teeth interface was replicated by placing each inlay in its corresponding uncemented clinical preparation and taking interface impressions with silicone material from occlusal and free surfaces. Interface analysis was made using white light confocal microscopy (WLCM) (scanning area: 694 × 510 µm) from the impression samples. The gap size and the inlay overextension were measured from the microscopy topographies. For analytical purposes (i.e., 95-%-confidence intervals calculations and -value calculations), the procedure REGRESS in SUDAAN was used to account for clustering (i.e., multiple measurements). For p-value calculation, the log transformation of the dependent variables was used to normalize the distributions.
RESULTS
Marginal fit values for occlusal and free surfaces were affected by the type of impression. There were no differences between surfaces (occlusal vs. free). Gap obtained for DI group was 164 ± 84 µm and that for CI group was 209 ± 104 µm, and there were statistical differences between them ( = .041). Mean overextension values were 60 ± 59 µm for DI group and 67 ± 73 µm for CI group, and there were no differences between then ( = .553).
CONCLUSION
Digital impression achieved inlays with higher clinical marginal fit and performed better than the conventional silicone materials.
PubMed: 38455677
DOI: 10.4047/jap.2024.16.1.57 -
Journal of the Mechanical Behavior of... Apr 2024The existing knowledge is insufficient for comprehending the fatigue survival and fracture resistance of molars that have deep approximal direct and indirect...
STATEMENT OF PROBLEM
The existing knowledge is insufficient for comprehending the fatigue survival and fracture resistance of molars that have deep approximal direct and indirect restorations, whether with or without deep margin elevation (DME).
PURPOSE
The aim of this laboratory and in silico study is to investigate the fatigue survival, fracture strength, failure pattern and tooth deformation of molars restored with DME in combination with a direct or indirect restoration.
MATERIAL AND METHODS
This study utilized 45 extracted sound human molars, divided into three groups (n = 15). Standardized 100% inter-cuspal inlay preparations were performed, extending 2 mm below the CEJ and immediate dentin sealing (IDS) was applied. Group 1 (Co_1) was restored with direct composite; Group 2 (Hyb_2) with a 2 mm DME of direct composite and a glass-ceramic lithium disilicate restoration; Group 3 (Cer_3) a glass-ceramic lithium disilicate restoration. All specimens were exposed to a fatigue process involving thermal-cyclic loading (50N for 1.2 × 10 cycles at 1.7 Hz, between 5 and 55 °C), if teeth survived, they were fractured using a load-to-failure test and failure types were analyzed. Finite element analysis (FEA) was conducted to assess tooth deformation and tensile stress in the restorations. Statistical evaluation of fracture strength was conducted using the Kruskal-Wallis test. Fisher's exact test was utilized to analyze the fracture types and repairability. A statistical significance level of α < 0.05 was set for all analyses.
RESULTS
All specimens successfully withstood the fatigue testing procedure, and no statistically significant differences in fracture strength were observed among the three groups (P > 0.05). The Fisher's exact test indicated a significant association between the restorative material and fracture type (F = 18.315, df = 2, P = 0.004), but also for repairability (F = 13.725, df = 2, P = 0.001). Crown-root fractures were significantly more common in the Cer_3 group compared to the Co_1 group (P = 0.001) and the Co_1 group had significantly more repairable fractures (F = 13.197, df = 2, P = 0.001). FEA revealed comparable outcomes of deformation among models and higher maximum tensile stress on models with higher frequency of catastrophic failures.
CONCLUSIONS
All tested restoration materials exhibited comparable fatigue survival and fracture strength in this laboratory and in silico study. However, it is important to recognize the potential for more severe and irreparable fractures when opting for deeply luted glass-ceramic inlay restorations in clinical practice. In such cases, it would be prudent to consider the alternative option being a direct composite approach, because of its more forgiving fracture types and repairability.
CLINICAL IMPLICATIONS
Molars with deep approximal direct and indirect restorations, whether with or without DME, are comparable in their fatigue survival and fracture resistance to withstand intra-oral forces. Deep direct restorations exhibit more repairable fractures compared to deeply luted glass-ceramics.
Topics: Humans; Molar; Finite Element Analysis; Flexural Strength; Fractures, Bone; Laboratories; Tooth Fractures
PubMed: 38394767
DOI: 10.1016/j.jmbbm.2024.106459 -
Dental Materials : Official Publication... Apr 2024Zein-coated magnesium oxide nanoparticles (zMgO NPs) can potentially improve cement adaptation to the tooth-restoration interface, which would aid in minimizing marginal...
OBJECTIVES
Zein-coated magnesium oxide nanoparticles (zMgO NPs) can potentially improve cement adaptation to the tooth-restoration interface, which would aid in minimizing marginal leakage and secondary caries. The aim of this study was to assess the effect of incorporating zMgO NPs on the adaptation of self-adhesive resin cement using cross-polarization optical coherence tomography (CP-OCT) and scanning electron microscopy (SEM).
METHODS
Resin inlays were fabricated to be cemented in Class-I cavities of extracted human molars. All specimens were randomly divided into five groups (n = 10), and the resin inlays were cemented using self-adhesive resin cement with various concentrations of zMgO NPs (0% [control], 0.3%, 0.5%, 1%, 2%). Characterization was done by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and SEM. The specimens were examined for interfacial adaptation under CP-OCT. Floor and wall adaptation measurements were analyzed by software on 20 B-scans, and samples were sectioned for interfacial measurement by SEM.
RESULTS
Results for CP-OCT and SEM showed a statistically significant increase of adaptation in the floor and wall of resin cement filled with zMgO NPs compared to the control. The samples enhanced with 0.3% and 0.5% showed a statistically significantly better adaptation in floor and wall in CP-OCT and SEM. However, there was no significant difference between the 1%, 2%, and control groups for CP-OCT and SEM analysis.
SIGNIFICANCE
The incorporation of zMgO NPs in self-adhesive resin cement can enhance the cement's properties by significantly improving its wall and floor adaptation.
Topics: Humans; Resin Cements; Dental Cements; Tomography, Optical Coherence; Inlays; Glass Ionomer Cements; Composite Resins; Dental Marginal Adaptation; Dental Bonding
PubMed: 38383250
DOI: 10.1016/j.dental.2024.02.004 -
Folia Medica Oct 2023Silver diamine fluoride (SDF) is a topical agent that has recently gained popularity for its ability to stop and prevent dental caries.
Silver diamine fluoride (SDF) is a topical agent that has recently gained popularity for its ability to stop and prevent dental caries.
Topics: Humans; Dental Caries; Fluorides, Topical; Ceramics; Aluminum Silicates; Quaternary Ammonium Compounds; Silver Compounds
PubMed: 38351764
DOI: 10.3897/folmed.65.e97183 -
Bioengineering (Basel, Switzerland) Jan 2024Hip implants have a modular structure which enables patient-specific adaptation but also revision of worn or damaged friction partners without compromising the...
Hip implants have a modular structure which enables patient-specific adaptation but also revision of worn or damaged friction partners without compromising the implant-bone connection. To reduce complications during the extraction of ceramic inlays, this work presents a new approach of a shape-memory-alloy-actuator which enables the loosening of ceramic inlays from acetabular hip cups without ceramic chipping or damaging the metal cup. This technical in vitro study exam-ines two principles of heating currents and hot water for thermal activation of the shape-memory-alloy-actuator to generate a force between the metal cup and the ceramic inlay. Mechanical tests concerning push-in and push-out forces, deformation of the acetabular cup according to international test standards, and force generated by the actuator were generated to prove the feasibility of this new approach to ceramic inlay revision. The required disassembly force for a modular acetabular device achieved an average value of 602 N after static and 713 N after cyclic loading. The actuator can provide a push-out force up to 1951 N. In addition, it is shown that the necessary modifications to the implant modules for the implementation of the shape-memory-actuator-system do not result in any change in the mechanical properties compared to conventional systems.
PubMed: 38247952
DOI: 10.3390/bioengineering11010075 -
Journal of Yeungnam Medical Science Apr 2024This study aimed to compare and evaluate the marginal fit of nanocomposite computer-aided design/computer-aided manufacturing (CAD/CAM) inlays. Three types of...
BACKGROUND
This study aimed to compare and evaluate the marginal fit of nanocomposite computer-aided design/computer-aided manufacturing (CAD/CAM) inlays. Three types of nanocomposite CAD/CAM blocks (HASEM, VITA Enamic, and Lava Ultimate) were used as materials.
METHODS
Class II disto-occlusal inlay restorations were prepared on a typodont mandibular right first molar using diamond rotary instruments. The inlays were fabricated using CAD/CAM technology and evaluated using the silicone replica technique to measure marginal gaps at five locations on each inlay. The data were analyzed by two-way analysis of variance and Tukey post hoc tests ( α=0.05).
RESULTS
There were no significant differences in the marginal gaps based on the type of nanocomposite CAD/CAM inlay used (p=0.209). However, there was a significant difference in the marginal gaps between the measurement regions. The gingival region consistently exhibited a larger marginal gap than the axial and occlusal regions (p<0.001).
CONCLUSION
Within the limitations of this in vitro study, the measurement location significantly influenced the marginal fit of class II disto-occlusal inlay restorations. However, there were no significant differences in the marginal gaps among the different types of CAD/CAM blocks. Furthermore, the overall mean marginal fits of the class II disto-occlusal inlay restorations made with the three types of nanocomposite CAD/CAM blocks were within the clinically acceptable range.
PubMed: 38247035
DOI: 10.12701/jyms.2023.00934 -
Evidence-based Dentistry Mar 2024Pubmed, EMBASE, Scopus, Web of Science and Cochrane library databases were used as the data sources for this systematic review. Manual search of the reference lists of...
DATA SOURCES
Pubmed, EMBASE, Scopus, Web of Science and Cochrane library databases were used as the data sources for this systematic review. Manual search of the reference lists of the included studies was also conducted.
STUDY SELECTION
The aim of the systematic review was to compare a fully digital workflow to a fully conventional workflow in the fabrication of partial coverage restorations. Partial coverage restorations were defined as inlays, onlays, overlays and endocrowns. Four independent calibrated reviewers screened studies that fulfilled a predefined PICOS framework. Population was specified as an abutment tooth requiring a partial coverage restoration. The intervention was a fully digital workflow compared to a fully conventional workflow. Outcomes were accuracy, marginal and internal fit, success, survival, complication rates and patient-reported outcomes. Study design included both clinical and in vitro studies.
DATA EXTRACTION AND SYNTHESIS
A total of 23 articles were included in qualitative synthesis ranging from 2007 to 2021. Twenty-one of these were in vitro studies. Two authors independently reviewed the included articles, performed data extraction, and evaluated the risk of bias via an adapted Checklist for Reporting In Vitro studies (CRIS) for in vitro studies and Reporting Randomised Clinical studies (RoB2) for clinical studies.
RESULTS
Seventeen studies assessed the marginal and internal fit of onlay and inlay restorations, eight of which found that a conventional workflow demonstrated improved fit compared to digital, whilst the remaining nine studies found the contrary. Differing methods were utilised across the studies to assess fit, including: the silicone replica method, microcomputed tomography, microscopy and software-based measurements. Similar fracture strengths were reported between both conventional and digital workflows in three studies. One clinical study assessed survival rates of both pressed and CAD/CAM ceramic restorations and found the survival outcomes to be similar after seven years. No studies were found that investigated patient-reported outcomes or endocrowns.
CONCLUSIONS
No consensus was reached as to whether the digital or conventional workflow is better.
Topics: Humans; X-Ray Microtomography; Dental Prosthesis Design; Dental Marginal Adaptation; Ceramics; Inlays
PubMed: 38243025
DOI: 10.1038/s41432-024-00971-2 -
BMC Oral Health Jan 2024This is a randomized, controlled, superiority, double-blinded, parallel-group, two-arms trial with an allocation ratio of 1:1. The aim of this trial was to compare the... (Randomized Controlled Trial)
Randomized Controlled Trial
Two‑year clinical performance of indirect restorations fabricated from CAD/CAM nano hybrid composite versus lithium disilicate in mutilated vital teeth. A randomized controlled trial.
TRIAL DESIGN
This is a randomized, controlled, superiority, double-blinded, parallel-group, two-arms trial with an allocation ratio of 1:1. The aim of this trial was to compare the two-year clinical performance of partial indirect restorations fabricated from CAD/CAM nano-hybrid composite and ceramic lithium disilicate blocks using the modified USPHS criteria.
METHODS
In two parallel groups (n = 50 restorations), fifty participants having mutilated vital teeth with a minimum of two remaining walls were randomly enrolled in this trial and received indirect restorations of either nano-hybrid composite resin blocks (Brilliant, Coltene, Switzerland) or Lithium Disilicate (IPS Emax CAD). The restorations were assessed using modified USPHS criteria by two independent blinded assessors at baseline, six months, one-year and two years follow-up visits. Categorical and ordinal data were presented as frequencies and percentages. Categorical data were analyzed using the chi-square test. Ordinal data were analyzed using the Mann-Whitney U test for intergroup comparisons and Freidman's test followed by the Nemenyi post hoc test for intragroup comparisons. Numerical data were presented as mean and standard deviation values. They were analyzed for normality using the Shapiro-Wilk test. Data were found to be normally distributed and were analyzed using the independent t-test. The significance level was set at p ≤ 0.05 within all tests.
RESULTS
Forty-eight participants received the allocated intervention and completed the follow-up periods. There was a statistically significant difference between both tested materials for all USPHS criteria regarding Marginal integrity and Marginal discoloration at six-months Follow-up, but with no statistically significant difference at one- and two-year follow-up.
CONCLUSIONS
Both materials showed an acceptable, successful clinical performance along the two-years follow-up period.
CLINICAL RELEVANCE
The CAD/CAM nano-hybrid composite blocks are as reliable as Lithium disilicate for restoring mutilated vital teeth.
Topics: Humans; Ceramics; Computer-Aided Design; Dental Materials; Dental Porcelain; Inlays; Materials Testing
PubMed: 38233771
DOI: 10.1186/s12903-023-03847-6 -
Journal of Cataract and Refractive... Jan 2024The pinhole effect is commonly used to discriminate uncorrected refractive error from ocular diseases. A small aperture limits the width of light beams entering the eye,...
The pinhole effect is commonly used to discriminate uncorrected refractive error from ocular diseases. A small aperture limits the width of light beams entering the eye, thus increasing the depth of focus. The pinhole effect has also been used in spectacles, contact lenses, corneal inlays, and intraocular lenses (IOLs) to improve reading by compensating for loss of accommodative function. Pinhole spectacles improve near visual acuity, but reduce reading speed, increase interblink interval, and decrease tear break-up time. For contact lenses and IOLs, pinhole devices are usually used in the nondominant eye, which allow compensation of various refractive errors and decrease spectacle dependence. Pinhole corneal inlays are implanted during laser in situ keratomileusis or as a separate procedure. Pinhole IOLs are gaining popularity, particularly as they do not bring a risk of a local inflammatory reaction as corneal inlays do. Disadvantages of using the pinhole effect include high susceptibility to decentration, decrease in retinal luminance levels, and difficulties in performing fundus examinations or surgery in eyes with implanted devices. There are also concerns regarding perceptive issues with different retinal illuminances in the 2 eyes (the Pulfrich effect).
Topics: Humans; Vision, Ocular; Visual Acuity; Lenses, Intraocular; Accommodation, Ocular; Contact Lenses; Refractive Errors
PubMed: 38133648
DOI: 10.1097/j.jcrs.0000000000001318