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ABSTRACT Objectives Material and Methods Results Conclusions Clinical Significance To analyze survival and complication rates for anterior and premolar laminate‐veneers out of different ceramic materials (feldspathic, leucite‐reinforced glass–ceramic [LRGC], lithium‐disilicate [LDS] and zirconia).A systematic literature search was conducted across multiple databases for clinical studies on ceramic laminate‐veneers with a minimum‐follow‐up of ≥ 1 year. The date of last search was on February 19, 2024. Survival, technical, esthetic and biological events were assessed for different laminate‐veneer materials at three observation periods (short‐ [1–3 years], mid‐ [4–6 years] and long‐term [≥ 7 years]).Twenty‐nine studies were included. Meta‐analysis revealed a pooled survival‐rate of 96.13% for feldspathic, 93.70% for LRGC and 96.81% for LDS at 10.4 years. No difference was found between materials. Complication rates (technical/esthetic/biological) were as follows: Feldspathic: 41.48%/19.64%/6.51%; LRGC: 29.87%/17.89%/4.4%; LDS: 6.1%/1.9%/0.45% at 10.4 years. Zirconia showed a 100% survival‐rate with no complications at 2.6 years. No long‐term data was available for zirconia.Feldspathic, LRGC and LDS laminate‐veneers showed high survival‐rates at long‐term observation. LDS slightly outperforms feldspathic and LRGC laminate‐veneers with lower long‐term complication rates. More studies providing long‐term data on zirconia laminate‐veneers are needed.Ceramic laminate‐veneers are a reliable treatment option. LDS may be preferred as a restorative material for long‐term success. [ABSTRACT FROM AUTHOR]

The primary aim of this in vitro study was to compare the load-bearing capacity of lithium disilicate occlusal veneers, fabricated via different manufacturing processes. Secondary objectives included assessing internal accuracy and production time-efficiency. Four fabrication methods for ultra-thin lithium disilicate occlusal veneers on extracted human molars with simulated erosive defects were compared (n = 20/group): CAM: milled lithium disilicate (IPS e.max CAD); HPR: heat-pressed lithium disilicate (IPS e.max Press) out of a milled PMMA template (Ddpmma CAST); 3DP: 3D-printed lithium disilicate (experimental lithium disilicate); PTE: heat-pressed lithium disilicate (IPS e.max Press) out of a 3D-printed template (SilaPrint cast). Internal accuracy was measured prior to thermo-mechanical aging, followed by static loading to measure the load-bearing capacity (F max). Fabrication time (time-efficiency) was also recorded. Statistical analysis was performed using the Kruskal-Wallis (KW) test. No statistically significant differences were found in median load-bearing capacities (F max) between the groups (KW p = 0.5902): CAM 1821 N, HPR 1896 N, 3DP 2003 N, PTE 1687 N. Significant differences were found in internal accuracy between the groups that employed printing processes (3DP, PTE) and all other groups in margins (p < 0.001), cusps (p < 0.0018), and fossae (p < 0.0346). The time-efficiency measurements indicated an increase in fabrication time, starting from CAM 67.2 ± 5.8 min, followed by HPR 200.8 ± 33.0 min, PTE 289.2 ± 38.7 min, and peaking with the highest duration observed for 3DP 701.6 ± 8.1 min. The fabrication method of ultra-thin lithium disilicate occlusal veneers does not significantly impact their load-bearing capacity, but affects the clinical fit and adaptation of the veneers. • All fabrication methods exhibited high load-bearing capacities, with no significant differences between the groups. • Milled or heat-pressed restorations demonstrated minimal marginal discrepancies and high internal accuracy. • 3D-printed restorations showed larger marginal gaps but superior internal accuracy in the cusp and fossa regions. • Direct milling was the most time-efficient; 3D-printing the most time-consuming, and procedures involving methacrylate-based templates were intermediate. [ABSTRACT FROM AUTHOR]

Background. Multilayer zirconia has more optical and aesthetic features than regular zirconia. Therefore, its mechanical properties should be compared with monochromatic zirconia. Among the mechanical characteristics that can be checked are the wear of the opposite tooth and the bond to the porcelain. This study assessed the effect of zirconia type (multilayer versus monochromatic) on the shear bond strength (SBS) to feldspathic porcelain and the wear of the opposing teeth. Methods. The present in vitro study was conducted in two phases. In the first phase, 15 multilayer and 15 monochromatic zirconia blocks measuring 10×5×5 mm were designed, milled, sintered, veneered with porcelain, and underwent thermocycling. Their SBS was then measured in a universal testing machine. In the second phase, 15 multilayer and 15 monochromatic zirconia blocks were placed in a chewing simulator, and 30 sound premolars served as antagonistic teeth. The magnitude of wear of the buccal cusp of premolars was quantified from a 4-mm reference point after 100000 cycles. Data were analyzed by independent t test (α=0.05). Results. The mean SBS of monochromatic zirconia to porcelain (24.49±3.58 MP) was slightly higher than that of multilayer zirconia (22.98±2.98 MP), but the difference was not significant (P>0.05). The mean wear of the opposing teeth was also slightly higher in the monochromatic group (284.1±66.53 µm) than in the multilayer group (263.2±58.69 µm), but this difference was not significant either (P>0.05). Conclusion. Monochromatic and multilayer zirconia showed comparable SBS to feldspathic porcelain and caused comparable wear of the opposing teeth in vitro. Thus, multilayer zirconia may serve as an alternative to monochromatic zirconia.

Porcelain laminate veneers (PLV) offer a conservative aesthetic solution for interdental space closure. However, space is typically not distributed symmetrically, and the mesiodistal width of the restored teeth may increase unless multiple teeth are prepared for conventional PLV to maintain appropriate individual tooth proportion. Ceramic fragments can be suggested to close the space without modifying tooth size and dental proportion. This article presents two cases where interdental gaps were closed using lingually placed porcelain laminate (LPPL). All stages of the restorative procedures, including treatment planning, temporization, tooth preparation, and cementation of these delicate restorations, are detailed. Based on the results of these clinical reports, we regard the use of LPPL as a successful treatment option in selected cases, as evidenced by 2- and 6-year follow-ups. The Modified United State Public Health Criteria is reported. [ABSTRACT FROM AUTHOR]

In addition to many materials, silver vanadate (AgVO3) has gained interest due to its antimicrobial properties, which opens up the potential for use as an antibacterial agent for biomedical applications. This work aimed to study the effect of AgVO3 addition on the structural and morphological properties of a developed dental porcelain (DP) prepared from natural raw materials. AgVO3 nanowires, prepared by the coprecipitation method, were added in different amounts (1, 3, and 5 wt.%) to a DP mass with the initial composition of 80 wt.% feldspar, 15 wt.% quartz, and 5 wt.% kaolin, obtained by sintering the mixture at 1300 °C. The structural and morphological properties of AgVO3 and DP were investigated by X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), and transmission electron microscopy (TEM). The results showed the formation of α-AgVO3 nanowires coated with semispherical metallic silver nanoparticles. Moreover, α-AgVO3 additions do not influence the structural and morphological properties of DP, with the presence of Ag and V clearly identified in the DP with the α-AgVO3 addition. Our findings highlight the potential of this novel material for use in various dental applications. Future studies need to establish the antibacterial properties of the prepared dental material. [ABSTRACT FROM AUTHOR]

PURPOSE. This study assessed the effect of storage time on chemical structure of a single-bottle and a two-bottle experimental ceramic primer and micro-shear bond strength (µSBS) of composite to ceramic. MATERIALS AND METHODS. This study was conducted on 60 sintered zirconia and 60 feldspathic porcelain blocks. Half of the specimens (n = 30) were subjected to surface treatment with the single-bottle Clearfil ceramic primer (n = 15) and two-bottle experimental primer (n = 15) after 24 hours. The remaining half received the same surface treatments after 6 months storage in distilled water. Composite cylinders were bonded to the ceramics, and they were then subjected to µSBS test. Also, the primers underwent Fourier-transform infrared spectroscopy (FTIR) after 24 hours and 6 months to assess their chemical structure. Data were analyzed with 3-way ANOVA and adjusted Bonferroni test (alpha = 0.05). RESULTS. The µSBS of both ceramics significantly decreased at 6 months in one-bottle ceramic primer group (P = .001), but it was not significantly different from the two-bottle experimental primer group (P = .635). FTIR showed hydrolysis of single-bottle primer, cleavage of silane and 10-MDP bonds, and formation of siloxane bonds after 6 months. CONCLUSION. Six months of storage caused significant degradation of single-bottle ceramic primer, and consequently had an adverse effect on µSBS. [ABSTRACT FROM AUTHOR]

IntroductionThe aim of this study was to evaluate the fit performance of implant infrastructures manufactured by five different techniques: heat-press (IPS), milling (ZIR), lost wax (CER), calcinable cylinder (CAL), and CAD/Waxx® (CAD).MethodsThe methodology was based on the Replica Technique, which can simulate and evaluate the fit of the infrastructure on the implant component. Thus, each infrastructure was internally filled with low-viscosity silicone addition and seated on the component until its final setting, obtaining the replica of the cementation space. After removing the coping containing the silicone film, light-density silicone was inserted addition in place of the components, and in its surroundings, condensation silicone was applied, establishing support for the assembly. The joint was sectioned mesiodistally, photographed, and analyzed in image processing software in order to measure the thickness of the interface infrastructure/implant at five different areas: marginal opening (M), gingival-axial angle (G-A), axial region (A), axial-occlusal angle (A-O) and occlusal surface (O).ResultsThe lowest and the highest average thickness between groups was, respectively, IPS: 187.5 μm and CAD: 221.6 μm, with statistically significant differences (p

Despite the development of implant-supported prostheses, there are still patients for whom conservative treatments such as resin-bonded fixed dental prostheses (RBFDPs) are more appropriate. This study's objective was to analyze the available research on full-ceramic RBFDPs. In this study, Web of Science, MEDLINE/PubMed, Scopus, Embase, Cochrane Library, and Google Scholar databases were searched for articles published in English between 2010 and 2020. A total of 14 studies were reviewed based on the eligibility criteria. The results showed that using a cantilever design with one abutment had an advantage over two abutments. Additionally, it was proposed that preparations designed with retentive aids, such as a proximal box, groove, and pinhole, could improve RBFDP survival rates. IPS e.max ZirCAD, In-Ceram alumina, and zirconia CAD/CAM were the most commonly used framework materials. Most studies used air abrasion, salinization, or hydrofluoric acid for surface treatment. Adhesive resin cements were the most frequently used type of cement. The survival rate of In-Ceram ceramics (85.3%–94.8%) was lower than that of In-Ceram zirconia and IPS e.max ZirCAD. Debonding, followed by framework fracture, was the leading cause of failure. Following 3–10 years follow-up, the survival percentage of all-ceramic RBFDPs ranged from 76% to 100%. Although RBFDPs have demonstrated satisfactory success as a conservative treatment, long-term follow-ups and higher sample sizes in clinical research are required to gain more reliable outcomes on the clinical success rate of various RBFDP designs. [ABSTRACT FROM AUTHOR]

Background.: Multilayer zirconia has more optical and aesthetic features than regular zirconia. Therefore, its mechanical properties should be compared with monochromatic zirconia. Among the mechanical characteristics that can be checked are the wear of the opposite tooth and the bond to the porcelain. This study assessed the effect of zirconia type (multilayer versus monochromatic) on the shear bond strength (SBS) to feldspathic porcelain and the wear of the opposing teeth. Methods.: The present in vitro study was conducted in two phases. In the first phase, 15 multilayer and 15 monochromatic zirconia blocks measuring 10×5×5 mm were designed, milled, sintered, veneered with porcelain, and underwent thermocycling. Their SBS was then measured in a universal testing machine. In the second phase, 15 multilayer and 15 monochromatic zirconia blocks were placed in a chewing simulator, and 30 sound premolars served as antagonistic teeth. The magnitude of wear of the buccal cusp of premolars was quantified from a 4-mm reference point after 100000 cycles. Data were analyzed by independent t test (α=0.05). Results.: The mean SBS of monochromatic zirconia to porcelain (24.49±3.58 MP) was slightly higher than that of multilayer zirconia (22.98±2.98 MP), but the difference was not significant (P >0.05). The mean wear of the opposing teeth was also slightly higher in the monochromatic group (284.1±66.53 µm) than in the multilayer group (263.2±58.69 µm), but this difference was not significant either (P >0.05). Conclusion.: Monochromatic and multilayer zirconia showed comparable SBS to feldspathic porcelain and caused comparable wear of the opposing teeth in vitro. Thus, multilayer zirconia may serve as an alternative to monochromatic zirconia. [ABSTRACT FROM AUTHOR]

Porcelain laminate veneers (PLV) offer a conservative aesthetic solution for interdental space closure. However, space is typically not distributed symmetrically, and the mesiodistal width of the restored teeth may increase unless multiple teeth are prepared for conventional PLV to maintain appropriate individual tooth proportion. Ceramic fragments can be suggested to close the space without modifying tooth size and dental proportion. This article presents two cases where interdental gaps were closed using lingually placed porcelain laminate (LPPL). All stages of the restorative procedures, including treatment planning, temporization, tooth preparation, and cementation of these delicate restorations, are detailed. Based on the results of these clinical reports, we regard the use of LPPL as a successful treatment option in selected cases, as evidenced by 2- and 6-year follow-ups. The Modified United State Public Health Criteria is reported.

Abstract 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.

Objectives: The objective of this in vitro study was to evaluate the shear bond strength between the ceramic veneer and additively manufactured titanium with different surface treatments, and to compare with milled titanium. Also, to characterize the surface and the presence of an α‐case layer of additively manufactured and milled titanium. Material and Methods: Sixty additively manufactured titanium grade 23, and 20 milled titanium grade 4 cylindrical specimens were divided into four groups based on surface treatments, air‐particle abrasion and grinding. After ceramic veneering half of each group were thermocycled. The bond strength was analyzed using a shear bond strength test. The surfaces were analyzed using interferometry and scanning electron microscopy. Results: The grinding procedure and air‐particle abrading pressure had no significant effect on the shear bond strength (p =.264 and p =.344). Thermocycling showed a tendency towards an effect but not significant (p =.052). The group with the highest air‐abrading pressure showed the highest surface roughness. No presence of an α‐case layer was detected in any of the groups. Conclusion: Additively manufactured titanium grade 23 may be veneered with ceramics without prior grinding of the surfaces. [ABSTRACT FROM AUTHOR]

In addition to many materials, silver vanadate (AgVO3) has gained interest due to its antimicrobial properties, which opens up the potential for use as an antibacterial agent for biomedical applications. This work aimed to study the effect of AgVO3 addition on the structural and morphological properties of a developed dental porcelain (DP) prepared from natural raw materials. AgVO3 nanowires, prepared by the coprecipitation method, were added in different amounts (1, 3, and 5 wt.%) to a DP mass with the initial composition of 80 wt.% feldspar, 15 wt.% quartz, and 5 wt.% kaolin, obtained by sintering the mixture at 1300 °C. The structural and morphological properties of AgVO3 and DP were investigated by X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), and transmission electron microscopy (TEM). The results showed the formation of α-AgVO3 nanowires coated with semispherical metallic silver nanoparticles. Moreover, α-AgVO3 additions do not influence the structural and morphological properties of DP, with the presence of Ag and V clearly identified in the DP with the α-AgVO3 addition. Our findings highlight the potential of this novel material for use in various dental applications. Future studies need to establish the antibacterial properties of the prepared dental material.

Abstract Purpose This study aimed to assess the diagnostic accuracy of cone-beam computed tomography (CBCT) and digital intraoral radiography for the detection of proximal caries adjacent to amalgam, e.max porcelain, and metal-ceramic restorations (MCRs). Materials and methods Parallel intraoral radiographs were obtained from 40 posterior teeth using PSP sensors. To obtain CBCT scans, the teeth were first radiographed alone, and were then positioned next to a tooth with an amalgam restoration, MCR, and e.max porcelain crown, and radiographed again. Two blinded observers scored radiographs using a four-point scale (0: absence of proximal caries, 1: enamel caries, 2: carious lesion extending to the outer half of dentin, 3: carious lesion extending to the inner half of dentin). Tooth sections were made, and the grade of caries was determined under a light microscope at x12 magnification. The sensitivity, specificity, and accuracy of CBCT and intraoral radiographs were then calculated. Results Artifact-free CBCT scans and intraoral radiographs had the highest diagnostic accuracy (0.826 and 0.657, respectively) while CBCT images of the teeth next to the amalgam restorations (0.526) had the lowest accuracy. The diagnostic accuracy of CBCT images of the teeth next to the porcelain crowns and MCRs was 0.613 and 0.601, respectively. Conclusion Artifact-free CBCT images had higher diagnostic accuracy than intraoral radiography for the detection of all grades of proximal caries. The diagnostic accuracy of CBCT images of teeth adjacent to amalgam, porcelain, and MCRs was lower compared to intraoral radiographs and artifact-free CBCT images.

Abstract Objectives The objective of this in vitro study was to evaluate the shear bond strength between the ceramic veneer and additively manufactured titanium with different surface treatments, and to compare with milled titanium. Also, to characterize the surface and the presence of an α‐case layer of additively manufactured and milled titanium. Material and Methods Sixty additively manufactured titanium grade 23, and 20 milled titanium grade 4 cylindrical specimens were divided into four groups based on surface treatments, air‐particle abrasion and grinding. After ceramic veneering half of each group were thermocycled. The bond strength was analyzed using a shear bond strength test. The surfaces were analyzed using interferometry and scanning electron microscopy. Results The grinding procedure and air‐particle abrading pressure had no significant effect on the shear bond strength (p = .264 and p = .344). Thermocycling showed a tendency towards an effect but not significant (p = .052). The group with the highest air‐abrading pressure showed the highest surface roughness. No presence of an α‐case layer was detected in any of the groups. Conclusion Additively manufactured titanium grade 23 may be veneered with ceramics without prior grinding of the surfaces.

Porcelain fused to metal (PFM) is commonly used in dental restorations but is prone to fractures. Packable resin composites, influenced by various surface treatments like hydrofluoric acid, serve as alternatives. The acid treatment's specifics affect the porcelain's microstructure. Recently, ceromer resin composites have been introduced for indirect restorations. The purpose of this study is to determine the differences in packageable resin composites and ceromers as dental restorative materials. Cylindrical dental feldspathic porcelain was used, while the hydrofluoric acid was applied on the surface of the dental porcelain. The adhesive behaviours were measured, and the determination of the relationship between the timing effects and resin composites was carried out via statistical analysis. The atomic force microscopy (AFM) characterizations were performed to determine the surface roughness of restorative technique. The results showed that there were differences in packable resin composites and ceromers, in which every treatment times showed relationship to the adhesive behaviours on the cohesive fractures. The average value of adhesive strengths of packageable resin composites and ceromers respectively accounted for 2.73±1.69 MPa and 4.43±2.43 MPa. Statistical results showed that the highest adhesive strength was found in the 4-minutes of etching time due to more and deeper pores in accordance with AFM results, indicating easier penetration of silane as coupling agents and repairing materials. The conclusion of this study is that as the time of etching of hydrofluoric acid in porcelain increases, the value of the adhesive strength of the restorative material increases with a higher ceromer value than packable. [ABSTRACT FROM AUTHOR]

Background: This study aims to investigate the color stability of feldspathic porcelains with different concentrations of silver nanoparticles (AgNPs). Materials and Methods: In this experimental study, feldspathic porcelain disks with AgNPs of 0 parts per million (ppm), 250 ppm, and 500 ppm were used (sample size = 180). These ceramic discs were subjected to thermocycling in tea, orange juice, and artificial saliva.The optical parameters of disks were measured before and after being immersed in the solutions. Then, the color change (ΔE 00) of the samples was measured by using the CIEDE 2000 formula. The data were analyzed by one-way analysis of variance (ANOVA) and Tukey's post hoc test. The level of significance was determined to be 0.05. Results: The results of the ANOVA test show that there was a significant difference in ΔE 00 (P < 0.05).The maximum ΔE 00 was visible in the samples with AgNPs 0 ppm that were exposed to orange juice, and the minimum ΔE 00 was related to the disks with AgNPs 500 ppm in artificial saliva. Conclusion: Based on the results of this study, adding AgNPs to feldspathic porcelain increases the color stability of the ceramic discs. [ABSTRACT FROM AUTHOR]

Purpose: This systematic review aimed to evaluate the medium-term (3-year) overall survival and success rates, marginal bone loss and different biological parameters displayed with one-piece zirconia implants. Materials and methods: Electronic searches were conducted of the MEDLINE (via PubMed), Scopus (Elsevier), Cochrane Library (Wiley) and Web of Science (Clarivate Analytics) databases and manual searching was also performed for relevant articles published up to 14 November 2022. The review included human studies with a minimum of 10 subjects and/or 20 implants and with a follow-up period of at least 3 years after implant placement. Results: Twelve studies met the inclusion criteria and were included for analysis, giving a total of 1,621 one-piece zirconia implants. Eleven studies were included to perform a meta-analysis of survival rates, and six for success rates and marginal bone loss. The survival and success rates at the 3-year follow-up were 94.4% (95% confidence interval 90.4%–98.4%; P < 0.001) and 91.6% (95% confidence interval 84.2%–98.9%; P < 0.001), respectively, and marginal bone loss was 0.231 mm (95% confidence interval 0.190–0.272; P < 0.001). Conclusions: One-piece zirconia implants appear to be a reliable option for restoring missing teeth, obtaining an implant survival rate of 94.4% and a success rate of 91.6% after a follow-up period of at least 3 years. Moreover, the results showed acceptable rates of marginal bone loss and adequate biological parameters. [ABSTRACT FROM AUTHOR]

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Purpose: This study aimed to assess the diagnostic accuracy of cone-beam computed tomography (CBCT) and digital intraoral radiography for the detection of proximal caries adjacent to amalgam, e.max porcelain, and metal-ceramic restorations (MCRs). Materials and methods: Parallel intraoral radiographs were obtained from 40 posterior teeth using PSP sensors. To obtain CBCT scans, the teeth were first radiographed alone, and were then positioned next to a tooth with an amalgam restoration, MCR, and e.max porcelain crown, and radiographed again. Two blinded observers scored radiographs using a four-point scale (0: absence of proximal caries, 1: enamel caries, 2: carious lesion extending to the outer half of dentin, 3: carious lesion extending to the inner half of dentin). Tooth sections were made, and the grade of caries was determined under a light microscope at x12 magnification. The sensitivity, specificity, and accuracy of CBCT and intraoral radiographs were then calculated. Results: Artifact-free CBCT scans and intraoral radiographs had the highest diagnostic accuracy (0.826 and 0.657, respectively) while CBCT images of the teeth next to the amalgam restorations (0.526) had the lowest accuracy. The diagnostic accuracy of CBCT images of the teeth next to the porcelain crowns and MCRs was 0.613 and 0.601, respectively. Conclusion: Artifact-free CBCT images had higher diagnostic accuracy than intraoral radiography for the detection of all grades of proximal caries. The diagnostic accuracy of CBCT images of teeth adjacent to amalgam, porcelain, and MCRs was lower compared to intraoral radiographs and artifact-free CBCT images. [ABSTRACT FROM AUTHOR]

Feasibility investigation of natural teeth shades replication on dental prosthetics fabricated via functionally graded additive manufacturing (FGAM) using combination of feldspathic porcelain (FP) and yttrium aluminum garnet cerium (Y 3 Al 5 O 12: Ce, YAG:Ce) as a promising esthetic restoration option. Color-graded feldspathic crown fabrication parameter through FGAM method was comprehensively examined from the slurry rheology, cure depth, debinding to sintering temperature. Effect of light absorbent also checked towards overcuring reaction during UV exposure by the shape comparison. Lastly, the flexural bending strength measured following ISO 6872:2015 to assure the applicability. Applying the studied parameter, natural teeth shades then imitated and investigated by alteration of FP and FP + 0.1 wt% YAG:Ce (Y-FP). Generated color across the structure captured through mobile camera, interpreted through the CIELAB coordinate and the gradation confirmed by the color differences (ΔE 00) calculated using CIEDE2000 formula. Parameter study indicated that 70 wt% of FP slurry with 3 wt% dispersant and 0.2 wt% light absorbent is favored. It produces excellent flowability in our FGAM system with less overcuring justified by edge margin reduction from 95.65° to 90.00° after UV exposure on rectangle shapes masking. The obtain structure also offers adequate flexural bending strength of 106.26 MPa (FP) and 101.36 MPa (Y-FP) after sintering at 780 °C. This validated the materials as class 2 dental prosthetics citing ISO 6872:2015. Color gradation was verified by the yellow b* value reduction (14.8 to −3.33) as it shifted from cervical to incisal area while ΔE 00 further affirmed the differences from each segment in comparison with the FP and Y-FP. Color gradation was successfully replicated by FP and YAG:Ce composition shift via FGAM technique. This result highlights the potential of FGAM as an alternative for fabricating dental prosthetics with high efficiency and improved esthetic appeal. [Display omitted] [ABSTRACT FROM AUTHOR]

Background and Objective: This study aimed to compare the surface finish of milled leucite-reinforced ceramics polished with ceramic and composite polishing systems based on the manufacturers' recommendations. Materials and Methods: Sixty subtractive computer-aided manufactured (s-CAM) leucite-reinforced glass-ceramic specimens (IPS-Empress-CAD) were assigned into six groups: no polishing, a ceramic polishing kit, and four composite kit groups. The roughness average (Ra) was evaluated in microns using a profilometer, and scanning electron micrographs were obtained for qualitative analysis. A Tukey HSD posthoc test (α = 0.05) was used to determine significant intergroup differences. Results: After surface evaluation of the ceramics, the Ra values of the polishing systems ranked OptraFine (0.41 ± 0.26) < Enhance (1.60 ± 0.54) < Shofu (2.14 ± 0.44) < Astropol (4.05 ± 0.72) < DiaComp (5.66 ± 0.62) < No Polishing (5.66 ± 0.74). Discussion: Composite polishing systems did not provide as smooth surfaces as the ceramic polishing kit for CAD-CAM leucite-reinforced ceramics. Thus, using ceramic polishing systems, polishing leucite ceramics is recommended, whereas composite polishing systems should not be considered as an alternative for use in minimally invasive dentistry. [ABSTRACT FROM AUTHOR]

In the Horn of Africa, little is known about temporal changes in hydroclimate owing to the influence of multiple weather systems, the complex terrain, and the sparse instrumental records. Absolutely dated tree-ring records offer the potential to extend our understanding of climate into the pre-instrumental era, but tree-ring studies in this region, and indeed all of tropical Africa, have been rare largely due to lack of an annual climate cycle that reliably produces annual tree-rings. In this study, 40 cores were obtained from 31 Juniperus procera trees growing in the grounds of Ethiopian Orthodox Tewahedo churches in the Gonder region of Ethiopia. The samples were cross-dated using a re-iterative process involving identifying anatomical features from high-resolution images. The tentative ring-width chronologies were revised after the determination of bomb-peak accelerator mass spectrometry radiocarbon dates. Individual series were significantly correlated to the respective master chronologies (r > 0.55; P

The main disadvantage of conventional zirconia is its high opacity. Depending on different conditions, especially the content of the yttrium stabilizer, it is possible to circumvent this issue, in view of this, several generations of yttrium stabilized zirconia were developed seeking to combine the robustness of zirconia with the aesthetics of porcelain veneers. The present work aimed to carry out an analysis on how the increase or decrease in the percentage of yttrium in the composition of monolithic zirconia can influence their properties, especially with regard to translucency. This study was carried out through a review in the Scielo, PubMed and Google Scholar databases with articles published between 2008 and 2021. In this way, it was concluded that the higher content of Y2O3 tended to increase the amount of isotropic cubic phase present and reduce the amount of birefringent tetragonal phase in ZrO2 together with a minimization of light scattering by secondary phases, leading to increased translucency and aging resistance. As yttrium oxide increases, zirconia grain sizes tend to increase as well, and translucency may improve with increasing grain size. Toughness and fracture toughness can be sacrificed considerably.

Background and Aim : One of the main reasons for the failure of metal-ceramic restorations is insufficient bond strength between porcelain and metal, which depends on various factors, including the manufacturing method. The purpose of this study was to evaluate the effect of manufacturing method on bond strength of porcelain to titanium substructure made by EBM or Milling method. Materials and methods: In this in-vitro study two groups comprised of twenty metal bars each were prepared with EBM or Milling method. first a resin bar was molded into standard ISO:9693 dimensions of 25 mm × 3 mm × 0.5 mm. then it scanned and Ten bars from each group were manufactured using milling device from titanium disks or from an EBM device from Ti-6Al-4Va titanium alloy. bars were sandblasted with 110 μm aluminum oxide particles and were impregnated with bonding agent before the application of 1/1 mm of porcelain onto 8 mm × 3 mm rectangular area in the center of each bar porcelain. Afterwards, bond strengths of the samples were assessed using 3-point bending test with a Universal Testing Machine. Statistical analysis was performed using T-test and a significant level of 0.05 was considered Results: The mean bond strength of EBM group (34.36±3.67MPa) was lower than Milling group (46.52±4.34 MPa) and there was statistically significant difference between groups (p-value<0.001). Conclusion: Bond strength of EBM-manufactured samples were lower than milled group while both groups exceed the minimum requirement of bond strength for metal-ceramic restoration according to ISO9693. [ABSTRACT FROM AUTHOR]

Tooth reduction guides allow clinicians to obtain the ideal space required for ceramic restorations. This case report describes a novel design (CAD) for an additive computer-aided manufactured (a-CAM) tooth reduction guide with channels that permitted access for the preparation and evaluation of the reduction with the same guide. The guide features innovative vertical and horizontal channels that permit comprehensive access for preparation and evaluation of the reduction with a periodontal probe, ensuring uniform tooth reduction and avoiding overpreparation. This approach was successfully applied to a female patient with non-carious lesions and white spot lesions, resulting in minimally invasive tooth preparations and hand-crafted laminate veneer restorations that met the patient's aesthetic demands while preserving tooth structure. Compared to traditional silicone reduction guides, this novel design offers greater flexibility, enabling clinicians to evaluate tooth reduction in all directions and providing a more comprehensive assessment. Overall, this 3D printed tooth reduction guide represents a significant advancement in dental restoration technology, offering clinicians a useful tool for achieving optimal outcomes with minimal tooth reduction. Future work is warranted to compare tooth reductions and preparation time for this guide to other 3D printed guides. [ABSTRACT FROM AUTHOR]

Dental porcelain was produced by mixing feldspar, silica, kaolin and bone ash by varying the contents of feldspar and silica. The processing steps include milling, sieving, pressing/shaping, drying, and sintering while the characterisation techniques were Hardness, Compressive strength, X-ray diffraction, Scanning electron microscopy and Fourier Transform Infrared (FTIR). The mixture was subjected to temperatures of 1100 and 1200 °C in a sintering furnace. The chemical composition was determined using X-ray fluorescence and they confirm that SiO2 and Al2O3 are the two major constituents in feldspar and kaolin while CaO is the major constituent in bone ash. For samples sintered at 1200°C, the X-ray diffraction showed that some glass phase possibly consisting of hedenbergite, ilmenite and silica were formed while crystalline phases namely microcline and sanidine were obtained for samples sintered at 1100°C. The morphology of the grains revealed that samples sintered at 1200°C had some hexagonal silica crystals while flakes f different sizes were obtained for samples sintered at 1100°C. Hardness values between 262 and 536 BHN, compressive modulus values ranging from 219 MPa to 324 MPa and linear shrinkage values between 6.34 and 7.6% were obtained. The batches of different compositions with ranges: quartz (silica) (15-25%), feldspar (70-80%), kaolin (Edda/Bauchi) (4%) and bone ash (1%) were fired at 1100, 1200°C, and the developed properties were tested. The sample with 70 wt.% of feldspar, 25 wt.% silica, 4 wt.% of Bauchi clay, and 1 wt.% bone ash sintered at 1200°C gave the best properties and has the potential to be used in dental restoration. [ABSTRACT FROM AUTHOR]

The field of dental materials has undergone more of a revolution than an evolution over the past 100 y. The development of new products, especially in the past half century, has occurred at a staggering pace, and their introduction to the market has been equally impressive. The movement has mostly come in the area of improved esthetics, marked by the gradual replacement of dental amalgam with dental composite and all-metal and porcelain-fused-to-metal indirect restorations with reinforced dental ceramics, all made possible by the rapid improvements in dental adhesive materials. This article covers the time course of dental materials development over the past century in which the Journal of Dental Research has been published. While there have been advances in nearly all materials used in the field, this article focuses on several areas, including dental amalgam, dental composites and light curing, dental adhesives and dental cements, ceramics, and new functional repair materials. A few short statements on future advances will be included at the end.

Aim: The aim of this study was to investigate the influence of the quantity and positioning of feldspathic ceramic specimens inside the furnace on their flexural strength and translucency. The tested hypotheses were that the arrangement of specimens in the furnance would not influence 1) the translucency or 2) the biaxial strength of the porcelain. Methods: Ninety porcelain specimens were made (1.2 mm thickness and 13.5 mm diameter) and assigned into two main groups (n=15): G1 group - 15 firing cycles containing only one specimen each, always at the center of the refractory; and G5 group - 15 firing cycles containing five specimen each, where one specimen was at the center of the refractory and four specimens positioned equidistantly on the periphery. The translucency test was performed using a spectrophotometer, followed by the flexural strength test, according to ISO 6872:2015. T-student test was performed for both the mechanical and optical obtained data. Results: The flexural strength of the porcelain was not affected by the positioning (center x periphery) of the specimens inside the furnace (p =0.08), but the translucency was affected (periphery > center; p =0.009). Regarding to the number of feldspathic ceramic specimens, the biaxial flexural strength was affected (p =0.025), as well as the translucency (p <0.05). Conclusion: A higher quantity of feldspathic ceramic specimens for each firing cycle decreased its biaxial flexural strength and translucency. Also, specimens positioned at the center of the refractory became less translucent than those positioned at the periphery. [ABSTRACT FROM AUTHOR]

Abstract Objective The purpose of this study is to evaluate the color changes of lithium disilicate ceramics when cemented with different brands of cement by varying the thickness of the ceramic. Materials and Methods Forty ceramic discs, shade A2, were fabricated with 0.5 and 0.8 mm thickness. Forty composite resin discs, shade A3, were also produced. The ceramic samples were cemented to the composite resin discs, with two colors of resin cement, Neutral and Warm. A spectrophotometer evaluation was made. Translucency and color change analysis was performed by calculating the ΔE. A two‐way analysis of variance test and multiple comparisons were performed using the Bonferroni method with a 95% confidence interval. Results There are statistically significant differences between the two ceramic thicknesses with different brands of cement (p

Background: This systematic review and meta-analysis aimed to evaluate the wear of the antagonist tooth in ceramic restorations. Material and methods: This study was carried out based on Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) recommendations; it was also registered in PROSPERO (register number: CRD42022316252). Three databases were consulted in the literature search, Embase, Scopus, and Web of Science. The citation searching was conducted by two researchers independently. The clinical studies that evaluated wear in antagonist teeth concerning ceramic restoration were included. Twelve articles were selected after eliminating duplicates ones and applying the inclusion criteria, and two were chosen through citation. Fourteen articles were considered for the qualitative and quantitative analysis (meta-regression and meta-analysis). Results: The mean linear wear of the antagonist tooth in relation to feldspathic was 8.914 μm, for lithium disilicate it was 0.018 μm, and for zirconia it was 0.257 μm. The mean volumetric wear of the antagonist tooth in relation to feldspathic was 0.273 mm3, for hybrid ceramic it was 0.030 mm3, for lithium disilicate it was 0.018 mm3, and for zirconia it was 0.014 mm3. The mean natural tooth wear was 0.7974 μm per month. Tooth wear caused by zirconia at six months was 31.755 μm, at 12 months it was 24.648 μm, and at 24 months it was 20.662 μm. Conclusions: Feldspathic produces greater wear of the antagonist tooth from ceramic restorations linearly and volumetrically. In addition, zirconia generates the least wear that will decrease over time, and it will be equal to or less than the natural wear in the tooth. [ABSTRACT FROM AUTHOR]

Purpose: is to investigate the longevity, survival and complications rate of laminate veneers produced from Feldspathic and Glass Ceramic. Materials and Methods: Literature search was conducted, using electronic MEDLINE database, relevant references, citations and hand search. Inclusion Criteria were human cohort studies (prospective and retrospective) reporting on survival and complications of ceramic veneers fabricated of Feldspathic and Glass ceramic with a minimum follow up of 2.5 years. The search period spanned from 01.01.2000 up to 30.11.2018. Of the 522 articles identified, 110 went throw full text screening for eligibility and 20 studies were included in our study. Survival rate were assessed. Complication rates for Laminate veneers most common complications were in subgroups calculated using forest plot. Comparison between complication of poor marginal adaptation and fracture of feldspathic and Glass Ceramic Veneers were conducted using random effect models. Results: The mean observation time of the veneers 8.2 years. Survival rate of both materials was over 90%. The most frequent complications reported were: poor marginal adaptation 4% (95% CI: 2% to 8%), fracture 4% (95% CI: 3% to 6%) and marginal discoloration 9% (95% CI: 5% to 15%). There was no statistically significant difference in the complication rates of poor marginal adaptation and fracture between the subgroups of both materials. Clinical significance: Complication rate of both Feldspathic and Glass Ceramic Veneers was similar. Survival rate was remarkably higher in glass ceramics, but was still considered to be satisfactory in both materials, which leads us to conclude that porcelain laminate veneers are reliable treatment methods. [ABSTRACT FROM AUTHOR]

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Background: For all-ceramic restorations to last a long time, the ceramic veneering and substructure need to have a strong sufficient bond. This research compared how two different surface treatments affected the tensile and shear bond strengths of zirconium-reinforced lithium silicate and porcelain (Suprinity). Materials and Methods: A total of 120 samples were divided into three groups at random: control (no surface treatment), aluminium oxide sandblasting, Erbium, Chromium-doped Yttrium, Scandium, Gallium, and Garnet (Er, Cr: YSGG) laser irradiation, and 60 samples to evaluate tensile bond strength and 60 samples to evaluate shear bond strength. By using one-way ANOVA and the post-hoc Tukey's test, the tensile and shear bond strength between Suprinity and porcelain (VITA VM 11) was analyzed in all groups. Results: The maximum and minimum tensile bond strength was seen in sandblasting group (7.86 ± 2.22 Mpa) and control group (4.88 ± 1.58 Mpa), respectively (P < 0.001). The amount of shear bond strength in the laser group, sandblast group, and control group was (5.16 ± 1.66 Mpa), (5.00 ± 1.34 Mpa), (4.39 ± 1.54 Mpa) respectively (P = 0.252). In tensile and shear bond strength tests, most failures were cohesive in VITA VM 11 layering porcelain (65.0% vs. 66.7%) followed by mixed failures (33.3% vs. 20%). Conclusion: Suprinity and layering porcelain produced higher tensile bonds as a result of Al2O3 sandblasting and Er, Cr: YSGG laser irradiation. While no pure adhesive failure was seen, cohesive failure was predominant. [ABSTRACT FROM AUTHOR]

Objective: This case report presents a novel technique for bridge restoration using polytetrafluoroethylene (PTFE) tape and split dam isolation in situations where achieving complete dental dam isolation is challenging., Clinical Considerations: Achieving high-quality isolation by controlling gingival crevicular fluid and intraoral relative humidity is important during cementation. However, an improved technique during bridge restoration is needed due to the difficulties faced with dental dam isolation. A porcelain fused to zirconia bridge extending from the maxillary canine to the first molar was used to demonstrate the novel restoration technique in this case report. Split dam isolation lowers the relative humidity in the oral cavity, and PTFE blocks the gingival crevicular fluid. The effects of combining PTFE tape with split dam isolation on isolation (controlling crevicular fluid, saliva, and relative humidity in the operative field) were similar to those obtained with dental dam isolation and made for easier removal of excess cement., Conclusions: The novel technique introduced in this case report can enhance isolation quality during bridge restoration., (©Operative Dentistry, 2024.)

Objectives: This study aimed to evaluate the impact of battery levels on the emission of a multi-peak cordless LED light-curing unit (LCU) and the effect on the degree of conversion (DC) and Knoop hardness (KH) of a light-cure resin luting agent activated through varying lithium disilicate (LiS2) ceramic thicknesses and translucencies., Methods: High and low translucency LiS2 discs (IPS e.max Press HT and LT, respectively; shade A1) with thickness of 0.5, 1.0, 1.5, and 2.0 mm were fabricated. Resin luting agent specimens (Variolink Esthetic LC) were prepared and cured using a Bluephase G2 LCU at different battery levels (100%, 50%, and 10%) through the LiS2 ceramics. The transmitted irradiance was evaluated using USB4000 MARC, while FTIR and a microhardness tester assessed DC and KH, respectively. After ensuring homoscedasticity, the data wee analyzed using analysis of variance and Tukey HSD test (α=0.05)., Results: The study found strong positive correlations between battery levels and irradiance, particularly with no ceramic interposition and through HT ceramics (R2=0.9471), although this correlation diminished with thicker HT (R2=0.7907) and LT ceramics (R2<0.2980). Both battery levels and ceramic thickness significantly influenced transmitted irradiance (p<0.0001), resulting in lower values with decreased battery levels and increased ceramic thicknesses (p<0.0001). LT ceramics showed lower transmittance than HT. DC was significantly affected by both battery levels and ceramic thicknesses, with generally lower DC values except for LT ceramics at a 10% battery level (p<0.0001). No significant differences in DC were observed between HT and LT translucencies (p=0.548). KH was higher in HT than LT ceramics at 100% and 50% battery levels, with thicker ceramics showing lower KH values at 10% battery level (p<0.0001). Conclusion: Reduced battery levels in cordless LED curing units significantly affect the irradiance, degree of conversion, and hardness of light-curable resin luting agents. Maintaining battery levels above 50% is recommended for optimal performance. Thicker and more opaque ceramics significantly impacted incident irradiance. However, preserving radiant energy could potentially mitigate these limitations., (©Operative Dentistry, 2024.)

Statement of Problem: Because the use of zirconia in dentistry is relatively new, the number of published studies on the subject is scarce, even though material selection is an important factor in clinical performance. Therefore, a systematic assessment of the impact of the prosthetic material, framework design, veneering material, and manufacturing process is required., Purpose: The purpose of this systematic review and meta-analysis was to investigate the survival and success rates of feldspathic porcelain veneered zirconia (VZir) in comparison with monolithic zirconia (MZir) complete arch implant-supported prostheses (CAISPs). A secondary objective was to assess the influence of the type of loading, the presence or absence of a cantilever, the type of zirconia used, the location, and the opposing arch on complications rates and patient satisfaction., Material and Methods: An electronic search of the MEDLINE database (via PubMed), Scopus, Science Direct, Cochrane Library, and OpenGrey was carried out. The criteria described in the preferred reporting items for systematic reviews and meta-analyses statement were used. The search was restricted from January 2000 to January 2022., Results: The systematic search resulted in 20 articles that met the established criteria. In total, 751 patients (VZir=302; MZir=449) with 3038 CAISPs (VZir=368; MZir=2670) were analyzed. Higher prosthetic survival and success rates were found in MZir compared with VZir CAISPs (100% and 95.45%, respectively). The meta-analysis found significantly fewer complications related to MZir (9.4% [4.8%-14.1%]) compared with VZir (33.7% [17.5%-49.9%])., Conclusions: Based on the findings of this systematic review, MZir CAISPs had higher survival and success rates than VZir CAISPs, with significantly fewer prosthetic complications. The influence of factors such as the type of functional loading, the presence of a cantilever, the material used in the prosthodontic workflow, the location of the CAISP, and the type of antagonist arch on the performance of Zir CAISPs remains unclear., (Copyright © 2024 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

The main goal of the modern dentist should be to address the urgent need to promote treatments focused on conservative dentistry, together with maintaining the health of the periodontium. Instead, iatrogenesis that results in the invasion of the biologic space is a significant and increasing problem in dentistry. The present case report illustrates a 5-year computed tomography follow-up of a successful minimally invasive rehabilitation involving ceramic veneers. The study highlights the importance of pretreatment planning as well as a step-by-step clinical execution to achieve long-term health, function, and esthetics, respecting both restorative and periodontal principles.

This case report presents the conservative management of a malposed implant in the maxillary anterior region caused by craniofacial bone remodeling. The patient expressed dissatisfaction with the position and shade of an implant that was placed almost three decades previously. After evaluating different treatment options, the patient opted to replace the implant prosthesis. The selected treatment consisted of a zirconia crown layered with feldspathic porcelain (including pink porcelain) cemented onto a screw-retained customized zirconia abutment with an angled screw channel for the single-unit permanent fixed implant prosthesis. The report highlights the importance of informed decision making and patient preferences in treatment option selection. It emphasizes the conservative approach of replacing a malposed implant prosthesis with pink porcelain to address the patient's esthetic concerns. Dental photographs and shade-matching protocols were crucial in achieving satisfactory esthetic outcomes. The report also underscores the potential for infraocclusion as well as proclination caused by craniofacial growth in implant therapy, and emphasizes the significance of patient education regarding long-term considerations.

Purpose: This in vitro study investigated the influence of material selection, crown morphology, and vertical crown height on the biomechanical behavior of screw-retained monolithic hybrid abutment crowns (HACs)., Methods: Ninety implants were embedded in accordance with ISO standard 14801; ninety HACs were mounted (N=90). Monolithic crowns with varying group-specific designs were luted using titanium bases. HACs were fabricated from monolithic lithium disilicate ceramic (LD) or zirconia-reinforced lithium silicate ceramic (ZLS). The crown morphology was either maxillary premolar (LD&#95;PM, ZLS&#95;PM) or molar (LD&#95;MO). The three groups were further divided into three subgroups of ten specimens, each designed with a small (7.5 mm), middle (10.5 mm), and high (13.5 mm) configuration of crown heights (N=10). A load-to-failure test at 30° off-axis was conducted using a universal testing machine until failure. For statistical analysis, Kolmogorov-Smirnov and Mann-Whitney U tests were conducted (P < 0.05)., Results: All LD&#95;MO groups presented the highest failure values (808.7 to 947.9 N), followed by the LD&#95;PM (525.8 to 722.8 N) and ZLS&#95;PM groups (312.6 to 478.8N). A comparison between LD and ZLS materials (P < 0.001) as well as the crown morphology (P < 0.001) showed significant differences in failure values. The values in the subgroups of ZLS&#95;PM (low, middle, high) decreased as the crown height increased. The fracture modes showed no consistent patterns across the test groups., Conclusions: Material selection, crown morphology, and vertical crown height appear to be important factors that may influence the clinical failure values and patterns of screw-retained single implant crowns.

Aim: The objective of the present study was to investigate the effect of using different materials for the fabrication of implant abutments and crowns on the mechanical behavior of implant-supported single crowns after artificial aging. The materials were tested in different combinations to reveal whether using stiff or resilient materials as an abutment or a crown material might influence the fracture strength of the whole structure., Materials and Methods: A total of 40 implants (blueSKY) were restored with identical custom-made CAD/CAM abutments milled out of lithium disilicate or ceramic-reinforced polyetheretherketone (PEEK) and divided into five test groups (n &#61; 8). Forty crowns made of three different materials (zirconia, lithium disilicate, and ceramic-reinforced PEEK) were used to restore the abutments. Specimens were subjected to mechanical loading up to 1,200,000 cycles in a chewing simulator (Kausimulator) with additional thermal cycling. The surviving specimens were subjected to quasi-static loading using a universal testing machine (Z010)., Results: The PEEK abutments with zirconia crowns showed the highest median failure load (3890.5 N) while the PEEK abutments with lithium disilicate crowns exhibited the lowest (1920 N). Fracture and deformation occurred in both the crowns and abutments., Conclusion: The failure load of the restorations was influenced by the material of the abutment and crown. Restoring PEEK abutments with zirconia crowns showed a high failure load and no screw loosening.

In fixed prosthodontics, clear exposure of the preparation margin is the prerequisite for obtaining accurate digital impressions and improving the marginal fit of restorations. To resolve the issues associated with the cord retraction technique, such as pain, acute injury, and prolonged procedural time, this study proposes a new technology for intraoral digital impression taking with pneumatic gingival retraction. The new scanning head blows a high-speed airflow that instantaneously separates the free gingiva, locally exposing the subgingival preparation margin. Combined with the farthest point preservation stitching algorithm based on the distance from the normal vector and high-speed laser scanning photography, it achieves global preparation edge data and gingival reconstruction, realizing painless, non-invasive, and efficient precise acquisition of the preparation margin. Using this new technique, a patient with a full porcelain crown restoration on a posterior tooth was treated. The digital impression revealed a clear margin of the preparation, and the crown made from this data has a good marginal fit.

Background: This study evaluates the fracture strength and patterns of feldspathic porcelain restorations made using CAD/CAM technology for lower first molars with extensive crown destruction. The restorations include post-core and full-contour crown, composite resin core and full-contour crown, and endocrown. This research provides insights into effective restorative options to address tooth fracture risk, supporting minimally invasive procedures and CAD/CAM integration in dental practices., Methods: This study utilized 80 permanent mandibular first molars, which were divided into four groups: Group I (Post-Core-Full-contour crown), Group II (Core- Full-contour crown), Group III (Endocrown), and Group IV (Control). Root canal treatment was performed on all samples except for the control group. Following access cavity preparation, restorations for each tooth were fabricated using the CAD/CAM system and cemented with resin cement. The specimens were embedded in acrylic blocks. After undergoing thermomechanical aging, the samples were subjected to fracture resistance testing using a universal testing machine, which applied force until fracture occurred. The fracture patterns were subsequently analyzed, and the data were statistically evaluated using the Kruskal-Wallis and Chi-Square tests (p < 0.05)., Results: A significant difference in fracture values under axial forces was observed (p < 0.05). The control group had the highest fracture strength (1830 ± 277 N), while the Core- full-contour crown group showed the lowest (1532 ± 371 N). Failure types varied significantly among the groups (χ2 = 26.886, df = 9, p = 0.001). The most common failure type was Type-2 (33.75%), characterized by restorable fractures, while Type-3 fractures, unrestorable, were the least common (12.5%)., Conclusions: The findings underscore the significance of technological advancements in CAD/CAM for effectively restoring endodontically treated teeth with extensive crown damage. This study contributes valuable insights, emphasizing the clinical relevance of selecting appropriate restorative options to mitigate the risk of tooth fracture associated with coronal restoration failures., (© 2024. The Author(s).)

Objectives To review the current literature surrounding chairside polishing systems for resin composites, zirconia and lithium disilicate restorations.Methods A literature search was undertaken and databases were hand-searched for the most relevant articles.Discussion The current marketplace contains a wide variety of polishing systems, each with different abrasive compounds and number of steps. Current efforts are aimed at reducing the number of steps required for polishing to improve clinical effectiveness. Reduced step systems showed some comparable results to the more traditional multi-step protocols, but the most effective results were achieved with the use of polishing paste as an additional step.Conclusions Based on the current available literature, the use of material-specific polishing systems is effective for chairside polishing of direct and indirect restorative materials. However, it is important to emphasise that, for optimum outcomes, it is essential to follow manufacturers' recommendations for each step, with particular considerations of the handpiece speed, time spent per step and use of adjunct water coolant., (© 2024. The Author(s).)

Objective: Dental implants placed in adolescent patients pose a challenge to restore and maintain an esthetic outcome over longer period of follow-up. Maxillomandibular changes throughout adulthood may lead to complications such as implant infraocclusion and interproximal contact loss. This case report describes an alternate prosthetic treatment strategy for maxillary single implant placed in an adolescent patient in the esthetic zone with inappropriate implant axis and screw hole placement., Clinical Considerations: With temporary restorations, the gingiva and soft tissues were shaped to imitate the emerging profile of the contralateral side. A zirconia screw-retained abutment was customized as a copy-mirror from the contralateral prepared tooth to mimic the exact shape and to avoid labiolingual over contour by computer-aided design/computer-assisted manufacture (CAD/CAM). The porcelain laminate veneer was bonded to the zirconia abutment. Porcelain adhesive approach was used instead of traditional principles of retention and resistance form of the abutment., Conclusions: A functional and esthetic outcome was achieved and maintained, while a minimally invasive procedure was implemented to use the malplaced implant instead of explanting it., Clinical Significance: The present report illustrates the prosthetic management of a malpositioned dental implant placed 20 years ago, utilizing a minimally invasive digital protocol., (© 2024 Wiley Periodicals LLC.)

Statement of Problem: Completely veneered zirconia ceramic (ZC) fixed partial dentures (FPDs) have been reported to have a higher incidence of ceramic chipping than the standard metal-ceramic FPDs. However, data from comparative long-term studies are sparse., Purpose: The purpose of this retrospective study was to compare the long-term survival, chipping-free survival, and success of ceramic-veneered high noble metal alloy (HN), base metal alloy (cobalt-chromium alloy) (CC), and ZC FPDs and to isolate risk factors for the incidence of failure, veneer chipping, and overall complications., Material and Methods: Data from 289 study participants (58.7% women; mean age, 57.97 ±11.51 years) provided with a total of 400 FPDs comprising 197 (49.3%) HN FPDs, 121 (30.3%) CC FPDs, and 82 (20.5%) ZC FPDs fabricated from presintered 3 mol% yttria-stabilized zirconia (mean time of service, 6.85 ±3.25 years) were evaluated. Of these, 278 (69.5%) FPDs were provided by dentists and 122 (30.5%) by dental students. Five- and 10-year survival, chipping-free survival, and success rates were calculated using the Kaplan-Meier method and compared with the log-rank test. Risk factors were assessed using Cox regression analysis. The study was exploratory, so all P values were considered exploratory and descriptive., Results: The 5- and 10-year survival rates were 94.7% and 77.8% for HN, 93.7% and 81.2% for CC, and 92.9% and 53.3% for ZC FPDs, respectively, indicating no clear difference in survival among the framework materials. The 5- and 10-year chipping-free rates were 94.1% and 82.8% for HN, 96.1% and 78.9% for CC, and 82.6% and 62.2% for ZC FPDs, respectively, indicating a difference between HN and ZC, and CC and ZC restorations. The 5- and 10-year success rates were 83.7% and 55.3% for HN, 86.5% and 51.4% for CC, and 68.9% and 30.2% for ZC FPDs, respectively, indicating a difference between HN and ZC, and CC and ZC restorations. The Cox regression model indicated framework material as an influencing risk factor for success, and this influence persisted when chipping was investigated. Compared with zirconia, the use of a metal alloy reduced the risk of chipping or the occurrence of complications by up to one-third., Conclusions: All FPDs showed high 5-year survival rates and acceptable 10-year survival rates with no strong differences among the materials. Higher success and chipping-free rates were observed for both HN and CC restorations compared with ZC restorations. Metal frameworks had a lower risk for complications or veneer chipping than zirconia frameworks., (Copyright © 2022 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Background: Amelogenesis imperfecta (AI) is a group of genetic disorders characterized by tooth discoloration and enamel defects. Patients with AI always exhibit generalized attrition and defective tooth structure, leading to the loss of occlusal vertical dimension (OVD). Appropriate rehabilitation is challenging and essential to improve patients' aesthetics and function., Case Presentation: This case report presents a comprehensive management of a 30-year-old woman with hypoplastic AI. A 52-month follow-up revealed satisfactory full-mouth rehabilitation performances of lithium disilicate ceramic crowns after clinical crown lengthening, with increased vertical dimension., Conclusions: Patients with severe hypoplastic AI require proper full-mouth rehabilitation. Using full-crown lithium disilicate restorations to increase the OVD by 2‒4 mm is a safe and predictable recommendation for such cases. In addition, patients with AI require complex and comprehensive management. The long-term effects of full-mouth rehabilitation with lithium disilicate ceramic crowns still necessitate further follow-ups., (© 2024. The Author(s).)