Long-Term Bonding Efficacy of CAD/CAM Hybrid Restorative Materials and Universal Adhesives.

OBJECTIVES: In-office and lab milled prostheses are the staple for indirect restorations. It is therefore critical to determine their long-term bonding durability. METHODS: CAD/ CAM blocks of two classes of restorative materials: 1) a nano-ceramic reinforced polymer matrix (NCPM) and, 2) a polymer-infiltrated ceramic network (PICN) were bonded using four different universal adhesives (UA) and silane systems. A lithium disilicate glassceramic (LDS) was used as a reference. The blocks were bisected and bonded with different UA/resin-cement pairs. Bonded blocks were then cut into 1.0x1.0x12.0 mm bar specimens for microtensile bond testing. Half the bars were subjected to bond strength testing immediately and the other half after aging by 50,000 thermal cycles between 5°C and 55°C. ANOVA and post-hoc tests were used to compare mean bond strength among groups. RESULTS: NCPM presented consistently high bond strength regardless of bonding techniques, while the bond strength of PICN and LDS were lower when bonded with UA relative to traditional silanes. The more hydrophilic UA produced higher bond strengths. DISCUSSION: Glass-ceramics exhibited lower bond strength with UA than the conventional etch-rinse-silane techniques. However, UAs preserved bonding interface in the long-term. SIGNIFICANCE: NCPM displayed superior bond strength relative to PICN and LDS regardless of the type of adhesives and bonding techniques.

Effect of Particle Size and Application Pressure in Air-Borne Particle Abrasion on the Adhesion of Polyetheretherketone.

INTRODUCTION: This study aims to investigate the effect of different particle sizes and pressures on the shear bond strength (SBS) and the roughness (Ra) of polyetheretherketone. MATERIALS AND METHODS: A total of 117 polyetheretherketone specimens were fabricated and divided into a control (CN: no air-particle abrasion) and eight pre-treatment groups (air-abraded with 50- or 110-µm Al2O3 particles at 1(A), 1.5(B), 2(C), and 2.5(D) bar). The adhesive, Visio.link was used. Thermal aging was performed. Surface properties, SBS and failure mode were assessed. Data was analyzed by linear regression, Pearson correlation and Dunnett's T3 test for pairwise comparisons (p⟨0.05). RESULTS: The highest and lowest Ra were found in the 110D and CN groups respectively, and the highest SBS results were obtained from the 50B group. Pressure and particle size showed significant difference on the investigated properties (p⟨0.001). Only adhesive failure was observed in the CN, and resin cohesive failure was observed in addition to adhesive failure in the overall study groups. CONCLUSION: The air-borne particle abrasion procedures and the adhesive material combination are critical to the strength of the polyetheretherketone bond. The combination of visio.link with the pre-treatment option of 50-µm Al2O3 particles applied at 1.5-bar pressure delivered the most favorable results.

Clinical Performance of Minimally Invasive Monolithic Ultratranslucent Zirconia Veneers: A Case Series up to Five Years of Follow-up.

There is a lack of reports in the literature on the long-term clinical performance of ultratranslucent zirconia, especially considering its use in manufacturing monolithic veneers. The purpose of this case series is to describe the aesthetic treatment steps of three patients with minimally invasive ultratranslucent zirconia veneers and to report the clinical findings up to five years. Three patients (woman: 2, man: 1; mean age: 30 years) unsatisfied with their dental aesthetics sought dental treatment. The treatment plan involved cementing ultratranslucent zirconia veneers. Air-abrasion was performed on the internal surface of zirconia with alumina particles coated by silica (silicatization), followed by silane and adhesive applications for the adhesive cementation. All veneers were adhesively cemented to enamel with resin cement (Variolink Esthetic, Ivoclar). The patients were clinically evaluated annually considering the Ryge modified/ California Dental Association criteria. After a mean follow-up of 4.33 years (4-5 years), a survival rate of 100% was detected for the 28 minimally invasive ultratranslucent zirconia veneers cemented in the 3 patients. There were no absolute failures such as debonding, veneer fracture, or secondary caries. Superficial marginal discoloration was observed in one element (maxillary left lateral incisor) of one patient. Ultratranslucent zirconia is a viable option for manufacturing veneers due to its excellent clinical performance and longevity. However, further long-term clinical studies are essential to consolidate this material as an option for esthetic restorations.

Patient Satisfaction and Accuracy of Partial Denture Frameworks Fabricated using Conventional and Digital Techniques.

This case report compares a conventional and a digital workflow for manufacturing metal frameworks for maxillary and mandibular removable partial dentures (RPDs). Two sets of maxillary and mandible RPDs were produced. The metal framework of one set of RPDs was produced conventionally using the lost wax casting technique. Intraoralscanning and computer-aided designing (CAD) were used to fabricate the metal frameworks of the other set of RPDs using direct metal laser sintering (DMLS) technology. The accuracy of fit of the two sets of RPDs was evaluated after 3 months using replica models. Patient satisfaction was assessed. Two years later, the fit accuracy of the DMLS prosthesis and patient satisfaction were re-evaluated. The accuracy of fit in the maxillary RPD with the DLMS manufactured metal framework showed better results in all areas except areas of rests (457 vs. 421 µm) and the major connector (850 vs. 512 µm). The mandibular RPD with DLMS manufactured metal framework showed only in the areas of the reciprocal arm and major connector better fit accuracy compared to the conventional RPD. The patient satisfaction with the DLMS manufactured RPDs was rated equally to the conventional one. The use of digital technologies in manufacturing RPDs seems promising regarding accuracy and patient satisfaction.

EPA Consensus Project Paper: Anterior Full or Partial Coverage Single Tooth Restorations - A Systematic Review of Survival and Complication Rates.

INTRODUCTION: The aim of this systematic review was to assess the literature reporting on the failure rates, survival rates and complication rates and patient reported outcome measures (PROMs) of anterior full (FC) or partial (PC) coverage single tooth restorations after a mean observation period of at least 3 years. METHODS: Systematic search was conducted using the electronic databases: MEDLINE, EMBASE and Cochrane library. Data regarding survival (restoration failure) and complication rates and PROMs were extracted and presented descriptively. RESULTS: Altogether 42 studies were included in the analysis (28 with FC, 12 with PC and 2 with both types of restorations). For FC restorations the estimated annual failure rate was 0.72 (95%CI: 0.33-1.57), resulting in a 5-year survival rate of 96.4% (95%CI: 92.4-98.3). For PC restorations, the estimated annual failure rate was 0.62 (95%CI: 0.27-1.46), resulting in a 5-year survival rate of 96.9% (95%CI: 93.0-98.7). There was no significant difference between the groups regarding survival or technical complications, while significantly fewer biological complications were observed with PC compared to FC restorations (test for subgroup differences, p=0.01). CONCLUSIONS: FC and PC restorations showed high 5-year survival rates but the teeth restored with FC restorations may be more prone to biological complications.

Evaluation of oxidative stress cycle in healthy and inflamed dental pulp tissue: a laboratory investigation.

OBJECTIVES: The purpose of this study was to investigate the oxidative stress cycle consisting of reactive oxygen molecules (ROS), glutathione (GSH) and glutathione S-transferase (GST) in caries-related pulp inflammation. METHODOLOGY: Fifty-four pulp tissue samples were collected from healthy donors with the diagnosis of reversible pulpitis, symptomatic irreversible pulpitis, and healthy pulp. Twelve pulp samples from each group were homogenized and total protein, ROS, GSH, and GST were measured by spectrophotometer. The remaining 6 samples from each group were prepared for paraffin block and used for the histopathologic and immunohistochemical evaluation of oxidative stress parameters and TUNEL labeling. Data were analyzed statistically. RESULTS: The results revealed that total protein levels significantly decreased; however, ROS levels increased in both reversible and irreversible pulpitis compared to the healthy pulp (p < 0.01). Also, as inflammation increases, GST enzyme levels decrease while GSH levels increase significantly (p < 0.05). It was found that the number of TUNEL (+) cells was increased in irreversible pulpitis samples compared to healthy and reversible pulpitis groups (p < 0.05). GSTP1 and GSH immunoreactivity were also observed in irreversible pulpitis samples. CONCLUSIONS: It has been revealed that caries-related inflammation alters the oxidative stress cycle in dental pulp tissue. The increase in GSH levels in the inflamed dental pulp due to the increase in ROS levels may improve the defensive ability of the dental pulp. CLINICAL RELEVANCE: There is a relationship between oxidative stress and inflammation. Control of excessive oxidative stress in pulpitis can stimulate reparative and regenerative processes. The present findings may provide an overview of the management of oxidative stress in cases with pulpitis during regenerative treatments.

Clinical longevity of intracoronal restorations made of gold, lithium disilicate, leucite, and indirect resin composite: a systematic review and meta-analysis.

OBJECTIVES: The aim of this systematic review and meta-analysis is to assess the comparative clinical success and survival of intracoronal indirect restorations using gold, lithium disilicate, leucite, and indirect composite materials. MATERIAL AND METHODS: This systematic review and meta-analysis were conducted following the Cochrane Handbook for Systematic Reviews of Interventions and PRISMA guidelines. The protocol for this study was registered in PROSPERO (registration number: CRD42021233185). A comprehensive literature search was conducted across various databases and sources, including PubMed/Medline, Embase, Cochrane Library, Web of Science, ClinicalTrials.gov, and gray literature. A total of 7826 articles were screened on title and abstract. Articles were not excluded based on the vitality of teeth, the language of the study, or the observation period. The risk difference was utilized for the analyses, and a random-effects model was applied. All analyses were conducted with a 95% confidence interval (95% CI). The calculated risk differences were derived from the combined data on restoration survival and failures obtained from each individual article. The presence of heterogeneity was assessed using the I2 statistic, and if present, the heterogeneity of the data in the articles was evaluated using the non-parametric chi-squared statistic (p < 0.05). RESULTS: A total of 12 eligible studies were selected, which included 946 restorations evaluated over a minimum observation period of 1 year and a maximum observation period of 7 years. Results of the meta-analysis indicated that intracoronal indirect resin composite restorations have an 18% higher rate of failure when compared to intracoronal gold restorations over 5-7 years of clinical service (risk difference = - 0.18 [95% CI: - 0.27, - 0.09]; p = .0002; I2 = 0%). The meta-analysis examining the disparity in survival rates between intracoronal gold and leucite restorations could not be carried out due to methodological differences in the studies. CONCLUSIONS: According to the currently available evidence, medium-quality data indicates that lithium disilicate and indirect composite materials demonstrate comparable survival rates in short-term follow-up. Furthermore, intracoronal gold restorations showed significantly higher survival rates, making them a preferred option over intracoronal indirect resin-composite restorations. Besides that, the analysis revealed no statistically significant difference in survival rates between leucite and indirect composite restorations. The short observation period, limited number of eligible articles, and low sample size of the included studies were significant limitations. CLINICAL SIGNIFICANCE: Bearing in mind the limitations of the reviewed literature, this systematic review and meta-analysis help clinicians make evidence-based decisions on how to restore biomechanically compromised posterior teeth.

Comparative Evaluation of Apically Extruded Debris During Root Canal Preparation Using Three Different File Systems Applied Under 2.5% Sodium Hypochlorite or 2% CHX Irrigation.

The chemomechanical cleaning of the root canal system is performed using manual and rotary files. This study aimed to compare the effect of ProTaper, Reciproc and HyFlex rotary files considering 2.5% sodium hypochlorite and 2% chlorhexidine (CHX) as irrigating solutions on apical extrusion of intracanal debris. Single-canal mandibular premolars (N=165) were evaluated. The teeth were divided into 6 experimental groups (N=25) for root canal instrumentation using 3 file systems, (Reciproc, HyFlex and ProTaper) and two irrigation solutions, namely 2.5% sodium hypochlorite or 2% CHX. Fifteen teeth were also assigned into three control groups (n=5) with saline as irrigation solution. Eppendorf tubes were weighed and the teeth were placed inside. The canals were instrumented and the tubes weighed to determine the dry weight of extruded debris. Data were analyzed using one-way ANOVA and Bonferroni test (α=0.05). The mean amount of extruded debris using the sodium hypochlorite solution was significantly higher than other irrigating solutions (p⟨0.001). The mean amount of extruded debris using the Reciproc file system was significantly higher compared to ProTaper and HyFlex (p⟨0.001). The use of the sodium hypochlorite solution, single-file systems and reciprocal movement are associated with higher debris extrusion and might be associated with higher risk of postoperative pain.

Evaluation of Clinical Periodontal Parameters of Abutment Teeth Supporting Distal-Extension Base Removable Partial Dentures: A Cross-sectional Study.

To assess the clinical periodontal status of abutment teeth in regards of different design components of distal-extension removable partial dentures. Subjects (N=100) with acrylic or cobalt-chromium distal-extension removable partial dentures were enrolled and their periodontal parameters plaque and gingival indices [PI, GI], probing depths [PD], clinical attachment loss [CAL] and a mobility index [MI] evaluated. Denture base type, major connector, occlusal rests position, design of direct retainers, retention, stability and denture wearing habits were further evaluated. Acrylic RPDs were associated with higher mean±SE PI [1.70±0.74], GI [1.76±0.55], PD scores [2.47±1.02 mm] and CAL values [4.46±2.11 mm] compared to CO-CR RPDs [p⟨0.05]. For abutments, the PI [1.6±0.83], GI [1.72±0.57], PD [2.32±1.03] and CAL [4.26±2.08] were higher than their non-abutments counterparts [p⟨0.05]. CAL scores were found to be significantly higher for mandibular abutments compared to maxillary ones [P=0.002]. The highest PI [1.83±1.10] and GI [2.00±0.00] scores were associated with lingual bars and horse-shoe connectors, respectively. Full palatal coverage and lingual plates were associated with the highest PD [2.80±0.48] and CAL [4.70±0.37] scores. Acrylic RPDs, type of major connector, wrought wire clasps and distal occlusal rests may be considered as risk factors for periodontal disease progression in distal-extension removable partial denture wearers.

Effect of Thickness and Translucency on Color Change and Masking Ability of Ceramic Materials used for Laminate Veneers.

This study evaluated the effect of the thickness and translucency of lithium disilicatebased glass ceramics on resin composite substrates on color change and masking effect. Laminate veneers were fabricated using IPS e.max CAD (A1) blocks with two different light transmittance values (High translucent [HT], Low translucent [LT]). Slices of two different thicknesses (0.3 mm, 0.5 mm) were obtained (n=10) and laminate veneers were cemented on the resin composite substrates of two different shades (A2, A3.5). The color change (ΔE values) was evaluated with the CIELab color system using a spectrophotometer, while the masking effect was calculated. The data were analyzed using independent-samples t-test and two-way analysis of variance. The ceramic thickness and translucency had a significant effect on final color and masking. When HT was used, and the laminate veneer thickness decreased (0.3 mm), the masking effect in ΔE values were lower (p⟨0.05). The ΔE values (⟩3.7) were clinically unacceptable. With the increase in thickness, translucency of porcelain laminate veneers decreases showing better color masking ability. Veneer thickness seems to be more effective on the restoration's masking ability than the shade of the substrate and translucency. Cinically, in case a 0.5-mm or thinner laminate veneer is planned, tooth color, resin cement and ceramic type should be considered.

Clinical survival and performance of premolars restored with direct or indirect cusp-replacing resin composite restorations with a mean follow-up of 14 years.

OBJECTIVES: The objective is to evaluate the long-term clinical survival and performance of direct and indirect resin composite restorations replacing cusps in vital upper premolars. METHODS: Between 2001 and 2007, 176 upper premolars in 157 patients were restored with 92 direct and 84 indirect resin composite restorations as part of an RCT. Inclusion criteria were fracture of the buccal or palatal cusp of vital upper premolars along with a class II cavity or restoration in the same tooth. RESULTS: Forty patients having 23 direct and 22 indirect composite restorations respectively, were lost to follow-up (25.6%). The cumulative Kaplan-Meier survival rates were 63.6% (mean observation time: 15.3 years, SE 5.6%) with an AFR of 2.4% for direct restorations and 54.5% (mean observation time: 13.9 years, SE: 6.4%) with an AFR of 3.3% for indirect restorations. The Cox regression analysis revealed a statistically significant influence of the patient's age at placement on the survival of the restoration (HR 1.036, p = 0.024), the variables gender, type of upper premolar, type of restoration, and which cusp involved in the restoration had no statistically significant influence. Direct composite restorations failed predominantly due to tooth fracture, indirect restorations primarily by adhesive failure (p < 0.05). SIGNIFICANCE: There was no statistically significant difference in survival rates between direct and indirect composite cusp-replacing restorations. Both direct and indirect resin composite cusp-replacing restorations are suitable options to restore compromised premolars. The longer treatment time and higher costs for the indirect restoration argue in favor of the direct technique.

Evaluation of New Alkasite Based Restorative Material for Restoring Non- Carious Cervical Lesions- Randomized Controlled Clinical Trial.

Two different restoration materials, an alkasite-based resin composite and a resinmodified glass ionomer cement were used to assess restoration of non-carious cervical dental lesions. This split mouth randomized controlled trial included 40 patients. After randomization both sides of the dental arch were restored with either an alkasite-based (Cention N, Ivoclar Vivadent) or a resin-modified glass ionomer cement (Voco GmbH) restoration. The placed fillings were evaluated by blinded additional operators 1, 6 months and 1 year after to the USPHS criteria (retention, marginal integrity and discoloration, anatomical form and secondary caries). Data were analyzed using Kendall's Coefficient of Concordance test and Chi-square tests using SPSS software (SPSS Inc., Version 20) (P=0.05). As for retention and anatomic form both materials performed similar after one month. However, the retention and anatomic form for alkasite based restorative Cention showed significantly better results after 6 months (p=0.013/p=0.003) and one year (p=0.026/p=0.008). The resin modified glass ionomer restoration showed higher discoloration after 6 months (p=0.025) and one year (p=0.018), while Cention performed better regarding marginal integrity at all time intervals. No secondary caries occurred. Alkasite based restorative materials displayed superior technical, mechanical and aesthetical performance in a follow-up period of one year and can therefore be recommended as an alternative to resin-modified glass ionomer cements.

Immediate and Late Repair of Microhybrid Resin Composites: Effect of Silane Coupling Agent, Universal Adhesives and Photo Polymerization.

This study investigated the effect of silane coupling agent and universal adhesive application on repair bond strength of resin-based composite after bur grinding. Microhybrid resin composite (Charisma Smart) blocks (N=80; 8x8x4 mm3) were prepared, aged (37°C; 1 month), roughened, etched and randomly divided into two groups. Silane was applied to half of the groups (Porcelain Primer, Bisco), before one of the following universal primers/adhesives was applied: a) Scotchbond Universal (3M), b) All-Bond Universal (Bisco), c) G-Premio Bond (GC), and d) Clearfil SE Bond (Kuraray). In each adhesive group half of the group was photo-polymerized. The blocks were repaired with the same size resin composite and segmented into beams. Half of the beams were subjected to micro-tensile bond test (1 mm/min), while the other half was aged (37°C; 6 months) prior to testing. Failure modes were analyzed using Scanning Electron Microscopy (SEM). Data were analyzed using repeated measures of ANOVA, Tukey's post-hoc, and paired t-tests (alpha=0.05). The silane application did not affect the repair bond strength regardless of photo-polymerization of the adhesive resin. The repair bond strength decreased significantly after 6 months when adhesive resin was not photopolymerized (p⟨0.05). Photo-polymerizing universal adhesives might ensure higher repair bond strength and its maintenance after aging.

Clinical Evaluation of Low-shrinkage Bioactive Material Giomer Versus Nanohybrid Resin Composite Restorations: A Two-year Prospective Controlled Clinical Trial.

This study evaluated the clinical performance of low-shrinkage bioactive resin composite compared with a conventional nanohybrid resin composite. A total of 35 patients (18 males, 17 females; mean age: 29±9 years old) received, randomly, 35 pairs of fillings restored with either low-shrinkage bioactive material employing Giomer filler technology (Beautifil II LS, Shofu Inc, Kyoto, Japan) or conventional nanohybrid resin composite (Clearfil Majesty Posterior, Kuraray, Japan) in Class I and Class II cavities. Two operators made all the restorations using the corresponding adhesive resins: FL-Bond II (Shofu Inc) and Clearfil SE Bond (Kuraray), according to each manufacturer's instructions. Two calibrated operators evaluated the restorations two weeks after placement (baseline), at six months, and at one and two years using FDI criteria (Scores 1-5). Data were analyzed using the McNemar test (α=0.05). Mean observation time was 27.4 ± 4.1 months (min=20.8; max=33.7). In both groups, according to FDI criteria, the restorations were mostly rated with best scores (Score 1 or 2) for biological, functional, and optical parameters. For one filling in the group restored with nanohybrid resin composite, a small and localized secondary caries lesion was observed and monitored at the one- and two-year follow-ups. One restoration in the low-shrinkage Giomer restorative group was accepted as a failure due to retention loss. Over the two-year follow-up, both the Giomer and the nanohybrid resin composite restorations' performance was clinically acceptable.

Longevity of Direct Resin Composite Restorations in Maxillary Anterior Crown Fractures: A 4-year Clinical Evaluation.

OBJECTIVES: To investigate the longevity of direct composites for Class IV restorations and the possible reasons of failure. METHODS AND MATERIALS: The longevity of 168 Class IV restorations in 50 adult patients was evaluated, in terms of modified United States Public Health Service criteria, for 4 years. Restorations were performed using a monochromatic layered microhybrid, resin-based composite (RBC) (Essentia, Universal Shade, GC Corporation, Japan; n=76) and polychromatic layered micro/nanohybrid (MD and LE shades, Essentia, GC Corporation, Japan; n=92) RBCs, by a single operator. RESULTS: The majority of the teeth (n=156) remained acceptable at the end of 4 years, and the overall survival (OS) rate was considered as 92.86%. Survival rates for the monochromatic layering technique (MLT) and polychromatic layering technique (PLT) were 90.8% and 94.6%, respectively. Mean survival was 46 months for MLT and 47 months for PLT, indicating no significant difference (p=0.343). Fracture of the restoration was the most common reason for failure (4.2% out of 7.1% of general failures) for both the layering techniques. CONCLUSIONS: Under the conditions of this mid-term clinical study, MLT and PLT as well as microhybrid and nanohybrid resin composite materials, showed similar clinical durability. In terms of simplicity, monochromatic layering can be preferred for Class IV restorations, when the right indication criteria are met.

Implant-Supported Extra-Orally Cemented Monolithic Zirconia Crowns: A Prospective Controlled Clinical Study up to 18 Months in Function.

This study evaluated the clinical performance of implant supported, extra-orally cemented, monolithic zirconia crowns after a follow-up to 18 months. Thirty-one patients with 50 posterior dental implants were consecutively selected for this study. A total of 50 crowns were cemented onto titanium abutments extra-orally and then screwed to the implants with the required torque intra-orally. The patients were followed at 12 months and 18 months after placement of restorations. During the follow-up period, all restorations were evaluated according to following technical parameters: implant failure, crown fracture, screw loosening, loss of retention due to decementation, fracture of antagonist tooth or restoration. Data were analyzed using Kaplan Meier method. One implant and its corresponding crown was lost during the follow-up period, yielding a 18 months survival rate of 98%. During the study, 2 complication events were observed, including one screw loosening and one veneering porcelain chipping in an antagonist bilayered zirconia restoration. The overall success rate of the observed prosthesis was 96%. According to the results of this study, the extra-orally cemented, monolithic zirconia crowns resulted in a favorable short-term outcome for posterior implant supported restorations within this short observation time.

Clinical Performance of Complete-Arch Implant- Supported Rehabilitations Using Monolithic Lithium Disilicate Restorations Bonded to CAD/CAM Titanium and Zirconia Frameworks up to 5 Years.

This clinical study evaluated the survival of monolithic lithium disilicate (ML) (IPS Emax, Ivoclar Vivadent) restorations bonded to complete-arch CAD/CAM made titanium or zirconia frameworks. Between August 2007 and December 2009, 15 patients (7 female, 8 male; mean age: 56.8 years old) received 30 implant-supported screw-retained rehabilitations with ML restorations cemented to CAD/CAM made titanium (T) (n=6) or zirconia (Z) frameworks (n=24) adhesively (Multilink Automix, RelyX Unicem) and followed up until December 2015. The evaluation protocol involved technical failures (chipping, debonding or fracture of crown/framework, screw loosening), Californian Dental Association (CDA) quality criteria (Romeo: Excellent; Sierra: Acceptable; Tango: Retrievable; Victor: Not acceptable) and biological failures (mucositis, peri-implantitis). Mean observation time was 60.3 months. No implants were lost, and all the prostheses were in situ. Four mechanical failures occurred in the form of minor chipping (n=3 in ML-Z, n=1 in ML-T) and major fracture in ML crown (n=1 in ML-Z). Romeo scores (N=370) decreased until final observation (N=347) and 23 Sierra scores were given to the restorations. Mucositis was observed in 3 patients and peri-implantitis in one patient. Complete-arch implant-borne FDPs made of monolithic lithium disilicate bonded to titanium or zirconia frameworks could be a promising alternative.

Water as Veneering Modeling Liquid Affects Microhardness of Glassy Matrix Veneering Ceramic.

PURPOSE/AIM: To evaluate the effect of different veneering liquids used for modeling on microhardness, fracture toughness and biaxial flexural strength of a glass-veneering ceramic. MATERIAL AND METHODS: The manufacturer recommended modeling liquid (ML), distilled water (DW), isopropyl alcohol (IA), 0.5% (P05), 1% (P1), and 2% (P2) polyethylene glycol solutions were mixed with feldspathic ceramic powder to form disc-shaped samples (n=20, 15 mm × 1.2 mm). After sintering, samples were mirror-polished and subjected to Vickers indentation (n=5) for measurement of microhardness and fracture toughness. The remaining 15 samples from each group were subjected to biaxial flexural strength. Data were subjected to one-way ANOVA and Weibull analysis. RESULTS: The microhardness was affected by veneering liquid (p=0.002): DW promoted higher microhardness values than ML and IA. Fracture toughness (p=0.301) and flexural strength (p=0.930) were not affected by the veneering liquid but Weibull parameters were affected. All groups presented surface pores under high magnification. CONCLUSION: Even though the use of DW led to higher values of surface microhardness than the ML, all obtained values are inside the range of enamel microhardness values reported in the literature. Such parameters may affect antagonist wear and should be reported in clinical trials.

Two-Year Survival of Ceramic Endocrowns and Partial Coverage Ceramic Restorations with Fiber Post: A 2-Year Double-Blind Randomized Clinical Trial.

PURPOSE: This double-blind randomized clinical trial (RCT) aimed to evaluate the 2-year survival rates of endocrowns and partial coverage ceramic restorations (PCCR) with fiber posts. MATERIAL AND METHODS: Forty (40) participants fulfilled the elegibility criteria, and they were randomly allocated in 2 groups: Endocrown or PCCR+post. The survival rates were assessed based on USPHS modified and radiographic examinations. A Chi-square test was used to assess the distribution of characteristics between groups. Kaplan-Meier and Log-rank tests were used to estimate the survival rate. To evaluate the association between survival of the restorations and the explanatory variables, the Multivariate Cox regression model was used. Only variables presenting p⟨0.20 were maintained in final model (α= 0.05). RESULTS: The highest 2-year survival rates were recorded for the Endocrown group (100%), whereas the PCCR+post group exhibited the lowest performance (66.7%). Most of the restoration failures was due to lack of marginal adaption, fracture, and recurrent caries. Cox Regression unadjusted analysis showed that only type of restoration presented a significant effect (p⟨0.20). Thus, adjusted analysis was not performed. CONCLUSIONS: Endocrowns appear to be a promising conservative restorative option and to be feasible and reliable approach restoring endodontically.

Evaluating the Bond Strength of a Polymer Infiltrated Ceramic Network to Zirconia Using the Crossbeam Push-Off Method.

Porcelains and glass-ceramics have been used to produce CAD-milled veneers and crowns for zirconia copings and implant-abutments. This study evaluated the bondstrength of a polymer-infiltrated-ceramic-network to zirconia using two adhesive cement systems: Panavia 21 and Multilink Automix. Lithium disilicate and feldspathic porcelain were also tested as reference CAD-On materials. Long beams (3x6x40 mm³) of zirconia and short beams (3x6x15 mm³) of the CAD-On materials were prepared. Zirconia and each CAD-On material were bonded in a crossbeam arrangement and subjected to a modified tensile bond-strength test. Half of the samples in each group (n=10) were tested 5 days after bonding (baseline) and the remaining (n=10) underwent aging (50,000 thermocycles at 5°C and 55°C) prior to bond-strength testing. The effects of material, cement, and aging on the tensile bond-strength were tested using a three-way ANOVA. The reference lithium disilicate/Multilink system showed no significant differences in bond strength compared to polymer-infiltrated-ceramic-network and porcelain. The long-term retention of polymer-infiltrated-ceramic-network was not statistically different compared to the baseline values and the two reference materials. With comparable bond strength between all materials, polymer-infiltrated-ceramic-network is the favorable choice for CAD-On to zirconia copings and implant-abutments due to its superior resistance to fatigue fracture relative to porcelain.