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To assess the influence of bonding system and restorative material on the marginal integrity and pull-off forces of monolithic all-ceramic crowns bonded to titanium base (Ti-base) abutments.A total of 108 Ti-bases were sandblasted and divided into 9 experimental groups (n = 12 each) according to the combination of crown material (polymer-infiltrated ceramic network [PI], lithium disilicate [LD], and zirconia [ZI]) and bonding system (Multilink Hybrid Abutment [mh], PANAVIA V5 [pv], RelyX Ultimate [ru]), with their respective primers. After bonding the crowns to the Ti-base abutments, the restorations were screw-retained on implants and thermomechanically aged (1,200,000 cycles, 49 N, 1.67 Hz; 5°C to 55°C). Marginal integrity and bonding failure were evaluated under a light microscope, and pull-off forces (N) were calculated. Chi-square tests for marginal integrity, as well as one-way and two-way ANOVA for the pull-off forces, were applied (α = .05).PI presented higher marginal integrity than LD (P = .023). The bonding system pv revealed higher marginal integrity than mh (P = .005) and ru (P = .029). Differences in pull-off forces were found between restorative material and resin cement (P.001), with the highest values for ZI + ru (598 ± 192 N), PI + pv (545 ± 114 N), LD + mh (532 ± 116 N), and PI + ru (528 ± 81 N). Specimens with marginal integrity revealed higher pull-off forces than those with alteration (P = .006). Specimens presenting bonding failures (micromovements) showed lower pull-off forces than those without bonding failures (P.001).The tested CAD/CAM materials show favorable bonding performances with different bonding systems; nevertheless, a specific bonding system has to be recommended for each restorative material.

Monolithic zirconia implant-supported restorations connected to titanium bases or titanium inserts are increasing in popularity due to their application in a full digital workflow. These prefabricated abutments are connected to the all-ceramic superstructure by adhesive cementation. Although limited clinical data on the outcomes of this type of restoration are available, a few laboratory studies have shown possible debonding issues. This case report presents a bonding failure of a fixed dental prosthesis supported by titanium bases after short clinical use. A treatment alternative is also proposed using the available digital dental technology.

Purpose To evaluate the effect of cementation protocols on the bonding interface stability and pull-out forces of temporary implant-supported crowns bonded on a titanium base abutment (TiB) or on a temporary titanium abutment (TiA). Materials and methods A total of 60 implants were restored with PMMA-based CAD/CAM crowns. Five groups (n = 12) were created: Group 1 = TiB/SRc: crown conditioned with MMA-based liquid (SR Connect, Ivoclar Vivadent); Group 2 = TiB/50Al-MB: crown airborne particle-abraded with 50-μm Al2O3 and silanized (Monobond Plus, Ivoclar Vivadent); Group 3 = TiB/30SiOAl-SRc: crown airborne particle-abraded with 30-μm silica-coated Al2O3 (CoJet, 3M ESPE) and conditioned with MMA-based liquid (SR Connect); Group 4 = TiB/30SiOAl-MB: crown airborne particle-abraded with 30- μm silica-coated Al2O3 (CoJet) and silanized (Monobond Plus); and Group 5 = TiA/TA-PMMA: crown manually enlarged, activated, and rebased with PMMA resin (Telio Lab, Ivoclar Vivadent). Specimens in the TiB groups were cemented using a resin cement (Multilink Hybrid Abutment, Ivoclar Vivadent). After aging (120,000 cycles, 49 N, 1.67 Hz, 5°C to 55°C, 120 seconds), bonding interface failure was analyzed (50x). Pull-out forces (N) (0.5 mm/minute) and modes of failure were registered. Chi-square and Kruskal-Wallis tests were used to analyze the data (α = .05). Results Bonding failure after aging varied from 0% (Group 5) to 100% (Groups 1, 2, and 4) (P .05). Conclusion The cementation protocol had an effect on the bonding interface stability and pull-out forces of PMMA-based crowns bonded on a titanium base. Airborne particle abrasion of the crown internal surface and conditioning it with an MMA-based liquid may be recommended to improve retention of titanium base temporary restorations. Yet, for optimal outcomes, conventional temporary abutments might be preferred.

This in vitro research aimed to quantitatively evaluate the enamel and dentin tissue removal and the residual adhesion surface area (RAS) after different margin designs and locations for indirect partial restorations (IPR).A human molar was scanned using a Micro-CT and the STL file obtained was used to 3D-print 50 resin-tooth replicas. IPR standardized preparations were performed. The specimens were randomly assigned to 5 groups (n = 10), according to preparation and margin location to the dental equator (DE): 1) Rounded shoulder above the DE (SA); 2) Hollow chamfer above the DE (CA); 3) Butt joint above the DE (BJ); 4) Rounded shoulder below the DE (SB); 5) Chamfer below the DE (CB). Then, the tooth replicas were scanned and each STL file was aligned and superimposed to the original STL model file. Data of enamel and dentin volume removal and RAS were assessed and statistically analyzed (one-way ANOVA and Kruskal-Wallis tests for the two dental substrates respectively). Significance was set at p0.05.Differences in dental tissue reductions were related to the margin location. Above the equator, SA, CA, and BJ performed comparably (p0.05). Below the equator, CB was significantly more conservative in enamel reduction than SB (p0.05) and showed the highest enamel adhesive surface exposure among the tested preparations (p0.05).When the preparation margin is placed above DE, BJ determines a greater exposure of dentin, reducing the adhesive surface in enamel. Below DE, SB seems to be more aggressive in terms of tissue removal compared to CB.The results of this in vitro study suggest that in teeth requiring partial restoration with the margin below the dental equator, a chamfer preparation would be more conservative than a shoulder preparation. When above the equator, preparations with flat designs would expose more dentine providing a worse substrate for adhesion.

Objectives The aim of the present systematic literature review was to determine whether long-term treatment results with single-tooth implants may differ depending on the timing of implant placement in relation to tooth extraction (immediate IP/early EP/delayed DP) and the timing of prosthetic loading (immediate IL/early EL/delayed DL). Material and methods Electronic and manual searches were performed to identify studies reporting on long-term results (survival rate and/or marginal bone resorption after ≥3 years) of maxillary single-tooth implants in the aesthetic zone using defined placement and loading protocols. Comparative trials were subjected to meta-analyses whilst data from single-arm studies were pooled to evaluate differences between timing protocols. Results A total of 7 controlled trials were considered for meta-analyses: immediate loading was compared to delayed loading in 3 studies on immediate placement (IPIL vs. IPDL, p = .306) and in 2 studies on delayed placement (DPIL vs. DPDL, p = 1.000) whilst 2 studies compared early versus delayed placement with delayed loading (EPDL vs. DPDL, p = .600), however, without significant differences. Pooled data analysis of 29 studies (965 implants) did not show differences between timing of placement or loading as well as marginal bone remodelling. No impact of the one abutment - one time concept, flap design and simultaneous bone or soft tissue augmentation could be established. Conclusions Insufficient data are available for meta-analytic comparison of all combinations of implant placement and loading protocols.

The present paper presents clinical guidelines for the selection of the abutment material and level of customization for single-implant reconstructions. A systematic literature search was conducted previous to a Consensus Conference, resulting in two systematic reviews. One review focused on esthetic clinical outcomes, including esthetic indices and linear measurements, and the second focused on peri-implant soft tissue color outcomes, evaluated with spectrophotometry. The outcomes of esthetic indexes and linear measurement were highly heterogenic, hence, a meta-analysis was not feasible. All-ceramic and customized solutions showed a trend for improved results of the esthetic outcomes. Regarding soft tissue color outcomes, all-ceramic abutments induced significantly less soft tissue color changes. Both metallic and all-ceramic abutments/standard and customized components may result in clinically and esthetically acceptable reconstructions.

The aim of this study was to investigate the effects of saliva contamination and the cleaning of the bond surface of titanium base (ti-base) abutments on the bonding stability and retention force values. The bond surface of the ti-base abutments was treated with airborne-particle abrasion. After contamination, the ti-base abutments underwent different cleaning protocols: water spray (H2O), alcohol (ALC), suspension of zirconium particles (SZP), reapplied airborne-particle abrasion (APA), and a control condition without contamination and cleaning (CTR). All lithium disilicate crowns were bonded to the ti-base abutments using a primer and a self-curing composite. Bonded specimens underwent thermo-mechanical aging. Bond failure analysis and pull-off testing were performed. Bond failure occurred more frequently in groups H2O, ALC, SZP, and APA (p &lt, 0.05). Significant differences in retention force values were only found between CTR and ALC (p &lt, 0.05). Specimens which did not show bond failure after ageing had higher retention force values than the specimens that showed bond failure (p &lt, 0.05). Saliva contamination with cleaning can degrade the bonding properties to titanium. For the retention force values, only the protocol with alcohol after contamination could not restore the values.

OBJECTIVE To investigate the impact of timing of implant placement and loading on implant survival and biological outcomes of multiple-unit implant-supported fixed dental prosthesis (FDPs). MATERIAL AND METHODS A literature search was performed by three independent reviewers for studies reporting on ≥10 patients with FPDs supported by ≥two implants over ≥3 years of follow-up. Data were analyzed on implant survival and biological complications as primary outcomes and biological events, including changes in peri-implant marginal bone level (MBL), probing depth, soft-tissue level, and health condition as secondary outcomes. RESULTS 7002 titles were identified, 360 full-texts were screened, and 14 studies were included. These comprised 6 randomized controlled studies (RCTs), 5 cohort studies, and 3 case series with identifiable implant placement and loading protocols in five of 09 possible combinations. All groups but one (IPIL) showed implant survival rates >90%. A meta-analysis based on 3 RCTs found no differences in survival rate between DPIL and DPDL (p = .227). CONCLUSIONS High survival rates for all studied implant placement and loading combinations were shown for FPDs over ≥3 years of follow-up. When a delayed implant placement protocol is applied, immediate or delayed loading demonstrated similar survival rates. The heterogeneity of the data did not allow to draw any further conclusions on the occurrence of biological complications related to timing of implant placement/loading.

Purpose To systematically review the influence of abutment material and configuration on the soft tissue esthetic outcomes of implant-supported single crowns (iSCs) after 3 years. Materials and methods An electronic search on MEDLINE (PubMed) from January 2000 to July 2019 was conducted for clinical trials with no language restrictions. The focus question was: In partially edentulous patients with iSCs, does the abutment material (metal vs ceramic) or the configuration (standardized vs customized) have an effect on the soft tissue esthetic outcomes? Randomized controlled trials, controlled clinical trials, and prospective or retrospective case series with at least 10 patients and a minimum of 3 years of follow-up were included. The esthetic outcomes Pink Esthetic Score (PES), PES/White Esthetic Score (WES; ie, modPES), Papilla Index (PI), soft tissue recession, and papilla height change were extracted. Meta-analysis was performed when applicable. Results Of the 6,399 titles identified, 27 studies were included. Combined mean PES/modPES scores, translated into a scale of 0 to 100, were 68.8 for ceramic, 74.2 for metal (P = .392), 71.9 for customized, and 71.3 for standard (P = .981) abutments. Mean soft tissue recession was also similar between the abutment groups, abutment material (P = .850), and configuration (P = .849), ranging from -1.09 mm to +0.59 mm gain. Papilla height changes ranged from -1.22 mm to +1.0 mm gain. The reported mean PI was 2.16 for customized, 2.06 for standard (P = .552), 2.01 for ceramic, and 2.28 for metallic (P = .04) abutments. Conclusion This systematic review showed that the abutment material and configuration had minimal impact on the evaluated soft tissue esthetic outcomes. Future research focusing on the included parameters in a randomized controlled manner is needed to validate the present findings.

To digitally evaluate the volumetric wear of four different implant-crown materials and their antagonists after artificial aging using an intraoral scanner (IOS) device and a laboratory desktop scanner.A total of 48 implants were restored with monolithic crowns divided according to restorative material: lithium disilicate (LDS), zirconia (ZR), polymerinfiltrated ceramic network (PICN), and porcelain fused to metal (PFM). Each specimen was scanned using a desktop scanner (LAB; iScan D104, IMETRIC 3D) and an IOS (TRIOS 3, 3Shape) before and after chewing simulation (1,200,000 cycles, 49 N, steatite antagonist, 5°C to 50°C). The obtained STL files were superimposed, and the volumetric loss of substance of the crowns and their antagonists was quantified (Materialise 3-matic). Kruskal-Wallis, Spearman rho, and paired t tests were used to analyze the data (α = .05).The means of volume loss for each restorative material varied between 0.05 ± 0.06 mmPolished ZR was the most wear-resistant material and the least abrasive to the respective antagonist among the tested ceramics. For the quantification of wear, this IOS device can be used as an alternative to desktop scanners.

OBJECTIVES To evaluate mechanical stability (survival and complication rates) and bending moments of different all-ceramic monolithic restorations bonded to titanium bases (hybrid abutment-crowns) or to customized titanium abutments compared to porcelain-fused-to-metal crowns (PFM) after thermo-mechanical aging. MATERIAL AND METHODS Sixty conical connection implants (4.3 mm-diameter) were divided in five groups (n = 12): PFM using gold abutment (GAbut-PFM), lithium disilicate crown bonded to customized titanium abutment (TAbut+LDS), lithium disilicate abutment-crown bonded to titanium base (TiBase+LDS), zirconia abutment-crown bonded to titanium base (TiBase+ZR), polymer-infiltrated ceramic-network (PICN) abutment-crown bonded to titanium base (TiBase+PICN). Simultaneous thermocycling (5°-55°C) and chewing simulation (1,200,000-cycles, 49 N, 1.67 Hz) were applied. Catastrophic and non-catastrophic events were evaluated under light microscope, and survival and complication rates were calculated. Specimens that survived aging were loaded until failure and bending moments were calculated. RESULTS Survival rates after aging were 100% (TAbut+LDS, TiBase+LDS), 91.7% (GA-PFM), 66.7% (TiBase+ZR) and 58.3% (TiBase+PICN) and differed among the groups (p = .006). Non-catastrophic events as screw loosening (GA-PFM) and loss of retention or micro-/macro-movement (TiBase groups) were observed. Complication rates varied among the groups (p

Purpose: To evaluate survival, complication rates, and bending moments of one- and two-piece zirconia implants restored with different abutment materials and lithium disilicate crowns after aging, compared to titanium implants restored with titanium base-supported lithium disilicate crowns. Materials and methods: Sixty anterior crowns were either screwretained on two-piece titanium implants (C) and two-piece zirconia implants (T1, T2, T3) or cemented on one-piece zirconia implants (T4), resulting in 5 groups with 12 specimens each. For the screw-retained crowns, different abutment materials and implant connections were tested: titanium base with internal conical connection and horizontal joint component (C and T2), zirconia with internal hexagonal connection and horizontal joint component (T1), and polyetherketoneketone with internal hexagonal connection and horizontal joint component (T3). After artificial aging with thermocycling (5°C to 50°C) and chewing simulation (1,200,000 cycles, 49 N, 1.67 Hz), the surviving specimens were loaded until fracture, and the bending moments were calculated. Survival rates and respective differences during aging were analyzed with the Kaplan-Meier log-rank test, while complication rates were compared with chi-square tests. Bending moment data were evaluated using the Kruskal-Wallis test (α = .05). Results: Survival rates after artificial aging ranged from 75% (T1) to 100% (C and T4) without significant differences between the groups (P > .05). Only 41.5% of the surviving specimens were free of complications, while the remaining presented screw-loosening, loss of retention of crowns, or cracks on the crown or implant level. The complication rates varied significantly among the groups (P < .05). The mean bending moments were 173.7 × 20.1 (C), 114.5 × 20.1 (T1), 171.1 × 46.1 (T2), 258.1 × 147.4 (T3), and 194.7 × 30.9 Ncm (T4), and group T1 exhibited significantly lower median bending moment values than the other groups (P < .001). Conclusion: The zirconia one- and two-piece implants presented high survival rates after aging, yet the number of technical complications was high. New prosthetic solutions, such as titanium bases or polyetherketoneketone abutments, may offer a comparable treatment option to restore two-piece zirconia implants.

Statement of problem Published data have shown that a mechanical surface treatment of titanium surfaces increases bonding potential. However, most of the studies are based on shear or tensile tests performed on flat-surfaced specimens and do not take into consideration the retention given by the titanium base (ti-base) axial walls and the thermomechanical loading seen in a clinical setting. Purpose The purpose of this in vitro study was to evaluate the influence of different airborne-particle abrasion (APA) methods of the ti-base surface on the stability of the bonded interface and retention forces between these titanium bases and lithium disilicate crowns after thermomechanical aging. Material and methods Sixty internal connection implants (Conelog) were restored with lithium disilicate crowns and bonded to the corresponding ti-bases (Conelog). The ti-bases were divided into 4 groups (n=15), 3 experimental groups applying different APA methods, 30-μm silica-modified Al2O3 particles (CoJet) (30-SiO-AlO), 50-μm Al2O3 (Cobra Aluoxyd) (50-AlO), 110-μm silica-modified Al2O3 particles (Rocatec Plus) (110-SiO-AlO), and 1 control group (NoT). Ti-bases were airborne-particle abraded (10 seconds, 0.25 MPa at a 10-mm distance) under standardized conditions in a custom-made APA device. All crowns were cemented with a resin cement (Multilink Hybrid Abutment). After aging (1 200 000 cycles, 49 N, 1.67 Hz; 5 °C-55 °C, 120 seconds), all specimens were assessed for the presence of bond failures by optical microscopy (×50). The retention forces (N) were tested by using a pull-off test (0.5mm/min). Modes of failure were classified (Type 1, 2, or 3). An additional ti-base representing each group was prepared for surface roughness (μm) calculation (Ra, Rc, Rz) with a noncontact laser profilometer, and representative scanning electron microscope (SEM) images were recorded (×1000). Chi-squared tests were performed to analyze the bonded interface failure and modes of failure, and a Kruskal-Wallis test was selected to evaluate retention force values (α=.05). Results The percentages of bonding failure after aging were 73.3% (NoT), 40% (30-SiO-AlO), 6.7% (50-AlO), and 40% (110-SiO-AlO). The stability of the bonded interface was influenced by the APA method applied (P Conclusions Airborne-particle abrasion of the titanium surface increased the bond stability and retention forces between the ti-base and the respective crown. The use of 50-μm Al2O3 provided the most stable bonded interface among the different treatments.

Objective To evaluate the influence of implant and prosthetic components on peri-implant tissue health. A further aim was to evaluate peri-implant soft-tissue changes following surgical peri-implantitis treatment. Materials and methods Group discussions based on two systematic reviews (SR) and one critical review (CR) addressed (i) the influence of implant material and surface characteristics on the incidence and progression of peri-implantitis, (ii) implant and restorative design elements and the associated risk for peri-implant diseases, and (iii) peri-implant soft-tissue level changes and patient-reported outcomes following peri-implantitis treatment. Consensus statements, clinical recommendations, and implications for future research were discussed within the group and approved during plenary sessions. Results Data from preclinical in vivo studies demonstrated significantly greater radiographic bone loss and increased area of inflammatory infiltrate at modified compared to non-modified surface implants. Limited clinical data did not show differences between modified and non-modified implant surfaces in incidence or progression of peri-implantitis (SR). There is some evidence that restricted accessibility for oral hygiene and an emergence angle of >30 combined with a convex emergence profile of the abutment/prosthesis are associated with an increased risk for peri-implantitis (CR). Reconstructive therapy for peri-implantitis resulted in significantly less soft-tissue recession, when compared with access flap. Implantoplasty or the adjunctive use of a barrier membrane had no influence on the extent of peri-implant mucosal recession following peri-implantitis treatment (SR). Conclusions Prosthesis overcontouring and impaired access to oral hygiene procedures increases risk for peri-implantitis. When indicated, reconstructive peri-implantitis treatment may facilitate the maintenance of post-operative peri-implant soft-tissue levels.

Statement of problem Saliva contamination has been shown to decrease bonding to zirconia. Adopting a less contamination-sensitive cement system may be an alternative to decontamination. Purpose The purpose of this in vitro study was to assess the ability of different primer/cement systems to promote a durable bond to zirconia after saliva contamination. Material and methods Zirconia blocks (Lava Plus) (N=320) were airborne-particle abraded (50 μm Al 2 O 3 ) and divided into 32 experimental groups (n=10) according to the variables in the study: saliva contamination; primer/cement system (Panavia SA [PSA]; RelyX Unicem 2 [RU2]; Bifix SE [BSE]; Panavia F2.0 [PF2]; Scotchbond Universal + RelyX Ultimate [SBU+RXU]; Futurabond M+ + Bifix QM [FBM+BQM]; All-Bond Universal + Duo-link [ABU+DL]; Z-Prime Plus + Duo-link [ZPP+DL]; and aging period (72 hours; 30 days with 10 000 thermal cycles at 5°C to 55°C). After half of the blocks had been contaminated with fresh human saliva for 10 minutes, rinsed with water, and air-dried, each primer/cement was applied. Polymerized composite resin disks were then placed over the cement, and the resin cement was light-polymerized for 20 seconds each at 2 opposite margins. After the aging time, the specimens were tested in shear (1 mm/min). The failure mode was classified as adhesive, cohesive, or mixed. Statistical analysis of the shear bond strength (SBS) data was performed with ANOVA followed by Tukey honest significant difference post hoc tests. Chi-square tests were used to analyze the failure mode data (α=.05). Results The mean SBS ranged between 4.2 and 34.5 MPa. Shear bond strength was influenced ( P P P >.05). Failure was predominantly classified as adhesive. Conclusions In general, saliva contamination and aging decreased bonding efficacy. Two systems, combining an application of a universal adhesive and a resin cement (SBU+RXU and FBM+BQM) were not affected by saliva contamination.

To evaluate the effect of age and intra-oral scanner (IOS) on the learning curve of inexperienced operators.Thirty-four operators pertaining to 1 of 3 groups: (G1) students ≤ 25 years (y), (G2) dentists ≥ 40y, and (G3) a control group of experienced IOS operators (no age limitation), were included. All participants performed baseline and final quadrant scans on a volunteer subject, before and after a training program of 3 sessions, with two different IOS: TRIOS 3 (S1) and True Definition (S2). Baseline and final scanning times were registered in seconds. A Pearson correlation was applied to evaluate the correlation between age and scanning time. An ANOVA of repeated measures test was applied to evaluate inter-group (G1, G2, G3) and inter-system performance. Significance level was set at a = 0.05.Age and scanning time for inexperienced operators showed a weak positive correlation for final scanning time (r = 0.29, p0.05). When comparing groups and filtering by IOS, S1 failed to show differences between groups (p0.05). With S2, the control group demonstrated a better performance than G2 (p0.05), while G1 only demonstrated a better performance than G2 at final scanning time (p = 0.005). Overall, the type of IOS had a significant impact on the scanning time (p0.001).Results from this study indicate that age and type of IOS have an impact on the performance and learning curve of inexperienced IOS operators.Gaining knowledge on how different aspects, such as age, experience or IOS system, influence the learning curve to IOSs is relevant due to the financial and strategical impact associated with the acquisition of an IOS.

Purpose To systematically review the current literature on the influence of abutment material (metal vs ceramic) and soft tissue thickness on peri-implant soft tissue discoloration in partially edentulous patients restored with implant-supported single crowns. Methods An electronic MEDLINE search was performed to identify randomized controlled clinical trials (RCTs) up to and including March 2017. The search was complemented by a manual search of related bibliographies. Selection of studies was made independently by two reviewers based on the inclusion criteria. Spectrophotometric data (ΔE values) and soft tissue thickness values were extracted, and, whenever applicable, a meta-analysis using a random-effects approach was performed. Results The search resulted in 208 titles and 30 abstracts. Full-text analysis was performed for 13 articles, resulting in 6 included RCTs. Meta-analysis of a total of 266 abutments revealed significantly lower ΔE values for ceramic abutments when compared to the overall metal abutments (z test value = 1.99, P = .05), with a mean difference of 1.41 (95% CI 0.02, 2.80). Nonsignificant differences were found between titanium and zirconia (z test value = 1.59, P = .11). Limited information on the correlation between soft tissue thickness and ΔE values was found. Hence, it was not possible to perform a meta-analysis of this question. Conclusion The color outcome of the peri-implant soft tissue might be influenced by the abutment material. Ceramic abutments appear to provide an improved color matching between peri-implant soft tissues and soft tissues around natural teeth when compared to metallic abutments. These findings support the preference for all-ceramic or "white" abutments in esthetically demanding cases.

To evaluate the bending moments and failure modes of zirconia meso-abutments bonded to titanium bases restored with different monolithic all-ceramic crowns after aging, and to compare them to titanium abutments restored with all-ceramic crowns.Forty-eight internal conical connection implants (Conelog, Camlog 4.3 mm diameter) were restored with four different computer-aided design/computed-aided manufacturing (CAD/CAM) abutment-crown combinations (n = 12). Thirty-six customized zirconia meso-abutments were bonded to titanium bases (Conelog Titanium Base CAD/CAM crown, Camlog) and divided into three groups according to the different crown materials: (T1) monolithic lithium-disilicate (e-max CAD, Ivoclar), (T2) monolithic PICN (polymer-infiltrated ceramic network [Enamic, Vita]), and (T3) monolithic zirconia (Lava Plus, 3M ESPE). Twelve titanium customized abutments restored with monolithic lithium-disilicate (e-max CAD, Ivoclar) crowns served as the control group (C). The crowns were equal maxillary central incisors and were adhesively bonded with a resin-based cement (Panavia 21, Kuraray). All samples were embedded in acrylic holders. After aging (1,200,000 cycles, 49 N, 1.67 Hz, 5°C to 50°C, 120 seconds), static load was applied until failure. Bending moments were calculated for comparison of the groups. Data were statistically treated with one-way analysis of variance (ANOVA) followed by Tukey post hoc test (P.05). Failure modes were analyzed descriptively.The means of the bending moments were 356.4 ± 20.8 Ncm (T1), 357.7 ± 26.3 Ncm (T2), 385.5 ± 21.2 Ncm (T3), and 358.8 ± 25.3 Ncm (C). Group T3 revealed significantly higher mean bending moments than the other groups (P.05). No differences were found between zirconia meso-abutments supported by titanium bases and customized titanium abutments when lithium-disilicate crowns were used (P.05). No failures were identified during and after aging. After static load, failures occurred due to fracture of the abutment in the internal connection in all the groups.Zirconia meso-abutments bonded to titanium bases showed similar mechanical stability compared with customized titanium abutments. Regarding the crown material, all three tested ceramics (lithium-disilicate, PICN, and zirconia) revealed very good stability when used in the monolithic state.

The development of titanium bonding bases allows for the use of implant-supported monolithic reconstructions in a digital workflow. Different base configurations are available according to each clinical indication. In this case report, the selection of titanium bonding bases for crowns was considered for a multiple-unit fixed dental prosthesis (FDP).

ResumoObjetivosAvaliar a influência da distância e do tempo de exposição à luz na capacidade de polimerização de 4 compósitos.MétodosForam fabricados 160 discos, com 2mm de espessura, de acordo as combinações possíveis entre compósito (FiltekTM Supreme XTE [3M‐ESPE]; FiltekTM Silorane [3M‐ESPE]; Grandio® SO [Voco]; Herculite® XRV Ultra [Kerr]), distância à fonte de luz (0, 2, 4, 6mm) e tempo de exposição (recomendado pelo respetivo fabricante; dobro do recomendado pelo fabricante). Foram constituídos 32 grupos experimentais (n=5). Após determinação da microdureza Knoop (KH) na superfície do disco de compósito mais perto da fonte luminosa (topo) e na mais distante (base), foi calculado o rácio de microdureza (KH base / KH topo). Os dados de KH do topo foram analisados com testes de Kruskal‐Wallis e Mann‐Whitney (alfa=0,05).ResultadosTanto o tipo de compósito (p

Objetivo: Estudar o efeito do método de fotopolimerização, da presença do oxigénio e da remoção da camada inibida na microdureza de compósito fotopolimerizado através de matrizes oclusais. Métodos: Discos de compósito (GrandioSO, VOCO) foram fotopolimerizados com LED através de matrizes oclusais (2 polivinilsiloxano: Memosil 2 [Heraeus Kulzer] e Registrado Clear [Voco] e um polietileno: Bite-perf [Biteperf Dental Products]) (n = 10). Foram criados grupos controlo, sem matriz e com matriz de acetato. O estudo foi constituído por 3 etapas. Na primeira foi avaliado o método de fotopolimerização (40 segundos através da matriz; 20 segundo através da matriz + 20 segundos sem matriz). Na segunda etapa os espécimes foram fabricados em diferentes atmosferas (oxigénio; azoto). Na terceira os espécimes fabricados com os polivinilsiloxanos foram polidos com acetona ou borracha. A microdureza Knoop foi testada 24 horas após a polimerização. Os resultados foram analisados com Kruskal-Wallis e Mann-Whitney com correc¸ão de Bonferroni (alfa = 0,05). Resultados: Apenas nos grupos Bite-perf foi obtida microdureza semelhante (p > 0,05) à obtida com matriz de acetato. Nos espécimes fabricados com Memosil, Registrado e sem matriz a atmosfera de azoto permitiu obter microdureza mais elevada que com o oxigénio (p < 0,05). O polimento conduziu a microdureza inferior à obtida com matriz de acetato (p < 0,05). Conclusões: Após 40 segundos de fotopolimerização através de Bite-perf a microdureza do compósito foi semelhante à obtida após 20 segundos de polimerização através da matriz de acetato. A polimerizac¸ão do compósito através dos polivinilsiloxanos levou à criação de uma camada superficial inibida pelo oxigénio que não foi eficazmente removida com os métodos empregues neste estudo laboratorial., Objective: To study the effect of the curing method, of the presence of oxygen and of the removal of the oxygen inhibited layer on the microhardness of the resin composite cured through oclusal matrix. Methods: Composite disks (GrandioSO, VOCO) were cured with a LED through oclusal [two polyvinylsyloxanes: Memosil 2 (Heraeus Kulzer) e Registrado Clear, (Voco) and one polyethylene: Bite-perf (Biteperf Dental Products)] (n = 10). Control groups without matrix and with a mylar strip matrix were also created. The study had three steps. On the first step, the curing method was evaluated (40 seconds through the matrix; 20 seconds through the matrix + 20 seconds without matrix). On the second step, specimens were prepared in different atmospheres (oxygen; nitrogen). On the third step, specimens prepared with polyvinylsyloxanes were polished with acetone or rubber cup. Knoop microhardness was tested 24 h after curing. Data were treated with Kruskal-Wallis e Mann-Whitney (p = 0.05). Results: Only with the Bite-perf microhardness was similar (p > 0.05) to the mylar matrix group. In nitrogen, specimens from the groups with Memosil, Registrado and without matrix yielded significantly higher microhardness than the same groups in oxygen atmosphere (p < 0.05). After treatment of the superficial layer, microhardness was still lower than in the mylar matrix group (p < 0.05). Conclusions: Curing through the Bite-perf for 40 seconds the composite microhardness was similar to the one obtain after 20 seconds curing through the mylar matrix. Composite curing through the polyvinilsiloxanes lead to an inhibited oxygen layer that was not totally removed by the methods applied in this laboratory study.

Objetivos: Avaliar a qualidade do sono e estimar a prevalência das perturbações do sono em crianças dos dois aos 10 anos de idade num centro de saúde da área metropolitana do Porto. Tipo de estudo: Estudo observacional descritivo e transversal. Local: Consulta de saúde infantil e juvenil num centro de saúde na área urbana do ACeS Grande Porto VII - Gaia. População: Crianças dos 2 aos 10 anos inscritas num centro de saúde do ACeS Grande PortoVII - Gaia. Métodos: Aplicação do questionário Portuguese Children's Sleep Habits Questionnaire (CSHQ-PT), traduzido e validado para a população portuguesa, bem como um inquérito padronizado com questões individuais a crianças entre os 2-10 anos, observadas em Consulta de Saúde Infantil e Juvenil, de abril a junho de 2014. Resultados: A amostra foi composta por 131 crianças com mediana de idades de cinco anos, 55% em idade pré-escolar, com predomínio do sexo masculino (53,5%). O índice de perturbação do sono (IPS) associou-se com o grupo etário (maior na idade pré-escolar, p=0,032) e, considerando o cut-off de 41, 80,2% apresentaram um IPS elevado (mediana=47). Um IPS superior associou-se à necessidade de um familiar no quarto (p=0,005) ou na cama (p

Objetivo: Determinar a influência de 3 materiais utilizados como matriz oclusal na eficácia de fotopolimerização de uma resina composta e na prevenção da inibição da polimerização superficial. Métodos: Cem espécimes de resina composta (GrandioSO, VOCO) com 2 mm de espessura foram polimerizados (20 segundos), com um LED (800 mW/cm2) interpondo o material em estudo. Estes espécimes formaram os 10 grupos estudados (n = 10) de acordo com o material interposto [sem material interposto, tira de acetato, Registrado Clear (VOCO), Memosil-2 (Heraeus Kulzer) e Bite-perf (BITEPERF Dental Products)] e espessura/distância da luz (1 ou 2 mm). Após 24 horas efetuaram-se testes de microdureza Knoop na base e no topo dos espécimes. Os dados foram tratados estatisticamente com uma MANOVA de 2 dimensões, seguindo-se testes post-hoc pelo método de Tukey, estabelecendo-se 0,05 como nível de significância. Resultados: A distância da luz não produziu diferenças de microdureza estatisticamente significativas (p ≥ 0,05). Os grupos com tira de acetato obtiveram valores de microdureza no topo estatisticamente superiores (p < 0,05) aos obtidos nos outros grupos, seguidos dos grupos com Bite-perf que obtiveram valores estatisticamente inferiores em relação aos grupos com acetato, mas superiores ao restantes grupos (p < 0,05). Para a base, o grupo do Bite-perf foi o único que apresentou valores de microdureza estatisticamente inferiores (p < 0,05), não se verificando diferenças estatisticamente significativas entre os restantes grupos (p ≥ 0,05). Conclusões: O Bite-perf foi o único material que interferiu com a polimerização em profundidade da resina composta e o único que indicia prevenir a inibição da polimerização pelo oxigénio., Objective: To evaluate the influence of three occlusal matrix materials in the light curing effectiveness of a resin composite. Furthermore, we intend to determine if the application of these materials could prevent the oxygen-inhibited layer of the composite surface. Methods: One-hundred composite (GrandioSO, VOCO) specimens, 2 mm thick, were lightcured (20 seconds) with a LED curing device (800 mW/cm2) through the study materials. The specimens were divided into ten groups (n = 10) according to the placed material [no interposed material, mylar strip, Registrado Clear (VOCO), Memosil-2 (Heraeus Kulzer) e Bite-perf (BITEPERF Dental Products)] and thickness / light-cure tip distance (1 and 2 mm). After 24 hours, Knoop microhardness tests were performed at top and bottom surfaces. The data was analyzed with a two-way MANOVA followed by the Tukey post-hoc test. Statistical testing was performed at a 0.05 level of significance. Results: The light-cure tip distance did not show statistical differences (p≥ 0.05). The mylar strip groups showed the highest (p < 0.05) microhardness values on top surface. The Biteperf groups showed lower hardness values comparing to the mylar strip groups, but higher than the other groups (p < 0.05). On the bottom surface, the Bite-perf group presented the lowest values (p < 0.05). There were no statistically significant differences between the other groups (p ≥ 0.05). Conclusions: The Bite-perf was the only material that influenced the resin composite depth of cure and the only that seems to prevent the oxygen-inhibited layer.