Marginal adaptation of two-step self-etch versus universal adhesives for Class V restorations: Effect of Er:YAG laser vs. bur prepared cavities.

PURPOSE: To compare the in vitro effect of laser and bur preparation on marginal adaptation of Class V cavities restored with a 2-step self-etch and distinct universal one-component universal adhesives used in self-etching mode. METHODS: 96 Class V cavities were prepared with conventional burs or with an Er:YAG laser. Four universal self-etch (Unibond Extra Low Shrinkage, All Bond Universal, SKB-100 and Prime&Bond active) and a 2-step self-etch adhesive (Clearfil SE Bond) that served as control were used to restore the cavities with direct composite. The percentages of continuous margins were evaluated by quantitative SEM analysis before and after a fatigue test consisting of 240,000 occlusal loads and 600 warm/cold thermal cycles. RESULTS: The marginal adaptation of bur prepared restorations was statistically superior to laser-prepared ones. Class V cavities restored with Clearfil SE Bond and the one-component self-etching universal adhesives All Bond Universal and Prime&Bond active presented the highest and statistically similar percentages of continuous margins before and after loading under both bur and laser cavity preparation. The lowest percentages of continuous margins were observed in the groups restored with the low shrinking adhesive (Unibond ELS), with medians of 49 and 21 for bur and laser prepared cavities after loading. CLINICAL SIGNIFICANCE: Class V cavities presented smoother and higher percentages of continuous margins when prepared by bur rather than by laser. The 2-step self-etch adhesive Clearfil SE Bond and 1-step self-etch universal adhesives All Bond Universal and Prime&Bond active showed a comparable marginal performance.

ToF-SIMS Analysis of Demineralized Dentin Biomodified with Calcium Phosphate and Collagen Crosslinking: Effect on Marginal Adaptation of Class V Adhesive Restorations.

This study aimed to assess the effect of biomodification before adhesive procedures on the tooth-restoration interface of class V restorations located in caries-simulated vs. sound dentin, and the quality of dentin surface by time-of-flight secondary ion mass spectrometry (ToF-SIMS). Class V cavities located on cervical dentin were prepared on the buccal surfaces of extracted human molars under the simulation of intratubular fluid flow. Two dentin types, i.e., sound and demineralized by formic-acid, were biomodified with 1% riboflavin and calcium phosphate (CaP) prior to the application of a universal adhesive (Clearfil Universal Bond) in etch and rinse or self-etch mode, and a conventional micro hybrid composite (Clearfil APX). Restorations were subjected to thermo mechanical fatigue test and percentages of continuous margins (% CM) before/after fatigue were compared. Bio modification of dentin surfaces at the molecular level was analyzed by Time-of-Flight Secondary Mass Spectometry (ToF-SIMS). % CM were still significantly higher in tooth-restoration interfaces on sound dentin. Meanwhile, biomodification with riboflavin and CaP had no detrimental effect on adhesion and in carious dentin, it improved the % CM both before and after loading. Etching carious dentin with phosphoric acid provided with the lowest results, leading even to restoration loss. The presence of molecule fragments of riboflavin and CaP were detected by ToF-SIMS, evidencing dentin biomodification. The adhesive interface involving carious dentin could be improved by the use of a collagen crosslinker and CaP prior to adhesive procedures.

Surface degradation of composite resins for direct restorations: effects on wear and gloss retention.

The purpose of this in vitro study was to compare the 2-body wear resistance of 7 direct composite resin materials (Synergy, Filtek Supreme XTE, GrandioSO, Tetric EvoCeram, G-ænial Anterior, Venus Pearl, and Ceram.X Duo) following thermomechanical loading as well as their gloss stability following toothbrushing. For measurement of resistance to wear, 8 specimens of each material were thermomechanically challenged under 200,000 load cycles at a maximum force of 49 N and 500 thermal cycles between 5°C and 50°C simultaneously. Wear was analyzed by measuring the volume and vertical loss of the contact point area using a high-speed 3-dimensional scan. For gloss measurements, 8 additional specimens of each material were evaluated using a glossmeter after being subjected to 15 minutes of brushing with an electric toothbrush at a 200-N application force. Filtek Supreme XTE had the least volumetric wear, while G-ænial Anterior and Ceram.X Duo had the greatest. The greatest vertical loss was recorded for G-ænial Anterior and Ceram.X Duo. Ceram.X Duo also had the greatest loss of gloss units, together with Venus Pearl. The universal composite Filtek Supreme XTE demonstrated the lowest wear rates and the best gloss retention.

Influence of 9.3 µm CO2 and Er:YAG laser preparations on marginal adaptation of adhesive mixed Class V composite restorations with one component universal adhesive.

PURPOSE: To examine the marginal adaptation in enamel and dentin of mixed Class V saucer shaped restorations where cavities were prepared by two different lasers. METHODS: A handpiece-integrated Er:YAG laser @ 4.5 W, 300 mJ, 15 Hz (LiteTouch III) and a novel CO2 laser @ 12.95 W, 19.3 mJ, 671 Hz (Solea 9.3 µm). Diamond bur preparation with a 25 µm diamond bur (Intensiv) in a red contra angle at high speed under water spray cooling served as the control. Eight cavities per group were readied and restored under simulation of dentin fluid with a one bottle universal adhesive (One Coat 7 Universal) and a nanohybrid resin composite (Everglow), applied in two layers. For every preparation technique, the adhesive system was applied in the selective-etch and the self-etch mode, resulting in six experimental groups. Marginal analysis was performed immediately after polishing and after simultaneous thermal (5-50°C, 2 minutes each) and mechanical (max. 49 N; 200,000 cycles) loading by using a SEM (x200 magnification). RESULTS: Significant differences were found for all groups - except groups 2 and 5 - between initial and terminal results and between the groups as well (P< 0.05, 2-way ANOVA with Fisher's post-hoc test). The bur prepared group with selective-etch technique showed the best overall results after loading, followed by Er:YAG prepared self-etch group and CO2-prepared selective-etch group. CLINICAL SIGNIFICANCE: By using a universal one-component adhesive system, marginal adaptation in enamel and in dentin depended on the preparation method and on the adhesive's application technique as well. When using lasers, Er:YAG in self-etch mode and CO2 9.3 µm in selective-etch mode total marginal adaptation showed results which were comparable to conventional bur preparation with selective-etch technique.

Optical Coherence Tomography (OCT) for the evaluation of internal adaptation of class V resin restorations on Dentin.

Internal adaptation of adhesive restorations affects their longevity. In a clinical setting, the dentists use visual and tactile examination to evaluate marginal adaptation, while radiographs provide somewhat reliable information about adaptation or secondary caries present. For class V restorations located on the vestibular (buccal) surfaces, none of the tools available can provide any information about the internal adaptation or the presence of secondary caries. OCT has been proven to be a useful tool for non-destructive assessment of internal adaptation of adhesive restorations. This paper is evaluating the use of a new high-resolution handheld OCT prototype with a pen-shaped intraoral tip and an imaging depth of 8mm to examine the internal adaptation and the presence of demineralization under resin restorations on the vestibular dentin surface. The Axsun OCT system helped evaluate the internal adaptation of composite restorations, differentiate between healthy and demineralised dentin, adhesive, and restoration layers. OCT provided a unique visualization and characterization of internal structures as well as non-contact assessment of marginal adaptation.

Influence of pulse duration when performing Er:YAG laser irradiation on dental tissues.

PURPOSE: To evaluate the marginal adaptation of mixed Class V composite restorations in cavities prepared with the Quantum Square Pulse (QSP) mode Er:YAG laser, compared to Super Short Pulse (SSP) and diamond bur. The impact of Er:YAG laser finishing with low pulse energy and two irradiation distances was also evaluated. METHODS: Class V cavities were prepared in enamel and dentin by varying the above parameters, and then restored with Clearfil SE Bond and Clearfil AP-X composite under dentin fluid simulation. The control groups were prepared and finished using conventional diamond burs (80 and 25 µm respectively). Scanning electron microscope (SEM) marginal adaptation analysis at x200 magnification was performed on replicas before and after thermo-mechanical cyclic loading in order to determine the percentage of continuous margins (i.e. from 0 to 100% of gap free margins). The differences between groups were analyzed with one-way ANOVA and Duncan post hoc test. RESULTS: Dentin treated with SSP showed significantly lower percentages of "continuous margin" than the QSP and control groups. QSP was as effective as bur preparation. CLINICAL SIGNIFICANCE: The preparation and finishing protocol may no longer be necessary when using the QSP mode, reducing clinical time without compromising marginal adaptation.

Coating of enamel and dentin with bioactive materials: Effect on adhesive interface of class V restorations.

PURPOSE: To evaluate the effect of coating enamel and dentin with a calcium phosphate powder, a calcium fluoride silicon polymer, an oxalate and a functionalized tricalcium phosphate, on marginal adaptation of class V cavities restored with a universal adhesive containing the adhesive monomer with chemical bonding potential 10-MDP (Clearfil Universal Bond) and a hybrid composite (Clearfil APX). METHODS: Class V cavities with margins located in enamel and dentin were coated with the different bioactive materials prior to the application of the adhesive and composite. After restoration polishing, the samples were subjected to a thermo-mechanical fatigue test. Gold coated resin-based replicas were readied to analyze the percentages of continuous margins (%CM) before and after loading to evidence differences between different enamel/dentin pre-treatments (Kruskal-Wallis, Duncan post hoc test). RESULTS: The highest %CM was observed in the group in which enamel and dentin were coated with calcium phosphate powder prior to the application of the 10-MDP-containing adhesive. This was also the most stress-resistant group. CLINICAL SIGNIFICANCE: The adhesive interface formed between 10-MDP-containing universal one component adhesive and enamel/dentin with enriched mineral content may improve the quality of restoration margins.

Non-invasive proximal adhesive restoration of natural non-cavitated proximal lesions.

PURPOSE: To investigate the infiltration potential of different self-etch adhesives into natural non-cavitated proximal lesions and the effect of dehydration protocol on the infiltration of a self-etch adhesive. METHODS: 29 extracted molars and premolars with natural proximal lesions (ICDAS 1-2) were sectioned through the lesion providing two samples from each lesion. To compare the different adhesives, three groups of eight lesions were abraded with fine metallic strips and then etched with 37% H3PO4 acid for 120 seconds. All teeth were stained with rhodamine isothiocyanate. After drying with compressed air and ethanol application, lesions were infiltrated with Scotchbond Universal, Clearfil SE Protect or OneCoat 7 Universal for 180 seconds and then coated with a thin layer of flowable composite (Tetric Flow). To compare the effect of dehydration protocol on infiltration, two groups of nine paired lesions were pretreated as described above. One group was dried using compressed air alone and the second group was dried using compressed air and ethanol, both groups were then infiltrated with Scotchbond Universal then coated with a thin film of flowable composite. After light curing, un-encapsulated dye was bleached by immersion in hydrogen peroxide. Remaining lesion pores were stained with sodium fluorescein solution. Thin cuts of the teeth were observed with confocal microscopy and computer image analysis was performed (ImageJ). RESULTS: ANOVA and Duncan post-hoc tests showed no significant differences of the infiltrated area between the three adhesives (P= 0.835), no significant difference was found between the group dried with air compared to the one dried with air and ethanol. It can be concluded that the tested adhesives may be used for infiltration of natural lesions following the described pretreatment. CLINICAL SIGNIFICANCE: Enamel pretreatment with metallic strip and 37% H3PO4 acid promotes the infiltration of different adhesives into natural non-cavitated caries lesions.

Non-invasive proximal adhesive restoration (NIPAR) compared to resin infiltration for treating initial proximal carious lesions.

PURPOSE: To compare a new technique of non-invasive proximal adhesive restoration (NIPAR) to the infiltration concept technique (ICON). METHODS: Extracted human posterior teeth with non-cavitated proximal carious lesions (ICDAS code 1-2) were cut vertically to obtain two symmetrical lesions. Group 1 (NIPAR):Half of the paired lesions surfaces (n=13) were abraded with metallic strips and etched with 37% H3PO4 for 120 seconds. Group 2 (ICON):The other half of the paired lesions' surfaces (n=13) were etched with 15% HCl gel for 120 seconds. All samples were then stained with rhodamine isothiocyanate (RITC). After ethanol drying and isolation of the cut surface, Group 1 samples were infiltrated with Scotchbond Universal for 180 seconds and coated with a thin film of Tetric flow. Group 2 samples were infiltrated with ICON infiltrant following manufacturer's instructions. After light curing, unbound rhodamine was bleached by immersion in 30% hydrogen peroxide for 12 hours. Remaining lesion pores were stained with sodium fluorescein solution. Samples were observed with confocal microscopy (CLSM) and the percentage of infiltration (area of resin infiltration/area of total demineralization ×100) was calculated using ImageJ. RESULTS: 11 samples out of 13 showed larger infiltrated area of the lesions in Group 1 (NIPAR) compared to Group 2 (ICON). Statistical analysis revealed a significant difference between the two groups (P< 0.05). Within the limitations of this study, NIPAR allowed for better infiltration of non-cavitated proximal carious lesions when compared to ICON. CLINICAL SIGNIFICANCE: The combination of infiltration and sealing using non-invasive proximal adhesive restoration (NIPAR) offers a suitable non-invasive treatment option for non-cavitated proximal lesions combining the advantages of sealing and infiltration.

In-office bleaching efficacy on stain removal from CAD/CAM and direct resin composite materials.

OBJECTIVE: To evaluate the efficacy of in-office bleaching on stain removal from stained resin composite and ceramic computer-assisted design/computer-assisted manufacturing (CAD/CAM) blocks and direct resin composites. METHODS: Forty disk-shaped samples were fabricated from each of nine materials: six CAD/CAM (VITABLOCS Mark II, Paradigm MZ100, Exp Vita Hybrid Ceramic, VITA ENAMIC, Exp Kerr, and LAVA Ultimate) and three direct resin composites (Filtek Supreme, Venus Diamond, and Filtek Silorane). Samples were randomly divided into five groups (n = 8), each stained with a particular staining solution. Using a calibrated spectrophotometer and a black background, L*a*b* values were assessed before and after 120 days of staining. Samples were subjected to in-office bleaching using 40% hydrogen peroxide gel for one hour. At subsequent assessment, color change (ΔE) was calculated as the difference between L*a*b* values. Both ANOVA and the Duncan test were used to identify differences between groups (α = 0.05). RESULTS: Bleaching resulted in significant differences in ΔE values for all materials (P < .001). Bleaching efficacy was highly influenced by material composition and staining solution. Residual color values after bleaching for ceramic and hybrid ceramics ranged from -0.49 to 2.35, within the clinically acceptable maximum of 3.3. Values after bleaching for resin-based CAD/CAM ranged from -0.7 to 7.08 while direct resin composites values ranged from -1.47 to 25.13. Coffee left the greatest residual color on all materials. CONCLUSIONS: Based on material nature, 40% hydrogen peroxide bleaching can remove staining. The new resin-based CAD/CAM blocks showed promising results in terms of color stability. CLINICAL SIGNIFICANCE: Bleaching using 40% hydrogen peroxide can be an effective method to remove stains from dental restorations. In this way, restoration replacement as a result of discoloration may no longer be necessary.

Effects of riboflavin, calcium-phosphate layer and adhesive system on stress-strain behavior of demineralized dentin.

PURPOSE: To evaluate if three dentin treatments improved mechanical properties of demineralized dentin. METHODS: Dentin slices were demineralized and treated with a universal adhesive, Scotchbond Universal (SBU), a cross-linker, Riboflavin (RF), and a calcium phosphate-based product, Teethmate (TM). The groups (n= 8 per group) were: Group 1: SBU, Group 2: RF + SBU, Group 3: RF + TM + SBU. Tensile tests were performed; stress/strain curves and E modulus were calculated. Differences between groups were assessed by one-way ANOVA and Duncan post hoc test. RESULTS: At high strains, no significant differences in E moduli were observed between dentin specimens treated only with SBU and those treated with RF + SBU. A significantly higher E modulus was observed in dentin specimens treated with RF + TM + SBU. In the presence of an adhesive system, crosslinking collagen with RF and TM addition significantly improved mechanical properties of dentin. CLINICAL SIGNIFICANCE: Restitution of mineral content into dentin, in addition to collagen strengthening, may significantly improve mechanical properties of previously demineralized dentin, when covered by an adhesive system in a reasonable clinical timeframe.

Effect of caries-affected dentin on one-step universal and multi-step etch-and-rinse adhesives' bond strength / Efeito da dentina cariada na resistência adesiva de um sistema adesivo universal e um de condicionamento ácido total

Objective: To evaluate the influence of caries-affected dentin on bond strength of a universal one-step and a multi-step etch-and-rinse adhesive system. Material and method: Enamel of 60 third human molars with and without caries was removed to expose dentin. The teeth were randomly assigned to six groups: Single Bond Universal (3M ESPE, St. Paul, MN, USA) in etch-and-rinse and in self-etch mode and Prime & Bond NT (Dentsply Co, Konstanz, Germany), all on sound and caries-affected dentin. Smear layer of the 30 sound dentin specimens was standardized by polishing with 600-grit SiC paper under water cooling. Residual infected dentin of the 30 caries-affected specimens was removed with a number 4 CA carbide bur until no caries smooth tissue was detectable by tactile-visual inspection. Cylinders of a light cured composite resin (Filtek Z350 XT, 3M ESPE) were built up using starch tubes and microshear test was performed until failure. The data was analyzed by one-way ANOVA and Tukey's post hoc test. Result: Significant differences in microshear bond strength (μSBS) were observed for the caries-affected groups, but not for sound dentin. The μSBS of Single Bond Universal were not influenced by the application protocol on sound dentin, however they were lower in the caries-affected group with both application protocols. The μSBS for Prime & Bond NT was not influenced by the dentin conditions. Conclusion: Caries-affected dentin decrease in bond strength of Single Bond Universal in comparison to sound dentin. The bond strength of Prime & Bond NT was not altered by substrate conditions.

Objetivo: Avaliar a influência da dentina afetada na resistência de união de um sistema adesivo universal e de um adesivo de condicionamento ácido total acetonado. Material e método: As faces oclusais de 60 terceiros molares humanos, hígidos e cariados, foram removidas a fim de expor o substrato dentinário. Os dentes foram divididos aleatoriamente em 6 grupos: Single Bond Universal (3M Dental Products, Seefeld, Germany), nos protocolos de condicionamento total e autocondicionante, e Prime&BondNT (DentsplyDeTrey, Konstanz, Germany), em dentina hígida e afetada. A smearlayer de 30 espécimes de dentina hígida foi padronizada com lixas de granulação 600. A dentina residual infectada de 30 espécimes foi removida com uma broca carbide número 4 até que nada fosse detectável por uma inspeção clínica. Pinos de resina composta (Filtek Z350 XT, 3M ESPE, St. Paul, MN) foram construídos usando tubos de amido como matriz. O teste de microcisalhamento foi realizado em uma máquina universal de testes até que houvesse a fratura. Resultado: Diferenças significantes foram observadas na resistência de união apenas para os espécimes de dentina afetada. A resistência de união do Single Bond Universal não foi influenciada pelo protocolo de aplicação nos espécimes de dentina hígida, mas diminuiu para os espécimes de dentina afetada, enquanto que o desempenho da adesão do Prime&BondNT não foi influenciada pela condição dentinária. Conclusão: A dentina afetada reduziu a resistência de união do Single Bond Universal, em comparação à dentina hígida. A resistência de união do Prime & Bond NT não foi alterada pela condição dos substratos.

Laser-prepared and bonding-filled fissure sealing: SEM and OCT analysis of marginal and internal adaptation.

This study assessed the effect of bur or Er:YAG laser preparation on marginal and internal adaptation of conventional and extended fissure sealing (FS) with a 3-component etch-and-rinse (Optibond FL; OFL) and a 1-component self-etch (Scotchbond Universal; SB) adhesive system. Scanning electron microscope analysis was performed before and after thermocycling/occlusal load and additional optical coherence tomography evaluation was carried out for internal marginal assessment. Significant differences were observed between the groups (ANOVA, p<0.05). Laser-prepared and non-etched FS suffered from marginal degradation after fatigue. When enamel was etched with H3PO4 and independently of the adhesive system, laser technique was equally effective to bur-preparation with percentages of continuous margins ranging from 96 to 99%, being laser less invasive than bur preparation. This is clinically relevant in paediatric dentistry as minimally invasive FS can be performed with laser and adhesive systems used as fissure sealants. Nevertheless, enamel etch with phosphoric acid is still necessary.

Effect of 180-Day Water Storage on Bonding Effectiveness of Self-Adhesive Systems to Occlusal and Proximal Dentin.

PURPOSE: This study aimed to evaluate the microshear bond strength (µSBS) values of adhesive systems to occlusal and proximal dentin submitted to water storage aging. MATERIALS AND METHODS: Occlusal and proximal dentin surfaces were obtained from 90 molars, polished with 600-grit SiC and divided according to the type of adhesive system: one total-etch and two self-etch. Starch tubing was used to perform 1 mm2 cylindrical composite resin restorations. The specimens were aged in distilled water during different storage times: 24 hours, 3 months, and 6 months (n = 10). The specimens were submitted to µSBS test. The µSBS values in MPa were subject to three-way ANOVA and post hoc Tukey test (p < 0.05). RESULTS: There was no statistical difference in the µSBS values among the storage times (p = 0.72); however, the dentin region (p < 0.01) and the adhesive system (p < 0.01) significantly affected the µSBS. The proximal surface (14.7 ± 3.3 MPa) presented higher µSBS values than the occlusal dentin (10.9 ± 4.1 MPa). The all-in-one adhesive system (GB) achieved the highest µSBS mean (17.0 ± 1.7 MPa). CONCLUSION: Both material and dentin surface factors affected the composite-dentin bond strength; however, the water storage did not influence bonding effectiveness over time.

Stain susceptibility of composite and ceramic CAD/CAM blocks versus direct resin composites with different resinous matrices.

To evaluate the stain susceptibility of CAD/CAM blocks and direct composite after long term exposure to various staining agents. 40 disk-shaped samples were fabricated from each of nine materials; six CAD/CAM (Vitablocs Mark II, Paradigm MZ100, Experimental Vita Hybrid Ceramic, Vita Enamic, Experimental Kerr and Lava Ultimate) and three direct composites (Filtek Supreme, Venus Diamond and Filtek Silorane). Samples were randomly divided into five groups (n = 8) according to different staining solutions (distilled water, tea, red wine, coffee and artificial saliva). Initial L*a*b* values were assessed using a calibrated digital spectrophotometer. Specimens were immersed in staining solutions and stored in an incubator at 37 °C for 120 days. L*a*b* values were assessed again and color change (∆E) was calculated as difference between recorded L*a*b* values. ANOVA, and Duncan test were used to identify differences between groups (α = 0.05). Significant differences in ∆E values were detected between materials (p = 0.000). Among all staining solutions, the highest ∆E value was observed with red wine. The new CAD/CAM blocks (Vita Enamic, Vita Hybrid Ceramic and Lava Ultimate) showed the highest resistance to staining compared to the MZ100 composite resin blocks. Filtek Silorane, a direct composite, showed high stain resistance values compared to CAD/CAM materials and other direct composites. Ceramic and composite CAD/CAM blocks had lower staining susceptibility than methacrylate based direct composite. Staining susceptibility of the new resin based CAD/CAM materials Vita Enamic and Lava Ultimate was comparable to feldspathic ceramic blocks (Vitablocs Mark II). Filtek Silorane showed promising results that were comparable to some CAD/CAM blocks.

Marginal integrity of low-shrinking versus methacrylate-based composite: effect of different one-step self-etch adhesives.

The aim of the study was to evaluate the influence of composite type and adhesive system on the quality of marginal adaptation in standardized Class V cavities before and after thermo-mechanical loading (TML). The cavities were restored using different combinations of three adhesive systems [(Silorane System Adhesive (SSA), Clearfil S3 Bond (S3), G-Bond (G-B)] and two resin composite materials (Filtek Silorane, Clearfil AP-X). Six groups (n = 10): Group A (SSA-Primer + SSA-Bond, Filtek Silorane), Group B (SSA-Primer + SSA-Bond, Clearfil AP-X), Group C (S3 + SSA-Bond, Filtek Silorane), Group D (S3 + SSA-Bond, Clearfil AP-X), Group E (G-B + SSA-Bond, Filtek Silorane) and Group F (G-B + SSA-Bond, Clearfil AP-X) were defined. Marginal adaptation was assessed on replicas in the SEM at 200 × magnification before and after TML (3000 × 5-55 °C, 1.2 106 × 49 N; 1.7 Hz) under simulated dentinal fluid. The highest scores of continuous margins (%CM) were observed in the group F (G-B + SSA-Bond, Clearfil AP-X: before loading 96.4 (±3.2)/after loading 90.8 (±7.0)). A significant effect of adhesive system, composite type and loading interval was observed on the results (p < 0.05). Significantly lower scores of %CM were observed for silorane-based composite (Filtek Silorane) after TML in comparison with methacrylate-based composite (Clearfil AP-X) considering total marginal length (p < 0.05). For both Filtek Silorane and Clearfil AP-X, G-Bond performed significantly better than SSA-Primer and Clearfil S3 Bond (p < 0.05). For all combinations of one-step self-etch adhesives and SSA-Bond resin coating, silorane-based low-shrinking composite exhibited inferior marginal adaptation than did the methacrylate-based composite.

Marginal integrity of resin composite restorations restored with PPD initiatorcontaining resin composite cured by QTH, monowave and polywave LED units.

This study evaluated the influence of curing devices on marginal adaptation of cavities restored with self-etching adhesive containing CQ and PPD initiators and hybrid composite. Twenty-four class V (3 groups, n=8) with margins located on enamel and dentin were restored with Clearfil S3 Bond and Clearfil APX PLT, light-cured with a monowave LED, multiwave LED and halogen light-curing unit (LCU). Marginal adaptation was evaluated with SEM before/after thermo-mechanical loading (TML). On enamel, significantly lower % continuous margins (74.5±12.6) were found in group cured by multiwave LED when compared to monowave LED (87.6±9.5) and halogen LCU (94.4±9.1). The presence of enamel and composite fractures was significantly higher in the group light-cured with multiwave LED, probably due to an increased materials' friability resulted from an improved degree of cure. The clinician should aware that due to a distinct activation of both initiators, marginal quality may be influenced on the long-term.

Comparing different enamel pretreatment options for resin-infiltration of natural non-cavitated carious lesions.

PURPOSE: To compare two different enamel pretreatments and their effect on the efficiency of penetration of a one-component adhesive into natural carious lesions. METHODS: Eight extracted human molars and premolars with non-cavitated interproximal lesions were selected. ICDAS code 1-2 was assessed by visual, microscopic, X-ray and Diagnocam record analysis. Samples were cut vertically across the demineralization to obtain two symmetrical lesions, (n=16). After isolating the cut surfaces with nail varnish, paired lesion halves' surfaces were pretreated with two different techniques: Group 1: surfaces were firstly abraded with fine diamond-coated metallic strips (Steelcarbo) and then etched with 37% H3PO4 acid (Omni-etch, 120 seconds); Group 2: lesion surfaces were etched with 15% HCl acid (Icon-etch, 120 seconds). All teeth were stained with rhodamine isothiocyanate (RITC) solution (12 hours) and subsequently stored in dry chamber (3 hours). All samples were penetrated with a one-component adhesive (Scotchbond Universal) for 180 seconds and coated with a thin layer of flowable composite (Tetric Flow). After light curing, un- encapsulated dye was bleached by immersion in 30% hydogen peroxide for 12 hours at 37°C. Remaining lesion pores were stained with sodium fluorescein solution. Thin cuts of the teeth were observed with confocal microscopy and computer image analysis was performed (ImageJ). The percentage of penetration (area of resin penetration/area of total demineralization x100) was calculated. RESULTS: Pretreatment with fine aluminum oxide-coated metallic strip followed by 37% H3PO4 acid showed a larger infiltration area (51.7% ± 12.2) in almost all samples compared to pretreatment with 15% HCl acid alone (22.1% ± 13.2). Statistical analysis using t-test showed a significant difference between the two groups (P = 0.011).

Influence of a heating device and adhesive temperature on bond strength of a simplified ethanol-based adhesive system / Influência de um dispositivo de aquecimento e da temperatura do adesivo na resistência de união de um sistema adesivo à base de etanol

Introduction: Increased adhesive temperature has been reported to promote solvent evaporation, reduce viscosity, and improve monomeric permeation into dentin. Objective: The aim of this study was to determine the influence of different heating methods on the microtensile bond strength of an etch-and-rinse adhesive to dentin. Material and method: Twenty-four caries-free extracted human third molars were transversally sectioned to expose a flat dentinal surface. The samples were etched with 37% phosphoric acid gel and divided into three groups (n = 8): 1) Control - the adhesive system (Adper Single Bond 2; 3M ESPE) was applied at room temperature; 2) Warming device - the adhesive was warmed to 37°C in a custom device before application; and 3) Warm air - the adhesive was warmed to 50°C with an air jet after application on dentin. The specimens were restored with a composite resin (Filtek Z250 A2, 3M ESPE) and prepared for microtensile bond strength testing, after 24 h in water storage. The data were subjected to one-way ANOVA and Tukey's test (p < 0.05). Result: There was no significant difference among the groups (p > 0.05). The mean bond strength values in the control, the warming device, and the warm air groups were 48.5 (± 5.2), 40.35 (± 4.9), and 47.2 (± 5.3) MPa, respectively (p = 0.05). Conclusion: The different heating methods had no significant influence on the immediate microtensile bond strength of an etch-and-rinse ethanol-based adhesive to dentin.

Introdução:O aumento da temperatura do adesivo tem sido pesquisado como forma de melhorar a evaporação do solvente, reduzir a viscosidade e melhorar a permeação dos monômeros na dentina. Objetivo: Investigar a influência de diferentes métodos de aquecimento na resistência de união à dentina sob um ensaio de microtração de um adesivo de condicionamento ácido total. Material e método: Vinte e quatro terceiros molares hígidos foram seccionados transversalmente a fim de expor a superfície plana da dentina. As amostras foram condicionadas ácido fosfórico a 37% e dividido em três grupos (n=8). São eles: 1) Controle - onde o adesivo (Adper Single Bond 2, 3M ESPE) foi aplicado em temperatura normal (25°C); 2) Dispositivo de aquecimento - O adesivo foi aquecido em um dispositivo específico até alcançar a temperatura de 37°C e só então aplicado à dentina; 3) Ar quente - Usou-se jato de ar aquecido a 50°C por 10 segundos a uma distância de 10cm para facilitar a evaporação do solvente. Os espécimes foram restaurados com resina composta (Filtek Z250 A2, 3M ESPE) e preparados para o ensaio de microtração, após 24h de armazenamento em água destilada. Os dados obtidos foram submetidos para análise de variância (ANOVA) e teste de Tukey (p< 0,05). Resultado: Não houve diferença significativa entre os grupos (p> 0,05). As médias da resistência de união para o grupo controle, dispositivo de aquecimento e ar quente foram, respectivamente, 48,5 (± 5,2), 40,35 (± 4,9), e 47,2 (± 5,3). Conclusão: Os diferentes métodos de aquecimento não influenciaram significativamente na resistência de união imediata à dentina de um Sistema adesivo de condicionamento ácido total.

Comparative in vitro wear resistance of CAD/CAM composite resin and ceramic materials.

STATEMENT OF PROBLEM: Composite resin is a promising option in computer-aided design and computer-aided manufacturing (CAD/CAM) dentistry; however, the wear resistance of composite resin remains a primary concern. PURPOSE: The purpose of this in vitro study was to evaluate the wear resistance of 5 CAD/CAM materials (n=10), consisting of 4 composite resins (3M Lava Ultimate, Kerr experimental composite resin material, Vita Enamic, 3M Paradigm MZ100) and 1 ceramic (Vita Mark II) in contact with natural human enamel cusps. MATERIAL AND METHODS: Specimens were loaded into a computer-controlled mastication simulator and subjected to 200000 mechanical cycles (49 N) against natural human enamel simultaneously with 500 thermal cycles (5°C to 50°C to 5°C). The wear resistance was analyzed by measuring the vertical substance loss (the maximum depth of the worn area) in the contact point area of the specimen. The worn surfaces were observed by scanning electron microscopy to determine the wear patterns. RESULTS: Vita Mark II exhibited the best wear resistance among the tested materials, followed by 3M Lava Ultimate, Vita Enamic, and 3M Paradigm MZ100. The Kerr experimental material exhibited the lowest wear resistance, yet its results were not significantly different from those of the 3 other composite resin blocks (P>.05). CONCLUSIONS: Within the limitations of this in vitro study, the wear resistance of composite resin blocks in contact with enamel cusps was significantly lower than that of a ceramic block.