Efficacy of topical drug application to manage in-office bleaching sensitivity: a systematic review and meta-analysis of randomized clinical trials.

OBJECTIVES: To answer whether the topical drug application can reduce in-office tooth bleaching sensitivity without impairing the color change. MATERIALS AND METHODS: This review was registered on PROSPERO (CRD42024524171). Two reviewers screened PubMed, Web of Science, Scopus, Embase, and clinicaltrials.gov in March 2024 independently for randomized clinical trials investigating the efficacy of topical drug application to manage in-office tooth bleaching sensitivity. The risk of bias was assessed using Cochrane's Risk of Bias tool (RoB2). Certainty of the evidence was assessed using the Grading of Recommendations: Assessment, Development, and Evaluation tool (GRADE). The meta-analyses evaluated the bleaching sensitivity and color change with RevMan 5.4 software. RESULTS: 334 articles were retrieved. The final sample was composed of four articles. Tested drugs were Otosporin, Eugenol, Ibuprofen with arginine, and Dipyrone. The meta-analysis evidenced no difference in bleaching sensitivity up to 1 h (MD, -0.39; 95% CI, -0.89, 0.11), 24 h (MD, -0.26, 95% CI, -0.71, 0.18), or 48 h (MD, 0.00, 95% CI, -0.16, 0.16). Meta-analysis for color change evidenced no difference for color change (MD, 0.03; 95% IC, -0.56, 0.61). The risk of bias was low. The certainty of the evidence was rated moderate for bleaching sensitivity and high for color change. CONCLUSIONS: Although topical drug application did not impair color change, it was ineffective in reducing in-office tooth bleaching sensitivity. CLINICAL RELEVANCE: topical drug application on dental enamel is not an effective approach in reducing bleaching sensitivity, but several modifications can be made in future studies to possibly achieve a better outcome.

Are bodybuilding and cross-training practices dangerous for promoting orofacial injuries? A scoping review.

Bodybuilding and cross-training exercises bring health benefits. However, orofacial injuries can occur during practice. This study aimed to map, analyze, interpret, and synthesize data from studies on the main orofacial injuries resulting from bodybuilding and cross-training practices. This scoping review followed the Joanna Briggs Institute and PRISMA-ScR methods, with high-sensitivity searches in PubMed, Web of Science, Scopus, ScienceDirect, Embase, Virtual Health Library and the Google Scholar. Original scientific articles published up to May 2024 were included, which evaluated the presence of self-reported or professionally diagnosed orofacial injuries by bodybuilding and cross-training practitioners aged 18 years or older. Literature reviews, editorials, and guidelines were excluded. Tables and figures were used to map and summarize the results. Out of 30.485 potentially eligible articles, four were included. The main orofacial injuries identified in both bodybuilding and cross-training practitioners were dental damage (n = 4), temporomandibular joint (TMJ) disorders (n = 3), and traumas to oral soft tissues (n = 2) and facial soft tissues (n = 2). Dental damage and TMJ disorders were the most prevalent conditions among bodybuilding and cross-training practitioners. Therefore, dental damage and TMJ disorders were the most prevalent conditions among bodybuilding and cross-training practitioners. However, further prospective studies with more in-depth methodological designs and fewer biases are necessary.

Addition of substances to reduce the erosive potential of acidic beverages to tooth enamel: A scoping review.

OBJECTIVE: This scoping review aimed (1) to map, analyse, interpret and synthesize data from in situ studies on which substances were added to acidic beverages to reduce the erosive potential on tooth enamel and (2) to establish the level of evidence of the effectiveness of adding substances to acidic beverages to reduce the erosive potential on tooth enamel. DESIGN: This is a scoping review, according to the methods from the Joanna Briggs Institute and PRISMA-ScR, with high-sensitivity searches in the databases PubMed (MEDLINE), Virtual Health Library, Embase (Elsevier), Scopus (Elsevier), Web of Science and ScienceDirect (Elsevier). In situ studies published in English until December 2022 were included. Studies that did not report a control group were excluded. To map and summarize the results, tables and figures were used. RESULTS: From 895 potentially eligible articles, nine were included. Blackcurrant juices (n = 5) with the addition of calcium (n = 3) or xanthan gum (n = 2) formulations were the most tested in terms of reducing the erosive potential of the beverages on tooth enamel. The profilometer was the equipment of choice (n = 8) for evaluating the loss of enamel structure after the experimental tests. CONCLUSIONS: Calcium and xanthan gum are among the most tested by in situ studies, offering promising results in reducing the erosive potential of fruit juices and carbonated and energy drinks.

Direct and semi-direct resin composite restoration in large cavity preparations: analysis of dentin bond strength stability and bottom/top microhardness ratio in a cavity model.

To evaluate the influence of the restorative approach and aging time on dentin bond strength (BS), failure mode (FM), and bottom/top microhardness ratio (B/T) in a large dentin cavity model. A total of 102 bovine incisors were used to produce models of conical dentin cavities (4.0 mm thickness × 4.8 mm top diameter × 2.8 mm bottom diameter), which were restored using semi-direct filling (SDF) (Filtek™ Z250 XT + Scotchbond™ Universal/RelyX™ Ultimate luting system), direct bulk filling (DBF) (Filtek™ One Bulk Fill), and direct incremental filling (DIF) (Filtek™ Z250 XT) techniques. B/T, BS, and FM (n = 17) were analyzed in a microhardness tester, a universal testing machine, and a stereomicroscope, respectively, after 24 h and 6 months of water storage. BS and B/T data were analyzed using two-way ANOVA/Tukey post-hoc test (p < 0.05), while FM data were analyzed descriptively. There was a statistically significant difference in BS between the restorative techniques, and BS was influenced by aging time in the DBF and SDF groups. Mixed failure was predominant for the SDF technique in both aging times. There was no statistically significant difference in B/T among the restorative approaches regardless of the aging time (p > 0.05). Although all restorative approaches provided similar B/T, the semi-direct technique showed better performance on the material bond strength to dentine in large cavities.

Effects of ionizing radiation on surface properties of current restorative dental materials.

To investigate the impact of radiotherapy on surface properties of restorative dental materials. A conventional resin composite-CRC (Aura Enamel), a bulk-fill resin composite-BFRC (Aura Bulk-fill), a conventional glass ionomer cement-CGIC (Riva self cure), and a resin-modified glass ionomer cement-RMGIC (Riva light cure) were tested. Forty disc-shaped samples from each material (8 mm diameter × 2 mm thickness) (n = 10) were produced according to manufacturer directions and then stored in water distilled for 24 h. Surface wettability (water contact angle), Vickers microhardness, and micromorphology through scanning electron microscopy (SEM) before and after exposition to ionizing radiation (60 Gy) were obtained. The data were statistically evaluated using the two-way ANOVA and Tukey posthoc test (p < 0.05). Baseline and post-radiation values of contact angles were statistically similar for CRC, BFRC, and RMGIC, whilst post-radiation values of contact angles were statistically lower than baseline ones for CGIC. Exposition to ionizing radiation statistically increased the microhardness of CRC, and statistically decreased the microhardness of CGIC. The surface micromorphology of all materials was changed post-radiation. Exposure to ionizing radiation negatively affected the conventional glass ionomer tested, while did not alter or improved surface properties testing of the resin composites and the resin-modified glass ionomer cement tested.

The combined use of systemic analgesic/anti-inflammatory drugs and a bioactive topical desensitizer for reduced in-office bleaching sensitivity without jeopardizing the hydrogen peroxide efficacy: a randomized, triple blinded, split-mouth clinical trial.

OBJECTIVE: To evaluate the effect of combined systemic administration of paracetamol 500 mg/codeine phosphate 30 mg (PACO) and postoperative topical application of a bioactive desensitizer on in-office bleaching sensitivity and tooth color change. MATERIALS AND METHODS: A randomized, triple-blind, split-mouth clinical trial was conducted. Forty volunteers ingested PACO (n = 20) or placebo (PLA) (n = 20). Their left/right hemiarches received topical application of a bioactive desensitizer [Nano-P™(NP)] and prophylactic paste (PAS), generating four treatment approaches: PACO/NP, PACO/PAS, PLA/NP, and PLA/PAS. Two bleaching sessions (35% hydrogen peroxide) were performed, and the PAS/NP were applied after the procedure. Sensitivity was obtained since the first bleaching session up to 7 days post-bleaching. The color change was evaluated using CIEDE2000 and whiteness index parameters up to 7 days post-bleaching. Data were analyzed using one- and two-way ANOVA/Tukey post hoc tests (p < 0.05). RESULTS: The PLA/PAS showed a sensitivity average of at least two times higher than the PACO/NP. The treatment approaches promoted statistically similar bleaching patterns (p > 0.05). CONCLUSION: The combined approach of systemic administration of PACO and postoperative topical application of NP reduced the level of in-office bleaching sensitivity without jeopardizing hydrogen peroxide efficacy. CLINICAL RELEVANCE: Professionals can adopt the combined approach of systemic administration of analgesic/anti-inflammatory drugs and topical application of a bioactive desensitizer for decreased bleaching sensitivity caused by 35% hydrogen peroxide in-office.

Relationship of Porphyromonas gingivalis and Alzheimer's disease: a systematic review of pre-clinical studies.

OBJECTIVES: This study aimed to analyze the following PICO question: Are animals infected with Porphyromonas gingivalis (P. gingivalis) or bacterial lipopolysaccharide (Pg-LPS) more affected by neurodegeneration, similar to the pathogenesis generated by Alzheimer's disease (AD), compared with non-infected animals? METHODS: Databases PubMed, Lilacs, SciELO, Science Direct, Scopus, Web of Science, and Cochrane were searched for pre-clinical in vivo studies in which mice were infected with P. gingivalis or received Pg-LPS, in order to assess the brain tissue and cognitive impairment. No limit for date or publication language was imposed and this study was registered at the International Prospective Register of Systematic Reviews (PROSPERO), with nine articles included. Syrcle's protocol was used to evaluate bias in the selected studies. RESULTS: Nine articles were included. Infection by P. gingivalis or the administration of Pg-LPS increased the production of the inflammatory mediators, TNF-α (tumor necrosis factor-alpha), IL-6 (interleukin-6), and IL-1ß (interleukin-1beta), augmented Aß (amyloid beta) production, and activated the complement system, causing inflammation, brain tissue degeneration, and cognitive impairment, consistent with the damage in AD. CONCLUSIONS: Infection by P. gingivalis and Pg-LPS administration appears to be in relation with the pathogenesis of AD by activating the complement cascade, increasing Aß production and augmenting pro-inflammatory cytokine expression, causing age-dependent brain inflammation, neuroinflammation, and neurodegeneration. CLINICAL RELEVANCE: Taking into account the importance of holistic treatment in the dental office, this study focuses on identifying highly prevalent oral diseases, such as periodontal disease, as risk factors for the aggravation of degenerative diseases in the elderly population.

Efficacy of ibuprofen and codeine + paracetamol to reduce immediate bleaching sensitivity caused by in-office tooth bleaching: A randomized, controlled, double-blind clinical trial.

PURPOSE: To evaluate (1) the efficacy of Ibuprofen and codeine + paracetamol to control immediate bleaching sensitivity caused by in-office tooth bleaching performed with 35% hydrogen peroxide, and (2) tooth shade change caused by 35% hydrogen peroxide. METHODS: In this randomized, controlled and double blind clinical trial, 60 volunteers were divided into three treatment groups: 400 mg placebo (PL)(n=20), 400 mg ibuprofen (IB)(n=20), or 30 mg codeine + 500 mg paracetamol (CP)(n=20). The volunteers were submitted to two bleaching sessions with 35% hydrogen peroxide in 2 applications of 20 minutes each. In both sessions, the medication was given to the volunteers 1 hour before the bleaching procedure. The sensitivity values were obtained with the analogic visual pain scale. Tooth shade was assessed before and after bleaching. Statistical analysis was done through the one-way ANOVA and Tukey post-hoc tests. RESULTS: For bleaching sensitivity, there were statistically significant differences among the medications (P< 0.01). The lowest sensitivity means were found in the CP group (PL:4.7 = IB:4.8 > CP:1.0). In regards to tooth shade, participant's teeth were statistically significantly lighter after bleaching than before bleaching (P< 0.01), with no statistically significant difference between the medications (P< 0.05). CLINICAL SIGNIFICANCE: The use of codeine + paracetamol 1 hour before in-office tooth bleaching can drastically reduce immediate sensitivity.

Low-level laser therapy (780 nm) combined with collagen sponge scaffold promotes repair of rat cranial critical-size defects and increases TGF-ß, FGF-2, OPG/RANK and osteocalcin expression.

The aim of this study was to evaluate the effect of collagen sponge scaffold (CSS) implantation associated with low-level laser therapy (LLLT) on repairing bone defects. A single 5-mm cranial defect was surgically created in forty Wistar rats, which then received one of the following four interventions (n = 10 per group): no treatment (G0); bone defect implanted with collagen sponge scaffold (CSS) alone (G1); defect treated with low-level laser therapy (LLLT) (wavelength 780 nm; total energy density 120 J/cm2 ; power 50 mW) alone (G2); and CSS associated with LLLT treatment (G3). After surgery, animals in each group were euthanized at 21 days and 30 days (n = 5 per euthanasia time group). Bone formation was monitored by X-ray imaging analysis. Biopsies were collected and processed for histological analysis and immunohistochemical evaluation of transforming growth factor-beta (TGF-ß), fibroblast growth factor-2 (FGF-2), osteoprotegerin (OPG) and receptor activator of nuclear factor ƙ (RANK). Osteocalcin (OCN) was detected by immunofluorescence analysis. Compared to the G0 group, defects in the 30-day G3 group exhibited increased bone formation, both by increase in radiopaque areas (P < 0.01) and by histomorphometric analysis (P < 0.001). The histopathological analysis showed a decreased number of inflammatory cells (P < 0.001). The combined CCS + LLLT (G3) treatment also resulted in the most intense immunostaining for OPG, RANK, FGF-2 and TGF-ß, and the most intense and diffuse OCN immunofluorescent labelling at 30 days postsurgery (G3 vs. G0 group, P < 0.05). Therefore, the use of CCS associated with LLLT could offer a synergistic advantage in improving the healing of bone fractures.

Marginal and internal analysis of preheated dental fissure-sealing materials using optical coherence tomography.

OBJECTIVES: This study aimed to evaluate the influence of pre-photoactivation temperature on the marginal and internal integrity (occurrence of voids) of fissure-sealing materials on occlusal fissures using optical coherence tomography (OCT). METHODS: Occlusal fissures of 40 human third molars were sealed using a resin-based fissure sealant (Fluroshield) and a flowable composite (Permaflo) photoactivated at 68 °C (preheated) or at room temperature (25 °C) (n=10). After sealing, the teeth were subjected to thermocycling (500 cycles, 5-55 °C) and 14 days of pH cycling (demineralisation for 6 hours/day and remineralisation for 18 hours/day). The occlusal surfaces were scanned in a buccolingual direction, and 20 tomographic images parallel to the long axis of each tooth were obtained. Images presenting marginal gaps and internal voids were counted and statistically analysed using analysis of variance and Tukey's test (P<0.05). RESULTS: There were statistically significant differences between materials and temperatures (P<0.01). The flowable composite had a lower percentage of gaps and internal voids than the resin-based sealant. Preheated materials had a lower percentage of gaps and internal voids than the materials at room temperature. CONCLUSION: Therefore, preheated flowable composite provided the best marginal sealing of fissures, and internal homogeneity of the material.

Effect of Instrument Lubricants on the Surface Degree of Conversion and Crosslinking Density of Nanocomposites.

PURPOSE: The surface degree of conversion and crosslink density of composites should not be affected by the use of instrument lubricants in order to provide long-lasting tooth restorations. This study aimed to analyze the effect of instrument lubricants on the degree of conversion and crosslink density of nanocomposites. MATERIALS AND METHODS: Samples (N = 10) were fabricated according to the composites (Filtek Z350 XT, 3M ESPE, St. Paul, MN, USA; and IPS Empress Direct, Ivoclar Vivadent AG, Schaan, Liechtenstein and lubricants used (Adper Single Bond 2 and Scotchbond Multi-Purpose bonding agent adhesive systems, 3M ESPE; 70% ethanol, absolute ethanol, and no lubricant). Single composite increments were inserted into a Teflon mold using the same dental instrument. The composite surface was then modeled using a brush wiped with each adhesive system and a spatula wiped with each ethanol. The control group was fabricated with no additional modeling. The surface degree of conversion and crosslink density were measured by Fourier transform infrared spectroscopy and the hardness decrease test, respectively. Data were analyzed using two-way analysis of variance and the Tukey's test (p < 0.05). RESULTS: Filtek Z350 XT showed statistically similar degree of conversion regardless of the lubricant used, whereas the use of adhesive systems and 70% ethanol decreased the degree of conversion for IPS Empress Direct. Only Scotchbond Multi-Purpose bonding agent decreased crosslink density for Filtek Z350 XT, whereas both adhesive systems decreased crosslink density for IPS Empress Direct. CONCLUSION: Filtek Z350 XT appeared to be less sensitive to the effects of lubricants, and absolute ethanol did not affect the degree of conversion and crosslink density of the nanocomposites tested. CLINICAL SIGNIFICANCE: Although the use of lubricants may be recommended to minimize the stickiness of dental instruments and composite resin, dentists should choose materials that do not have a negative effect on the surface properties of composites. Only the use of absolute ethanol safely maintains the surface integrity of nanocomposites in comparison with adhesive system and 70% ethanol.

Impact of toothbrushing with a dentifrice containing calcium peroxide on enamel color and roughness.

This in vitro study sought to evaluate both the bleaching potential and changes to average surface roughness (Ra) of enamel after brushing with a dentifrice. Fifty-four enamel specimens (4 x 4 x 2 mm) were divided into 3 groups (n = 18) and treated with 1 of 3 dentifrices: 1 with calcium peroxide, and 2 without. The samples were submitted to 20,000 brushing cycles. Color and Ra were measured before and after brushing. Although the Ra increased in all groups after brushing, only the dentifrice containing calcium peroxide resulted in an increase in reflectance.

Can carbamide peroxide be as effective as hydrogen peroxide for in-office tooth bleaching and cause less sensitivity? A systematic review.

This study aimed to answer the question through a systematic review: Can carbamide peroxide be as effective as hydrogen peroxide and cause less in-office bleaching sensitivity? A literature survey was performed in PubMed/MEDLINE, Embase, Scopus, ISI Web of Science, and gray literature. Primary clinical trials that compared the efficacy or the in-office bleaching sensitivity between carbamide and hydrogen peroxides were included. The risk of bias was evaluated using the RoB2. The certainty of the evidence was assessed using the GRADE approach. DPI training significantly improved the mean scores of the dental undergraduates from 7.53 in the pre-DPI-training test to 9.01 in the post-DPI-training test (p < 0.001). After 6 weeks, the mean scores decreased marginally to 8.87 in the retention test (p = 0.563). DPI training increased their confidence level from 5.68 pre-DPI training to 7.09 post-DPI training. The limited evidence suggests that the 37% carbamide peroxide may be similarly effective to the 35% hydrogen peroxide for bleaching teeth in-office and causes less bleaching sensitivity. However, more well-designed split-mouth clinical trials are necessary to strengthen the evidence.

Thermo-mechanical degradation of composite restoration photoactivated by modulated methods-a SEM study of marginal and internal gap formation.

OBJECTIVE: To evaluate the influence of thermal-mechanical degradation on superficial and internal gap formation of composite restorations photoactivated using modulated methods. MATERIALS AND METHODS: An experimental composite was prepared using a resin matrix containing 65wt% Bis-GMA and 35wt% TEGDMA. Camphorquinone (0.5wt%) and dimethylaminoethyl-methacrylate (0.5wt%) were dissolved in the resin as a photo-initiator system and 65wt.% silanized glass fillers were added to the matrix. Ground buccal surfaces of bovine lower incisors were used to make 160 preparations (3 mm × 3 mm × 2 mm in depth). An adhesive system (Adper Single Bond 2) was applied and the specimens were assigned into 16 groups (n = 10), according to the photoactivation method [high intensity (HI), low intensity (LI), soft-start (SS) and pulse-delay (PD)] and the degradation protocol [(control/no degradation; thermal cycling (TC); mechanical loading (ML); thermo-mechanical loading (TC+ML)]. Marginal and internal interfaces of bonded restorations were replicated in epoxy resin and analyzed by SEM. Gaps were expressed as a percentage of the total length of the margins. Data were submitted to 2-way ANOVA and Tukey's test (α = 0.05). RESULTS: For the control group no significance was noted among the photoactivation methods. TC had no effect in gap formation. ML and TC+ML increased the incidence of superficial gaps for both HI and SS groups as well as increased the internal gaps for all groups. CONCLUSION: Although photoactivation methods do not influence gap formation at first, composite restoration photoactivated by low intensity or modulated methods showed improved resistance to thermo-mechanical degradation. Mechanical loading is determinant for interfacial degradation of composite restorations, while thermal cycling has no effect on gap formation.

Impact of remineralizing agents on enamel microhardness recovery after in-office tooth bleaching therapies.

OBJECTIVE: It has been shown that bleaching with 35/38% hydrogen peroxides may alter both enamel morphology and mineral content. This study aimed to analyze the morphology and microhardness of enamel bleached with in-office hydrogen peroxides and exposed toremineralizing agents. MATERIALS AND METHODS: After recording initial enamel morphology and microhardness, 60 bovine incisors were bleached using either a calcium-containing 35% hydrogen peroxide (Whiteness HP Blue) or a calcium-free 35% hydrogen peroxide (Whitegold Office) (n = 30). Then, the teeth were subjected to one of three post-bleaching remineralizing treatments (n = 10): storage in artificial saliva only, application of a sodium fluoride gel or application of a nanohydroxyapatite-based agent (Nano-P). After 24 h and 14 days of post-bleaching treatments, the enamel morphology and microhardness were re-evaluated. The microhardness data were analyzed by means of two-way ANOVA with repeated measurements and Tukey tests (p < 0.05), while the enamel morphology was analyzed descriptively. RESULTS: Samples exposed to Nano-P presented statistically the highest microhardness 24 h after its application in comparison with other remineralizing agents. The microhardness recovery did not occur in any of the groups 14 days after treatment. The morphology of all samples 14 days after the application of all remineralizing agents presented a higher number of irregularities. CONCLUSION: Although some remineralizing products provided microhardness recovery and a positive effect on enamel morphology at 24 h post-bleaching, none of them were able to maintain microhardness and enamel morphology at 14 days post-bleaching.

Effect of the application of a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste and adhesive systems on bond durability of a fissure sealant.

This study aimed to evaluate the effect of the previous application of a casein phosphopeptide-amorphous calcium phosphate paste (MI Paste, MI) and adhesive systems on the bond durability of a fissure sealant. Ninety-eight enamel blocks were obtained from proximal surfaces of erupted third molars. Specimens were divided into 14 groups (n = 7) according to the previous application of MI (with and without) and the adhesive systems used (no adhesive system; hydrophobic resin of a three-step etch-and-rinse adhesive system; etch-and-rinse single-bottle adhesive system; all-in-one adhesive system; two-step self-etching adhesive system; additional phosphoric acid conditioning and all-in-one adhesive system; additional phosphoric acid conditioning and two-step self-etching adhesive system). A fissure sealant (Fluroshield) was applied and photoactivated for 20 s. Beams (~0.7 mm(2)) were prepared for the microtensile bond strength test, which was executed after 24 h or 6 months of water storage. Fractured specimens were analyzed by scanning electronic microscopy. Data were analyzed by two-way ANOVA with repeated measures/Tukey's test (P < 0.05). Groups that received MI application and adhesive systems presented higher means than those groups where MI was not applied. Higher frequency of cohesive failures was observed for groups with MI. Applying a CPP-ACP containing paste on enamel before adhesive systems was an effective method to increase bond durability of the sealant tested.

A glimpse into the curricular format of comprehensive care clinics in Brazilian dental schools.

OBJECTIVE: This study aimed to describe some curricular aspects of comprehensive dental care clinics in Brazil. MATERIALS AND METHODS: An email survey was sent to all academic affairs deans of Brazilian undergraduate dental programmes. It contained questions regarding the (1) curricular format and (2) characteristics of comprehensive dental care clinics. RESULTS: Sixty-seven dental schools agreed to participate. It was observed that curricular changes have contributed to modify the structure of these clinics in 88.1% of the schools surveyed. The main alteration was related to an increase in credit hours and offer of this type of care at different levels of the dental curriculum. In 95.5% of the schools, clinical procedures were prioritized according to level of complexity. Inter-disciplinarity (37.3%) and teaching innovation (58.2%) were frequent challenges in the process of change. Progress in combining teaching and clinical services was reported by 50.8% of schools. In 32.8%, clinical procedures were still being performed intra-murally. CONCLUSIONS: Changes in the curriculum of Brazilian comprehensive dental care clinics were observed by this survey.

Effect of dentin pre-treatment with a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste on dentin bond strength in tridimensional cavities.

OBJECTIVE: This study aimed to evaluate the push-out bond strength of dimethacrylate (Clearfil SE Bond/Filtek Z250; and Adper SE Plus/Filtek Z250) and silorane-based (Filtek P90 adhesive system/Filtek P90 composite resin) restorative systems following selective dentin pre-treatment with a CPP-ACP-containing paste (MI Paste). MATERIALS AND METHODS: Sixty bovine incisors were utilized. The buccal surface was wet-ground to obtain a flat dentin area. Standardized conical cavities were then prepared. Adhesive systems were applied according to manufacturers' directions and the composites were bulk-inserted into the cavity. The push-out bond strength test was performed at a universal testing machine (0.5 mm/min) until failure; failure modes were analyzed by scanning electron microscopy. Data were analyzed by two-way ANOVA and Tukey post-hoc test (p < 0.05). RESULTS: For Clearfil SE Bond/Filtek Z250 and Filtek P90 adhesive system/Filtek P90 composite resin, the dentin pre-treatment did not influence bond strength means. For Adper SE Plus/Filtek Z250, dentin samples treated with MI Paste had statistically higher bond strength means than non-treated specimens. Adhesive failures were more frequent. CONCLUSION: Dentin pre-treatment with the CPP-ACP containing paste did not negatively affect bond strength for Clearfil SE Bond/Filtek Z250 and Filtek P90 adhesive system/Filtek P90 composite resin restorative systems and improved bond strength for the Adper SE Plus/Filtek Z250 restorative system.

Influence of the curing mode on the degree of conversion of a dual-cured self-adhesive resin luting cement beneath ceramic.

OBJECTIVE: To evaluate the effect of the delayed photoactivation and ceramic barrier on the degree of conversion (DC) of self-adhesive resin cement. MATERIALS AND METHODS: Circular specimens (5 mm in diameter × 1 mm in thickness) of the RelyX U-100 resin cement were made using the following curing protocols (n = 10): (G1) 40 s beneath a IPS Empress II ceramic; (G2) 40 s of direct photocuring; (G3) 80 s beneath the ceramic; (G4) 80 s of direct photocuring; (G5) self-curing; (G6) 5 min in the absence of light (self-curing) followed by transceramic photocuring for 40 s; (G7) 5 min in the absence of light (self-curing) followed by transceramic photocuring for 80 s. All the specimens were photoactivated by LED (800 mW/cm(2)). After 24 h of dry storage, the DC was measured by FTIR, on the top surface of the specimens. Data were submitted to one-way ANOVA and Tukey test (p ≤ 0.05). RESULTS: Direct photocuring with no ceramic interposition, regardless of the curing time (40 s and 80 s) promoted the highest conversion mean (56.79 ± 1.19 and 59.98 ± 2.93, respectively) and the 5 min delay time for the transceramic photocuring presented a similar mean compared to the immediate transceramic photocuring. The DC was influenced by the ceramic barrier, decreasing the conversion values (49.72 ± 1.91 for 40 s and 52.36 ± 2.50 for 80 s), with no statistical difference from the groups with the previous 5 min of photoactivation delay. The self-cure only showed the worst DC values. CONCLUSION: Direct photocuring provided a higher degree of conversion for the self-adhesive resin cement. The delayed light activation did not influence the degree of conversion for the resin cement tested.

Filler morphology of resin-based low-viscosity materials and surface properties after several photoactivation times.

AIM: This study aimed to characterize the morphology of filler particles and to analyze the effect of shortened and extended photoactivation times on hardness (VHN) and cross-link density (CLD) of resin-based low-viscosity materials. METHODS: Sixteen commercially available materials were tested: four fissure sealants (Alpha Seal, Fluroshield Yellowed, Bioseal and Fluroshield White) and 12 flowable composites (Opallis T, Permaflo T, Opallis A2, Natural Flow A2, Master Flow A2, Permaflo A2, Filtek Z350 A2, Natural Flow O, Master Flow OA2, Opallis OA3.5, Filtek Z350 OA3, Opallis OP) at six curing times (10 s, 20 s, 30 s, 40 s, 50 s and 60 s). Specimens were fabricated (n = 5), analyzed by Scanning Electron Microscopy, by VHN and by CLD. RESULTS: Unimodal and multimodal filler particles sizes with spherical and irregular shapes were observed. Unfilled materials were also detected. There were no differences among curing times for either VHN or CLD. Opallis A2 and Opallis OA3.5 showed the highest VHN at all curing times, whereas Master Flow A2 and Master Flow OA2 presented the lowest VHN. Opallis A2 presented the highest CLD at all curing times and Alpha Seal showed the lowest CLD. CONCLUSIONS: Filler particle morphology differed among the resin-based low-viscosity materials tested. The shortest photoactivation time tested could yield similar VHN and CLD means to those provided by the most extended photoactivation time.