The Influence on Fracture Resistance of Different Composite Resins and Prefabricated Posts to Restore Endodontically Treated Teeth.

Recent formulations of resin-based composites have incorporated different combinations of materials. However, the mechanical and bonding behavior of these materials with intraradicular posts are unclear. This study aimed to evaluate the effect of light-cure and dual-cure resin composite posts on the fracture resistance of endodontically-treated teeth. Materials and Methods: Ninety extracted human upper canines were selected and randomly divided into nine groups (n=10): (G1) endodontically treated teeth without endodontic posts; (G2) glass-fiber post cemented with glass-ionomer cement; (G3) endodontic post by dual-cure composite resin (Rebilda DC); (G4) endodontic post by dual-cure composite resin (Cosmecore); (G5) endodontic post by dual-cure composite resin (Bis-Core); (G6) endodontic post by light-cure composite resin; (G7) glass-fiber post customized with flowable composite resin; (G8) glass-fiber post cemented with light-cure composite resin; (G9) glass-fiber post cemented with self-adhesive resin cement. After the post insertion, all specimens were subjected to mechanical (250,000 cycles) and thermocycling (6000 cycles, 5 °C/55 °C) and immediate loading at 45 degrees in a universal testing machine until fracture. The data were analyzed by one-way ANOVA and multiple comparisons using the Fisher LSD Method (p < 0 05). Results: The mean failure loads (±SD) for the groups ranged from 100.7 ± 22.6 N to 221.9 ± 48.9 N. The G1 group (without endodontic posts) had a higher fracture strength than all experimental groups (p < 0.001). Conclusions: Within the limitations, the light- and dual-cure post technique did not present lower fracture resistance values as compared to the conventional glass-fiber post.

Effect of Curing Modes on the Mechanical Properties of Commercial Dental Resin-Based Composites: Comparison between Different LEDs and Microwave Units.

Resin-based composites (RBCs) have transformed restorative dentistry and its procedures. However, the characteristics of RBCs have been modified over the years to enhance the physical and chemical properties of the materials. This context raises the need for studies that evaluate whether the properties of the RBCs that are commercially available are clinically adequate with different curing modes. This study aimed to evaluate the mechanical behavior of commercial RBCs after undergoing different curing modes. Twenty-three RBCs of different classes were evaluated. For curing the specimens, a microwave (BMS45, Brastemp) (for 3 min at 450 W) and three LED units were used: an Emitter A Fit (Schuster (second generation)) (light-curing for 15 s with an irradiance of 1250 mW/cm2), VALO (Ultradent (third generation)) (light-curing for 15 s with an irradiance of 1100 mW/cm2), and Emitter Now Duo (Schuster (second generation)) (light-curing for 15 s with an irradiance of 1100 mW/cm2). A total of 670 RBC specimens of 8 mm in diameter and 1 mm in depth were obtained. Afterward, a biaxial flexure strength test was performed until the failure of the specimens, using a universal testing machine set at a speed of 0.5 mm/min. The same specimens were subjected to infrared spectroscopy for evaluating the degree of conversion. Tukey's test was used for multiple comparisons at a significance level of 5%. The light-curing mode did not affect the flexure strength of the RBCs (p > 0.05), but the type and shade of RBCs did so (p < 0.05). In conclusion, the type of RBC directly interferes with the mechanical behavior of the material. However, the curing modes within the same RBC did not change the mechanical properties.

Impact of Nonsurgical Treatment of Asymptomatic Apical Periodontitis on the Oral Health-related Quality of Life: A Prospective Study.

Introduction: The aim of this study was to evaluate the impact of nonsurgical root canal treatment (nRCT) and the healing of asymptomatic apical periodontitis (AAP) on the oral health-related quality of life (OHRQoL) in a Brazilian population. Materials and Methods: This prospective longitudinal observational study included 56 adults, in which 84 teeth with asymptomatic apical periodontitis underwent nonsurgical root canal treatment. Socio-demographic and medical data were collected; the primary outcome oral health-related quality of life was measured by the short form of the Oral Health Impact Profile (OHIP-14). Statistical analysis was carried out by Mann-Whitney U-test, and changes in the oral health-related quality of life scores post-treatment were estimated by Student t-test. Results: The mean age was 51.0±15.2 years, with 53.5% of females. Overall, nRCT significantly improved the OHRQoL (P<0.001, effect size=0.76). Gender (female) was associated with a higher OHRQoL after nRCT (P<0.05). OHIP-14 showed a significant reduction six months after root canal treatment compared to baseline scores. Conclusion: Present findings revealed that nonsurgical root canal treatment improved the oral health-related quality of life in patients with asymptomatic apical periodontitis.

Effect of ultrasonic activation of the adhesive system on dentin tubule penetration and the pushout bond strength of fiber posts.

STATEMENT OF PROBLEM: Whether ultrasonic activation of the adhesive system improves dentin tubule penetration and the bond strength of fiber posts to root dentin is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the effect of ultrasonic activation of 2 adhesive systems (etch-and-rinse and self-etch) and 1 glass ionomer cement on the dentin tubule penetration and pushout bond strength of fiber posts to root dentin. MATERIAL AND METHODS: Sixty maxillary central incisors were endodontically treated and divided into 6 groups (n=10) as per the post cementation strategy: etch-and-rinse, etch-and-rinse and ultrasonic, self-etch, self-etch and ultrasonic, glass ionomer cement, and glass ionomer cement and ultrasonic. The primers, the adhesives, and the glass ionomer cement were activated for 20 seconds each, and the fiber posts were cemented with a resin cement. Dentin tubule penetration was evaluated by confocal laser scanning microscopy and the pushout bond strength measured at 3 post locations: cervical, middle, and apical. The failure patterns were also described after pushout testing. RESULTS: Self-etch and ultrasonic showed higher dentin tubule penetration than the other cementation strategies (P<.05) and improved the bond strength values (P<.05), which were higher than etch-and-rinse and ultrasonic and glass ionomer cement and ultrasonic (P<.05). Adhesive failures at the cement and dentin interface were predominant in the etch-and-rinse, self-etch, and self-etch and ultrasonic groups. CONCLUSIONS: Ultrasonic activation improved the dentin tubule penetration of a self-etch adhesive system. The bond strength of fiber posts cemented with a self-etch adhesive system and a resin cement was improved after ultrasonic activation.

Spectrophotometric analysis of dental bleaching after bonding and debonding of orthodontic brackets.

INTRODUCTION: The aim of this study was to evaluate the bleaching effect after aging simulation in teeth submitted to bonding and debonding of orthodontic brackets. MATERIALS AND METHODS: For this study, 90 human premolars were selected, and randomly divided into 6 groups: control, bleaching, and other 4 groups submitted to bleaching after bonding and debonding brackets using different methods. Color measurement of sample through the CIE L*a*b* system was performed in three moments: T1 - after brackets debonding, T2 - after staining cycling, and T3 - after bleaching. For evaluation of results among the components L*, a* and b*, the two criteria analysis of variance and the multiple comparison Tukey test (p < 0.05) were used. RESULTS: Statistically significant difference was observed among the groups submitted to brackets bonding and debonding through self-conditioning adhesive system and tungsten drill, also the control and bleaching groups between the moments T1 e T2. CONCLUSION: Bonding and debonding brackets methods tested in this study showed influence on the sample color change, and after the tooth bleaching process, only the group without brackets previous bonding achieved the color value presented before the staining and aging of samples in the brackets absence.

Analysis of microleakage and marginal gap presented by new polymeric systems in class V restorations: An in vitro study.

OBJECTIVE: Evaluating the contraction of polymerization effect of silorane-based composite on dental interface in enamel. MATERIALS AND METHODS: Eighty class V cavities were confectioned in forty extracted molar teeth and restored with different combinations of resinous-based and bond system. They were divided into the following groups: (G1) three-step etch-and-rinse adhesive system and methacrylate-based resin, (G2) two-step etch-and-rinse adhesive system and methacrylate-based resin, (G3) Filtek P-90 self-conditioning adhesive system and methacrylate-based resin, (G4) Adper SE Plus self-conditioning adhesive system and methacrylate-based resin, (G5) three-step etch-and-rinse adhesive system and silorane-based resin, (G6) two-step etch-and-rinse adhesive system and silorane-based resin, (G7) Filtek P-90 self-conditioning adhesive system and silorane-based resin, (G8) Adper SE Plus self-conditioning adhesive system and silorane-based resin. RESULTS: Group 7 showed lower marginal leakage when compared with all other groups (p = 0.001). CONCLUSIONS: The results allows suggesting that silorane-based resinous system is adequate to promote more satisfactory marginal sealing than any other combination, since the system is combined with its own bond system.

Push-out bond strength of fiberglass posts cemented with adhesive and self-adhesive resin cements according to the root canal surface.

Evaluating the bond strength of fiberglass posts cemented with different resin cements. MATERIALS AND METHODS: Seventy freshly extracted roots of healthy human canines were endodontically treated and prepared to receive fiberglass posts. The roots were randomly divided into seven groups: (G1) RelyX ARC, (G2) Enforce, (G3) BisCem, (G4) Duo-Link, (G5) Cement Post, (G6) Variolink II, and (G7) RelyX U200. After post cementation, the specimens were sectioned perpendicularly to the root axis using a high-speed diamond disc, totaling 340 specimens. The strength values obtained in the push-out test were submitted to two-factor ANOVA and Tukey test (p = 0.05). RESULTS: The root thirds (p = 0.001) and the type of cement (p = 0.001) influenced the bond strength values. The relation between these two factors was also significant (p = 0.011). CONCLUSIONS: The bond strength of self-adhesive resin cements was significantly higher as compared to other cements. Besides the cervical third in roots cemented with conventional cements types presented the highest bond strength values (p < 0.05).

Comparison between isolated and associated with codeine acetaminophen in pain control of acute apical abscess: a randomized clinical trial.

OBJECTIVES: The study aimed to compare the acetaminophen administration efficacy or its combination with codeine for pain control in acute apical abscesses cases. MATERIALS AND METHODS: Thirty-nine patients who sought emergency treatment in the Faculty of Dentistry of the Federal University of Rio Grande do Sul were included, all of them with acute apical abscess diagnosis. These patients were divided into two groups: acetaminophen group-prescription of acetaminophen (1000 mg) and acetaminophen-codeine group-prescription of acetaminophen (1000 mg) + codeine (30 mg), both with oral intake every 6 h for 3 days. The pain scores were recorded by the patients on their own at 6, 12, 24, 48, and 72 h after finishing clinical assistance, by filling a pain evolution journal, containing a visual analogue scale (VAS). Student t test was conducted to investigate different mean ages between groups 1 and 2. A comparison of weight and means of initial pain scores between groups was carried out using the Mann-Whitney U test. Chi-square test was performed to compare gender, affected tooth, education, initial swelling, and frequency of adverse effect between test and control groups. Mann-Whitney U test was applied to compare groups in the same period. Friedman's test was used to compare results from the same group over time. RESULTS: Both groups showed score reduction over time (P < 0.05). Paracetamol-codeine group showed significant pain score reduction at 48 h registers when compared to baseline and at 6 h scores (P < 0.05). Further, pain scores at 72 h were significantly lower, when compared to the baseline, at 6 h, and at 12 h scores (P < 0.05). Acetaminophen group showed significant pain score reduction observed at 72 h, when compared to the baseline and at 6 h scores (P < 0.05). There were no significant differences in pain score reduction over time between groups (P > 0.05). There was no difference between the groups regarding the frequency of adverse reactions (P > 0.05). CONCLUSION: Both medications were effective for pain control in acute apical abscess cases. The findings might have inferred in pain control of acute apical abscess associated pain in patients who used an antibiotic drug. External validity of the findings for acute apical abscess cases with no need for an antibiotic prescription is uncertain. CLINICAL RELEVANCE: This paper suggests acetaminophen 1000 mg can be used for pain control in the treatment of acute apical abscess associated with systemic manifestation.

Intratubular penetration of endodontic sealers depends on the fluorophore used for CLSM assessment.

Root canal filling aims at eliminating empty spaces into the root canal system using biologically compatible materials. Three-dimensional root canal obturation must prevent or minimize the reinfection caused by microorganisms' leakage. This study aimed at evaluating whether fluorophore (Rhodamine or Fluo-3) influences the CLSM images of intratubular penetration of four endodontic sealers. Eighty bovine teeth were prepared using K files up to a size #70 and irrigated with 2.5% sodium hypochlorite. All roots were divided into eight groups (n = 10) according to the sealer and fluorophore used: AH Plus/Rhodamine, AH Plus/Fluo-3, Sealer Plus/Rhodamine, Sealer Plus/Fluo-3, Sealer Plus BC/Rhodamine, Sealer Plus BC/Fluo-3, Endosequence/Rhodamine, and Endosequence/Fluo-3. All roots were filled using cold lateral compaction technique. After 7 days, the roots were transversely sectioned, and three slices, one of each canal third, were obtained. Intratubular penetration was evaluated using CLSM. Sealer Plus BC/Rhodamine and Endosequence BC/Rhodamine presented higher intratubular penetration than AH Plus/Fluo-3 and Sealer Plus/Fluo-3 (p ˂ .05). The intragroup analysis showed similar intratubular penetration, regardless of the root third, except for the apical third in AH Plus/Fluo-3 and Sealer Plus BC/Fluo-3 groups. The type of fluorophore influences the calcium silicate sealers' tubular penetration but not of epoxy resin-based ones using CLSM. Bioceramic sealers should not be used associated with Rhodamine for CLSM evaluation. RESEARCH HIGHLIGHTS: The type of fluorophore influences the calcium silicate sealers' tubular penetration but not of epoxy resin-based ones when CLSM is used for assessment. Bioceramic sealers should not be used associated with Rhodamine.

A New Calcium Silicate-Based Root Canal Dressing: Physical and Chemical Properties, Cytotoxicity and Dentinal Tubule Penetration.

The aims of this study were to evaluate the physical and chemical properties, cytotoxicity and dentinal tubule penetration of a new calcium silicate-based root canal dressing. For pH and calcium ion release evaluation (1, 24, 72 and 168 h) were used a pH meter and colorimetric spectrophotometer, respectively. Radiopacity evaluation followed the ISO 6876:2012. Cytotoxicity was evaluated by the percentage of cell viability using MTT assay. Illustrative images of dentinal tubule penetration were obtained using confocal laser scanning microscopy (CLSM). Data from pH and calcium ion release were statistically analyzed by two-way analysis of variance and Tukey test. Radiopacity was analyzed using the Student t-test. The statistical tests for cytotoxicity results were the one-way analysis of variance and Tukey test. Both materials showed alkaline pH in all experimental times. The pH values for calcium hydroxide paste were higher than bioceramic paste at 1, 24, and 72 h (p<0.05). The calcium ion release of bioceramic was lower than the calcium hydroxide paste only at 24 h (p<0.05). The bioceramic was more radiopaque than the calcium hydroxide paste (p<0.05). Bioceramic paste presented a dose and time-dependent cytotoxic effect after MTT assay. CLSM images showed absence of tubule penetration for both pastes. The new calcium silicate-based canal dressing presented alkaline pH, high calcium release, and acceptable radiopacity. Bio C Temp showed a dose and time-dependent cytotoxic and absence of dentinal tubule penetration.

A new calcium silicate-based root canal dressing: physical and chemical properties, cytotoxicity and dentinal tubule penetration

Abstract The aims of this study were to evaluate the physical and chemical properties, cytotoxicity and dentinal tubule penetration of a new calcium silicate-based root canal dressing. For pH and calcium ion release evaluation (1, 24, 72 and 168 h) were used a pH meter and colorimetric spectrophotometer, respectively. Radiopacity evaluation followed the ISO 6876:2012. Cytotoxicity was evaluated by the percentage of cell viability using MTT assay. Illustrative images of dentinal tubule penetration were obtained using confocal laser scanning microscopy (CLSM). Data from pH and calcium ion release were statistically analyzed by two-way analysis of variance and Tukey test. Radiopacity was analyzed using the Student t-test. The statistical tests for cytotoxicity results were the one-way analysis of variance and Tukey test. Both materials showed alkaline pH in all experimental times. The pH values for calcium hydroxide paste were higher than bioceramic paste at 1, 24, and 72 h (p<0.05). The calcium ion release of bioceramic was lower than the calcium hydroxide paste only at 24 h (p<0.05). The bioceramic was more radiopaque than the calcium hydroxide paste (p<0.05). Bioceramic paste presented a dose and time-dependent cytotoxic effect after MTT assay. CLSM images showed absence of tubule penetration for both pastes. The new calcium silicate-based canal dressing presented alkaline pH, high calcium release, and acceptable radiopacity. Bio C Temp showed a dose and time-dependent cytotoxic and absence of dentinal tubule penetration.

Resumo Os objetivos deste estudo foram avaliar as propriedades físicas e químicas, citototoxidade e penetração tubular de uma nova medicação à base de silicato de cálcio. Para o teste de pH, e liberação de íons cálcio (1, 24, 72 e 168 h) foi usado medidor de pH e espectofotômetro colorimétrico, respectivamente. Avaliação da radiopacidade, seguiu a ISO 6876:2012). A citotoxicidade foi avaliada pela porcentagem de células viáveis usando o ensaio MTT. Imagens ilustrativas de penetração tubular foram obtidas usando microscopia confocal de varredura a laser (CLSM). Os dados de pH e liberação de cálcio foram analisados através do teste de Análise de Variância de duas vias e teste de Tukey. A radiopacidade foi avaliada usando o teste T de Student. Para a citotoxicidade foi empregada a Análise de Variância de uma via e teste de Tukey. Ambos os materiais apresentaram pH alcalino em todos os tempos experimentais. Os valores de pH da pasta de hidróxido de cálcio foram superiores à pasta biocerâmica em 1, 24 e 72 h (p<0,05). A liberação de cálcio da pasta biocerâmica foi inferior à pasta de hidróxido de cálcio apenas em 24 h (p<0,05). Bio-C Temp foi mais radiopaco que o Ultracal XS (p<0,05). A pasta biocerâmica apresentou efeito citotóxico dependente da dose e do tempo de exposição. Imagens de CLSM mostraram ausência de penetração intratubular para ambas as pastas. A nova medicação à base de silicato de cálcio apresentou pH alcalino, alta liberação de cálcio e boa radiopacidade. Bio C Temp apresentou um efeito citotóxico dependente da dose e do tempo de exposição e ausência de penetração tubular.

The influence of titanium base abutments on peri-implant soft tissue inflammatory parameters and marginal bone loss: A randomized clinical trial.

BACKGROUND: Some techniques in implant dentistry have been suggested that may potentially alter peri-implant soft and hard tissue parameters. PURPOSE: To evaluate the peri-implant soft tissue inflammatory parameters and crestal bone loss around titanium base abutments. MATERIALS AND METHODS: Fifty two implants were placed in 21 patients and restored by single crowns. Subjects were randomly allocated into two groups: cement-retained abutment (n = 24) and titanium base (n = 28). Peri-implant probing depth, and mesial and distal marginal bone loss (MBL) were evaluated at implant loading (T1), 6 and 12 months (T2 and T3, respectively). Peri-implant bleeding-on-probing was evaluated at T2 and T3. Two-way repeated measures analysis of variance, Tukey test, Man Whitney, and Pearson correlation were performed for statistical analysis at P < .05. RESULTS: The mean difference of peri-implant MBL from implant installation to 12 months in function was 1.15 ± 0.82 mm for the cement-retained group, and 1.23 ± 0.79 mm for the titanium base group. No statistically significant difference was found between the two groups for clinical and radiographic peri-implant evaluation. CONCLUSIONS: Titanium base abutments present no negative effect on peri-implant soft tissue and MBL. When used to support single crowns, both approaches performed likewise regarding clinical and radiographic parameters.

Beneficial Effects of Ethyl-Cyanoacrylate Coating Against Candida Albicans Biofilm Formation.

The aim of this study was to verify whether modifications made in a hard chairside reline resin by an ethyl-cyanoacrylate adhesive, ECA (Super Bonder®, Loctite, Itapevi, SP, Brazil) would be able to inhibit or reduce Candida albicans biofilm formation on its surface, comparing to a commercial surface sealant (BisCover®, Bisco, Schaumburg, USA). Reline resin specimens were fabricated and randomly divided into 6 groups (n=8): CG (control group), no surface treatment; ECA1, ECA coating on the surface before sterilization; ECA2, ECA coating after sterilization; ECA3, ECA incorporated in the resin bulk; DPE1, BisCover® coating before sterilization; DPE2, BisCover® coating after sterilization. Specimens were inoculated with C. albicans SC5314 (1x107 cells/mL) and incubated for 24 h. Then, the biofilm were stained with LIVE/DEAD® BaclightTM L7007 Kit and analyzed by Confocal Laser Scanning Microscopy. The images were evaluated by bioImageL® v.2.0 software and total biovolume (µm3), viable cells (%), and covered area (%) were calculated. Data were statistically analyzed by Kruskal-Wallis and Dunn tests (p<0.05). Results showed that ECA-coated groups presented better results, reducing C. albicans biofilm formation. Acquired images revealed that these groups (ECA1 and ECA2) presented a reduced number of cells, mostly in yeast form (less pathogenic), while the other groups presented higher number of cells, mostly in hyphae form (more pathogenic). Based on these findings, a beneficial effect of Super Bonder® coating reline resins surface could be demonstrated, suggesting a promising way to prevent fungal biofilm formation on dentures.

Effect of fiber post space irrigation with different peracetic acid formulations on the bond strength and penetration into the dentinal tubules of self-etching resin cement.

STATEMENT OF PROBLEM: The post space must be irrigated with solutions that do not interfere with the bond strength and enhance penetration into the dentinal tubules of self-etching resin cement. Which solution is best is unclear. Peracetic acid with different formulations appears to be a good option. PURPOSE: The purpose of this in vitro study was to evaluate the effect of irrigating the fiber post space by using 1% peracetic acid (PA) at low (LH) or high (HH) hydrogen peroxide concentration on the bond strength and penetration into the dentinal tubules of RelyX U200 self-etching resin cement. MATERIAL AND METHODS: After intraroot preparation for fiber posts in 60 endodontically treated teeth, the specimens were divided into 4 groups (n=15) according to the irrigation protocol: CG (control), distilled water; NA (NaOCl), 2.5% sodium hypochlorite; LHPA, PA with a low concentration of hydrogen peroxide; and HHPA, PA with a high concentration of hydrogen peroxide. The fiber posts were then cemented with self-etching resin cement labeled with rhodamine. Cross sections of the thirds were obtained by confocal scanning microscopy and submitted to the push-out and cement penetration tests. The data obtained in the push-out tests were evaluated by using ANOVA and the Tukey post hoc test, and those data obtained in the confocal screening were evaluated by using the Kruskal-Wallis and Dunn (Bonferroni correction) tests (α=.05). RESULTS: Bond strength values in the cervical third of the CG were higher than those in NA (P=.035) but similar to those of the other groups (P=.05). In the other thirds, CG and LHPA values were similar to one another (P=.05) but higher than those of NA and HHPA (P<.001). The penetration rate assessed by confocal scanning microscopy revealed similar results in the cervical third for all groups (P=.075), except for NA which provided the lowest penetration. In the remaining thirds, CG and LHPA provided the highest penetration rate (P=.015). CONCLUSIONS: The LHPA group had no negative effects on the bond strength and penetration into the dentinal tubules of the self-etching resin cement.

Beneficial effects of ethyl-cyanoacrylate coating against candida albicans biofilm formation

Abstract The aim of this study was to verify whether modifications made in a hard chairside reline resin by an ethyl-cyanoacrylate adhesive, ECA (Super Bonder®, Loctite, Itapevi, SP, Brazil) would be able to inhibit or reduce Candida albicans biofilm formation on its surface, comparing to a commercial surface sealant (BisCover®, Bisco, Schaumburg, USA). Reline resin specimens were fabricated and randomly divided into 6 groups (n=8): CG (control group), no surface treatment; ECA1, ECA coating on the surface before sterilization; ECA2, ECA coating after sterilization; ECA3, ECA incorporated in the resin bulk; DPE1, BisCover® coating before sterilization; DPE2, BisCover® coating after sterilization. Specimens were inoculated with C. albicans SC5314 (1x107 cells/mL) and incubated for 24 h. Then, the biofilm were stained with LIVE/DEAD® BaclightTM L7007 Kit and analyzed by Confocal Laser Scanning Microscopy. The images were evaluated by bioImageL® v.2.0 software and total biovolume (µm3), viable cells (%), and covered area (%) were calculated. Data were statistically analyzed by Kruskal-Wallis and Dunn tests (p<0.05). Results showed that ECA-coated groups presented better results, reducing C. albicans biofilm formation. Acquired images revealed that these groups (ECA1 and ECA2) presented a reduced number of cells, mostly in yeast form (less pathogenic), while the other groups presented higher number of cells, mostly in hyphae form (more pathogenic). Based on these findings, a beneficial effect of Super Bonder® coating reline resins surface could be demonstrated, suggesting a promising way to prevent fungal biofilm formation on dentures.

Resumo O objetivo deste estudo foi verificar se as modificações feitas com o adesivo etil cianoacrilato, ECA (Super Bonder ®, Loctite, Itapevi, SP, Brasil) sobre as resinas acrílicas para reembasamento, poderiam inibir ou reduzir a formação de biofilmes de C.albicans sobre sua superfície quando comparado com um selante de superfície comercial (BisCover®, Bisco, Schaumburg, EUA). Amostras de resina acrílica para reembasamento foram fabricadas e divididas aleatoriamente em 6 grupos (n=8): CG (grupo controle), sem tratamento superficial; ECA1, revestimento de ECA na superfície antes da esterilização; ECA2, revestimento de ECA após esterilização; ECA3, ECA incorporado no volume da resina; DPE1, revestimento de BisCover® antes da esterilização; DPE2, revestimento de BisCover® após esterilização. Os espécimes foram inoculados com C. albicans SC5314 (1x107 células/mL) e incubados durante 24 h. Seguidamente, o biofilme foi corado com LIVE/DEAD® BaclightTM L7007 Kit e analisado no microscópio confocal de varredura a laser. As imagens foram avaliadas pelo software bioImageL® v.2.0, no qual foram calculados o biovolume total (μm3), as células viáveis (%) e a área coberta (%). Os dados foram analisados estatisticamente pelos testes de Kruskal-Wallis e Dunn (p<0,05). Os resultados mostraram que os grupos revestidos com ECA apresentaram os melhores resultados, reduzindo a formação do biofilme de C. albicans. As imagens adquiridas revelaram que esses grupos (ECA1 e ECA2) apresentaram um número reduzido de células, principalmente na forma de levedura (menos patogênico), enquanto os outros grupos apresentaram um maior número de células, principalmente na forma de hifas (mais patogênicas). Com base nessas descobertas, encontra-se um efeito benéfico na aplicação do adesivo ECA sobre as superfícies das resinas acrílicas para reembasamento, sugerindo assim uma nova alternativa de prevenir a formação de biofilme fúngico em próteses dentárias.

Osseointegrated implant as an auxiliary of orthodontic leveling in case of asymmetric vertical skeletal discrepancy: case report / Implante osteointegrado como auxiliar do nivelamento ortodôntico em caso de discrepância esquelética vertical assimétrica: relato de caso

Objective: To present a case report that used an osseointegrated implant as skeletal anchorage unit in asso-ciation with fixed orthodontic appliance for the treatment of an adult patient with vertical asymmetric skeletal discrepancy. Case report: In this case, the pre-existing osseointegrated implant in the region of element 21 was used as an auxiliary of skeletal anchorage for leveling the upper occlusal plane. This was performed with the straight wire technique, Capelozza prescription pattern I, .022" slot, using the sequence of thermal--activated nickel-titanium arches of .014", .016", .017"X.025" and .019"X.025", followed by the steel arch of.019" X.025". Final considerations: The results presented in this report showed the osseointegrated implant asa good option when used as a resource of auxiliary anchorage in orthodontics, providing better comfort andaesthetic conditions to the treatment and simplifying the technique. (AU)

Objetivo: apresentar um relato de caso em que se utilizou um implante osteointegrado como uni-dade de ancoragem esquelética em associação com aparelho ortodôntico fixo, no tratamento de um paciente adulto com discrepância esquelética vertical assimétrica. Relato do caso: neste caso, foi utilizado o implante osteointegrado pré-existente na região do elemento 21 como auxílio de anco-ragem esquelética para o nivelamento do plano oclusal superior, por meio da técnica straight-wire, prescrição Capelozza padrão I, slot .022", utilizan-do a sequência de arcos de níquel-titânio termo-ativado .014", .016", .017"X.025" e .019X.025", seguido por arco de aço .019" X.025". Conside-rações finais: os resultados apresentados neste re-lato demonstraram ser o implante osteointegrado uma boa opção, quando utilizado como recurso de ancoragem auxiliar em ortodontia, conferindo melhores condições de conforto e estética ao trata-mento, bem como simplificação técnica. (AU)

Mechanical Degradation of Different Classes of Composite Resins Aged in Water, Air, and Oil.

A significant deterioration of the properties can drastically compromise the survival rate of restorative materials. The aim of this study was to assess flexural strength and hardness of three composite classes: hybrid composite resin (HCR), nanoparticulate composite resin (NCR), and silorane-based composite resin (SBCR). One hundred specimens were prepared for hardness testing by using a split metallic mold measuring 10 mm in diameter and 2 mm deep. Twenty specimens were prepared for each restorative material, randomly assigned for storage in air, distilled water, or mineral oil. After intervals of 24 hours, 30, 60, 90, and 120 days, hardness and flexural strength tests were initially compared in two levels: "storage medium" and "time" within each material group. A two-way analysis of variance was performed (p<0.05) on the variables "material" and "storage time" (p<0.05). The HCR showed to be stable with regard to the evaluation of flexural strength and hardness (p<0.05). A significant reduction occurs for the NCR in comparison to the other groups (p<0.05). The NCR presented the lowest values of hardness and flexural strength kept on water over time. The characteristics of material showed a strong influence on the decrease of the mechanical properties analyzed.

The surface treatment of dental ceramics: an overview

This review proposes to present some aspects of dental ceramics surface treatments, which involve the related physical and mechanical properties, as well as new technologies. The correct cementation of prosthetic restoration is essential for clinical success. However, the adhesive technique is a very recent procedure and clinicians should have a more detailed knowledge about the technique and related materials so that they can use them in their day-to-day clinical practice. Information about the the principles, indications and contraindications of adhesive cementation technique were obtained from the literature. The studies indicate that the adhesive system seems to be a valid option for fixed prosthesis cementation, since it has several advantages over conventional cementation method, especially in all-ceramic restorations. In clinical practice, the clinician should always keep in mind the characteristics of the material they are working with, so that they can select the best technique and the best cement for each clinical situation. Although more research is required in this field, there are no scientific reasons to contraindicate in routine practice.

Lentes de contato: harmonização e estética com preparos conservadores

Este trabalho teve como objetivo abordar a reabilitação do sorriso devolvendo estética e função utilizando lentes de contato dentaria com preparos conservadores, avaliando suas indicações e limitações. Para tal, foi realizada uma revisão de literatura descritiva e bibliográfica utilizando como fonte de dados para a pesquisa livros e artigos extraídos das bases Medline, Lilacs, Scielo, Pubmed. Durante o trabalho, observou-se a evolução da técnica utilizada pelo profissional juntamente com os materiais utilizados na confecção do laminado. As lentes de contato dentárias possibilitam ao dentista uma opção conservadora de utilizar materiais cerâmicos, o correto planejamento promove resultado previsíveis de sucesso, sendo assim importante o conhecimento técnico-cientifico do profissional odontológico para determinar qual material e técnica utilizar em cada caso.

Princípios básicos de oclusão ideal

A clínica odontológica engloba diversas modalidades de tratamento. Espera-se que o profissional realize os procedimentos alcançando objetivos estéticos e funcionais, com aprovação do paciente, o que representa o sucesso do tratamento. Considerando a importância dos conhecimentos acerca da oclusão estática e funcional para os procedimentos em clínica odontológica integrada, realizou-se uma revisão de literatura a fim de destacar e discutir os principais aspectos relacionados ao tema. O controle biomecânico da oclusão promove a longevidade dos tratamentos reabilitadores, minimiza a recidiva ortodôntica, impede o aparecimento de patologias oclusais, mantém restaurações estéticas em resina composta evitando possíveis fraturas e/ou desgastes. Na oclusão fisiológica há a transmissão resultante das forças oclusais para o longo eixo dos dentes posteriores, movimentos de lateralidade promovidos pelos caninos, guia anterior imediata, contatos dentários posteriores bilaterais e simultâneos, dimensão vertical de oclusão adequada e RC coincidindo com a MIH. Porém, quando ocorrem alterações, a oclusão pode tornarse patológica e os tratamentos realizados sem os devidos cuidados pouco estáveis. A má relação dos arcos dentários pode refletir em anormalidades nos dentes e/ou nos maxilares. Para corrigir aspectos ligados à oclusão há que se devolver ao paciente, por meio de reabilitação, ajustes oclusais direcionados ou movimentação ortodôntica, as características de normalidade da oclusão. Para isso, deve-se realizar abordagem única entre as especialidades, sem comprometer os aspectos estruturais e funcionais do paciente. Assim, compreende-se que uma oclusão estática e funcional correta é fundamental para qualquer tratamento odontológico, visando uma terapêutica com resultados que sejam preservados em longo prazo.