Abstract The aim of this study was to investigate the effect of acid challenge on the activation of matrix metalloproteinases (MMPs) in the Dentinoenamel junction of primary and permanent teeth submitted to radiotherapy. For this purpose, a total of 178 dental fragments obtained from molars were used, and randomly divided into 2 groups (primary and permanent teeth) / 4 experimental subgroups (irradiated and non-irradiated, demineralized and non-demineralized). The fragments were exposed to radiation, with a dose fraction of 2 Gy, for 5 consecutive days, until a total dose of 60 Gy was reached, with a total of 30 cycles, for 6 weeks. To determine the activity of MMPs on the dentinoenamel junction (DEJ), in situ zymography assays on 0.6mm dental fragments were performed. To assess whether MMP activity would be impacted by an acidic environment, the fragments were placed in a demineralizing solution (pH of 4.8). The finding was that irradiation activated MMPs in DEJ and these effects were more evident in permanent when compared with primary teeth. When the effect of an acid challenge on MMPs activity was investigated, demineralization was observed not to increase MMPs activity in non-irradiated teeth, but it did increase MMPs activity in irradiated teeth. In conclusion, an acid challenge was found to exacerbate activation of MMPs in DEJ of permanent teeth submitted to irradiation, but not in primary teeth. (MMPs radiotherapy purpose 17 used nonirradiated, nonirradiated non irradiated, nondemineralized. nondemineralized . non-demineralized) radiation days reached 3 cycles weeks DEJ, , (DEJ) 06mm mm 0 6mm performed environment pH 4.8. 48 4.8 8 4.8) investigated conclusion 1 non-demineralized (DEJ 4.

Abstract This study aimed to evaluate the influence of the Er,Cr:YSGG irradiation and 980-nm diode lasers on the surface roughness (SR) and volume loss (VL) of dentin subjected to cariogenic challenge. Subsequently, 130 specimens of bovine dentin were divided into the following 13 groups: NT: no treatment; FG: fluoride gel; FV: fluoride varnish; Di: 980-nm diode; Di + FG; Di + FV; FG + D; FV + Di; Er: Er,Cr:YSGG; Er + FG; Er + FV; FG + Er and FV + Er. Er,Cr:YSGG laser parameters were as follows: 0.25 W; 5.0 Hz; 4.46 J/cm2 without water and 55% air. Furthermore, the 980-nm diode laser parameters were 2.0 W; 2.0 Hz; 21.41 J/cm2. The samples from each group were subjected to pH cycling. A confocal laser scanning microscope was used to evaluate SR and VL. Difference between the volume of the reference and treated areas + DES/RE was used to determine SR and VL. The mean values of the different groups were subjected to analysis of variance and Tukey’s post-hoc test. The VL values were analyzed using the Kruskal–Wallis and Dunn post-hoc test (p < 0.05). The SR of the reference area did not show a statistically significant 1807-3107-bor-38-e025treatment and cariogenic challenge (p > 0.05). Moreover, VL in the FV + Di and FV + Er groups showed a statistically significant difference compared with areas submitted to different types of treatment and cariogenic challenge (p > 0.05). Er,Cr:YSGG and 980-nm diode lasers associated with fluoride varnishes decreased dentin VL in bovine teeth submitted to cariogenic challenge. Er,CrYSGG ErCrYSGG Er,Cr YSGG Cr 980nm nm 980 (SR (VL Subsequently 1 NT gel varnish D follows 025 0 25 0.2 W 50 5 5. Hz 446 4 46 4.4 Jcm2 Jcm J cm2 cm J/cm 55 air Furthermore 20 2 2. 2141 21 41 21.4 cycling DESRE DES RE Tukeys Tukey s posthoc post hoc KruskalWallis Kruskal Wallis p 0.05. 005 0.05 . 05 0.05) 18073107bor38e025treatment boretreatment 1807 3107 bor 38 e025treatment e Moreover CrYSGG ErCr 98 02 0. 44 4. 214 21. 00 0.0 180 310 3 etreatment 9 18 31

ABSTRACT Objective: To verify whether an infiltrant resin used to inactivate white spot lesions (WSL) on enamel can resist the abrasive challenges promoted by tooth brushing with different dentifrices. Material and Methods: WSL was induced on bovine enamel samples (pH cycling) and then treated with an infiltrant resin (ICON). Afterward, half of the sample was protected. The other half underwent an abrasive challenge using an electric toothbrush with soft bristles., using dentifrices with different abrasiveness (n=10): Group 1: Colgate Maximum Cavity Protection; Group 2: Sensodyne Repair & Protect; Group 3: Colgate Sensitive Pro-Relief; Group 4: Colgate 2 in 1 Watermelon Flavor; e Group 5: Colgate Luminous White Advanced. The wear profile after brushing was evaluated by confocal laser scanning microscopy (µm), and the enamel/resin interface was observed in scanning electron microscopy (SEM). Profilometry data were analyzed using one-way ANOVA followed by Tukey's test (α=5%). Results: Brushing produced more significant wear on group 5 (3.96±0.26) when compared to groups 1 (3.45±0.21), 2(3.22±0,4) and 4(3.11±0.34). Data from Group 3 (3.82±0.6) was similar to G5 but higher than G1, G2, and G4. SEM analysis showed that the adhesive interface remained intact in all groups after the abrasive challenge. Conclusion: Dentifrices with a higher relative dentin abrasiveness produced more significant wear of the infiltrant, but the composite/enamel interface was not altered after the abrasive challenges. Objective (WSL Methods pH cycling ICON. ICON . (ICON) Afterward protected bristles bristles. n=10 n10 n 10 (n=10) Protection Protect ProRelief Pro Relief Pro-Relief 4 Flavor Advanced µm, µm , (µm) enamelresin SEM. (SEM) oneway one way Tukeys Tukey s α=5%. α5 α α=5% (α=5%) Results 3.96±0.26 396026 96 0 26 (3.96±0.26 3.45±0.21, 345021 3.45±0.21 45 21 (3.45±0.21) 23.22±0,4 232204 3.22±0,4 22 2(3.22±0,4 43.11±0.34. 4311034 3.11±0.34 11 34 4(3.11±0.34) 3.82±0.6 38206 82 6 (3.82±0.6 G G1 G2 G4 Conclusion compositeenamel composite (ICON n=1 n1 (n=10 (µm (SEM α=5 (α=5% 3.96±0.2 39602 9 (3.96±0.2 34502 3.45±0.2 (3.45±0.21 23 23.22±0, 23220 32204 3.22±0, 2(3.22±0, 43 43.11±0.34 431103 311034 3.11±0.3 4(3.11±0.34 3.82±0. 3820 8 (3.82±0. n= (n=1 α= (α=5 3.96±0. 3960 (3.96±0. 3450 3.45±0. (3.45±0.2 23.22±0 2322 3220 3.22±0 2(3.22±0 43.11±0.3 43110 31103 3.11±0. 4(3.11±0.3 3.82±0 382 (3.82±0 (n= (α= 3.96±0 396 (3.96±0 345 3.45±0 (3.45±0. 23.22± 232 322 3.22± 2(3.22± 43.11±0. 4311 3110 3.11±0 4(3.11±0. 3.82± 38 (3.82± (n (α 3.96± 39 (3.96± 3.45± (3.45±0 23.22 32 3.22 2(3.22 43.11±0 431 311 3.11± 4(3.11±0 3.82 (3.82 3.96 (3.96 3.45 (3.45± 23.2 3.2 2(3.2 43.11± 31 3.11 4(3.11± 3.8 (3.8 3.9 (3.9 3.4 (3.45 23. 3. 2(3. 43.11 3.1 4(3.11 (3. (3.4 2(3 43.1 4(3.1 (3 2( 43. 4(3. ( 4(3 4(

Abstract The aim of this study was to assess roughness profile and surface roughness after simulated toothbrushing cycles, as well as the degree of conversion (DC) of bulk-fill resin composites at different depths. Forty nine composite discs were made from three low-viscosity bulk-fill resins (Filtek Bulk-Fill Flowable/3M Oral Care - FBF, Beautifil-Bulk Flowable/Shofu Inc. - BBF and Surefill SDR Flow/Dentsply Caulk - SDR), three high-viscosity bulk-fill resin composites (Filtek Bulk-Fill Restorative/3M Oral Care - FBR, Beautifil-Bulk Restorative/Shofu Inc. - BBR and Tetric EvoCeram Bulk Fill/Ivoclar Vivadent - TEB) and one conventional composite (Filtek Supreme Ultra/3M Oral Care - FSU) (n=7), using addition silicon molds (2 mm thick x 10 mm diameter). The roughness profile (Rv) and surface roughness (Sa) were analyzed after 30,000 brushing cycles using confocal laser scanning microscopy. Five samples (4 mm thick x 2 mm diameter) were produced per resin composite and light-cured for 20 seconds using a LED-curing unit. After 24 hours at 37oC, DC of samples was evaluated at four depths, using a confocal Raman microscope. The data were analyzed by ANOVA and Tukey post hoc multiple-comparison tests (α = 0.05). The Rv values of FSU were lower than those obtained for BBR and BBF. The toothbrushing significantly decreased the Sa for all composites. The DC was significantly reduced at 4 mm depth. Toothbrushing changed composite surface of all materials, especially for BBR and BBF. Composites were not able to maintain the DC values shown at the top compared with those at the bottom (4 mm depth). (DC bulkfill bulk fill depths lowviscosity low viscosity Filtek BulkFill Fill Flowable3M FlowableM Flowable 3M M FBF BeautifilBulk Beautifil FlowableShofu Shofu Inc FlowDentsply Flow Dentsply SDR, , SDR) highviscosity high Restorative3M RestorativeM Restorative FBR RestorativeShofu FillIvoclar Ivoclar TEB Ultra3M UltraM Ultra n=7, n7 n n=7 7 (n=7) ( 1 diameter. diameter . (Rv (Sa 30000 30 000 30,00 microscopy lightcured light cured LEDcuring LED curing unit 37oC oC microscope multiplecomparison multiple comparison α 0.05. 005 0.05 0 05 0.05) depth materials depth) n= (n=7 3000 3 00 30,0 0.0 (n= 300 30, 0. (n

Resumo Pacientes ortodônticos geralmente desenvolvem desmineralização e apresentam lesões de cárie após seis meses de tratamento. Procedimentos minimamente invasivos têm sido o objetivo na prática odontológica moderna. O objetivo deste estudo foi avaliar o efeito do ClinproTM XT selante ionomérico, ao redor do bráquete, com relação a rugosidade superficial do esmalte e a severidade da lesão induzida. Vinte pré-molares foram submetidos a colagem de bráquetes e indução experimental de desmineralização e divididos aleatoriamente em 2 grupos: GI - verniz fluoretado (Colgate Duraphat®); GII - Selante Ionomérico (ClinproTM XT). O tratamento foi aplicado ao redor dos bráquetes. A rugosidade da superfície dos espécimes foi analisada, antes do tratamento e 12 semanas após o tratamento por microscopia confocal a laser e severidade da lesão de mancha branca por dispositivo de fluorescência a laser. Os dados foram analisados pelo teste não paramétrico de Wilcoxon e Mann-Whitney, a 5% de significância. A taxa de redução da lesão foi calculada. A severidade da desmineralização diminuiu tanto no GI (p = 0,005) quanto no GII (p = 0,019). Os níveis de rugosidade superficial do esmalte diminuíram no GI e GII, assim como o percentual de rugosidade, sendo mais expressivo no grupo ClinproTMXT (85,09%). Colgate Duraphat® e Clinpro™ XT reduziram a severidade da desmineralização e diminuíram a rugosidade superficial do esmalte. O selante ionomérico Clinpro™ XT foi superior na redução percentual de rugosidade. moderna bráquete induzida prémolares pré molares grupos Duraphat Duraphat®) XT. . XT) analisada 1 MannWhitney, MannWhitney Mann Whitney, Whitney Mann-Whitney 5 significância calculada p 0,005 0005 0 005 0,019. 0019 0,019 019 0,019) 85,09%. 8509 85,09% 85 09 (85,09%) Clinpro 0,00 000 00 001 0,01 01 850 85,09 8 (85,09% 0,0 85,0 (85,09 0, 85, (85,0 (85, (85 (8 (

Abstract Orthodontics patients usual develop demineralization and present cavity caries lesions after six months. Minimally invasive procedures have been the goal in modern dental practice. The aim of this study was to evaluate the effect of ClinproTMXT Varnish, on the enamel surface roughness and severity of white spot lesions. Twenty premolars were submitted to bond brackets and experimental induction of demineralization and randomly divided into 2 groups: GI - fluoride varnish (Colgate Duraphat®); GII - Ionomeric Sealant (ClinproTMXT Varnish). The treatment was applied around the brackets. The surface roughness of specimens was analyzed, before treatment and 12 weeks after treatment by laser confocal microscopy, and the severity of the white spot lesion was by laser fluorescence device. The data were analyzed by non-parametric Wilcoxon and Mann-Whitney Test, at 5% significance, roughness percentage reduction was performed. The severity of demineralization decreased in both, GI (p = 0.005) and GII (p = 0.019). Enamel superficial roughness levels decreased in GI and GII. As well as the roughness percentage, being more expressive in the ClinproTMXT Varnish group (85,09%). Colgate Duraphat® or Clinpro™ XT Varnish reduced the severity of the demineralization and decreased the superficial roughness on the enamel. The Clinpro™ XT Varnish was superior to superficial roughness on enamel. months practice groups Duraphat Duraphat®) Varnish. . Varnish) 1 microscopy device nonparametric non parametric MannWhitney Mann Whitney Test 5 significance performed both p 0.005 0005 0 005 0.019. 0019 0.019 019 0.019) 85,09%. 8509 85,09% 85 09 (85,09%) Clinpro 0.00 000 00 001 0.01 01 850 85,09 8 (85,09% 0.0 85,0 (85,09 0. 85, (85,0 (85, (85 (8 (

Abstract The objective of this study was to compare the protein profile of the acquired enamel pellicle (AEP) formed in vivo in patients with or without gastroesophageal reflux disease (GERD), and with or without erosive tooth wear (ETW). Twenty-four volunteers were divided into 3 groups: 1) GERD and ETW; 2) GERD without ETW; and 3) control (without GERD). The AEP formed 120 min after prophylaxis was collected from the lingual/palatal surfaces. The samples were subjected to mass spectrometry (nLC-ESI-MS/MS) and label-free quantification by Protein Lynx Global Service software. A total of 213 proteins were identified, or 119, 92 and 106 from each group, respectively. Group 2 showed a high number of phosphorylated and calcium-binding proteins. Twenty-three proteins were found in all the groups, including 14-3-3 protein zeta/delta and 1-phosphatidylinositol. Several intracellular proteins that join saliva after the exfoliation of oral mucosa cells might have the potential to bind hydroxyapatite, or participate in forming supramolecular aggregates that bind to precursor proteins in the AEP. Proteins might play a central role in protecting the dental surface against acid dissolution. (AEP GERD, , (GERD) ETW. ETW . (ETW) Twentyfour Twenty four groups 1 GERD. GERD) 12 lingualpalatal lingual palatal surfaces nLCESIMS/MS nLCESIMSMS nLC ESI MS/MS MS (nLC-ESI-MS/MS labelfree label free software 21 identified 119 9 10 group respectively calciumbinding calcium binding Twentythree three 1433 14 14-3- zetadelta zeta delta 1phosphatidylinositol. 1phosphatidylinositol phosphatidylinositol phosphatidylinositol. 1-phosphatidylinositol hydroxyapatite dissolution (GERD (ETW nLCESIMS MSMS 11 143 14-3 14-

Abstract Dental alloys are widely used in fabrication of removable partial dentures, particularly as a dental framework. The present study aimed at studying the effect of the commercial mouthwashes on the corrosion behavior of the Co−Cr dental casting alloy. Corrosion behavior was investigated in alcohol-free and alcohol-containing mouthwashes added to artificial saliva solutions at room temperature by electrochemical tests recorded the open circuit potential (OCP) and current density, after the surface analysis of the samples was performed. During the early 250s, the OCP values showed significant changes, with the exception of one test group containing alcohol, where potential decreased continuously during the test, which also recorded the highest current density, different from the other groups. It was observed that the presence of alcohol increased the current density and the corrosion process in this alloy and the mouthwashes had more aggressive action in specimens submitted to solutions with alcohol in the composition.

Resumo O objetivo do presente estudo in vivo foi avaliar a contaminação bacteriana de protetores bucais esportivos, a rugosidade da superfície e a eficácia do spray de gluconato de clorexidina na desinfecção desses dispositivos. Um ensaio clínico randomizado, cego, cruzado foi realizado com vinte crianças de 9 a 13 anos, que praticavam artes marciais, participaram de todas as fases do estudo. As crianças foram orientadas a usar o protetor bucal por 3 dias alternados durante 1 hora e, após o uso, borrifar água de torneira estéril ou clorexidina 0,12%. Os protetores foram analisados por ensaio MTT, Hibridização DNA-DNA e microscopia confocal a laser antes e após o uso por 2 semanas. Os dados foram analisados pelos teste de Wilcoxon, teste t de Student, e correlação de Pearson, com nível de significância de 5%. Observou-se que os protetores bucais do grupo controle estavam mais contaminados com microrganismos cariogênicos do que os do grupo experimental (clorexidina) (p <0,05). O uso de protetores bucais com spray de clorexidina reduziu significativamente a contaminação bacteriana em relação ao grupo controle (p = 0,007). A rugosidade da superfície dos protetores bucais aumentou significativamente após o uso, independentemente da aplicação de spray de clorexidina. Uma correlação moderada (r = 0,59) foi observada entre a rugosidade da superfície e a contaminação do micro-organismo apenas para o grupo controle. Os protetores bucais esportivos apresentam intensa contaminação microbiana e aumento da rugosidade superficial após o uso. O uso de spray de clorexidina foi eficaz para reduzir a contaminação dos protetores bucais usados por crianças.

Abstract The aim of the present in vivo study was to evaluate the bacterial contamination of sports mouthguards, surface roughness, and the efficacy of chlorhexidine gluconate spray in the disinfection of these devices. A randomized, blinded cross-over clinical trial was performed with twenty 9 to 13 years old children who practiced martial arts and participated in all phases of the study. They were instructed to wear mouthguards 3 alternated days a week for 1 hour and, after use, to spray sterile tap water or chlorhexidine 0.12%. The mouthguards were analyzed by MTT assay, Checkerboard DNA-DNA hybridization, and confocal laser microscopy prior and after use for 2 weeks. Data were analyzed by Wilcoxon and t-Student, and Pearson correlation tests, with 5% significance level. Were observed that mouthguards of the control group were more contaminated with cariogenic microorganisms than those of the chlorhexidine group (p<0.05). The mouthguards use of spray of chlorhexidine reduced significantly the bacteria contamination compared with control group (p = 0.007). The surface roughness of the mouthguards increased significantly after use, irrespective of application of chlorhexidine spray. A moderate correlation (r=0.59) was observed between surface roughness and the cariogenic microorganism’s contamination only for control group. Sports mouthguards had intense microbial contamination and increased surface roughness after its use. The use of chlorhexidine spray was effective for reducing the mouthguards contamination used by children.

Resumo Este estudo in vitro avaliou a homogeneidade do feixe de um fotopolimerizador de múltiplos picos na microdureza superficial e o efeito da escovação na microdureza, rugosidade superficial, perfil de rugosidade, perda de volume e retenção do brilho de compósitos a base de resina (RBCs) incrementais ou bulk-fill. Um fotopolimerizador LED (VALO) com quatro LEDs na ponteira (405, 445, 465A e 465B nm de pico de emissão) foi usado de acordo com o tempo recomendado por cada fabricante para obtenção de discos (n=10) de seis RBCs: Estelite Sigma Quick, Charisma Classic, Tetric EvoCeram Bulk Fill, Filtek Z250, Filtek Supreme Ultra e Filtek Bulk Fill. Os valores de microdureza foram obtidos seguindo o posicionamento de cada LED na superfície superior das amostras e foram analisados antes e após a escovação quanto a microdureza, rugosidade superficial, perfil de rugosidade, perda de volume e retenção do brilho. A microdureza foi considerada homogênea no topo da superfície, independentemente do tipo de RBCs ou comprimento de onda testados (p>0.05). No geral, a escovação não reduziu a microdureza das RBCs, mas influenciou o brilho para a maioria das RBCs (p<0.001). Charisma Classic apresentou os maiores valores de rugosidade superficial e perfil de rugosidade após a escovação (p<0.05). A perda de volume não diferiu entre as RBCs (p>0.05). Em conclusão, os diferentes comprimentos de onda do LED não alteraram a microdureza do topo da superfície, independentemente das RBCs testadas; e as resinas bulk-fill apresentaram alterações superficiais similares (microdureza, rugosidade superficial, perfil de rugosidade, perda de volume e manutenção do brilho) quando comparadas às resinas convencionais após a escovação.

Abstract This in vitro study evaluated the effect of the beam homogeneity of a multiple-peak light-curing unit on the surface microhardness and the effect of toothbrushing wear on the microhardness, surface roughness, roughness profile, volume loss, and gloss retention of incremental and bulk-fill resin-based composites (RBCs). A LED light-curing unit (VALO) with four LEDs at the tip end (405, 445, 465A, and 465B nm emission peak) was used according to each manufacturer-recommended time to obtain disks (n=10) of six RBCs: Estelite Sigma Quick, Charisma Classic, Tetric EvoCeram Bulk Fill, Filtek Z250, Filtek Supreme Ultra, and Filtek Bulk Fill. Microhardness values were obtained according to each LED positioning of the light-curing unit on the top surface of the RBCs and were analyzed before and after toothbrushing regarding microhardness, surface roughness, roughness profile, volume loss, and gloss retention. Microhardness was considered homogeneous on the top surface regardless of the type of RBC or wavelength tested (p>0.05). Overall, toothbrushing did not reduce the microhardness of the RBCs but influenced the gloss values for most RBCs (p<0.001). Charisma Classic presented the greatest surface roughness and roughness profile after toothbrushing (p<0.05). Volume loss did not differ among RBCs (p>0.05). In conclusion, different wavelengths of the LED did not affect the top surface microhardness, regardless of the RBCs tested; and bulk-fill composites presented similar surface changes (microhardness, surface roughness, roughness profile, volume loss, and gloss retention) when compared to conventional composites after toothbrushing.

RESUMO Um padrão estético ideal consiste na harmonia facial e do sorriso. Dentes descoloridos geralmente causam um desequilíbrio na estética facial, levando a baixa auto-estima e interferência nas relações sociais. As causas da descoloração dos dentes são classificadas como intrínsecas ou extrínsecas. O clareamento é considerado um tratamento seguro e eficaz para os dentes não vitais escurecidos e pode ser associado ao tratamento restaurador para corrigir adequadamente a cor dental e maximizar os resultados estéticos. O objetivo deste trabalho é apresentar dois relatos de casos de dentes anteriores não vitais escurecidos e o protocolo utilizado para restabelecer a harmonia dentária desses pacientes por meio de clareamento e restauração direta em resina composta. Para exercer uma Odontologia minimamente invasiva é muito importante preservar a estrutura dentária e reduzir o risco de fratura. O clareamento interno, embora possa não ser suficiente para restabelecer a estética em alguns casos, é importante para minimizar o preparo dental para realizar uma restauração indireta ou direta. Os dentistas devem levar em consideração as expectativas dos pacientes, dominar a técnica restauradora e conhecer os materiais dentários para poder restaurar adequadamente a função e a estética e, consequentemente, melhorar a qualidade de vida e as relações sociais.

ABSTRACT An ideal aesthetic standard consists of facial and smile harmony. Discolored teeth generally cause an imbalance in facial aesthetics, leading to low self-esteem and disturbance in social relationships. Causes of teeth discoloration are classified as intrinsic or extrinsic. Bleaching is considered a safe and effective treatment for discolored nonvital teeth and can be associated with restorative treatment to properly correct the dental color and maximize the aesthetic results. This paper aims to present two case reports of single discolored nonvital anterior teeth and the protocol used to reestablish the dental harmony of these patients by bleaching and direct composite resin restoration. To exert minimally invasive dentistry is very important to preserve tooth structure and reduce the risk of fracture. Internal bleaching, although may not be sufficient to reestablish the aesthetic in some cases, it is important to minimize dental preparation to perform an indirect or direct restoration. Dentists must take into account the patients expectations, dominate the restorative technique and know the dental materials to properly be able to restore function and aesthetics and consequently improve life quality and social relationships.

Abstract Objectives: The aim of this in vitro study was to evaluate the bonding strength of non-simplified dentin bonding systems (DBS) to dentin irradiated with a diode laser (970 nm) immediately and after 12 months of water storage following either primer or bond application. Material and methods: The experimental design included three different factors: DBS type [AdperTM Scotchbond Multipurpose (MP) and Clearfil™ SE Bond (CSE)], irradiation [without irradiation - control (C), irradiation after primer application (AP), and irradiation after bond application (AB)], and time [initial (I) and after 12 months of water storage (12 m)]. Sixty sound human third molars (n = 10) were obtained, and their flat occlusal dentin areas were prepared and standardized. Laser irradiation was performed in the contact mode perpendicular to the dental surface over an automatically selected scanning area at a pulse energy of 0.8 W, frequency of 10 Hz, and energy density of 66.67 J/cm2. After 7 days of treatment, the specimens were cut, and half of them were subjected to microtensile testing (500 N/0.05 mm/min), whereas the remaining sticks were examined after 12 months of water storage. The obtained data were analyzed by three-way analysis of variance (ANOVA) followed by a Tukey test (p<0.05). The observed fracture modes were investigated using a portable digital microscope with a magnification of 40x. Results: Among the utilized DBS, MP generally exhibited higher bond strengths, but did not always differ from CSE under similar conditions. The irradiation factor was statistically significant only for the MP/AB groups. After 12 months of storage, all groups demonstrated a significant reduction in the bond strength, whereas the results of fracture analysis showed a predominance of the adhesive type. Conclusions: The laser treatment of non-simplified DBS was not able to stabilize their bonding characteristics after 12 months.

Resumo Pacientes submetidos a tratamento radioterápico apresentam maior suscetibilidade à cárie dentária e o uso de aparelho aumenta esse fator de risco devido ao acúmulo de biofilme dental ao redor dos bráquetes. Assim, o objetivo deste estudo foi avaliar a resistência ao cisalhamento de bráquetes ortodônticos colados com cimento de ionômero de vidro convencional (CIV) e o modificado por resina (CIVMR), devido à capacidade de liberação de flúor desse material em dentes permanentes irradiados. Noventa pré-molares humanos foram divididos em 6 grupos (n=15), de acordo com o materila de colagem e com o uso ou não de radiação: RC: Transbond XT; CIVMR: Fuji Ortho LC; RMGIC: Ketac Cem Easymix. Os grupos for irradiados (I) ou não-irradiados (NI) previamente à colagem dos bráquetes. Os espécimes foram submetidos a doses fracionadas de radiação de 2 Gy/dia, durante 5 dias consecutivos, por 6 semanas. Depois da termociclagem e radioterapia, os bráquetes foram colados sobre os espécimes com Transbond XT, Fuji Ortho LC e Ketac Cem Easymix. Depois de 24 h, os espécimes foram sumetidos ao teste de resistência ao cisalhamento. A imagem da superfície do esmalte (classificado pelo Índice de Remanescente Adesivo-IRA) também foi avaliada. O IRA foi distribuido em tabelas de contingência e analisado quanto à frequência entre grupos/subgrupos. O teste de resistência ao cisalhamento foi avaliado por ANOVA e pós-teste de Tukey. CIVMR apresentou os menores valores de adesão entre os grupos (p<0,05). Entre os grupos irradiados e não-irradiados não houve diferença estatística significante (p>0,05). Quanto ao IRA, RC-I apresentou maior retenção de compósito na superfície do esmalte do que os demais subgrupos. CIVMR pode ser utilizado para colagem de bráquetes metálico e apresentou IRA aceitável para práticas clínicas.

Abstract Patients undergoing radiotherapy treatment present more susceptibility to dental caries and the use of an orthodontic device increases this risk factor due to biofilm accumulation around the brackets. The objective of this study was to evaluate the shear bond strength to irradiated permanent teeth of orthodontic brackets bonded with conventional glass ionomer cement and resin-modified glass ionomer cement due to the fluoride release capacity of these materials. Ninety prepared human premolars were divided into 6 groups (n=15), according to the bonding material and use or not of radiation: CR: Transbond XT composite resin; RMGIC: Fuji Ortho LC conventional glass ionomer cement; GIC: Ketac Cem Easymix resin-modified glass ionomer cement. The groups were irradiated (I) or non-irradiated (NI) prior to bracket bonding. The specimens were subjected to a fractioned radiation dose of 2 Gy over 5 consecutive days for 6 weeks. After the radiotherapy, the brackets were bonded on the specimens with Transbond XT, Fuji Ortho LC and Ketac Cem Easymix. After 24 h, the specimens were subjected to shear bond strength test. The image of enamel surface (classified by Adhesive Remnant Index - ARI) was also evaluated and its frequency was checked among groups/subgroups. The shear bond strength variable was evaluated with ANOVA and Tukey’s post-hoc test. GIC group showed the lowest adhesion values among the groups (p<0.05). There was no statistically significant difference among non-irradiated and irradiated groups (p>0.05). As for the ARI, the CR-I group showed the highest material retention on enamel surface among the irradiated groups. RMGIC group showed the highest values for shear bond strength and presented ARI acceptable for clinical practices.

Abstract: The effects of tooth brushing could affect the long-term esthetic outcome of composite restorations. This study evaluated the effect of two different emission spectrum light-curing units on the surface roughness, roughness profile, topography and microhardness of bulk-fill composites after in vitro toothbrushing. Valo (multiple-peak) and Demi Ultra (single-peak) curing lights were each used for 10s to polymerize three bulk-fill resin composites: Filtek Bulk Fill Posterior Restorative (FBF), Tetric EvoCeram Bulk Fill (TET) and Surefil SDR Flow (SDR). After 30,000 reciprocal strokes in a toothbrushing machine, the roughness profile, surface roughness, surface morphology, and microhardness were examined. Representative SEM images were also obtained. When light-cured with the Demi Ultra, SDR showed the most loss in volume compared to the other composites and higher volume loss compared to when was light-cured with Valo. The highest surface roughness and roughness profile values were found in SDR after toothbrushing, for both light-curing units tested. FBF always had the greatest microhardness values. Light-curing TET with Valo resulted in higher microhardness compared to when using the Demi Ultra. Confocal and SEM images show that toothbrushing resulted in smoother surfaces for FBF and TET. All composites exhibited surface volume loss after toothbrushing. The loss in volume of SDR depended on the light-curing unit used. Toothbrushing can alter the surface roughness and superficial aspect of some bulk-fill composites. The choice of light-curing unit did not affect the roughness profile, but, depending on the composite, it affected the microhardness.

Abstract Simplified dentin-bonding systems are clinically employed for most adhesive procedures, and they are prone to hydrolytic degradation. Objective This study aimed to investigate the effect of laser diode irradiation on the degree of conversion (DC), water sorption (WS), and water solubility (WSB) of these bonding systems in an attempt to improve their physico-mechanical resistance. Material and Methods Two bonding agents were tested: a two-step total-etch system [Adper™ Single Bond 2, 3M ESPE (SB)] and a universal system [Adper™ Single Bond Universal, 3M ESPE (SU)]. Square-shaped specimens were prepared and assigned into 4 groups (n=5): SB and SU (control groups – no laser irradiation) and SB-L and SU-L [SB and SU laser (L) – irradiated groups]. DC was assessed using Fourier transform infrared spectroscopy with attenuated total reflectance. Additional uncured resin samples (≈3.0 µL, n=5) of each adhesive were also scanned for final DC calculation. For WS/WSB tests, similar specimens (n=10) were prepared and measured by monitoring the mass changes after dehydration/water storage cycles. For both tests, adhesive fluids were dropped into standardized Teflon molds (6.0×6.0×1.0 mm), irradiated with a 970-nm laser diode, and then polymerized with an LED-curing unit (1 W/cm2). Results Laser irradiation immediately before photopolymerization increased the DC (%) of the tested adhesives: SB-L>SB>SU-L>SU. For WS/WSB (μg/mm3), only the dentin bonding system (DBS) was a significant factor (p<0.05): SB>SU. Conclusion Irradiation with a laser diode improved the degree of conversion of all tested simplified dentin bonding systems, with no impact on water sorption and solubility.

Resumo O objetivo foi avaliar a rugosidade superficial e adesão bacteriana no esmalte dental irradiado com lasers de alta intensidade, associados ou não a um verniz fluoretado. Oitenta fragmentos de esmalte foram igualmente divididos em 8 grupos (n= 10). O grupo 1 não recebeu tratamento e o grupo 2 recebeu aplicação de verniz fluoretado a 5%. Os outros grupos foram irradiados com os lasers Er,Cr:YSGG (8,92 J/cm2), Nd:YAG (84,9 J/cm2) e um laser de diodo (199,04 J/cm2), associados ou não ao verniz fluoretado. A rugosidade superficial foi medida antes e após os tratamentos. Depois, todas as amostras foram imersas em suspensão de S. mutans a 37 °C durante 24 h. As unidades formadoras de colônia (UFC) foram contadas utilizando uma lupa estereoscópica, e os resultados foram expressos em UFC/mm2. Os resultados de rugosidade foram analisados por ANOVA e pelo teste de Tukey, e a adesão bacteriana foi analisada pelo teste de Student (a=5%). As amostras irradiadas sem verniz apresentaram a mesma rugosidade superficial e a mesma adesão bacteriana que as amostras não irradiadas. No entanto, as amostras irradiadas na presença do verniz fluoretado apresentaram maior rugosidade superficial e aderência bacteriana do que as amostras não irradiadas e daquelas irradiadas sem o verniz. A presença de pigmentos no verniz aumentou a ação dos lasers na superfície do esmalte, promovendo a ablação do tecido duro e aumentando significativamente a sua rugosidade superficial. Por isso, a adesão bacteriana no esmalte foi maior quando a irradiação foi realizada na presença do verniz fluoretado.

Abstract The aim was to evaluate the surface roughness and bacterial adhesion on enamel irradiated with high intensity lasers, associated or not to a fluoride varnish. Eighty fragments of bovine enamel were equally divided in 8 groups (n=10). Group 1 was not treated and Group 2 received only a 5% fluoride varnish application. The other groups were irradiated with an Er:Cr:YSGG (8.92 J/cm2), an Nd:YAG (84.9 J/cm2) and a diode laser (199.04 J/cm2), associated or not to a 5% fluoride varnish. The surface roughness was measured before and after treatments. Afterward, all samples were incubated in a suspension of S. mutans at 37 °C for 24 h. The colony-forming units (CFU) were counted by a stereoscope and the results were expressed in CFU/mm2. One-way ANOVA and the Tukey´s test compared the roughness data and the Student´s test compared the results obtained in the bacterial adhesion test (a=5%). The results showed that the irradiated samples without varnish presented the same roughness and the same bacterial adhesion that the non-irradiated samples. However, samples irradiated in the presence of fluoride varnish showed higher surface roughness and higher bacterial adhesion than the non-irradiated samples and those irradiated without varnish. Presence of pigments in the varnish increased the lasers’ action on the enamel surface, which produced ablation in this hard tissue and significantly increased its surface roughness. For this reason, the enamel’s susceptibility to bacterial adhesion was higher when the irradiation of the samples was made in presence of fluoride varnish.