Effect of dentin moisture on the adhesive properties of luting fiber posts using adhesive strategies

Abstract The purpose of this study was to evaluate the effect of dentin moisture (moist and dry) on the bonding of fiber posts to root dentin with different adhesive strategies (etch-and-rinse, self-etch, and self-adhesive). Seventy-two extracted single-rooted human teeth were endodontically treated and divided into six groups (n = 12) according to the moisture of dentin surface and adhesive systems as follows: a) etch-and-rinse/moist, b) etch-and-rinse/dry, c) self-etch/moist, d) self-etch/dry, e) self-adhesive/moist, and 6) self-adhesive/dry. The specimens were sectioned into six slices for push-out bond strength (BS), nanoleakage (NL) by SEM, and Vickers microhardness (VHN) of the resin cement. A universal testing machine (AG-I, Shimadzu Autograph) was used at a crosshead speed of 0.5 mm/min until post extrusion, with a load cell of 50 kg for evaluation of the push-out strength. Data on BS, NL, and VHN were evaluated by two-way ANOVA and Tukey's test (α = 0.05). Dentin moisture as the main factor was not significantly different for the push-out test. However, higher BS values can be observed for the etch-and-rinse group. A lower percentage of NL was found in the dry dentin groups. The moisture pattern was not significant in the hardness values for the pre-etching groups. Additional moisture did not increase the evaluated properties.

Effect of the application of different concentrations of Edta on the adhesion of fiber posts using self-adhesive cements

Abstract The purpose of this study was to analyze the effect of the application of different concentrations of EDTA on the adhesion of fiber posts to root dentin using self-adhesive resin cements. After endodontic treatment, 78 single roots were randomly divided into six groups (n = 13) according to the combination of the following factors: surface dentin treatment - control (distilled water), 17% EDTA and 24% EDTA; and self-adhesive resin cement - RelyX U200 (RX); and Multilink Speed (ML). After fiber post cementation, six slices were obtained for each root. Ten roots of each group were used for bond strength (BS) and three for microhardness (MH) evaluations. Data obtained from BS and MH tests for each resin cement were subjected to two-way ANOVA (surface treatment vs. root region) and to a post-hoc Tukey's test (α = 0.05). The lowest BS value was observed in the 24% EDTA group for RX cement, whereas the highest values for ML cement were observed for the control group in the middle and apical regions. In the MH test, the lowest value for RX was observed for 24% EDTA in the cervical region, whereas and the highest value for the ML cement was observed in the control group. Regarding both self-adhesive resin cements tested, the application of 24% EDTA was not able to improve the adhesion of fiber posts to root canal.

Effect of surface treatments on repair strength, roughness and morphology in aged metal-free crowns

Aim: The roughness and micromorphology of various surface treatments in aged metal-free crowns and the bond strength of these crowns repaired with composite resin (CR) was evaluated in vitro. Methods: A CR core build-up was confectioned in 60 premolars and prepared for metal-free crowns. Prepared teeth were molded with the addition of silicone, and the laboratory ceromer/fiber-reinforced crowns (SR Adoro/Fibrex Lab) were fabricated. Subsequently, the crowns were cemented and artificially aged in a mechanical fatigue device (1.2 X 106 cycles), then divided into 4 groups (n = 15) according to the surface treatment: 1) phosphoric acid etching (PA); 2) PA + silane application; 3) roughening with a diamond bur + PA; and 4) sandblasting with Al2O3 + PA. After the treatments, the crowns (n = 2) were qualitatively analyzed by scanning electron microscope (SEM) and surface roughness (n = 5) was analyzed before and after the surface treatment (Ra parameter). The remaining crowns (n = 8) received standard repair with an adhesive system (Tetric N-Bond) and a nanohybrid CR (Tetric N-Ceram), and the microshear bond strength (SBS) test was performed (0.5 mm/min). Roughness and SBS data were analyzed by one- and two-way ANOVA, respectively, as well as Tukey's post-test (α = 0.05). Results: Sandblasting with Al2O3 + PA resulted in the highest final roughness and SBS values. The lowest results were observed in the PA group, whereas the silane and diamond bur groups showed intermediate values. Conclusion: It may be concluded that indirect ceromer crowns sandblasted with aluminum oxide prior to PA etching promote increased roughness surface and bond strength values

Effect of conditioning protocols and ultrasonic application of an infiltrant resin in white spot lesions

Abstract The aim of this study was to evaluate different conditioning protocols and sonic/ultrasonic application of an infiltrant resin (IR) in artificial white spot lesions (AWSL). the V/L surfaces of 48 molars were induced to an AWSL and divided in 6 groups, according to the conditioning protocols and application technique: 15% hydrochloric acid (HA) + manual application of the IR; HA + 37% phosphoric acid (PA) + manual application of the IR; HA + ultrasonic application (U) of the IR; HA + sonic application (S) of the IR; PA+HA+S; and PA+HA+U. For the Penetration Depth (PD), the crowns were etched with HA for 120s. The IR Icon® (DMG) was applied according to the manufacturer`s instructions. The crowns were dye penetrated (0.1% red fluorophore rhodamine B isothiocyanate for 12h) and bleached with 30% hydrogen peroxide for 12 h. The discs were immersed in a 50% ethanol solution, containing 100 µM of sodium fluorescein. The PD (in µm) was measured using confocal laser scanning microscopy (20x). The bond strength (BS) was performed by michoshear test (0.5 mm/min). Data were submitted to 2-way ANOVA and Tukey (α=0.05). For BS, the interaction was not significant (p>0.05). For PD, the main factors were significant (application - p<0.001; conditioning technique - p=0.003). The ultrasonic application showed the highest PD values. PA+HA presented higher results than HA. The sonic/ultrasonic applications and the use of phosphoric acid prior to hydrochloric acid improved PD of the infiltrant resin. Conditioning protocols or application techniques did not influence BS values.

Resumo: O objetivo deste estudo foi avaliar diferentes protocolos de condicionamento e a aplicação sônica/ultrassônica de uma resina infiltrante (RI) em lesões de mancha branca produzidas artificialmente (LMBA). As superfícies vestibulares/linguais de 48 molares foram induzidas à formação de LMBA e divididas em 6 grupos, de acordo com os protocolos de condicionamento e técnica de aplicação da resina infiltrante: ácido hidroclorídrico 15% (AH) + aplicação manual da RI; AH + ácido fosfórico 37% (AF) + aplicação manual da RI; AH + aplicação ultrassônica da RI (U); AH + aplicação sônica da RI (S); AF + AH + S; e AF + AH + U. para o grau de penetração (GP), condicionou-se as coroas com AH por 120 s. A RI Icon® (DMG) foi aplicada de acordo com as instruções do fabricante. As coroas foram coradas (rodamina B 0,1% por 12 h) e clareadas com peróxido de hidrogênio 30% por 12 h. os discos foram imersos em solução de etanol 50%, contendo 100 µM de fluoresceína sódica. O GP (em µm) foi mensurado por meio de microscopia confocal a laser (20´). A resistência de união (RU) foi calculada pelo teste de microcisalhamento (0,5 mm/min). Os dados foram submetidos ao teste ANOVA 2 fatores e Tukey (α=0,05). Para RU, a interação não foi significante (p>0,05). Para GP, os fatores principais foram significantes (técnica de aplicação - p<0,001; protocolos de condicionamento - p=0,003). A aplicação U mostrou os maiores valores de GP. AF+AH demonstrou resultados superiores ao grupo AH. As aplicações sônica/ultrassônica e o uso do ácido fosfórico antes do ácido hidroclorídrico aumentaram o GP da resina infiltrante. Os protocolos de condicionamento ou as técnicas de aplicação não influenciaram os valores de RU.

Influence of light transmission through fiber posts: Quantitative analysis, microhardness, and on bond strength of a resin cement

Light transmission (LT) into deeper areas of the dentin root is limited. Aim: The aim of this study is to perform a quantitative investigation of the radial transmission of light (LT) through different fiber posts and its influence on the Knoop hardness number (KHN) and bond strength (BS) of a dual-cure self-adhesive resin cement at 3 different depths. Materials and Methods: Four types of fiber posts (2 translucent and 2 conventional) were used. LT and KHN analyses were performed in a specially designed matrix, which allowed measurements at 3 different depths. LT was measured using a volt-ampere meter while KHN tests were performed in a microhardness tester. For BS analysis, endodontically treated bovine roots were divided into 4 groups, each group receiving one type of post. After cementation, cross sections of the root were tested for resistance to displacement using a universal testing machine. Statistical Analysis Used: Statistical analysis was performed by using this ANOVA and Tukey's test. Results: For LT, translucent posts showed significantly higher values at all depths compared to the conventional ones. For all posts, LT decreased at the deeper depths. The KHN results showed no statistical differences among the different posts, regardless of depth. For BS, a translucent post showed the highest values, and comparative analyses between the different depths of posts also showed statistically significant differences while comparisons among the different depths of the same post showed no differences. Conclusions: LT depended on the type of post and on depth. The type of post did not significantly influence the cement KHN. A translucent post showed higher BS in pooled data.

Bond strength values of fiberglass post to flared root canals reinforced with different materials

Abstract The aim of this study was to compare in vitro the bond strength (BS) between fiberglass posts and flared root canals reinforced with different materials. The roots of 48 premolars were endodontically treated. After one week, the root canals were prepared to simulate an oversized root canal, except for the positive control group (PCG), which was cemented with a prefabricated fiber post (PFP) compatible with the root canal size, simulating an ideal adaptation. The other samples (n=8/group) were used to test alternative restorative techniques for filling root canals: negative control group (NCG [PFP with a smaller diameter than of the root canal]), composite resin group - CRG, bulkfill group - BFG, self-adhesive cement group - SAG, and glass ionomer group - GIG. The posts were cemented and after 1 week, each root was sectioned transversely into six 1-mm thick discs and the push-out test was done to evaluate the BS. Data were analyzed by two-way repeated measures ANOVA and Tukey's tests (α=0.05). The highest BS value was observed for PCG. The NCG and the GIG groups showed the lowest BS values. Root reinforcement with conventional and bulk-fill composite resins showed the highest BS values; however, the bulk-fill resin was the only treatment able to maintain high BS values in all regions of the root canal. The self-adhesive cement showed intermediate results between CRG and GIG. Root reinforcement with bulk-fill composite resin is an effective option for flared root canals before cementation of a prefabricated fiber post.

Influence of different burs and acid ultrasonic agitation on the bonding of fiber posts to root dentin

Aim: The objective is to evaluate the influence of different burs used to prepare the root canal space and acid ultrasonic agitation on bond strength (BS) between glass fiber posts (GFP) and root dentin. Methods: After endodontic treatment, the root canal spaces of 36 extracted human canines were prepared, according to the rotary instrument used (n=18): carbide bur (CB), provided by the post manufacturer and a diamond bur (DB). In both groups, the fiber posts were cemented with the adhesive system Ambar and resin cement Allcem, following the manufacturer`s instructions. Previously to the cementation procedures, the groups were subdivided into 2 groups (n=9), according to the phosphoric acid application mode: conventional etching (CE) and active etching (AE), performed by ultrasonic tip, both for 15s. Before the cementation procedures and after the acid application, 1 root of each group was randomly selected for ultrastructural morphological evaluation by SEM. After 1 week of the cementation, 8 specimens per group were transversely sectioned into six 1-mm thick slices, the root canal regions (cervical, medium and apical) were identified and the push-out test was performed to evaluate BS. Data were analyzed by 3-way ANOVA and Tukey test (α=0.05). Results: The results showed that the cross-product interaction of all factors was significant (P=0.035). Higher bond strength values were obtained when a DB with conventional etching, instead of CB, was used to prepare the root post space. Conclusion: It may be concluded that the use of diamond burs with conventional etching yields high BS values in all root canal thirds

Is the bonding of self-adhesive cement sensitive to root region and curing mode?

Abstract Objectives To evaluate the influence of two curing techniques on the degree of conversion (DC) of resin cements and on bond strength (BS) of fiber posts in different regions of root dentin. Material and Methods Twenty single-rooted premolars were endodontically treated, and the post spaces were prepared. The roots were randomly divided into two groups (n=10), according to the activation mode of the resin cement RelyX™ U200 (3M ESPE Saint Paul, MN, USA): conventional (continuous activation mode) and soft-start activation mode (Ramp). The posts (WhitePost DC/FGM) were cemented according to the manufacturer’s recommendations and, after one week, the roots were cross-sectioned into six discs each of 1-mm thickness, and the cervical, medium, and apical thirds of the root canals were identified. The DC was evaluated under micro-Raman spectroscopy and the BS was evaluated by the push-out test. The data were analyzed by two-way ANOVA and Tukey’s test (α=0.05). Results Neither the activation mode nor the root regions affected the DC of the resin cement. Higher BS was achieved in the soft-start group (p=0.036); lower BS was observed in the apical third compared to the other root regions (p<0.001). Irrespective of the activation mode and root region, the mixed failure mode was the most prevalent. Conclusion The BS of fiber posts to root canals can be improved by soft-started polymerization. The DC was not affected by the curing mode.

Effect of bleaching agents containing fluoride or calcium on enamel microhardness, roughness and permeability

To evaluate the effect of different in-office bleaching agents on the permeability, roughness and surface microhardness of human enamel. Methods: For evaluation of roughness and microhardness, 40 hemi-faces of 20 premolars were subjected to initial roughness (Ra parameter) and microhardness (VHN) measurements. Thirty-two premolar's crowns were used for permeability test. Then, all specimens were randomly divided into four groups: C - without bleaching (control), HP35 - bleaching with 35% hydrogen peroxide (HP), HPF38 - 38% HP+fluoride, HPC35 - 35% HP+calcium. Final roughness (FR) and microhardness (FM) measurements were evaluated. For permeability, the 32 crowns were immersed in 1% sodium hypochlorite (20 min) and silver nitrate solutions (2 h) and subjected to developing solution under fluorescent light (16 h). Three sections from the crowns were analyzed in light microscope (100x) to evaluate the scores of permeability: Score 0 - no tracer agent penetration; Score 1 - less than half the thickness of enamel penetration; Score 2 - tracer agent reaching half the enamel thickness; Score 3 - entire enamel depth penetration, without reaching dentin and Score 4 - tracer agent reaching dentin. For roughness and microhardness evaluation were used one-way ANOVA and Dunnet post-test for independent samples, and t test for paired samples. For permeability, the data were analyzed by Kruskal Wallis and Dunn tests. Results: A significantly higher permeability and surface roughness were observed in groups HP35, HPF38 and HPC35 compared to the C group, as well as decreased microhardness (p<0.05). Conclusions: All bleaching agents increased permeability and surface roughness, and decreased microhardness of human enamel; thus, the addition of fluoride or calcium was not beneficial...

Effects of immediate and delayed intraradicular preparation on bond strength of fiber posts.

Background: To assist the retention of restorations prepared in endodontically treated teeth, fiber posts are widely used in dental practice. The ideal time to prepare space for the post is still controversial. Aim: The purpose of this study was to evaluate the effects of immediate and delayed postspace preparation on the retention of the self‑adhesive resin cement. Materials and Methods: Twelve bovine teeth were used with sectioned roots standardized to 19 mm. The teeth were properly instrumented and filled with gutta‑percha and eugenol‑free cement AH Plus. Two experimental groups (n = 6) were created based on the different times of post preparation (immediate and delayed). Using cemented cylindrical fiber posts, the teeth were put in acrylic resin and polyvinyl chloride tubes, where the cuts were made. Two slices were obtained from the cervical third, two from the medium third and two from the apical third. Subsequently, the samples were subjected into push‑out tests. Statistical analysis were performed using ANOVA and Tukey’s test (P = 5%). Results: The results indicated that, for all of the evaluated thirds, delayed preparation showed greater bond strength than immediate preparation. Conclusion: A delayed post preparation of the root space, following the root canal filling, is recommended.

Effect of finishing and polishing on surface roughness of composite resins after bleaching

AIM : To evaluate the influence of finishing and polishing techniques on the surface roughness of two composite resins (CRs) subjected to bleaching procedure. METHODS : Forty-eight CR specimens were divided into six groups (n=8). For G1 to G3, a microhybrid CR (Opallis; FGM) was used, and G4 to G6, received a nanohybrid CR (Brilliant NewLine; Coltène/Whaledent). All specimens were subjected to bleaching procedure with 35% hydrogen peroxide (two 45-min applications, with a 5-day interval). The surface roughness of all specimens was evaluated before and after the bleaching and/or finishing/polishing (Ra parameter) by a roughness meter. After bleaching, the groups were subjected to finishing and polishing procedures: G2 and G5 - felt discs + diamond pastes; and G3 and G6 - silicon rubber tips. The control groups (G1 and G4) had no finishing or polishing treatment after bleaching. Data were analyzed by ANOVA and Tukey's post-test, and t test for paired samples (a=0.05). RESULTS : bleaching treatment increased Ra values for the nanohybrid CR specimens, but both finishing/polishing techniques were able to reduce these values; for the microhybrid specimens, only finishing/polishing with silicon rubber tips decreased the roughness values. CONCLUSIONS : For both microhybrid and nanohybrid CRs, the silicon rubber tips were effective to reduce the surface roughness after bleaching procedure...

Utilização de dentes humanos: aspectos éticos e legais / Human teeth use: ethical and legal aspects

O reconhecimento da importância do elemento dental como órgão humano é um fato muitas vezes negligenciado ou desconsiderado pela maioria dos odontólogos e por alguns profissionais vinculados à pesquisa científica, que utilizam grandes quantidades de dentes humanos em seus trabalhos, e por acadêmicos dos cursos de Odontologia. O presente estudo tem como propósito rever os aspectos éticos e legais envolvidos na utilização de dentes humanos por todos os envolvidos, sejam eles pesquisadores, professores e/ou alunos, promovendo assim um uso racional desses órgãos, o que vem sendo possível com a criação de Bancos de Dentes nas universidades. Diante do exposto, torna-se necessária a existência de um vínculo entre o Banco de Dentes e o Comitê de Ética da Instituição em que este se encontra, a fim de que se estabeleçam, desde o início de sua organização, diretrizes e normas de funcionamento conjuntas, visando ao cumprimento da legislação vigente.

The perception of the dental element as a human organ is neglected and disregarded many times by most of the dentists that use a great amount of human teeth in their works, by some of the professionals linked to scientific research, by professors and also by academics of dentistry courses. The main goal of this study is to review in the literature, the ethical and legal aspects involved in the use of human teeth in universities, demonstrating that that perception should be implicit in all its users, whether researchers, professors and/or students, resulting in a rational use of those organs, such as is possible with the creation of Bank of Teeth in universities. Facing the foregoing, it is necessary the existence of a link between the Bank of Teeth and the Ethics Institutional Committee of the university, in order to be establish guidelines, rules, standards and mode operations since the beginning of the bank organization, aimed at compliance with current legislation.

Evaluation of human enamel permeability exposed to bleaching agents

Aim: To evaluate the human enamel permeability after different external bleaching techniques.Methods: The coronal portions of 20 maxillary human incisors were covered with an acidresistant varnish, except the labial surface, to prevent dye penetration of silver nitrate. Thespecimens were divided randomly into four groups (n=5) according to the bleaching treatments:Group 1 (G1) - without bleaching agent (control group), Group 2 (G2) - 35% hydrogen peroxide(HP) – one session of three 10-min applications, Group 3 (G3) - 35% HP – 2 sessions of three10-min applications, and Group 4 (G4) - 6% HP – 14 days (1h/day). G1 was exposed to artificialsaliva only and in the other groups the bleaching agents were applied following the manufacturers’recommendations. After bleaching, teeth were immersed in a 50% silver nitrate solution for 2 hand photodeveloped for 16 h. Then, three longitudinal slices of each tooth were photographedby an optical microscope (100x). The degree of dye penetration was analyzed in the middle thirdof the dental crowns using a 0 to 4 score system (0= no dye penetration, 1= less than half theenamel thickness, 2= half of the enamel thickness, 3= full extent of enamel without reaching thedentin, and 4= tracer agent reaching dentin). The data were analyzed statistically by the Kruskal-Wallis and Dunn tests (α=0.05). Results: The median (1st/3rd interquartiles) ranges were: G1:0(0/0), G2: 2(2/3), G3: 3(3/3) and G4: 3(3/3). G2, G3 and G4 showed significantly higher dyepenetration compared with G1 (p=0.0017). Conclusions: The use of bleaching agents increaseddental enamel permeability, regardless of the bleaching technique.

Laminados cerâmicos minimamente invasivos / Minimally invasive porcelain laminate veneers

As facetas diretas em resinas compostas podem ser indicadas para solucionar diversos problemas estéticos, como diastemas, modificações de forma, posição, cor e textura dos dentes anteriores, porém, este material é suscetível ao desgaste e à alteração na coloração, limitando assim, o resultado estético ao longo do tempo. Para compensar tais limitações, foram então propostas restaurações indiretas, tais como laminados cerâmicos. O aperfeiçoamento nas propriedades físicas e mecânicas desses materiais, associado à evolução dos sistemas adesivos e cimentos resinosos, promoveram uma adequada união da cerâmica à estrutura dentária, que proporcionou um aumento na longevidade e desempenho clínico desta modalidade de restauração

Resin composite veneers can solve many aesthetic problems, such as diastema, alterations in shape, position, color and texture of the anterior teeth, but this material is susceptible to wearing and discoloration, limiting the aesthetic result. To compensate for these limitations, indirect restorations, such as porcelain laminate veneers were proposed. The improvement and development in the physical and mechanical properties of ceramic systems, associated with the adhesive systems and resin cements, have resulted in an adequate bonding to tooth structure and ceramics, and thereby increasing the longevity and clinical performance of this type of restoration

Efeito de diferentes agentes clareadores de uso caseiro na microdureza superficial de resinas compostas: microhíbrida X nanohíbrida / Effect of different at-home bleaching agents in microhardness surface of resin composites: microhybrid X nanohybrid

Avaliou-se o efeito de agentes clareadores de uso caseiro na microdureza de resinas compostas (RC) microhíbrida e nanohíbrida. Foram confeccionados 30 corpos-de-prova (cp), divididos em seis grupos (n=5). Os grupos G1 a G3 utilizaram RC microhíbrida (Opallis), e os grupos G4 a G6, RC nanohíbrida (BrilliantNewLine). Os agentes clareadores utilizados foram: peróxido de hidrogênio 6% (PH) (White Class Cálcio) e peróxido de carbamida 16% (PC) (Whiteness Perfect). Após a confecção dos cp, o clareamento foi realizado: G1 e G4: grupo controle sem agente clareador, G2 e G5: PH - 28 dias, G3 e G6: PC - 28 dias, de acordo com as recomendações dos fabricantes. Em seguida, o teste de microdureza foi realizado. Os dados obtidos foram analisados por ANOVA e Tukey (5%). Os resultados de microdureza (HV) e desvio-padrão foram: G1-26,56 ± 3,9, G2-25,98 ± 3,3 e G3-24,94 ± 4,4; G4-27,24 ± 3,3; G5-32,02 ± 6,4 e 37,72 G6- ± 8,1. O único grupo que apresentou diferenças significativas para os outros foi o G6 (p <0,05), mas não diferiu significativamente em relação ao G5 (p = 0,0058). Concluiu-se que o uso de agentes clareadores de uso caseiro não afetou negativamente a microdureza das resinas compostas testadas.

It was evaluated the effects of home bleaching agents on microhardness of microhybrid and nanohybrid composite resins. 30-of-body were made and divided into 6 groups (n=5). The groups G1 to G3 used a microhybrid CR (Opallis), while groups G4 to G6 used a nanohybrid CR (BrilliantNewLine). The bleaching agents used were: 6% hydrogen peroxide (PH) (White Class Cálcio) and 16% carbamide peroxide (PC) (Whiteness Perfect). After the specimens were prepared, the bleaching was realized as follows: G1 and G4: control group without bleaching agent, G2 and G5: PH - 28 days, G3 and G6: PC - 28 days, in accordance with the manufacturer's recommendations. After it, the microhardness test was performed. The data were statistically analyzed by ANOVA and Tukey's tests (5%). The results of microhardness (HV) and standard deviation of each group were: G1- 26.56±3.9; G2- 25.98±3.3; G3- 24.94±4.4; G4- 27.24±3.3; G5- 32.02±6.4 and G6- 37.72±8.1. The only group that showed significant differences to the anothers was the G6 (p<0.05), but did not differ significantly in relation to G5 (p=0.0058). It was concluded that the use of home bleaching agents didn't affect negatively the microhardness of the composite resins tested.

Effect of light-curing units on gap formation and microleakage of class II composite restorations

Aim: This in vitro study evaluated gap width formation and marginal microleakage in Class IIcomposite restorations light-cured with three different light-curing units. Methods: Standardizedcavities in the proximal surfaces of 36 human third molars were made with margins located belowthe cementoenamel junction. Cavities were restored with Filtek P60 (3M ESPE), inserted with aphotocondenser tip and light-cured with three different methods: GI - Optilux401 (halogen); GII –ColtoluxLED (LED) and GIII –UltraLumeLED5 (LED). After finishing the restorations, teeth weresubjected to a thermal cycling regimen of 500 cycles (5oC ± 2oC and 55oC ± 2oC), totalizing 500cycles. Thereafter, the teeth were sectioned in a buccolingual direction and in the center of therestorations. Half of the specimens (18) were used to evaluate marginal microleakage, by measuringof dye penetration in cross-sectioned specimens, and the other half was used to analyzed the gapformation width by SEM observations (1000X). Data were submitted to Kruskal-Wallis (α=0.05).Results: The mean values of gap width (μm) were: GI 3.28±3.34; GII 1.48±1.89 and GIII3.11±3.45, and microleakage was not affected by the light-curing units. Conclusions: Therewere no differences between the light-curing methods in gap formation and marginal microleakage.

Tratamento restaurador de alteração cromática intrínseca com resinas compostas / Restorative treatment of intrinsic chromatic alteration with composite resins

Alterações cromáticas intrínsecas nos dentes, provenientes de defeitos na formação da estrutura do esmalte e dentina, podem resultar em comprometimento estético do sorriso. Este relato é de um paciente de 20 anos, gênero masculino, com alteração cromática no dente 42. Após análise das características clínicas das manchas, sugeriu-se o diagnóstico de lesão hipoplásica em esmalte e comprometimento da dentina. Realizou-se a técnica de transiluminação, por meio da qual se verificou alta opacidade da lesão, o que indicou se tratar de manchamento profundo e com baixa capacidade de propagação de luz. O tratamento proposto foi intervenção restauradora com resinas compostas, e o resultado obtido foi extremamente satisfatório, pois se conseguiu, por meio de uma técnica estratificada, reproduzir o policromatismo dental e devolver a naturalidade do sorriso ao paciente.

The intrinsically change of teeth color resulted from defects in the formation of the structure of enamel and dentin, may result in aesthetic smile. This report is a patient with twenty years old, male, presented with chromatic alterations in tooth 42. After examining the clinical characteristics of the stains, it has been diagnosed hypoplastic lesion in enamel and dentin compromising. By transillumination it was observed a high opacity of the lesion, indicating a deep staining and with low ability to spread light. Thus, the proposed treatment was the intervention with restorative composite resins and the result was extremely satisfactory, since it was possible through a technique stratified the reproduction of the natural tooth polychromatic and the return of this patient’s smile.

Comparação da radiopacidade de cimentos resinosos pelos sistemas de radiografia convencional e digital / Comparison of radiopacity in luting resin cements using conventional and digital radiographic systems

Objective: To evaluate the radiopacity of three different resin composite luting cements using the histogram method (conventional radiography) and pixel counting method (digital radiography). Methods: Fifteen specimens were divided into 3 different resin composite luting cement groups: G-I) Cement-Post (Ângelus®, Londrina, Brazil), G-II) RelyX ARC (3MESPE, St. Paul, Minnesota, USA) and G-III) Variolink II (Ivoclar/Vivadent, Schaan, Liechtenstein). After 24 hours, conventional x-rays of the specimens were taken with a lead gauge, making a visual evaluation by scores, to classify the specimen?s radiopacity according to the scale shade (control); they were then scanned for the purposes of analyzing the histogram using Adobe Photoshop CS2, version 8.0. Using the same specimens, x-rays were taken using a Digital X-RAY Intra-Oral System (Gnatus DSR, Ribeirão Preto, Brazil). In this case, the capture of the digital images was performed using Cygnus Imaging® software and the digital radiopacity was measured by counting pixels, using the Image Tool® software (UTHSCSA). Results: The non-parametric Kruskal-Wallis test and Dunn?s post-test (p<0.05) showed that the means and respective standard deviation percentages of white pixels in the digital x-rays were: G-I) 48.94 ±3.16, G-II) 60.22 ±3.86 and G-III) 69.36 ±5.32. As for the conventional x-rays, the means and standard deviations of the histogram analyses that evaluated gray tones were: G-I) 71.98 ±13.02; G-II) 85.40 ±4.47; G-III) 130.51 ±5.82. Conclusion: In conclusion, regardless of the method used (conventional or digital x-rays), G-III obtained the largest radiopacity value.

Objetivo: Avaliar a radiopacidade de cimentos resinosos pelo método do histograma (radiografia convencional) e da contagem de pixels (radiografia digital). Métodos: Foram utilizados 15 corpos-de-prova divididos em três grupos de cimentos resinosos: Grupo I) Cement-Post (Ângelus®, Londrina, Brasil), Grupo II) RelyX ARC (3MESPE, St. Paul, USA) e Grupo III) Variolink II (Ivoclar/Vivadent, Schaan, Liechtenstein). Após 24 horas, foram realizadas radiografias convencionais dos corpos-de-prova juntamente com uma escala de chumbo, realizando assim uma avaliação visual por escores para classificar a radiopacidade dos corpos-de-prova de acordo com a tonalidade da escala (controle); e em seguida, foram escaneadas para análise do histograma no software Adobe Photoshop CS2 versão 8.0. Com os mesmos corpos-de-prova, realizaram-se tomadas radiográficas empregando-se o Sistema Intra-oral de Raio-X Digital (Gnatus, Ribeirão Preto, Brasil), sendo a captura das imagens digitais realizadas com o software Cygnus Imaging® e a radiopacidade digital mensurada pela contagem de pixels com o software Image Tool® (UTHSCSA). Resultados: O teste não-paramétrico de Kruskal-Wallis e Dunn (p<0,05) mostrou que as médias das porcentagens de pixels brancos das radiografias digitais e os seus respectivos desvios-padrão foram: Grupo I) 48,94 ±3,16; Grupo II) 60,22 ±3,86 e Grupo III) 69,36 ±5,32. Já nas radiografias convencionais, as médias e os desvios-padrão das análises do histograma avaliando tons de cinza foram: Grupo I) 71,98 ±13,02; Grupo II) 85,40 ±4,47 e Grupo III) 13,51 ±5,82. Conclusão: Pode-se concluir que utilizando tanto o sistema de radiografia convencional quanto o sistema digital, o Grupo III obteve uma maior radiopacidade.

Efeito de diferentes agentes clareadores na rugosidade superficial de resinas compostas / Effect of different bleaching agents on surface roughness of composite resins

O presente estudo avaliou o efeito de agentes clareadores na rugosidade superficial de resinas compostas (RC). Foram confeccionados 50 corpos-de-prova, divididos em 10 grupos (n=5). Os grupos G1 ao G5 utilizaram a RC Opallis (microhíbrida); G6 ao G10 a RC Brilliant NewLine (nanohíbrida). Os agentes clareadores foram: PH - Peróxido de hidrogênio 35% (Whiteness HP Max) e PC - Peróxido de carbamida 37% (Whiteness Super). Após 24 horas, realizou-se o clareamento: G1 e G6- sem agente clareador (controles); G2 e G7- uma sessão de PH com três aplicações; G3 e G8- duas sessões de PH com três aplicações cada; G4 e G9- uma sessão de PC com três aplicações e G5 e G10- duas sessões de PC com três aplicações cada. Após o clareamento, os cp foram avaliados no Rugosímetro. Os dados obtidos foram analisados por ANOVA com pós-teste de Bonferroni (α=0,05). Os resultados de rugosidade superficial (μm) foram: G1-0,07±0,02; G2-0,12±0,04; G3-0,40±0,33; G4-0,49±0,65; G5-1,33±1,76; G6-2,03±1,22; G7-1,15±0,46; G8-1,33±1,24; G9-0,56±0,59 e G10-1,87±1,31. Os resultados mostraram que para a RC Opallis, os valores de rugosidade aumentaram após o clareamento e para a RC Brilliant NewLine, os valores diminuíram. Concluiu-se que o uso de agentes clareadores afetou a rugosidade das resinas compostas testadas.

This study evaluated the effect of bleaching agents on surface roughness of composite resins (RC). 50-of-body were made and divided into 10 groups (n=5). In Groups G1 to G5 was used Opallis (a microhybrid RC), and in G6 to G10 Brilliant NewLine (a nanohybrid RC) was used. The bleaching agents were: PH-35% hydrogen peroxide (HP Max Whiteness) and PC-Carbamide peroxide 37% (Whiteness Super). After 24 hours, bleaching was performed: G1 and G6-without bleaching agent (control), G2 and G7-one session with three applications of PH, G3 and G8-two sessions of three applications of HP, G4 and G9-one session with three applications of PC and G5 and G10-two sessions of three applications of PC. After bleaching, specimens were evaluated in a roughness meter. Data were analyzed by ANOVA and Bonferroni's test (α=0.05). The results of surface roughness (μm) were: G1-0.07 ± 0.02, G2-0.12 ± 0.04, G3-0.40 ± 0.33, G4-0.49 ± 0.65; G5-1.33 ± 1.76; G6-2.03 ± 1.22; G7-1.15 ± 0.46; G8-1.33 ± 1.24; G9-0.56 ± 0.59 and G10-1.87 ± 1.31. The results showed that Opallis roughness values increased after bleaching and Brilliant NewLine values decreased. It was concluded that the use of bleaching agents affected the roughness of composite resins tested.

Reabilitação funcional e estética de dentes decíduos acometidos por cárie de início precoce / Rehabilitation functional and esthetic of deciduous teeth affected by early childhood caries

O comprometimento de dentes decíduos anteriores pode ocasionar perda da dimensão vertitical, redução da capacidade mastigatória, desvio no padrão de deglutição, distúrbios fonético,instalação de hábitos bucais nocivos, comprometimento estético e alterações emocionais na criança. O objetivo deste trabalho é relatar o caso de um paciente com 4 anos, gênero masculino, no qual o exame clínico apresentou destruição coronária e comprometimento pulpar dos dentes51, 52, 61 e 62. Após exame radiográfico, foi indicado tratamento endodôntico, cimentação de' pinos de fibra de vidro e reconstrução em resina composta. Os condutos radiculares dos quatro incisivos foram obturados com pasta Guedes-Pinto e selados com cimento de ionômero de vidro, deixando espaço para cimentar os pinos até a altura do terço cervical. Na sessão seguinte, foram cimentados os pinos e confeccionados núcleos de preenchimento em resina composta. Finalmente, os dentes 51 e 61 foram restaurados em resina composta com auxílio de um mockup de silicona confeccionado a partir do enceramento diagnóstico e os dentes 52 e 62 com auxílio de matriz de celulóide. Concluiu-se que as duas técnicas restauradoras utilizadas foram satisfatórias, sendo dependentes das condições de realização dos procedimentos restauradores pelo cirurgião-dentista e que ao manter os dentes decíduos na cavidade bucal até a esfoliação fisiológica, é possível evitar alterações no desenvolvimento da oclusão.

The involvement of anterior primary teeth can cause loss of vertical dimension, reduced ability to chew, the standard deviation of swallowing disorders phonetic, installation of harmful oral habits, aesthetic relevance and emotional changes in children. The aim of this study is to report the case of a patient with 4 year old male, in which the clinical examination showed destruction and impaired coronary pulp ofteeth 51, 52, 61 and 62. After radiographic examination, root canal treatment was indicated, glass fiber posts cementation and composite resin reconstruction. The incisors of the four root canais were filled with Guedes-Pinto and sealed with glass ionomer cement, leaving space for cementing the glass fiber posts to the height of the cervical third. The next session, posts were cemented and cores made of a composite resin filling. Finally, 51 and 61 teeth were restored with composite resin with the aid of a mock-up of silicone made from the diagnostic waxing and teeth 52 and 62 with the aid of matrix celluloid. It was concluded that both restorative techniques were satisfactory, being dependent on the conditions for carrying out restorative procedures by dentists and to keep the primary teeth in the mouth until the physiological exfoliation, ifs possible to avoid changes in the development of occlusion.