No description available.

As new adhesive products become available in restorative dentistry, investigating their potential application for orthodontic use is warranted. Vertise Flow (Kerr) is a self-adhering flowable resin and is being marketed for use as a sealant, porcelain repair and small class I restorations. It has potential for use as an orthodontic adhesive. Objective: Determine if Vertise Flow (Kerr) is suitable for bonding fixed orthodontic appliances to enamel, restorative resin composite and porcelain with minimal surface preparation. Methods: Shear Bond Strengths (SBS) from six (6) groups of fifteen (15) bonded stainless steel lingual buttons (Ormco) were obtained over three time points (24hr, 7 days, and 3 months). The six test groups were: 1.Vertise Flow to enamel (Tt) with coarse pumice debridement, 2. Transbond XT (3M, Unitek) to enamel (Tc) with phosphoric acid etching [control], 3.Vertise Flow to Herculite Ultra (Kerr) (Cc) with coarse pumice debridement, 4. Vertise Flow to Filtek Supreme Ultra (3M, ESPE) (Ct) with coarse pumice debridement, 5. Vertise Flow (Kerr) to porcelain (Pt) with diamond bur roughening, and 6. Transbond XT (3M Unitek) to porcelain (Pc) with hydrofluoric acid etching. Samples were stored in distilled water and incubated at 37C. The buttons were then debonded with a Zwick Universal Testing machine using a 10 kN load cell with a crosshead speed of 0.5mm/min. Debonded buttons were evaluated based on a modified Adhesive Remnant Index (ARI). Statistical assessment of the data was performed using parametric and non-parametric tests, with p<0.05 as the threshold for statistical significance. Results: The mean SBS obtained in all groups at each time point were >4MPa and varied between 8.69MPa and 27.44MPa. Statistical differences were found within the composite and porcelain groups at T1, and the enamel and composite groups at both T2 and T3. Nearly half of the sample (47.2%) achieved an ARI score of 5 (100% adhesive left on button base). Conclusion: Vertise Flow potentially provides clinically acceptable bond strengths to enamel, restorative resin composite and porcelain with minimal surface preparation. Furthermore, upon removal, minimal adhesive clean-up is required thus saving valuable chair time. Based on the results in this study, future in vivo investigation is suggested.

As new adhesive products become available in restorative dentistry, investigating their potential application for orthodontic use is warranted. Vertise Flow (Kerr) is a self-adhering flowable resin and is being marketed for use as a sealant, porcelain repair and small class I restorations. It has potential for use as an orthodontic adhesive. Objective: Determine if Vertise Flow (Kerr) is suitable for bonding fixed orthodontic appliances to enamel, restorative resin composite and porcelain with minimal surface preparation. Methods: Shear Bond Strengths (SBS) from six (6) groups of fifteen (15) bonded stainless steel lingual buttons (Ormco) were obtained over three time points (24hr, 7 days, and 3 months). The six test groups were: 1.Vertise Flow to enamel (Tt) with coarse pumice debridement, 2. Transbond XT (3M, Unitek) to enamel (Tc) with phosphoric acid etching [control], 3.Vertise Flow to Herculite Ultra (Kerr) (Cc) with coarse pumice debridement, 4. Vertise Flow to Filtek Supreme Ultra (3M, ESPE) (Ct) with coarse pumice debridement, 5. Vertise Flow (Kerr) to porcelain (Pt) with diamond bur roughening, and 6. Transbond XT (3M Unitek) to porcelain (Pc) with hydrofluoric acid etching. Samples were stored in distilled water and incubated at 37C. The buttons were then debonded with a Zwick Universal Testing machine using a 10 kN load cell with a crosshead speed of 0.5mm/min. Debonded buttons were evaluated based on a modified Adhesive Remnant Index (ARI). Statistical assessment of the data was performed using parametric and non-parametric tests, with p<0.05 as the threshold for statistical significance. Results: The mean SBS obtained in all groups at each time point were >4MPa and varied between 8.69MPa and 27.44MPa. Statistical differences were found within the composite and porcelain groups at T1, and the enamel and composite groups at both T2 and T3. Nearly half of the sample (47.2%) achieved an ARI score of 5 (100% adhesive left on button base). Conclusion: Vertise Flow potentially provides clinically acceptable bond strengths to enamel, restorative resin composite and porcelain with minimal surface preparation. Furthermore, upon removal, minimal adhesive clean-up is required thus saving valuable chair time. Based on the results in this study, future in vivo investigation is suggested.

<p><font face="Times New Roman" size="4"><font face="Times New Roman" size="4"> <p align="left">The aim of this study is to investigate the repair bond strength of composite resin following micromechanical and chemical means of retention in improving the repair of composite resin specimens.</p> </font></font></p>

<p><font face="Times New Roman" size="4"><font face="Times New Roman" size="4"> <p align="left">The aim of this study is to investigate the repair bond strength of composite resin following micromechanical and chemical means of retention in improving the repair of composite resin specimens.</p> </font></font></p>

The objective of this study was to determine whether the composite bond strength acquired using a single step self-etching bonding system is as or more effective when compared to the two step etch-rinse-bond system at clinically relevant in-vitro standards. A total of 80 extracted human deciduous with at least one intact smooth surface were collected with parental consent. Collected teeth were randomly assigned to one of four treatment protocols (n=20): single step self-etch (Adper Prompt L-Pop, 3M ESPE), two step etch (15s)-rinse-bond (Optibond Solo Plus, Kerr), single step self etch (Adper L Pop, 3M ESPE) with 30s pre-etch, and two step etch (30s)-rinse-bond (Optibond Solo Plus, Kerr). A composite cylinder of uniform shape was bonded to each tooth using the designated adhesive system and specimens were tested with a universal testing machine. Descriptive statistics and statistical analysis was performed. Median shear bond strengths for all specimens, regardless of treatment group, ranged from 3.25 MPa to 43.13 MPa. These values are above suggested minimum clinical required values of 3MPa. A Kruskal-Wallis analysis between treatment groups found statistical significance (p<0.05) for shear bond strength between the groups and both one step system protocols, had higher mean and median shear bond strength values than the two step systems. An adhesive remnant index (ARI) was analyzed to confirm uniform adhesive fracture between all four treatment groups. Both a Fisher’s exact test, and a Hantel-Haenszel statistic found no significant difference (p<0.05) between the samples. Based on these findings we concluded that: 1. The ARI score for all treatment groups was not statistically significant, suggesting that the type of bond breakage was consistent regardless of adhesive system used. 2. Both Optibond Solo Plus and Adper Prompt L-Pop systems achieve adequate shear bond strengths as described by current literature. 3. The use of a one-step system to save chair time and aid in patient behavior management may be clinically useful.

Magister Scientiae - MSc / The aim of this study is to investigate the repair bond strength of composite resin following micromechanical and chemical means of retention in improving the repair of composite resin specimens.

This research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Science in Dentistry. School of Oral Health Science, Faculty of Health Sciences, University of the Witwatersrand, South Africa Johannesburg, 2017 / Purpose: Resin restorative materials have improved over the years. A major obstacle to the acquisition of acceptable bond strength of bonding agents is the presence of contaminated dentine cavity preparations. The purpose of this study was to investigate the effects of oral contaminants such as blood, saliva and a disinfectant contamination on the shear bond strength of a nanocomposite on a self-etching adhesive system. Materials and Methods: Thirty-six caries free premolar teeth were extracted and placed in a disinfectant solution containing 0.5 % Chloramine T solution, and then randomly distributed into four groups. Each tooth was then placed into a stainless steel ring supported by clear self-curing acrylic. They were thereafter immersed into a saline solution of 37 ̊C - 37.5 ̊C in an incubator for 24 hours. The enamel surfaces of the premolars were then ground with a Pro-trim 1725 Hertz grinder using 600 grit silicon carbide fine grinding paper to expose the dentine surface of each tooth. The sample was then re-immersed in the saline solution and incubated at 37°C - 37.5°C. The teeth were then arranged into the four groups: Group 1 (control group); Group 2 (human blood contamination at 5 seconds); Group 3 (human saliva contamination at 5 seconds) and Group 4 (chlorine dioxide contamination at 5 seconds). A self-etching adhesive bonding system (Scotchbond universal™) and Filtek supreme XTE composite was applied to the exposed dentine surface. Samples were randomised and then sheared using an Instron testing machine to determine their bond strengths. The fractured components of each sample were measured, compared and further examined under a stereo microscope to determine the modes of failure. The data were analysed using a one-way analysis of variance (ANOVA) and the level of significance was set at a p-value of less than 0.05. Results: A significant difference was found in the shear bond strength between the control (group 1) and the blood contaminated group (group 2) (p-value of 0.00064). The chlorine dioxide group (group 4) that had no effect on shear bond strength to dentine (p-value of 0.55). Adhesive failures (between bonding agent and dentine) were predominant in group 2 and to a lesser extent in group 3. Most group 4 samples had cohesive fractures (within the dentine). Conclusion: The bond strength to dentine using a self-etching adhesive was reduced when contaminated with blood. Group 2 samples (blood) caused significantly greater bonding failure as compared to all the other groups. Chlorine dioxide solution is a powerful disinfectant and does not affect the bonding to dentine. The null hypothesis statement, which stated that there was no difference in the shear strength between any of the conditions, was thus rejected. Further studies on the application of chlorine dioxide as a disinfectant on cavity preparations need to be considered given the surprising positive results of chlorine dioxide group. / MT2018

No description available.

O objetivo desse estudo foi avaliar in vitro, a ação dos lasers de alta potência (Nd:YAG e diodo 980nm), associados ao carvão mineral como fotopotencializador, sobre a adesividade do cimento endodôntico, por meio do teste de pushout, e na interface dentina/material obturador, por meio de microscopia confocal a laser. 50 caninos foram instrumentados com sistema Mtwo até #50.04 e irrigados com hipoclorito a 1% a cada troca dos instrumentos. Os espécimes foram distribuídos em 5 grupos (n=10): GI - controle EDTAC, GII - EDTAC e laser Nd:YAG, GIII - EDTAC e laser diodo 980 nm, GIV - EDTAC, laser Nd:YAG e carvão mineral 5 g/100mL, e GV - EDTAC, laser diodo 980 nm e carvão mineral 5 g/100 mL. As aplicações de laser foram na potência de 1.5 W, frequência de 100 Hz pulsátil e fibra de 200&mu;m, por 16 segundos em movimentos elípticos (8 s no sentido coroa-ápice e 8 s no sentido ápice-coroa). Após, os espécimes foram obturados com cimento AH Plus, pela técnica de condensação lateral ativa. As raízes foram seccionadas no sentido transversal, em slices de 1mm de espessura, e submetidas ao teste de pushout em máquina universal de ensaios e o tipo de falha foi analisado em microscópio confocal a laser, e se determinou a profundidade e a uniformidade dos tags de cimento na interface dentina/material obturador. Os dados foram analisados por meio do teste ANOVA a nível de significância de 5%, seguidos dos testes de Kruskal-Wallis, Dunn e Tukey (para a comparação dos grupos). O GI apresentou a maior a resistência de união do cimento à dentina que o tratamento somente com EDTAC 17% (17,21 ± 21,75 MPa), sendo semelhante ao GII (12,21 ± 18,20 MPa) e ao GIV (14,92 ± 28,06 MPa), ambos tratados com laser Nd:YAG, com exceção do GIV, que foi adicionado de carvão mineral. O GV (8,75 ± 13,42 MPa) apresentou resultados similares aos dos grupos GII e GIV, mas a mesma similaridade foi observada quando comparado ao GIII (7,11 + 11,28 MPa), que apresentou os piores resultados. O terço apical (23,27 ± 29,21 MPa) apresentou valor de resistência de união maior que o cervical (5,92 ± 5,33 MPa) e médio (6,93 ± 7,11MPa), que foram semelhantes entre si (p>0,05). Houve predominância de falhas mistas, seguidas das coesivas. O GII (86,27&micro;m) apresentou os maiores valores de penetração de tags, com diferença estatisticamente significante em relação aos GIII (51,57&micro;m), IV (36,77&micro;m) e V (32,37&micro;m) (p<0,05). O GI (71,63&micro;m) não apresentou diferenças estatisticamente significantes em relação ao II e III (p>0,05). O GIV apresentou os menores valores, sem diferenças do III e V, (p>0,05). O terço cervical (58,44&micro;m) apresentou os melhores valores, seguidos dos terços médio (45,02&micro;m) e apical (42,24&micro;m) (p>0,05). Concluiu-se que o tratamento com laser Nd:YAG associado ou não ao carvão mineral, apresentou melhores resultados de força adesiva que o tratamento com laser diodo 980nm, exceto quando esse foi adicionado do carvão mineral. O grupo controle e o laser diodo 980nm apresentaram menores quantidades de falhas adesivas e maiores quantidades de falhas mistas comparados aos demais grupos. Ambos os lasers não interferiram de maneira negativa na penetração de cimento se comparados ao grupo controle, no que se relaciona à resistência adesiva do cimento obturador. / The aim of this study was to evaluate in vitro the influence of high-power lasers (Nd:YAG and diode 980nm) associated with mineral coal as fotopotencializer on Bond strenght of an epoxy resin-based root canal sealer to root dentin, using the push-out test, and on the dentin/filling material interface, using confocal laser microscopy. For this purposes, 50 canines were instrumented with Mtwo Rotary system up to #50.04 instrument, irrigating with sodium hypoclorite 1% at each instrument exchange. The specimens were randomly assigned to 5 groups (n=10), according the treatment of root canal dentin: group I - control EDTAC, group II - EDTAC and Nd:YAG laser, group III - EDTAC and diode laser 980 nm, group IV - EDTAC, Nd:YAG laser and mineral coal 5 g/100 mL, and group V - EDTAC, diode laser 980 nm and mineral coal 5 g/100 mL. All the lasers application was assigned according to the parameters: 1.5 W of power, 100 Hz pulsatile frequency and 200 &micro;m fiber, for 16 seconds in eliptical movements (8 s crown-down direction and 8 s apex-crown direction). Following irradiation, the canals were filled with active lateral condensation of AH Plus sealer and gutta-percha cones. After, the roots were sectioned transversally to obtain 1mm-thick slices. One of two slices from each third were subjected to a push-out test in a universal testing machine and the failure mode was analyzed with confocal laser microscopy and classified as: adhesive to the filling material, adhesive to dentin, cohesive in the filling material and mixed. The remaining slice was analyzed by confocal laser microscopy to evaluate the penetration and homogeneity of the perimeter of the root canal cross-section with sealer tags, at the dentin/filling material interface. All data were analyzed by ANOVA (at 5% significance level) following the Kruskal-Wallis, Dunn and Tukey tests (for groups comparation). Any of the proposing treatments increased more Bond strength of the sealer to root dentin that treatment with only EDTAC 17% (17.21 ± 21.75 MPa), similar to the group II (12.21 ± 18.20 MPa) and group IV (14.92 ± 28.06 MPa), both treated with Nd: YAG laser, with the exception of group IV, which was added to mineral coal. The group V (8.75 ± 13.42 MPa) had similar results to the groups II and IV, but the same similiarity were found when compared with group III (7.11 + 11.28 MPa), with lower results. Regarding the root thirds, the apical third (23.27 ± 29.21 MPa) presented a statistically higher value on Bond strenght than the cervical third (5.92 ± 5.33 MPa) and middle third (6.93 ± 7, 11 MPa) (p> 0.05). It was observed in general that there was a predominance of mixed failures, followed by cohesive failures. The lowest amount were the adhesive failures. Group II (86.27&micro;m) showed the highest tags penetration values, with a statistically difference to the group III (51.57 &micro;m), IV (36.77 &micro;m) and V (32.37 &micro;m) (p < 0.05). Group I (71.63 &micro;m) was statistically similar to groups II and III (p> 0.05). Group IV had the lowest values and was statistically similarity to groups III and V (p> 0.05). The cervical third (58.44 &micro;m) showed best values, followed by the middle third (45.02mm) and apical third (42.24 &micro;m) (p> 0.05). It was concluded that the treatment with Nd:YAG laser provides better results than the diode 980 nm laser, except when was added mineral coal. The control and diode 980 nm laser groups presented less adhesive failures and more mists failures than the other groups. Both lasers did not interfere negatively compared to the control group