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La percolation des obturations adhésives en Dentisterie Conservatrice reste le problème majeur en ce qui concerne la longévité clinique de ces restaurations. Le choix et la bonne utilisation de l'adhésif servant à coller le matériau de restauration (composite) aux parois dentaires résiduelles (généralement,après éviction du tissu carieux)sont deux facteurs primordiaux dans la gestion de ce problème. Les manipulations in vitro réalisées dans le cadre de cette thèse de Doctorat ont permis d'observer les différentes percolations permises par des obturations en composite réalisées avec différents systèmes adhésifs et selon différentes techniques.

Statement of Problem. Resin-based cements have become increasingly more popular for the cementation of prefabricated endodontic dowels due to their superior retention. The manufacturer of Panavia F 2.0 suggests that the product be stored under refrigerated conditions while not in use, however, there is no literature to support such a rationale. It is possible that these storage/use temperature cycling events may have a deleterious effect on the retention of prefabricated endodontic dowels. Purpose. The purpose of this in-vitro study was to investigate the retention of Panavia F 2.0 used to lute prefabricated endodontic dowels after the Panavia F 2.0 system has been kept under different storage conditions. Material and Methods. Sixty-four extracted human central incisors were selected to undergo root canal therapy and dowel retention testing. Four separate Panavia F 2.0 cement systems were placed under 4 different storage conditions for a period of 6 months, until retention testing was initiated. In the first group, the Panavia F 2.0 was stored under the manufacturer's suggested refrigerated conditions, at a constant temperature of 40°F. In the second group, the Panavia F 2.0 was stored under a constant 90°F temperature. In the third group, the Panavia F 2.0 was stored under room temperature conditions of 70°F. The fourth group attempted to mimic clinical usage conditions with the Panavia F 2.0 being cycled from refrigeration at 40°F for 22 hours/day to 2 hours/day of room temperature at 70°F 5 days per week for the duration of the 6-month storage condition period. Results. Stress values were analyzed using 1-way ANOVA. A Tukey's HSD multiple comparison analysis of the dowel retention strengths indicated that the group stored at 90°F resulted in the lowest retention. This group was significantly lower than all other groups' retention strength (p Conclusions. Within the limitations of this study, the storage of Panavia F 2.0 at either room temperature or cycling between refrigeration and room temperature yields similar dowel retention values. However, the storage of Panavia F 2.0 at temperatures of 90°F for prolonged periods causes poor dowel retention. Clinical Implications The results of this study do not support the necessity of storing Panavia F 2.0 under refrigerated conditions between clinical uses, if used within six months. However, the storage of the Panavia F 2.0 cementation system at temperatures of 90°F for prolonged periods will affect dowel retention and is therefore not advisable.

Magister Scientiae Dentium - MSc(Dent) / Aim: The aim of this study was to evaluate, in-vitro, the shear bond strength (SBS) and the resultant failure pattern after debonding of metal orthodontic brackets bonded with TransbondTM XT adhesive resin cement and RelyXTM Unicem 2 self-adhesive resin cement to pre-treated (35% ortho-phosphoric acid and silane coupling agent application) IPS eMax and porcelain veneered zirconia crowns. Material and methodology: A Typhodont maxillary lateral incisor was used and prepared in a conventional manner to receive a full ceramic crown. A CAD (computer aided design)/ CAM (computer aided manufacturing) machine was used to scan the prepared tooth and manufacture 40 IPS eMax crowns and 40 porcelain veneered zirconia crowns. Half the number of IPS eMax crown specimens (ie. 20) and half the number of porcelain veneered zirconia crown specimens (ie. 20) were thermocycled (ie. to mimic thermal changes which occur in the mouth), from 5 to 55o for 500 cycles as recommended by the International Organization for Standardization (ISO 6872, 2008). The remaining 20 IPS eMax crown specimens and 20 porcelain veneered zirconia crown specimens remained new and unexposed to thermal changes. The facial surfaces of all the thermocycled and non-thermocycled crown specimens were then etched. Etching of all the ceramic bonding surfaces was performed by the application of 35 per cent ortho-phosphoric acid liquid for 2 minutes, followed by a thin layer of a ceramic primer. A lateral incisor metal bracket with a bracket base area of 9mm2 (as confirmed by the manufacturer) was bonded to each of the etched and silane treated ceramic crown specimens and separated in the following manner: Group 1: (10 thermocycled, etched and silane treated IPS eMax and 10 thermocycled, etched and silane treated porcelain veneered zirconia crown specimens) RelyX™ Unicem 2 self-adhesive resin cement was used to bond the bracket to the ceramic crown specimens, Group 2: (10 thermocycled, etched and silane treated IPS eMax and 10 thermocycled, etched and silane treated porcelain veneered zirconia crown specimens) Transbond™ XT light cure adhesive primer was first applied onto the bonding surface of the crowns and then Transbond™ XT adhesive resin was used to bond the bracket to the ceramic crown specimens, Group 3: (10 non-thermocycled, etched and silane treated IPS eMax and 10 non-thermocycled, etched and silane treated porcelain veneered zirconia crown specimens) RelyX™ Unicem 2 self-adhesive resin cement was used to bond the bracket to the ceramic crown specimens, Group 4: (10 non-thermocycled, etched and silane treated IPS eMax and 10 non-thermocycled, etched and silane treated porcelain veneered zirconia crown specimens) Transbond™ XT light cure adhesive primer was first applied onto the bonding surface of the crowns and then Transbond™ XT adhesive resin cement was used to bond the bracket to the ceramic crown specimens. After bonding all samples were stored in distilled water for 24 hours before being submitted to the shear bond strength test. Debonding forces in Newtons (N) was determined by using a shear testing machine and converted into Mega Pascals (MPa). Results: The results after debonding were compared. The mean shear bond strength for RelyXTM Unicem 2 self-adhesive resin cement bonded to the all ceramic non-thermocycled crowns (Group 3) ranged from a low of 5.1 MPa (45.5 Newtons) when brackets were bonded to the IPS eMax crowns to a high of 5.8 MPa (51.9 Newtons) when brackets were bonded to the porcelain veneered zirconia crowns. The mean shear bond strength for Transbond XT adhesive resin cement bonded to the all ceramic non-thermocycled crowns (Group 4) ranged from a low of 6.4 MPa (57.3 Newtons) when brackets were bonded to the porcelain veneered zirconia crowns to a high of 8.1 MPa (72.7 Newtons) when brackets were bonded to the IPS eMax crowns. The side by side Box-and-Whisker plots of the shear bond strengths show wide and overlapping dispersions of the crown/adhesive resin combinations which consequently lessen the probability of significant differences between the crown/adhesive resin combinations in all 4 groups. According to the Kruskal-Wallis test (p < 0.05), and the Bonferroni Test the non-thermocycled crown/adhesive resin combinations do not differ significantly. Study of the mean ARI (Adhesive Remnant Index) values for the non-thermocycled crown/adhesive combinations shows that brackets bonded with Rely-XTM Unicem 2 to non-thermocycled porcelain veneered zirconia crowns failed entirely at the ceramic/adhesive interface and for all the other non-thermocycled ceramic/adhesive combinations most of the failures of the bond (70%) occurred at the bracket/adhesive interface, ie. cohesive fractures within the composite resin. No cohesive fractures of the porcelain crowns were noted. The results of the thermocycled groups (Group 1 and Group 2) show the TransbondTM XT/non-thermocycled IPS eMax crown combination yielded the highest overall mean shear bond strength of 8.1 MPa (72.7 Newtons) but dropped to a mean shear bond strength of 5.1 MPa (46.1 Newtons) (36.4% drop in shear bond strength) when the crowns were thermocycled prior to bonding. The TransbondTM XT/non-thermocycled porcelain veneerd zirconia crown combination yielded the second highest overall mean shear bond strength of 6.4 MPa (57.3 Newtons) and dropped to a mean shear bond strength of 5.1 MPa (45.8 Newtons) (19.3% drop in shear bond strength) when the crowns were thermocycled prior to bonding. The RelyXTM Unicem 2/non-thermocycled porcelain veneered zirconia crown combination yielded the third highest overall mean shear bond strength of 5.8 MPa (51.9 Newtons) but dropped significantly to a mean shear bond strength of 3.2 MPa (29.1 Newtons) (a significant 43.8% drop in shear bond strength) when the crowns were thermocycled prior to bonding. Lastly, the RelyXTM Unicem 2/non-thermocycled IPS eMax crown combination yielded the fourth highest mean shear bond strength of 5.1MPa (45.5 Newtons) but dropped to a mean shear bond strength of 4.9 MPa (44.5 Newtons) (a drop in shear bond strength of only 3%) when the crowns were thermocyled prior to bonding. Relaxing the significance level (p-value) somewhat demonstrates the negative influence of thermocycling on the shear bond strength of the crown/adhesive combinations. The non-thermocycled all ceramic crown/adhesive combinations showed mean ARI values of between 1.3 and 2.1 indicating cohesive fractures within the composite resin and efficient bonding of the adhesive material to the porcelain surface. However, all the thermocycled all ceramic crown/adhesive treatment combinations showed mean ARI values of between 0 and 0.8 indicating a bond failure between adhesive and porcelain and highlighting the negative influence of thermocycling on bond strength of both adhesive resin cements. Conclusion: Within the limitations of this study, it can be concluded that: 1.There was no significant difference in the shear bond strengths of metal orthodontic brackets bonded with RelyXTM Unicem 2 self-adhesive resin cement and metal orthodontic brackets bonded with TransbondTM XT adhesive resin cement to IPS eMax and porcelain-veneered zirconia crowns which were conditioned with 35 % phosphoric acid and a silane coupling agent. 2. Conditioning the porcelain surface with 35% phosphoric acid and a silane coupling agent (which is safer to use than Hydrofluoric acid) is sufficient for bonding metal orthodontic brackets to all ceramic crowns, and should make it simpler for clinicians to remove the remaining adhesive from the porcelain surface after debonding. 3. The negative influence of thermocycling prior to bonding can be seen on shear bond strength values. 4. Most of the failures of the bond occurred at the ceramic/adhesive interface and cohesive fractures within the composite resin. No cohesive fractures of the porcelain crowns were noted.

Aim: The aim of this study is to investigate if biaxial flexural strength for pressed glass ceramic with glazed, polished and grinded surface is affected by the acidic beverages Coca Cola and red wine. Material and method: 63 specimens were manufactured in IPS e.max Press®, divided into 6 test groups and one control group (KG) with 9 specimens in each group, in the dimensions 12 mm in diameter and in thickness, 1,8 mm without notch and 2,2 mm with notch. The specimens subdivided by different surface treatments; glazed surface (CCG, RVG), polished surface (CCP, RVP) and ground surface (CCS, RVS). Three groups underwent thermocycling for 970 cycles in 8°C Coca Cola® and three groups red wine at room temperature. Results: The results show significant difference between the groups with α=0,001. Biaxial flexural strength test showed that the CCS group had the highest mean value (340 MPa) and CCP the lowest mean value (214 MPa). CCS showed significant differences to all groups except RVP and RVS. Furthermore the RVP group showed no significant difference to any other group and RVS only towards CCP. Conclusion: Within the limitations of this in vitro study the following conclusions can be made; Acidic beverages do not affect the flexural strength for pressed lithium disilicate based glass ceramics. The flexural strength is affected by surface treatment, where grinding with sandpaper results in higher flexural strength. / Syfte: Syftet med föreliggande studie är att undersöka om den biaxiala böjhållfastheten på litiumdisilikatbaserad glaskeram som framställts genom pressteknik med tre olika ytbehandlingar (glansbränd yta eller för att efterlikna ocklusal inslipning eller abraderat slitage) påverkas av de sura dryckerna Coca Cola® och rödvin.Material och metod: 63 provkroppar tillverkades av IPS e.max Press®. Provkropparna delades in i 6 testgrupper, och en kontrollgrupp (KG), á 9 i varje, med måtten 12 mm i diameter och tjocklek 1,8 mm utan notch och 2,2 mm med notch. Provkropparna delades in utifrån olika ytbehandlingar, glansbränd (CCG, RVG), polerad (CCP, RVP) och slipad med sandpapper (CCS, RVS). 3 grupper genomgick termocykling i 970 cykler i 8°C Coca Cola®, och 3 grupper i rödvin i rumstemperatur, varvat med destillerat vatten i 37°C. Därefter utfördes biaxialt böjhållfasthetstest och resultaten analyserades med One-way ANOVA, Tukey’s test, signifikansnivå α= 0,05.Resultat: Resultaten visar att det finns signifikant skillnad mellan grupperna α=0,001. Det biaxiala böjhållfasthetstestet påvisade att gruppen CCS hade högst medelvärde (340 MPa) och CCP hade lägst medelvärde (214 MPa). CCS visade signifikant skillnad jämfört med samtliga grupper, förutom RVP och RVS. Vidare uppvisade RVP ingen signifikant skillnad jämfört med någon av de övriga grupperna och RVS endast mot CCP.Slutsats: Inom denna in vitro-studies begränsningar kan följande slutsatser dras; Sura drycker påverkar inte böjhållfastheten på litiumdisilikatbaserad glaskeram som framställts genom pressteknik. Hållfastheten påverkas beroende på ytbehandling. Genom att slipa ytan med slippapper resulterade det i högre biaxial böjhållfasthet.

SammanfattningSyfteSyftet med föreliggande pilotstudie är att undersöka abrasion på materialen polerad zirkonia (5YSZ) och glansbränd litiumdisilikat och abrasion på antagonist med eller utan termocykling. Emalj utgör referens. De inkluderade materialen är avsedda för CAD/CAM- framställning av monolitiska konstruktioner.Material och metodFrån en zirkoniadisk (5YSZ, Katana zirconia UTML) och tre litiumdisilikatblock (IPS e.max CAD LT) togs totalt sexton provkroppar fram. Åtta extraherade molarer användes som referensgrupp (n=8) och steatitkulor användes som antagonist. Provkropparna för zirkonia och litiumdisilikat utformades rektangulära med måtten 16x14x3,5 mm efter sintring respektive kristallisering. Provkropparnas testytor genomgick olika ytbehandlingar. Zirkoniaprovkropparna polerades till högglans (ZP), litiumdisilikat glansbrändes med glaze (LG) och de extraherade molarerna planslipades och emaljen polerades (EM). Hälften av materialgrupperna tuggsimulerades i 120 000 cyklar med termocykling i temperaturerna 15°C±2°C respektive 55°C±2°C (ZPT, LGT, EMT). Den andra hälften tuggsimulerades i 120 000 cyklar utan termocykling (ZPU, LGU, EMU). Resultaten analyserades med One-way ANOVA, Tukey’s test med en signifikansnivå på α=0,05 i statistikprogrammet SPSS.ResultatHögst materialförlust påvisades i EMT-gruppen och lägst i ZPU-gruppen. Ingen signifikant skillnad kunde påvisas mellan materialgrupperna. Hos antagonistgrupperna påvisade EMT- gruppen högst materialförlust och LGT-gruppen lägst materialförlust. Hos antagonistgrupperna hade EMT-gruppen en signifikant högre materialförlust i jämförelse med övriga antagonistgrupper förutom LGU- och ZPU-gruppen.SlutsatsPolerad ultratranslucent zirkonia, glansbränd litiumdisilikat, och emalj abraderas likvärdigt av antagonister med eller utan termocykling. Polerad ultratranslucent zirkonia och glansbränd litiumdisilikat abraderar mindre mot antagonister än emalj med termocykling. / AbstractPurposeThe purpose of this pilot study is to investigate the abrasion of polished zirconia (5YSZ) and glazed lithium disilicate on antagonist and antagonists’ abrasion on the materials with or without thermocycling, with enamel as reference. The materials are intended for CAD/CAM production of monolithic restorations.Material and methodFrom zirconia (5YSZ, Katana zirconia UTML) and lithium disilicate (IPS e.max CAD LT) sixteen specimens were made. Eight extracted molars were used as reference group (n=8) and steatite balls used as antagonists. The specimens were designed with the dimensions 16x14x3.5 mm. The zirconia specimens were polished to high gloss (ZP), the lithium disilicate glazed (LG) and the enamel ground flat and polished (EM). Half of the groups underwent chewing simulation in 120,000 cycles with thermocycling (15°C ±2°C/55°C ±2°C) (ZPT, LGT, EMT) and the other half without thermocycling (ZPU, LGU, EMU). The results were analyzed with One-way ANOVA, Tukey's test with a significance level of α= 0.05 in the statistical program SPSS.ResultsThe highest material loss was in EMT and the lowest in ZPU. No significant differences could be shown between the material groups. In the antagonist groups, EMT showed the highest material loss and LGT the lowest. In the antagonist groups, EMT had a significant higher loss in comparison with all the other antagonist groups except LGU and ZPU.ConclusionPolished ultratranslucent zirconia, glazed lithium disilicate and enamel are equally abraded by antagonists with or without thermocycling. Polished ultratranslucent zirconia and glazed lithium disilicate abrade less against antagonists than enamel with thermocycling.

OBJETIVOS:1a etapa: validar teste de cisalhamento utilizando um novo dispositivo de padronização através da comparação dos valores de resistência de união (RU) entre a zircônia com dois tratamentos de superfície e um cimento resinoso, aos resultados obtidos com testes de cisalhamento convencional e microcisalhamento; 2a etapa: avaliar o efeito dos primers metálicos à base de MDP por meio da RU entre zircônia Y-TZP e diferentes tipos de cimentos resinosos (de ativação química, duais e auto-adesivo); 3a etapa: avaliar o efeito de dois lasers Nd:YAG e Er:YAG e do jateamento com óxido de alumínio (JAT) na superfície da zircônia Y-TZP antes da sua sinterização final e da abrasão triboquímica mais silano (controle positivo) após a sinterização final, por meio da resistência à flexão (RF), rugosidade superficial (RS) e RU; 4a etapa: avaliar a estabilidade da união entre a zircônia e um cimento resinoso com um primer à base de MDP e de um laser de alta potência após a termociclagem. Os tratamentos superficiais utilizados nesta etapa foram escolhidos com base nos resultados da 2a e 3a etapas. MATERIAL E MÉTODOS: para os testes de RU foram confeccionados corpos de prova de Y-TZP com dimensões 6x6x3mm, e para o teste de RF 2,5x4,5x20 mm. Para 1a etapa os tratamentos de superfície foram JAT+Signum Ziconia Bond (SZB Heraeus), abrasão triboquímica foi realizada Rocatec (ROC 3M Espe), o silano utilizado foi RelyX Ceramic Primer (3M Espe) e os cimentos resinosos: Panavia F (Kuraray), NX3 (Kerr), seT (SDI), Multilink (Ivoclair). Durante a 3a etapa a abrasão triboquímica foi realizada ROC, o laser Nd:YAG (Power Laser ST6, Lares Research - 1,2W, 10 Hz) e Er:YAG (Kavo Key II, KaVo Co. - 120 mJ, 6 Hz). O teste de cisalhamento com dispositivo de padronização foi o método de avaliação da RU utilizado para as 2a, 3a e 4a etapas. Os dados dos testes de RU, RG foram analisados pela ANOVA e Tukey (=0,05) e RF por Kruskall-Wallis (=0,05). RESULTADOS: 1a etapa: pelo teste de microcisalhamento os materiais se comportaram da seguinte forma: JAT+SZB>ROC>CO, sendo que para os outros dois testes de cisalhamento o seguinte ranqueamente foi obtido: JAT+SZB=ROC>CO. 2a etapa: o SZB apresentou maiores valores de RU para todos os cimentos quando comparados aos grupos controle. O ZP aumento os valores para o cimento Panavia F e NX3. Já o AP aumentou os valores para o cimento seT. 3a etapa: para o teste de RU o JAT e Er:YAG resultaram em valores similares ao ROC, sendo que Nd:YAG resultou em maiores valores comparado ao ROC. Quando avaliados por RS: Nd:YAG>Er:YAG>JAT>ROC; já para RF: ROC>JAT=Nd:YAG= Er:YAG. 4a etapa: Após o teste de cisalhamento os seguinte ranqueamento foi obtido: Nd:YAG 24h>Nd:YAG termociclado=SZB 24h>SZB termociclado. CONCLUSÕES: Uma vez que o teste de cisalhamento com dispositivo de padronização mostrou resultados similares ao teste de cisalhamento convencional pode ser um método viável para avaliação da RU. O tratamento com Nd:YAG antes da sinterização final se mostrou efetivo nos valores de RU. / OBJECTIVES: first stage: validate shear test using a new device for standardized by comparing the values of bond strength (BS) with conventional shear test and microshear test, between zirconia and a resin cement with two surface treatments. Second stage: evaluate the effect of metal primers based on MDP by BS between YTZP and different types of resin cements. Third stage: evaluate Y-TZP surface treatments effect of two lasers (Nd:YAG and Er:YAG) and two sandblasting procedures, with Al2O3 (JAT) before final sintering and tribochemical slicatization after the final sintering, through the flexural resistance (FR) surface roughness (SR) and BS. Fourth stage: evaluate the bonding stability between zirconia and resin cement using a MDP-based primer or a high power laser, after thermal cycling. MATERIAL AND METHODS: BS Y-TZP specimens were prepared with dimensions of 6x6x3mm, and for FS test with 2,5x4,5x20 mm. In the first stage the surface treatments of the specimens were JAT+ Signum Ziconia Bond (SZB - Heraeus), tibochemical silicatization using Rocatec (ROC - 3MEspe) and control (CO - without treatment). In the second stage the primers used were Alloy-Primer (AP - Kuraray), SZB, Z-Prime Plus (ZP - Bisco), and the resin cements: Panavia F (Kuraray), NX3 (Kerr), set (SDI), Multilink (Ivoclair). During the third stage the tribochemical silicatization was perfomed using ROC. The shear bond strength device standardized was used to evaluate the BS of second, third and fourth stage. Test data for BS, SR were analyzed by ANOVA and Tukey test ( = 0.05) and FS by Kruskall-Wallis test ( = 0.05). RESULTS: first Stage: the microshear test groups behave as follow: JAT+SZB> ROC>CO, and for the other two shear tests following the ranking were obtained: JAT+SZB=ROC>CO. Second stage: the SZB showed higher BS for all cements when compared to control groups. The ZP values increased for Panavia F and NX3. AP values increased only for the seT cement. Third stage: BS values for JAT and Er:YAG were similar to ROC, and Nd:YAG was higher compared to the ROC. When evaluated by SR: Nd:YAG> Er:YAG>JAT> ROC, while for FS: ROC> JAT = Nd:YAG = Er:YAG. Fourth stage: after the shear test the following ranking was obtained: Nd:YAG 24h> Nd:YAG thermocycled = SZB 24h> SZB thermocycled. CONCLUSIONS: shear bond strength test with standardized device showed similar result to the conventional shear bond strength, and it can be considered a viable method for evaluating the BS. Treatment with Nd:YAG before the final sintering was effective in BS.

OBJETIVOS:1a etapa: validar teste de cisalhamento utilizando um novo dispositivo de padronização através da comparação dos valores de resistência de união (RU) entre a zircônia com dois tratamentos de superfície e um cimento resinoso, aos resultados obtidos com testes de cisalhamento convencional e microcisalhamento; 2a etapa: avaliar o efeito dos primers metálicos à base de MDP por meio da RU entre zircônia Y-TZP e diferentes tipos de cimentos resinosos (de ativação química, duais e auto-adesivo); 3a etapa: avaliar o efeito de dois lasers Nd:YAG e Er:YAG e do jateamento com óxido de alumínio (JAT) na superfície da zircônia Y-TZP antes da sua sinterização final e da abrasão triboquímica mais silano (controle positivo) após a sinterização final, por meio da resistência à flexão (RF), rugosidade superficial (RS) e RU; 4a etapa: avaliar a estabilidade da união entre a zircônia e um cimento resinoso com um primer à base de MDP e de um laser de alta potência após a termociclagem. Os tratamentos superficiais utilizados nesta etapa foram escolhidos com base nos resultados da 2a e 3a etapas. MATERIAL E MÉTODOS: para os testes de RU foram confeccionados corpos de prova de Y-TZP com dimensões 6x6x3mm, e para o teste de RF 2,5x4,5x20 mm. Para 1a etapa os tratamentos de superfície foram JAT+Signum Ziconia Bond (SZB Heraeus), abrasão triboquímica foi realizada Rocatec (ROC 3M Espe), o silano utilizado foi RelyX Ceramic Primer (3M Espe) e os cimentos resinosos: Panavia F (Kuraray), NX3 (Kerr), seT (SDI), Multilink (Ivoclair). Durante a 3a etapa a abrasão triboquímica foi realizada ROC, o laser Nd:YAG (Power Laser ST6, Lares Research - 1,2W, 10 Hz) e Er:YAG (Kavo Key II, KaVo Co. - 120 mJ, 6 Hz). O teste de cisalhamento com dispositivo de padronização foi o método de avaliação da RU utilizado para as 2a, 3a e 4a etapas. Os dados dos testes de RU, RG foram analisados pela ANOVA e Tukey (=0,05) e RF por Kruskall-Wallis (=0,05). RESULTADOS: 1a etapa: pelo teste de microcisalhamento os materiais se comportaram da seguinte forma: JAT+SZB>ROC>CO, sendo que para os outros dois testes de cisalhamento o seguinte ranqueamente foi obtido: JAT+SZB=ROC>CO. 2a etapa: o SZB apresentou maiores valores de RU para todos os cimentos quando comparados aos grupos controle. O ZP aumento os valores para o cimento Panavia F e NX3. Já o AP aumentou os valores para o cimento seT. 3a etapa: para o teste de RU o JAT e Er:YAG resultaram em valores similares ao ROC, sendo que Nd:YAG resultou em maiores valores comparado ao ROC. Quando avaliados por RS: Nd:YAG>Er:YAG>JAT>ROC; já para RF: ROC>JAT=Nd:YAG= Er:YAG. 4a etapa: Após o teste de cisalhamento os seguinte ranqueamento foi obtido: Nd:YAG 24h>Nd:YAG termociclado=SZB 24h>SZB termociclado. CONCLUSÕES: Uma vez que o teste de cisalhamento com dispositivo de padronização mostrou resultados similares ao teste de cisalhamento convencional pode ser um método viável para avaliação da RU. O tratamento com Nd:YAG antes da sinterização final se mostrou efetivo nos valores de RU. / OBJECTIVES: first stage: validate shear test using a new device for standardized by comparing the values of bond strength (BS) with conventional shear test and microshear test, between zirconia and a resin cement with two surface treatments. Second stage: evaluate the effect of metal primers based on MDP by BS between YTZP and different types of resin cements. Third stage: evaluate Y-TZP surface treatments effect of two lasers (Nd:YAG and Er:YAG) and two sandblasting procedures, with Al2O3 (JAT) before final sintering and tribochemical slicatization after the final sintering, through the flexural resistance (FR) surface roughness (SR) and BS. Fourth stage: evaluate the bonding stability between zirconia and resin cement using a MDP-based primer or a high power laser, after thermal cycling. MATERIAL AND METHODS: BS Y-TZP specimens were prepared with dimensions of 6x6x3mm, and for FS test with 2,5x4,5x20 mm. In the first stage the surface treatments of the specimens were JAT+ Signum Ziconia Bond (SZB - Heraeus), tibochemical silicatization using Rocatec (ROC - 3MEspe) and control (CO - without treatment). In the second stage the primers used were Alloy-Primer (AP - Kuraray), SZB, Z-Prime Plus (ZP - Bisco), and the resin cements: Panavia F (Kuraray), NX3 (Kerr), set (SDI), Multilink (Ivoclair). During the third stage the tribochemical silicatization was perfomed using ROC. The shear bond strength device standardized was used to evaluate the BS of second, third and fourth stage. Test data for BS, SR were analyzed by ANOVA and Tukey test ( = 0.05) and FS by Kruskall-Wallis test ( = 0.05). RESULTS: first Stage: the microshear test groups behave as follow: JAT+SZB> ROC>CO, and for the other two shear tests following the ranking were obtained: JAT+SZB=ROC>CO. Second stage: the SZB showed higher BS for all cements when compared to control groups. The ZP values increased for Panavia F and NX3. AP values increased only for the seT cement. Third stage: BS values for JAT and Er:YAG were similar to ROC, and Nd:YAG was higher compared to the ROC. When evaluated by SR: Nd:YAG> Er:YAG>JAT> ROC, while for FS: ROC> JAT = Nd:YAG = Er:YAG. Fourth stage: after the shear test the following ranking was obtained: Nd:YAG 24h> Nd:YAG thermocycled = SZB 24h> SZB thermocycled. CONCLUSIONS: shear bond strength test with standardized device showed similar result to the conventional shear bond strength, and it can be considered a viable method for evaluating the BS. Treatment with Nd:YAG before the final sintering was effective in BS.

Resinas compostas apresentam contração de polimerização e a tensão gerada durante essa polimerização compete com a força adesiva na interface dente/restauração. A técnica incremental e o uso de bases com alta resiliência e módulo de elasticidade próximo ao das estruturas dentárias são técnicas desenvolvidas para tentar diminuir a tensão originada pela contração de polimerização. O presente estudo teve como objetivo analisar a influência do uso de bases de cimento de ionômero de vidro convencional e modificado por resina na qualidade e adaptação marginal na interface dentina/resina composta, após a ciclagem térmica, usando testes de resistência adesiva e análise em microscopia confocal de varredura a laser. Foram confeccionadas cavidades na face oclusal (4,5mm x 3mm x 5mm) de 60 molares humanos extraídos divididos em 6 grupos: 1 e 4 - sistema adesivo (AdperTM Single Bond; 3M ESPE) + resina composta (Filtek Z250; 3M ESPE); 2 e 5 - base de cimento de ionômero de vidro convencional (Ketac Molar Easymix; 3M ESPE) + sistema adesivo + resina composta; e 3 e 6 - base de cimento de ionômero de vidro modificado por resina (Vitrebond; 3M ESPE) + sistema adesivo + resina composta. Os grupos 4, 5 e 6 sofreram um processo de termociclagem com dois banhos (5ºC 55ºC) durante 30 segundos em 5.000 ciclos. Após 24 horas, os dentes foram seccionados em uma máquina de cortes com disco de diamante em espessura de 0,8mm. Uma fatia de cada dente foi separada aleatoriamente para análise em Microscópio Confocal para observação e mensuração de possíveis fendas marginais internas. As demais fatias foram seccionadas para a confecção de palitos (0,8mm X 0,8mm) que foram submetidos a testes de microtração em uma máquina de ensaios universal EMIC. Os resultados de resistência adesiva foram submetidos à análise de variância a um critério (ANOVA) e ao teste t-Student (p< 0,05). A presença de fendas foi avaliada com o teste da razão de verossimilhança ou teste exato de Fisher e os valores de comprimento das fendas foram avaliados pelo teste não paramétrico de Kruskal-Wallis (p<0,05). Não foram observadas diferenças estatisticamente significantes na resistência adesiva em nenhum dos grupos sem termociclagem (G1 19,28 MPa; G2 16,29 MPa; e G3 15,95MPa) ou com termociclagem (G4 19,74 MPa; G5 16,58 MPa; e G6 16,01 MPa). A análise das medidas das fendas revelou não haver diferença estatisticamente significante entre os grupos G1 (1,4µm), G2 (2,88µm) e G3 (4,63µm) e entre os grupos G4 (4,2µm), G5 (12,5µm) e G6 (5,4µm). No entanto, a termociclagem determinou um aumento do tamanho médio das fendas no grupo com base de CIV convencional (G4 12,5µm). A análise da presença ou ausência de fendas mostrou um aumento na porcentagem do número de fendas quando os espécimes foram termociclados, para os grupos sem base e com base de CIV (G1 - 30%; G2 - 25% G3 25%; G4 - 53,33%; G5 70%; e G6 30%). Os resultados mostraram, ainda, não haver relação entre o comprimento e a formação das fendas com a resistência adesiva. Conclui-se, portanto, que o uso de base de cimento de ionômero de vidro modificado por resina mantém mais estável a qualidade da interface adesiva dentina/resina composta após envelhecimento artificial com termociclagem. / Polymerization shrinkage leads to a tension into dentin/resin composite interface that can cause marginal discoloration, poor marginal adaptation, secondary caries and post-operative sensitivity. The incremental restorative technique and the use of a resilient liner with a modulus of elasticity similar to dental structures are techniques used to decrease the shrinkage polymerization tension. The aim of this in vitro study was to analyze the effect of glass-ionomer cement as a liner on the adhesive interface dentin/resin of occlusal restorations after thermocycling aging. Occlusal cavities were prepared sixty human extracted molars, divided into six groups: 1 and 4 with no liner; 2 and 5 glass-ionomer cement (Ketac Molar Easymix); and 3 and 6 resin-modified glass-ionomer cement (Vitrebond). Resin composite (Filtek Z250) was placed after application of adhesive system Adper Single Bond 2. Adhesive system was mixed with fluorescent reagent (Rhodamine B) to allow confocal microscopy analysis. After that, the specimens of groups 4, 5, 6 were thermocycled into 2 baths (5ºC 55ºC) of 30s each in 5.000 cycles. After this period, teeth were sectioned in 0,8mm slices. One slice of each tooth was randomly selected for analysis in Confocal Microscopy. The other ones were sectioned in sticks, which were submitted to micro-tensile test. The results of adhesive strength were analyzed by one way ANOVA and t-Student tests. Gap formation were analysed by Fisher test and the gaps size were analyzed by Kruskal-Wallis test (p<0,05). No statistical difference on adhesive resistance was showed between groups. Confocal Microscopy analysis showed gaps with a higher mean sizes for group 4 (12,5µm) and higger percentage of marginal gaps formation for the thermocycled groups (G1 - 30%; G2 - 25%; G4 - 53,33%; G5 70%). Groups 3 (25%) and 6 (30%) showed the lowest percentage of marginal gap formation. The results revealed that gap formation is not related to adhesive strength. It can be concluded, therefore, that the use of a resin-modified-glassionomer cement liner showed less gap formation on dentin/composite adhesive interface after artificial aging compared to conventional glass ionomer cement liner and restorations with no lining.

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