The effect of copper alloy scaler tip on the surface roughness of dental implant and restorative materials / 대한치과보철학회지

PURPOSE: This study is designed to investigate the various impacts of different types of scaler tips such as cooper alloy base tip and the others on the surface roughness of teeth and implant by the method which is currently in clinical use. MATERIALS AND METHODS: Four different types of disc shaped porcelain, titanium, zirconia, and Type III gold alloy dental materials sized 15 mm diameter, 1.5 mm thickness were used for the experiment. Plastic hand curette (Group PS), cooper alloy new tip (Group IS), and stainless steel tip (Group SS) were used as testing appliances. A total of 64 specimens were used for this study; Four specimens for each material and appliance group. Surface roughness was formed with 15 degree angle in ultrasonic scaler tip and with 45 degree angle in hand curette of instrument tip and the specimen surface with 5 mm long, one horizontal-reciprocating motion per second for 30 seconds by 40 g force. To survey the surface roughness of each specimen, a field emission scanning electron microscope, an atomic force microscope, and a surface profiler were used. (Ra, microm). RESULTS: According to SEM, most increased surface roughness was observed in SS group while IS groups had minimal roughness change. Measurement by atomic force microscope presented that the surface roughness of SS group was significantly greater than those of PS, IS and control groups in the type III gold alloy group (P<.05). IS group showed lesser surface roughness changes compared to SS group in porcelain and gold alloy group (P<.05). According to surface profiler, surface roughness of SS group showed greater than those of PS, IS and control groups and IS group showed lesser than those of SS group in all specimen groups. Type III gold alloy group had large changes on surface roughness than those of porcelain, titanium, zirconia (P<.05). CONCLUSION: The result of this study showed that newly developed copper alloy scaler tip can cause minimal roughness impacts on the surface of implant and dental materials; therefore this may be a useful alternative for prophylaxis of implant and restored teeth.

Misfit profile of dental bridges

Ante la evidencia de que los puentes odontológicos (PO) desadaptan más que las restauraciones individuales y que la desadaptación en prótesis fija es un factor determinante del fracaso, se llevóa cabo un estudio comparativo del perfil de desadaptación de los PO más utilizados en rehabilitación bucal: el PO colado en oro y el colado en aleación no preciosa y porcelana fundida.A partir de este, podemos trasladar al clínico las ventajas y debilidades de un tipo de estructura con respecto a la otra. Los resultados obtenidos muestran dos perfiles diferentes, presentandoel PO ceramometálico un comportamiento más desordenado que el colado en oro, la restauración del pilarposterior se separa de la pieza dentaria por distal, se acerca por mesial y mantiene esta separación en distal y mesial del pilar anterior. El PO colado en oro se separa en los extremos, distal del molar y mesial del premolar y se acerca marcadamente en las caras vecinas al tramo, distal del premolar y mesial del molar. Ha quedado también demostrado que el comportamiento adaptativo,a pesar de ser diferente, es menor en las aleaciones no nobles con porcelana fundida con respecto a la aleación de oro, relegadas estas últimas, a un bajo porcentaje en su uso clínico en rehabilitación, debido a la demanda estética y los altos costos. El impacto de este trabajo en la clínica consiste en que el PO ceramometálico ha desadaptado más en las áreas donde su confección en boca es más dificultosa por su visión e inaccesibilidad

Influência do tipo de pilar de resistência mecânica pré-ciclagem, quantidade de toque retido e desajuste vertical pré e pós-ciclagem, com análise estrutural em MEV / Influence of abutment type in mechanical strength before cyclic loading, retained torque and vertical misfit before and after cyclic loading with structural analysis by SEM

Problemática: De ocorrência clínica comum, o afrouxamento dos parafusos que compõe uma prótese sobre implante é uma complicação que traz transtornos tanto para o profissional quanto para o paciente. Entre os fatores que interferem na estabilidade da união parafusada destaca-se a pré-carga gerada durante o torque do parafuso, as formas como as forças se dissipam através do conjunto implante/pilar/parafuso e as características dos componentes utilizados. Proposição: O objetivo deste estudo foi analisar comparativamente três tipos de pilares sobre implantes, quanto a resistência mecânica previamente ao ensaio de carga cíclica; a porcentagem de torque retido na união parafusada e os níveis de desajuste vertical entre o pilar e o implante antes e após ciclagem; e alterações estruturais na base de assentamento dos pilares através de microscopia eletrônica de varredura (MEV). Material e método: Quarenta e cinco implantes, com conexão tipo hexágono externo foram incluídos em cilindros de PVC utilizando-se resina epóxica com módulo de elasticidade semelhante à estrutura óssea. Os grupos foram estabelecidos de acordo com o tipo de pilar utilizado (n=15): Titânio (pré-fabricado), Ouro (com cinta metálica pré-fabricada e sobre fundido) e Zircônia (pré-fabricado). Cinco pilares de cada grupo foram submetidos a teste de resistência estática para estabelecimento do valor da força a ser utilizada no ensaio de carga cíclica. Os outros 10 pilares de cada grupo foram fixados sobre os respectivos implantes através de parafuso de titânio, sob torque e retorque de 32 Ncm (pilares metálicos) e 20 Ncm (pilar de zircônia). Os corpos de prova foram submetidos à aferição do torque retido (précarga) e dos níveis de desajuste vertical antes e após ensaio de carga cíclica. Os testes foram realizados de acordo com a norma ISO 14801, onde uma força variando entre 11 - 211 N foi aplicada com 30º de inclinação em relação ao longo eixo do implante por 500.000 ciclos e frequência de 15 Hz. Imagens em MEV foram realizadas antes e após os testes a fim de identificar alterações estruturais nos componentes. Quando efeitos significativos entre os grupos foram encontrados pelo teste ANOVA o teste de Tukey, com significância de 5% foi aplicado para identificar as diferenças. Resultado: Com relação à resistência mecânica, os pilares de ouro demonstraram os maiores valores médios com diferenças estatisticamente significantes em relação aos outros pilares (titânio e zircônia), não havendo diferenças estatisticamente significantes entre esses. Quanto à porcentagem de torque retido, previamente a ciclagem não houve diferença entre os grupos. Após a ciclagem, a porcentagem de torque retido diminuiu significativamente para todos os grupos. Os pilares de titânio apresentaram a maior retenção de torque, enquanto os pilares de zircônia a menor, com diferença estatisticamente significante entre os grupos. Os pilares de ouros apresentaram uma retenção de torque intermediaria, sem diferenças estatisticamente significante para os demais grupos. Com relação aos níveis de desajuste vertical, os pilares de ouro foram os que apresentaram as maiores médias, seguido pelo grupo titânio e zircônia respectivamente com diferenças estatisticamente significantes entre todos os grupos. Não foram encontradas diferenças nas análises pré e pós ciclagem, assim como entre as diferentes faces de medição. Imagens em MEV demonstraram alterações estruturais em todos os tipos de pilares após aplicação de carga cíclica, tais como desgastes, amassamento se perda de estrutura. Conclusão: A resistência mecânica dos pilares de zircônia foi considerada igual a dos pilares de titânio. Quanto à porcentagem de torque retido, em todos os grupos houve uma diminuição significativa após a aplicação de carga cíclica. Pilares obtidos através de procedimentos laboratoriais (sobre-fundição) apresentaram os piores níveis de desajuste vertical. Imagens em MEV demonstraram alterações evidentes na base de assentamento dos pilares após aplicação de carga cíclica

Purpose: The aim of this study was to evaluate comparatively three type of abutment in regard to mechanical resistance before cyclic loading, the maintenance of the applied torque and vertical misfit in abutment/implant interface before and after cyclic loading, and damage surface by SEM. Material and Method: Forty five external hex implants were embedded in an epoxy resin and received your respective abutments, randomly divided in three experimental groups (n=15): (A) machined titanium (Ti) abutments; (B) premachined gold (Au) abutments and (C) machined zirconia (ZrO2) abutments. For all groups, only one type of screw was used. The abutment screws were tightened according to the manufacture's recommended torque. Initially, a static bending test was performed using 5 specimens of each group to determine the load applied in the cyclic loading test. Thus, 10 specimens of each group were used to measure the reverse torque value (preload) of the abutment screw and vertical gap between the abutments and implant, before and after loading. The tests were performed according to ISO norm 14801. A cyclic loading (0,5 x 106 cycles; 15 Hz) between 11 - 211 N was applied at an angle of 30 degrees to the long axis of the implants. Group means were compared using ANOVA and Tukey test. Result: The mechanical strength test showed that the UFL mean for Au abutments was significantly higher than the mean of the other abutments (p<0.001). The analysis of reverse torque (preload) before cyclic loading showed no significant differences among abutment groups. After cyclic loading the lowest decrease in preload was observed in group Ti, whereas the highest was observed in group ZrO2, with significant differences between them. The group Au showed an intermediate decrease, with no significant difference to the other groups. In relation to the vertical misfit, the gold abutments showed the highest values, followed by the titanium and zirconia respectively. SEM images obtained after cyclic loading showed clear changes on the seating surfaces of abutments. Conclusion: The mechanical strength of the zirconia abutments was similar to titanium abutments. The load application on the joint implant/abutment/screw reduced significantly torque values in all groups. Premachined abutments presented the worst levels of vertical misfit. SEM images showed changes evident on the seating surfaces of abutments after cyclic loading application

Comparación In Vitro de la adaptación marginal entre incrustaciones MOD maquinadas con el sistema IPS e: max CAD y restauraciones MOD en oro colado tipo III / valuation of marginal adaptation In Vitro of MOD fillings with an enamel finish manufactured with IPS e: max CAD (computer assisted design) and with gold type III

Objetivo: comparar la adaptación marginal In Vitro de incrustaciones MOD con terminación en esmalte fabricadas con IPS e.max CAD (Computer Asisted Desing) y fabricadas en oro tipo III. Materiales y métodos: En este estudio experimental exploratorio se uso una muestra no probabilística de 15 premolares sanos por cada uno de los dos grupos; IPS e.max CAD y oro tipo III.A todos los premolares se les realizó cavidades MOD estandarizadas para los 2 grupos. Los dientes preparados fueron asignados aleatoriamente a cada grupo. Las incrustaciones del grupo IPS e.max CAD fueron elaboradas con el sistema CEREC 3 y las incrustaciones en oro fueron elaboradas por los investigadores. Se tomaron estereo microfotografías de todas las muestras sobre papel milimetrado, y las imágenes fueron analizadas mediante el programa ImageTool. Se tomaron tres medidas adaptación marginal en el área proximal mesial o distal de cada muestra, que fueron promediadas y reportadas en micras. Los datos fueron analizados mediante ANOVA y Test de Mann-Whitney. Resultados: el 98% del total de las incrustaciones en oro y el 47% del total de las incrustaciones de IPS e.max CAD presentaron una adaptación marginal < a 120 micras. El promedio de desadaptación marginal del grupo IPS e.max CAD fue 122.8 μ + 44.1, mientras que para el grupo oro fue de 75.3 μ+42,6 encontrándose diferencias estadísticamente significativas entre los dos. Conclusiones: El oro reporta mejor adaptación marginal en restauraciones inlays MOD que los sistemas maquinados como el sistema IPS e.max CAD.

Objective: To compare In Vitro, the marginal adaptation of MOD fillings with an enamel finish manufactured with IPS e.max CAD (Computer Assisted Design) and those manufactured with gold type III. Materials and methods: In this exploratory experimental study, a non-probabilistic sample of 15 healthy premolars for each of the two groups (IPS e.max CAD and gold type III) was used. Standardized MOD cavities were made in all the premolars for both groups. The prepared teeth were randomly assigned to each group. The IPS e.max CAD fillings were made using the CEREC 3 system and the gold fillings were made by the researchers. Stereo microphotographs of all the samples were taken on millimeter paper and the images were analyzed using the Image Tool software. Three marginal adaptation measurements in the mesial proximal or distal area were taken for every sample; they were averaged and reported in microns. The data was analyzed using ANOVA and the Mann-Whitney test. Results: 98% of all the gold fillings and 47% of all the IPS e.max CAD fillings showed a marginal adaptation of less than or equal to 120 microns. The marginal unfitness average for the IPD e.max CAD group was 122.8 + 44.1 μm, and for the gold fillings group it was 75.3 + 42.6 μm. There was a statistically significant differences between the groups. Conclusions: Gold reports a better marginal adaptation for inlay MOD fillings than manufactured systems like IPS e.max CAD system.

A morphologic evaluation of defects created by a piezoelectric ultrasonic scaler on casting gold alloy / 대한치주과학회지

PURPOSE: In this study we evaluated the morphologic aspects of defects created by a piezoelectric ultrasonic scaler with scaler tip on casting gold alloy using scanning electron microscope (SEM) images and defect surface profiles. METHODS: 54 blocks of type III casting gold alloy (Firmilay, Jellenko Inc, CA, USA) were scaled by a piezoelectric ultrasonic scaler (P-MAX, Satelec, France) with scaler tip (No. 1 tip) on a sledge device. 2-dimensional profiles of defects on all samples were investigated by a surface profilometer (a-Step 500, KLA-Tencor, CA, USA). The selected working parameters were lateral force (0.5 N, 1.0 N, 2.0 N), mode (P mode, S mode), and power setting (2, 4, 8). SEM images were obtained. Defect surface profiles were made on Microsoft Excel program using data obtained by a surface profilometer. RESULTS: Among P mode samples, there were similarities on defect surface profiles and SEM images regardless of lateral force. The defects created in P mode were narrow and shallow although the depth and the width increased as power setting changed low (2) to high (8). In P mode samples, the defect depth was the greatest when lateral force of 0.5 N was applied. However all the depths were smaller than 1 m. SEM images of Lateral force of 0.5 N, S mode, power setting 2 and 4 were similar to that of P mode, but the other SEM images of S mode showed discernible changes. Defect depth of S mode samples was the greatest when lateral force of 1.0 N was applied. CONCLUSIONS: Within the limitations of this study, it can be concoluded that removing capability of piezoelectric scaler with scaler tip becomes maximized as power level becomes higher but the capability is restricted when excessive lateral force is applied on scaler tip.

Experimental mechanics analysis of posterior galvano-ceramic bridges made by Ni-Cr pontic fired bonding galvano caps / 北京大学学报(医学版)

Objective: To measure the fracture strength of the posterior galvano-ceramic bridges made by Ni-Cr pontic fired bonding galvano caps with highly temperature-resistant adhesive and to provide re-ference data for clinical application. Methods: A standard low dental cast was achieved with 46 missing. Five posterior galvano-ceramic bridges made by Ni-Cr pontic fired bonding galvano caps, with abutments being 47 and 45 . The low dental cast was fixed on the panel of the universal testing machine, vertical load given on the central of the pontic as the velocity of 2 mm/min. Results: The fracture strength of the posterior galvano-ceramic bridges made by Ni-Cr pontic fired bonding galvano caps was (877.00?126.53) N, the fracture strength of the metal frame was (1 448.94?51.02) N. Conclusion: Posterior galvano-ceramic bridges made by Ni-Cr pontic fired bonding galvano caps could endure the normal human occlusal force.

Effect of five commonly used prosthesis materials on bacterial colonization: An in vivo study / 第二军医大学学报

typeⅢgold alloy. Candida albicans could be found on acrylic resin ,but there was little on the other 4 dental metals. Conclusion: From the perspective of reserving periodontal tissue, pure-Ti and typeⅢgold alloy seem to be the first choice, Co-Cr alloy and Ni-Cr alloy are the second.