Precision of fit and clinical evaluation of all‐ceramic full restorations followed between 0·5 and 5 years

Abstract

Currently CAD-CAM systems are rapidly gaining importance in dental practice as some of their products aim to combine aesthetics with strength and are free of metals. This study reports on the crown adaptation, marginal fit and clinical behaviour of 300 all-ceramic full coverage restorations (Procera, Gothenburg, Sweden) placed in one clinical centre and followed up to 5 years. The marginal fit and coping adaptation before and after luting was determined by direct measurement as well as after sectioning in a laboratory study. Three hundred all-ceram restorations were installed in 165 patients between 1994 and 1998. Before the end of 2000, patients were recalled to assess their restorations, using the California Dental Association quality evaluation index, their own appreciation, as well as the reaction towards the periodontium. The in vitro data revealed a mean marginal adaptation of 30 microm, before and after luting of the Al(2)0(3)-coping onto the tooth. However, at the deepest part of the chamfer, the distance increased to 135 microm. In the clinical study only one restoration fractured, while in 6% small porcelain infractions occurred. After polishing the latter, no persistent patient complaints remained. At the last recall visit 1.8% of the margins were rated unacceptable. Dentists rated 72 and 78% of the restorations excellent for surface, colour and anatomic form respectively. Eighty-seven per cent of the patients rated their restorations more than 7/10 on an ordered analogue scale for aesthetics as well as for function.

Influence of Different Luting Agents on the Marginal Discrepancy of Procera® AllCeram Alumina Crown Copings – An Experimental Study

“…Naert et al (19) found in their study that the luting media did not affect the marginal fit. They concluded that the marginal gap was increased after the cementation of the coping and they asserted that this situation was the clinical reality.…”

“…However, there are a few other confounding cement and cementation factors which can directly or indirectly affect the final fit of the crown (31). With AllCeram crown copings, Neart et al did notice the elevation of the coping but did not find any influence of different luting agents over the marginal discrepancy (19). Conventional cements like zinc phosphate cement, with all-ceramic crowns, showed the beneficial effect over the final aesthetics of the crown by masking underlying discolouration of the abutment tooth (4).…”

“…AllCeram material is one of the materials produced by Nobel Biocare Gothenburg, Sweden and used as substructure material for tooth and implant supported crown and bridge prosthesis. Five, six and 10 year survival rates were 97.7 %, 94.3 % and 93.5 % respectively (19,28,20). The published success rate is within the global success standard for new dental materials (23).…”

Adaptación de cofias metálicas confeccionadas con dos técnicas: cera pérdida colada por centrifugación convencional y fresado de bloque blando en CAD/CAM

“…Esta aleación se puede utilizar con los sistemas convencionales de colado o mediante sistemas digitalizados CAD/CAM para fresado y láser (21)(22)(23)(24)(25)(26)(27)(28). Para la obtención de cofi as metálicas se puede utilizar la técnica de cera perdida colada por centrifugación (CPC), que consiste en encerar un patrón de cera, posteriormente la cera es evaporada por calor en un horno, mediante un soplete se funde el metal y por último se impulsa el metal fundido por medio de una fuerza centrí-fuga en el molde a través de un canal denominado bebedero (29)(30)(31)(32).…”

Discrepancia Marginal De Cofias en Zirconio Elaboradas Con Dos Sistemas Cad/Cam

“…Otros estudios también realizaron medidas sobre dientes naturales extraídos. 3,10,24 Varios autores han elaborado troqueles de acero o resina para las mediciones, la ventaja de este método es la estandarización de la preparación para todos los pilares. 22 Sin embargo, estos materiales no dan información real sobre la microestructura del tejido dental.…”