Dr. Lionel Pelletier - Special Training, Procedures & Promotions
Novel Biomaterials
(added October 25, 2009)
Over the last thirty years, considerable research efforts were devoted to the development of aesthetic biomaterials for use in fixed (crown & bridge) prosthodontics. The prerequisites to a state of the art ceramic material for dental use are multiple. In addition to being non-toxic and biocompatible, the core material needs to offer high flexural strength as well as sufficient translucency, along with a coefficient of thermal expansion compatible with the sintering of feldspathic porcelain used to achieve the desired aesthetic result. Also, consistent fitting accuracy ( gap < 30 microns) of the manufactured restoration is primordial to prevent micro-leakage and therefore to ensure a successful long-term clinical outcome.
The zirconia core material used in various new ceramic systems offers a quantum leap advancement towards the strength and optical properties prerequisites. Also, computer aided design and manufacturing (CAD/CAM) is used to ensure the satisfactory fit of the core/framework onto which feldspathic porcelain -using conventional layering- is applied.
Following clinical tooth preparation and impression making, the resulting dental stone die is scanned. An ingot of the appropriate shade is then selected and a computerized milling machine is used to manufacture the core/framework to a .4 mm to .5 mm thickness, while the zirconia is still in a green state . The thickness of the luting medium to be used with the fabricated restoration is accounted for with a cementation gap optimized at 20 microns. The green state milled core/framework is then subjected to a high temperature sintering cycle and a high flexural strength is achieved. The core/framework is then ready for conventional porcelain application. Internal characterization to achieve mimesis is therefore possible.
Lionel Pelletier, DMD, MMSc - Prosthodontist
Rated: 5.0 out of 5
by 27 patients.
Dr. Lionel Pelletier DMD, MMSc. Prosthodontist, Brookline.
