PURPOSE This in vitro study evaluated and compared the vertical marginal gap of cast and milled full coverage gold copings using two margin designs (chamfer and chamfer bevel) before and after fitting adjustments. MATERIALS AND METHODS Ten impressions were made of two metal master dies (one chamfer margin, one chamfer-bevel margin) and poured twice in Type IV stone. The 20 subsequent casts wi...

The chamfer enhances the performance of the tool by strengthening the edge and reducing the possibility of tool wear and breakage. The strength of the chamfered tool can be investigated by analysis of process variables. This research investigates the effects of chamfer width and chamfer angle on process variables (force, stress, tool temperature and tool stress) in machining of a mild carbon lo...

OBJECTIVE One of the major problems of all ceramic restorations is their probable fracture against the occlusal force. The aim of the present in-vitro study is was to compare the effect of two marginal designs (chamfer & shoulder) on the fracture resistance of zirconia copings, CERCON (CAD/CAM). MATERIALS AND METHODS This in vitro study was done with single blind experimental technique. One s...

OBJECTIVE To investigate the influence of location and preparation design on the survival and complication rate of metal-free polymer crowns within a prospective clinical study. METHODS After randomization, a total of 114 (68 posterior and 46 anterior) single crowns were prepared, either with a chamfer finishing line or with a shoulder combined with occlusal reduction of at least 1 mm. Build-...

INTRODUCTION Base metals have a wide use in casting methods. Sometimes they are reused in laboratories which may have an adverse effect on the restoration marginal integrity. This study aimed to investigate the effect of recasting of alloys on marginal integrity of restorations. MATERIALS AND METHODS Models with two types of finishing lines shoulder bevel 45° and shoulder 135° were produced a...

The distance transform has found many applications in image analysis. Chamfer distance transforms are a class of discrete algorithms that offer a good approximation to the desired Euclidean distance transform at a lower computational cost. They can also give integer-valued distances that are more suitable for several digital image processing tasks. The local distances used to compute a chamfer ...

Abstract Deep hole drilling processes for high-alloyed materials are characterised by worn guide pads and chatter vibrations. In order to increase feed rates, process stability bore quality in STS deep drilling, various investigations were carried out with adjustments the tool. First, a new chain production of tribologically optimised their effects on pad shape is described detail. The results ...

An algorithm Mscan is proposed for the computation of the distance transform of a feature in an image with respect to a chamfer distance. The algorithm is na vely simple and can therefore be easily parallellized. It seems to be new, even for special cases. It is not correct for arbitrary chamfer distances but, by a general analysis of masks and their weights, suucient conditions for its correct...

Aim: The purpose of this study is to compare the marginal fit crowns manufactured using different CAD/CAM materials on 2 types finish line design.Material and Method: Tooth preparations were made by creating lines (rounded shoulder, chamfer) an acrylic mandibular second premolar model. Impressions taken each preparation polyvinylsiloxane impression material, blocks with three compositions inclu...

Objective The aim of this in vitro study was to investigate the effect of Shoulder versus Chamfer margin design on the marginal adaptation of zirconia (Zr) copings. Materials and Methods 40 extracted molar teeth were mounted in resin and prepared for zirconia crowns with two margin preparation designs (20=Shoulder and 20=Chamfer). The copings were manufactured by Cercon® (DeguDent GmbH, Germa...