J Adv Prosthodont.  2015 Dec;7(6):431-436. 10.4047/jap.2015.7.6.431.

Evaluation of biogeneric design techniques with CEREC CAD/CAM system

• Arslan Y
• Karakoca Nemli S
• Bankoglu Gungor M
• Tamam E
• Yilmaz H

• KMID: 2176617
• DOI: http://doi.org/10.4047/jap.2015.7.6.431

Abstract

PURPOSE
The aim of this study was to evaluate occlusal contacts generated by 3 different biogeneric design modes (individual (BI), copy (BC), reference (BR)) of CEREC software and to assess the designs subjectively.
MATERIALS AND METHODS
Ten pairs of maxillary and mandibular casts were obtained from full dentate individuals. Gypsum cast contacts were quantified with articulating paper and digital impressions were taken. Then, all ceramic crown preparation was performed on the left first molar teeth and digital impressions of prepared teeth were made. BI, BC, and BR crowns were designed. Occlusal images of designs including occlusal contacts were superimposed on the gypsum cast images and corresponding contacts were determined. Three designs were evaluated by the students.
RESULTS
The results of the study revealed that there was significant difference among the number of contacts of gypsum cast and digital models (P<.05). The comparison of the percentage of virtual contacts of three crown designs which were identical to the contacts of original gypsum cast revealed that BI and BR designs showed significantly higher percentages of identical contacts compared with BC design (P<.05). Subjective assessment revealed that students generally found BI designs and BR designs natural regarding naturalness of fissure morphology and cusp shape and cusp tip position. For general occlusal morphology, student groups generally found BI design "too strong" or "perfect", BC design "too weak", and BR design "perfect".
CONCLUSION
On a prepared tooth, three different biogeneric design modes of a CAD/CAM software reveals different crown designs regarding occlusal contacts and morphology.

Keyword

Crowns; Dental prosthesis design; Dental occlusion

MeSH Terms

Calcium Sulfate
Ceramics
Crowns
Dental Occlusion
Dental Prosthesis Design
Humans
Molar
Tooth
Calcium Sulfate
Ceramics

Figure

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  Fig. 1 Crown designs for each design mode. (A) Biogeneric individual (BI), (B) Biogeneric copy (BC), (C) Biogeneric reference (BR).

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  Fig. 2 Questionnaire to assess the naturalness of occlusal morphology of the restoration designs.

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