Computerized occlusal forces analysis in complete dentures fabricated by additive and subtractive techniques

Area of Science:

• Biomaterials Science
• Dental Engineering
• Prosthodontics

Background:

• Computer-aided designing and computer-aided manufacturing (CAD-CAM) are increasingly used for complete denture fabrication.
• Subtractive and additive techniques are the primary CAD-CAM methods, but comparative occlusal force data are limited.

Purpose of the Study:

• To compare occlusal forces in complete dentures made with additive, subtractive, and conventional techniques.
• To evaluate the influence of different occlusal schemes (bilateral balanced, lingualized, mono plane) on occlusal forces.
• To utilize a computerized occlusal force analysis system (T-Scan III) for objective measurements.

Main Methods:

• Three fabrication groups: Conventional Complete Dentures (CCD), Subtractive Complete Dentures (SCD), and Additive Complete Dentures (ACD).
• Each group divided into three occlusion scheme subgroups: bilateral balanced occlusion (BBO), lingualized occlusion (LO), and mono plane occlusion (MO).
• Occlusal force analysis (right-left side distribution, force centralization, maximum bite force) performed using T-Scan III on 45 denture samples.

Main Results:

• Statistically significant differences (p<0.01) were found in force distribution and maximum bite force based on fabrication technique and occlusion scheme.
• The combination of CCD and MO showed the greatest right-left side force difference (36.88 ± 2.82 N).
• SCD technique (89.14 ± 6.08 N) and LO scheme (92.17 ± 3.22 N) exhibited the highest maximum bite forces.

Conclusions:

• Subtractive CAD-CAM complete dentures demonstrated superior performance in occlusal force analysis compared to additive techniques.
• While digital techniques show promise, further in-vivo studies are essential to validate the clinical superiority of specific fabrication methods.