Computer modeling of occlusal surfaces of posterior teeth with the CICERO CAD/CAM system☆,☆☆
Section snippets
Material and methods
Fourteen acrylic resin dental elements were placed in the upper and lower jaws of a model of a human head (Patient Simulator, Kavo EWL). The relation between the maxilla and mandibular could be classified as Angle Class I with a sagittal overjet of 1 mm. The dental arches were fixed in the head and connected via a mechanical temporomandibular joint (TMJ). The inclination of the condylar path of the TMJ has been preset by the manufacturer. The contact movements of both jaws are guided manually
Results
Trajectories in mediotrusive, laterotrusive, and protrusive direction as obtained from the border movements in the KAVO simulator are shown on a projection of the STA design of the first mandibular molar in the occlusal, the buccolingual, and the mesiodistal view, respectively (Fig. 4, A through C ).
Discussion
Although the strength and the esthetic demands of dental restorations can be met by automated production system,7, 8, 9 and such systems are less time-consuming and thus will help to reduce the expenses of dental treatment, the functional properties of the restoration will determine its overall quality. For this reason, the production of crowns that do not cause interference in dynamic occlusion and in which there is optimal contact in centric occlusion will be of great value to dental practice.
Summary
This study demonstrated that, in the near future, computer techniques may help to monitor the ideal articulation in restorative dentistry. Electronic registration devices are an essential part of these new techniques. The CICERO CAD/CAM system is well equipped to demonstrate the influence of various articulator settings on the 3-dimensional configuration of occlusal surfaces. A study to demonstrate systematically the influence of these parameters is in progress.
Supplementary Files
References (30)
- et al.
Comparison of occlusal contacts in maximum intercuspation for two impression techniques
J Prosthet Dent
(1997) - et al.
Pattern of tooth contacts in eccentric mandibular positions in young adults
J Prosthet Dent
(1991) - et al.
Comparison of condylar settings using three methods: a bench study
J Prosthet Dent
(1991) - et al.
Computer-graphic representation of mandibular movements in three dimensions. Part I: the horizontal plane
J Prosthet Dent
(1978) - et al.
Computer-graphic representation of mandibular movements in three dimensions. Part II: the sagittal and frontal planes
J Prosthet Dent
(1978) - et al.
CAD-CAM in dentistry
J Am Dent Assoc
(1988) - et al.
A new method for generating ceramic restorations: a CAD-CAM system
J Am Dental Assoc
(1989) - et al.
Functional movements of the mandible
J Prosthet Dent
(1971) The generated path technique in reconstruction dentistry, parts I and II
J Prosthet Dent
(1959)- et al.
Porcelain occlusal posterior fixed partial dentures
J Prosthet Dent
(1975)
The Hardy chew-in technique: a modified procedure
J Prosthet Dent
Why dental restorations should have cusps
J Prosthet Dent
Concepts of occlusion
Dental Clin North Am
The influence of the mandibular lateral translation
Int J Prosthodontics
Ceramic-fused-to-metal restorations with a new CAD/CAM system
Quintessence Int
Cited by (30)
Design of wear facets of mandibular first molar crowns by using patient-specific motion with an intraoral scanner: A clinical study
2023, Journal of Prosthetic DentistryImpact of the occlusal contact pattern and occlusal adjustment on the wear and stability of crowns
2023, Journal of DentistryEffect of guide sleeve material, region, diameter, and number of times drills were used on the material loss from sleeves and drills used for surgical guides: An in vitro study
2022, Journal of Prosthetic DentistryCitation Excerpt :The left first premolar to second molar teeth were removed from the model to create a unilateral posterior edentulous space. The model was scanned and digitized by using a modified laser optical scanner (3D Scanner; NextEngine Inc) with 12-μm accuracy.5,41 A standard tessellation language (STL) file was generated to design drill-guided surgical guides.
Morphology and fracture behavior of lithium disilicate dental crowns designed by human and knowledge-based AI
2022, Journal of the Mechanical Behavior of Biomedical MaterialsCitation Excerpt :Knowledge-based AI is a problem-solving method based on a preset knowledge base (Haenlein and Kaplan, 2019; Steels and Lopez de Mantaras, 2018) that has been deployed in dental prosthesis design, namely “generic tooth” shape design in Cicero system (Elephant Industries, Netherlands) that can design fixed partial dentures and crown (van der Zel, 1993; Olthoff et al., 2000) and “biogeneric individual model” in CEREC CAD software (Sirona Dental Systems, Bensheim, Germany) that can automatically generate designs of single crowns, partial crowns, inlays, onlays and veneers (Bohner et al., 2016; Revilla-Leon et al., 2021). Based on the mathematical representation of tooth morphology, the algorithm captures features within the teeth library, computes average tooth size/shape/occlusal features quantitatively, then reconstructs the occlusal surface via different mechanism: For Cicero, static contact is used to search for the antagonist contact and then axiographic motions are inputted to simulate the dynamic jaw motion (Olthoff et al., 2000; van der Zel et al., 2001). For CEREC biogeneric individual (BI) mode, the morphology and occlusal relationship among the abutment tooth, the adjacent and antagonist teeth are inputted and analyzed, then the missing tooth structure is automatically generated based on principal component analysis (Revilla-Leon et al., 2021; Mehl and Blanz, 2005; Mehl et al., 2005a, 2005b; Richter and Mehl, 2006; Shan et al., 2021; Arslan et al., 2015).
The occlusal precision of milled versus printed provisional crowns
2022, Journal of DentistryCitation Excerpt :Obtaining a provisional restoration with an accurate occlusal surface and contacts, is essential to reduce the need for excessive intraoral adjustments, that could compromise the quality and thickness of the material. Furthermore, an adequate temporary would prevent patient's symptoms, such as pain and hypersensitivity, as well as abutment mobility an migration [10–12]. Currently, an increasing body of literature is focusing on the digital manufacturing of dental prosthesis[13].
Assessment of CAD-CAM zirconia crowns designed with 2 different methods: A self-controlled clinical trial
2018, Journal of Prosthetic DentistryCitation Excerpt :In this clinical trial, the correlation condition showed significantly less lateral interference than the library condition, indicating that the correlation method yielded functional occlusion that was improved compared with that of the library method. Olthoff et al24 investigated differences between crowns designed with the library method and the occlusal generated path technique and concluded that more correction of the static occlusion design was needed to allow functioning without interference; this was in agreement with the findings of the current clinical trial. Yeliz et al25 evaluated the occlusal contacts generated by using 3 different biogeneric design modes (individual, copy, and reference modes) of Cerec software and concluded that the biogeneric individual (library) method showed significantly better occlusion than the biogeneric copy design (correlation) method.
- ☆
This study was supported by a grant from the Foundation of Technological Sciences Utrecht under grant number STW.ATH.553637.
- ☆☆
Reprint requests to: Dr L. W. Olthoff, Department of Oral-Maxillofacial Surgery, Prosthodontics, and Special Dental Care, PO Box 80.037, 3508 Ta Utrecht, THE NETHERLANDS, Fax: (31)30-2535537, E-mail: [email protected]