Research and Education
Impact of digital prosthodontic planning on dental esthetics: Biometric analysis of esthetic parameters

https://doi.org/10.1016/j.prosdent.2015.07.005Get rights and content

Abstract

Statement of problem

Improving dental esthetics is a main objective of prosthodontic treatment. Recently, digital diagnostic waxing has been proposed as an alternative to conventional diagnostic waxing; however, the impact on esthetics has not been evaluated.

Purpose

The purpose of this study was to evaluate the impact of diagnostic waxing on biometric esthetic variables and to compare the esthetic outcome achieved by digital waxing with conventional waxing.

Material and methods

Three biometric variables were evaluated: perceived frontal proportion (PFP), width/height (W:H) ratio, and symmetry. Maxillary casts of 13 patients were collected. All of them had maxillary anterior teeth that required prosthodontic treatment. Two forms of diagnostic waxing were executed: conventional and digital waxing. Measurements of the esthetic variables were conducted digitally. For the PFP, a frontal image was made and the width of each tooth was measured. Subsequently, the PFP values of the lateral incisor to central incisor and of the canine to central incisor were calculated. In addition, the height and width of each tooth was measured to calculate the W:H ratio. Using the previous measurements, the symmetry between the right and left sides was determined.

Results

No consistent or recurrent PFP was detected for any cast. The diagnostic waxing did not alter the PFP of the pretreatment casts. The diagnostic waxing had restored the W:H ratio to what is assumed to be a natural ratio. An improvement in symmetry was detected after the diagnostic waxing and was more prominent after the digital waxing. However, no significant difference was found between the 2 diagnostic waxing methods.

Conclusions

The 2 diagnostic waxing methods influenced the esthetic variables of the anterior maxillary teeth and yielded similar outcomes. Digital waxing appears to be a reasonable alternative, but further investigations are needed to ensure its practicality.

Section snippets

Material and Methods

Thirteen patients participated in this study. All of them presented with all of their maxillary anterior teeth and required diagnostic waxing before prosthodontic treatment. The indications for the treatment were failing restorations, tooth wear, or unesthetic teeth. A human research ethics approval was obtained from the Human Research Ethics Committee of the University of Western Australia (RA/44/1/5079). The treatments were provided at the Oral Health Centre of Western Australia.

For all of

Results

The average PFP of the lateral incisors and canines to the central incisors for all the casts are presented in Figure 4. The reported average lateral incisor proportion for the pretreatment, conventional waxing, and digital waxing casts was 65.6%, 60.8%, and 60.5%, respectively, and the canine proportion was 49.4%, 46.5%, and 45.8%, respectively. An exact match between any cast and GP (lateral incisors=68%, canines=38%) was not observed. However, the PFP pattern was relatively comparable to GP.

Discussion

Historically, recurrent PFP between the maxillary anterior teeth, such as GP, is thought to be associated with greater harmony and esthetics.3, 4 Although an exact match with GP was not observed for any cast of this study, relatively close values were obtained for the lateral incisor proportion. However, the canine proportion was larger, which means that the total perceived maxillary anterior teeth width is greater than what has been proposed by GP. The observed PFP values in this study

Conclusions

Within the limitations of this study, diagnostic waxing had a positive impact on the esthetic variables. The PFP was minimally affected and no recurrent PFP was observed. The anterior tooth morphology in the form of the W:H ratio was restored by the waxing to natural morphology. There are indications that the perceived and the actual symmetry had improved following the diagnostic waxing. In terms of tooth dimensions, proportions, and symmetry, the 2 waxing protocols are similar. From the

Acknowledgments

The authors thank the National Imaging Facility at the Centre for Microscopy, Characterization & Analysis, University of Western Australia (a facility funded by the University, State, and Commonwealth Governments); and the staff at the technical facility of the Oral Health Centre of Western Australia.

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    Supported by the Research Development Award from the University of Western Australia and the Australian Prosthodontic Society.

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