Aesthetic assessment of maxillary lateral and canine implant-supported crowns by laypersons and orthodontists

Abstract

Introduction: The objectives of this study were to evaluate how laypersons and orthodontists evaluate and rank aesthetic parameters of an implant-supported crown (ISC) on the canine position (ISC-C) and lateral position (ISC-L).

Methods: A digital survey of 11 cases, 5 ISC-C, 5 ISC-L and 1 control case without ISC, was distributed to 207 laypersons and 296 orthodontists. All cases included one extraoral photograph and three intraoral photographs. The respondents were asked to identify the ISC and to evaluate the aesthetic parameters regarding colour of the implant (CI), shape of the implant (SI) and gingival colour around ISC (GCI). Differences within and between the groups were tested using Chi-2-test and Independent-Samples t-test.

Results: All invited laypersons and 184 orthodontists (62% response rate) answered the survey. Orthodontists (89%) more correctly identified the ISC, regardless of its position, than laypersons (50%) (p < 0.001). Both laypersons (54%) and orthodontists (23%) rated higher proportions of acceptance of CI, SI and GCI in favour for the ISC-L than ISC-C (laypersons: 40%, orthodontists: 10%) (p < 0.001). Assessing each parameter separately, orthodontists rated higher for ISC-L, compared to the ISC-C (p < 0.001). In general, laypersons and orthodontist ranked tooth colour (mean, standard deviation [SD]:8.0,1.5 and 9.0, 1.0) and tooth shape (mean, SD: 8.0, 1.7 and 8.8, 1.2) as aesthetically higher than the gingival colour (mean, SD: 7.2, 2.2 and 8.0, 1.7) (p > 0.001). Conclusion: Laypersons and orthodontists consider the ISC-L as aesthetically more preferable, compared to the ISC-C.

Figure 1

Smile photographs of cases where laypersons and orthodontists were asked to identify the artificial tooth. Implant-supported lateral crown on the right side is seen in cases #6, 8, 9, 10, and on the left side in case #7. Implant-supported canine crown on right side is seen in cases #1, 2, 4, 5, and on the left side in case #3. Highest score for orthodontists to correctly identify the implant-supported crown was seen for cases #2 and 3 (99%) and lowest score for case #8 (45%), while the laypersons showed the highest score to correctly identify the implant-supported crown for case #8 (92%) and lowest score for case #6 (8%).

Figure 2

Intraoral photos of all cases where laypersons and orthodontists were asked to rate the aesthetic parameters: colour of tooth, shape of tooth and gingival colour of the implant-supported crown, in comparison to the contralateral tooth. The implant-supported lateral crown on the right side is seen in cases #6, 8, 9, 10, and on the left side in case #7. The implant-supported canine crown on the right side is seen in cases #1, 2, 4, 5, and on the left side in case #3.

Figure 3

Boxplot of the general judgement of importance of the aesthetic parameters colour, shape of the implant-supported crown, and gingival colour evaluated by orthodontists and laypersons, using a VAS-scale ranging 0–10. 0: Parameter being not of importance, 10: Parameter being of the greatest importance. Orthodontists ranked tooth colour as being the most important parameter in relation to tooth shape (p < 0.05) and gingival colour (p < 0.001). Tooth shape was ranked being more important than gingival colour (p < 0.001). Laypersons ranked tooth colour and tooth shape being more important than gingival colour (p < 0.001). Comparisons of mean performed by independent-samples t-test, *p < 0.05, ***p < 0.001, ns = non-significant.