Indian Journal of Dental Sciences

ORIGINAL ARTICLE
Year
: 2020  |  Volume : 12  |  Issue : 2  |  Page : 80--86

Perception and practices with regard to tooth shade selection for composite restoration among dentists in Southwest, Nigeria


Lillian Lami Enone1, Afolabi Oyapero2, John O Makanjuola3,  
1 Department of Restorative Dentistry, Lagos State University Teaching Hospital, Ikeja, Nigeria
2 Department of Preventive Dentistry, Lagos State University College of Medicine, Ikeja, Nigeria
3 Department of Restorative Dentistry, Faculty of Dental Sciences, College of Medicine, University of Lagos, Lagos, Nigeria

Correspondence Address:
Afolabi Oyapero
Department of Preventive Dentistry, Lagos State University College of Medicine, Ikeja, Lagos
Nigeria

Abstract

Background: The perception of tooth color is an important goal for the dentist who needs to choose the right tooth shade to create satisfactory esthetic restorations as well as for the patient who desires a better smile. The success of any tooth-colored (anterior) restoration is however directly related to the accuracy of chairside shade selection The aim of this study was to determine the knowledge and practices of dentists on shade selection in composite restorations in Southwest, Nigeria. Materials and Methods: This descriptive self-administered questionnaire-based study was conducted among 200 randomly enlisted dentists selected by multistage sampling in the Southwest of Nigeria. Chi-square statistical test was utilized for categorical variables, while the independent t-test was used to compare the mean values in subgroups. A multivariate linear regression model was used to assess the association between predictor variables and knowledge scores. The level of significance in this study was set at 0.05. Results: Majority of respondents had good knowledge (67.5%), while 60.5% of them had good practices. The highest proportion (66.5%) used only visual shade selection in natural daylight (89.0%), while only 48% determine the tooth shade at the cervical, middle, and incisal third of the tooth; 73% had never taken a color blind test. Dentists had practiced for more than 10 years and restorative dentistry consultants had significantly better knowledge about shade selection. Respondents who had poor knowledge had significantly poorer shade selection practices (P = 0.036). After controlling for confounders by multivariate logistic regression, all categories of dentists with good knowledge and consultants still had significantly better dental shade selection practices. Conclusion: Experienced dentists and restorative consultants appear to have adequate knowledge about shade selection and this had a significant impact on their practice. A need however exists to bridge the gap among other categories of dental personnel to improve the esthetic outcome of composite restorations.



How to cite this article:
Enone LL, Oyapero A, Makanjuola JO. Perception and practices with regard to tooth shade selection for composite restoration among dentists in Southwest, Nigeria.Indian J Dent Sci 2020;12:80-86


How to cite this URL:
Enone LL, Oyapero A, Makanjuola JO. Perception and practices with regard to tooth shade selection for composite restoration among dentists in Southwest, Nigeria. Indian J Dent Sci [serial online] 2020 [cited 2020 Dec 2 ];12:80-86
Available from: http://www.ijds.in/text.asp?2020/12/2/80/284667


Full Text



 Introduction



Contemporary dentistry requires the effective use of dental restorative materials to achieve the best esthetic results.[1] In addition, the demand for better esthetic outcomes has increased over the years; hence, the need for precise color matching of the restorative materials used has become imperative.[1],[2] With recent improvements and innovations in composite resins, re-establishment of the exact tooth form can be achieved satisfactorily. Furthermore, due to its wide variety of color shades and effects, which facilitates different combinations of translucency and opacity, as well as its ease of handling, composite resins have become suitable restorative materials in patients requiring anterior restorative procedures to be integrated to the other teeth that compose their smile, with resultant satisfactory esthetic results.[3],[4],[5],[6],[7]

The success of any tooth-colored (anterior) restoration is directly related to the accuracy of chairside shade selection.[8] Patients are currently demanding esthetic replacement that must match their existing dentition and are more concerned about the shade match of their restorations rather than quality of the restoration.[9] Consequently, chairside shade selection has become a very important step even for experienced dental practitioners, in the overall treatment of the patient.[10] To ensure accuracy, various shade selection protocols have been devised for clinical setup, lighting, patient's setup, operator's position, and use of a standard shade guide. A thorough knowledge of these protocols is important so that visual shade selections can be carried out with accuracy and repeatability.[11],[12],[13] However, these protocols are either not known or are not fully understood by majority of the dental community,[14],[15] including undergraduate students, interns, and general dentists.

Tooth color has been shown to be one of the most important factors when assessing a patient's satisfaction with their dental appearance as demonstrated by some recent studies.[16],[17],[18] There may, however, be differences in the patient's evaluation of esthetic parameters such as the color of the tooth and restoration.[19] Restorative materials should match the natural teeth when placed, although several factors such as the color of the tooth and the luting agent as well as the translucency of the material used would affect the optical behavior of the final restoration.[20],[21] Three elements are important in color: hue, which is the color as perceived by the observer; chroma, which is the intensity or concentration of the hue, and the value, which refers to the lightness or darkness of a hue and is related to the amount of the existing white or black pigments.[22],[23] The paths of light inside the tooth determine the natural color of the tooth. Furthermore, the paths of light and the absorption along these paths determine natural tooth color, and the light paths inside the tooth are determined by scattering.[24]

The perception of tooth color is a very important goal for the dentist who needs to choose the right tooth shade to create satisfactory esthetic restorations as well as for the patient who desires a better smile;[25] thus, shade selection is a very important aspect of clinical practice.[26] The aim of this study was to determine the knowledge and attitude of dentists to shade selection and their perception of factors that influence tooth shade selection for composite restorations in Southwest, Nigeria.

 Materials and Methods



This descriptive, cross-sectional study was reviewed by the institutional ethics committee of the Lagos State University Teaching Hospital and ethical approval was obtained before the commencement of the study. The study was conducted in full accordance with ethical principles including the World Medical Association Declaration of Helsinki.

The inclusion criteria for the participants included being a house officer, dental officer/general dental practitioner who performs composite restoration procedure on a routine basis, junior registrar, senior registrar (specialist in training in restorative dentistry), and specialist conservative dentists. Dental students, dentists who do not routinely perform composite filling procedures, specialists in training, and specialists in other fields such as orthodontics, periodontics, oral medicine, or oral and maxillofacial surgery and also dentists who did not consent to participate in the study were excluded from the study.

A pilot study was carried out among 25 dental practitioners across the different cadres-house officers, dental officers, specialists in training (junior and senior resident doctors), and specialists in a tertiary health institution (who were not included in the final study) to test the clarity of the previously validated questionnaire used for this study.

A simple random sampling procedure was used in the selection of four tertiary hospitals and four private dental clinics representing the Southwestern part of the country. The well-structured self-administered questionnaires, with many multiple options and with every question indicated as mandatory, were randomly distributed to willing participants (house officers, dental officers, specialists in training, and conservative dental specialists in the selected Nigerian tertiary hospitals – Lagos University Teaching Hospital, Lagos State University Teaching Hospital, Obafemi Awolowo University Teaching Hospital, University College Hospital, and four private dental clinics) who gave their written consent after the investigator had explained the purpose of the study. The designed questionnaire consisting of 32 questions began with an introductory explanation of the purpose of the study and emphasized the anonymity of each participant. Sociodemographic and professional characteristics of the practitioners were collected. The study participants answered questions on their knowledge of composite restorations with regard to shade selection. They were also assessed on their attitude and practice with regard to shade selection for composite fillings.

Following data collation, statistical analysis was performed using the IBM SPSS Statistics 22.0 (IBM Corp., Armonk, NY, USA). Frequency distribution tables and cross-tabulations were generated for all inputs provided by the participants. The skewed nature of quantitative variables was first ascertained using the Kolmogrov–Smirov test. Descriptive statistics was generated; thereafter, Chi-square and Fisher's exact tests were used to examine differences between groups. Logistic regression analysis was used to confirm the significant effect of several variables on shade selection preferences between endodontists and other cadres of dental practitioners. Differences at 5% level were accepted as statistically significant.

 Results



A total of 240 dental practitioners were surveyed in this study, and 200 questionnaires were returned properly filled giving a response rate of 83.3%. The highest proportion of the respondents were aged between 31–40 years (116; 58%), were under training (185; 92.5%) and had been in dental practice for 5–10 years (79; 39.5%). Majority of them were female (105, 52.5%) [Table 1].{Table 1}

On the knowledge about shade selection, [Table 2] reveals that 98 (49.0%) respondents felt that the individual observer was most important, while 74 (37.0%) stated that the ideal time for shade selection was within 5–10 s. One hundred and seventy-four (87.0%) opined that shade selection is best done at the beginning of an appointment, while 178 (89%) stated that natural light should ideally be used.{Table 2}

[Table 3] shows that the cotton roll and absorbent wafers were most commonly used by respondents for isolation (120, 60%), while 96 (48%) correctly identified that the cervical third, middle third, and incisal third of the tooth should have the shade determined independently. The highest proportion stared at the tooth for 5 s doing shade selection 91 (45.5%), with their eye always at the same level with the patients tooth 118 (59.0%). Shade A2 was most commonly used by the highest proportion of respondents (125, 62.5%), but majority of the respondents had never taken a test for color blindness (146, 73.0%).{Table 3}

[Table 4] shows that 179 (89.5%) of the respondents stated that the upper central incisor was the indicator to determine tooth shade as a representative of individual natural tooth color, while 95 (47.5%) stated that the middle labial third of the tooth surface best illustrates the ideal tooth shade. However, 141 (70.5%) respondents consistently used only one type of shade for restoration.{Table 4}

Overall, 135 (67.5%) respondents had good knowledge about shade selection, while 65 (32.5%) had poor knowledge [Figure 1].{Figure 1}

With regard to practice, 121 (60.5%) respondents utilized good practices on shade selection, while 79 (39.5%) had poor practices [Figure 2].{Figure 2}

Bivariate analysis of the relationship between sociodemographic characteristics and knowledge of shade selection revealed that respondents had practiced for > 10 years and consultants were significantly more likely to have good knowledge about tooth shade selection (P< 0.05) [Table 5].{Table 5}

Bivariate analysis of the relationship between sociodemographic characteristics and practices about shade selection in [Table 6] revealed that respondents between 31 and 40 years of age, those that had practiced for >10 years, and those working in public hospitals were more likely to have good practices about shade selection even though none of the associations were significant.{Table 6}

[Table 7] shows that poor knowledge about shade selection was significantly associated with poor practices (P = 0.036).{Table 7}

[Table 8] shows the independent predictors of poor practices on shade selection among respondents. Logistic regression analysis revealed that dental surgeons in training (odds ratio [OR] = 0.123; confidence interval [CI] = 0.125, 0.595) and those who had poor knowledge (OR = 0.503; CI = 0.265, 0.970) had significantly poorer practices than other respondents.{Table 8}

 Discussion



To the authors' knowledge, this study is the first to provide a detailed survey on the knowledge and practice of Nigerian dental practitioners about tooth shade selection with regard to composite restoration. The sample was broadly selected and representative of the population of dental surgeons in Nigeria. The highest proportion of the respondents belonged to the 31–40 years age group, were under training, and had been in dental practice for 5–10 years. Majority of them were female.

On the knowledge about shade selection, about half of the respondents felt that the knowledge of the individual observer was the most important variable in dental shade selection. Half of them correctly identified that the cervical third, middle third, and incisal third of the tooth should have the shade determined independently. The perception of tooth color is complex and is influenced by the viewer's visual experience, the quality of light while viewing the tooth and the optical properties of the tooth such as translucency, opacity, scattering of light, and surface gloss.[8] Evaluation of color can be qualitative or quantitative and can be determined instrumentally or visually. The qualitative method involves the visual subjective comparison of the restoration or sample to a shade guide.[2],[27],[28],[29] Evaluating color quantitatively involves an instrumental measurement which consists of valid intraoral optical-electronic determination of the color or shade such as the use of a spectrophotometer,[30] Digital imaging method has also become increasingly relevant in contemporary dentistry.[31],[32] In addition, advanced computerized instruments (CIELab System) offers a precise quantification of color,[2] thus eliminating the subjective visual process variable from the shade selection process,[2] Okubo et al.[33] found that there was no significant difference between the shade matching accuracy of the colorimeter and human observers. In addition, the high cost and limited utility of these instruments prevent their common use in clinical dental practice.[34] However, whether instrumental or visual, for an accurate determination of color, the parameters to be measured must be known.[35]

Close to 40% of the study participants stated that the ideal time for shade selection was within 5–10 s, and majority of them opined that shade selection is best done at the beginning of an appointment and natural light should ideally be used. Wagenaar and Smit[36] have stated that whenever an object such as a tooth is viewed for longer than 10 s, the color vision capability of the eyes decreases rapidly and the perceived color does not remain stable. To overcome any inaccuracies arising from eye fatigue, it has been recommended to get a second opinion including the opinion of the patient whenever shade selection is being made. Shade matching should be determined in daylight or under standardized daylight lamps not the dental operatory lamps. Bright colors must be removed from the field of view and the walls of the operatory must be neutral in color. An important factor necessary good color perception during shade matching is the type and quantity of illumination. Too much light would overwhelm the observer and result in colors appearing higher in value and less chromatic. While on the other hand, low light intensity will cause a decreased perception of value and increased chroma.[37]

Cotton wool rolls and absorbent wafers were most commonly used by the respondents for isolation. The teeth to be matched must be clean before shade selection is carried out. Russell et al.[38] revealed that the teeth become brighter after drying; thus, shade matching procedures should be carried out with the teeth moist before dehydration.

The highest proportion stared at the tooth for 5 s doing shade selection with their eye always at the same level with the patients tooth. The central field of vision is regarded as most color sensitive and color perceptive because there is a large collection of color-sensitive cones in the center of the retina, surrounded by rods which can perceive only. For this reason, it has been recommended to view the patient at the eye level so that the central part of the retina is used in shade selection.

Majority of the respondents had never taken a test for color blindness 146 (73.0%). As esthetic dentistry becomes increasingly popular, dentists are required to ensure that modifications to teeth provide as close a match as possible to a patient's own teeth in terms of size, shape, and color.[39] In a study conducted among Nigerian dental practitioners, the prevalence of color blindness was found to be 6.3% and the prevalence was found to be higher in males (8.4%) than in the females (3.9%) giving a male-to-female ratio of 2.2:1.[40] Dentists have little or no training in vision physiology or color science. Although color perception can be improved with the training in dental procedures,[41] an understanding of how the eye perceives and the brain interprets light as color is important for successful esthetic restorations.[42]

Majority of respondents stated that the upper central incisor was the indicator to determine tooth shade as a representative of individual natural tooth color, while about half stated that the middle third labial surface was the region that best illustrates tooth shade. However, in spite of this, most of the respondents consistently used only one type of shade for restoration. Shade A2 was, however, the most commonly used shade in over 50% of restorations. In clinical dentistry, shade guides are the main tool of color assessment and communication. This, however, is not consistent and can vary within the same clinician as well as among different clinicians.[2] Although acceptable results are provided using contemporary clinical techniques for shade selection,[34],[35],[36] visual shade tabs are still commonly used and its use often depends on several factors such as the color vision acuity of the clinician and ambient lighting. In addition, all ranges of hue, value, and chroma present in the human tooth structure are not covered by all commercially available shade guides.[37],[38] Kim andUm[43] also reported that most shade guides do not accurately depict the true shades of resin composites, as they are often made of acrylic resin. Sidhu et al.[44] suggested that customized shade guides should be made from the composite material itself. Currently, shade guides such as the Vita classic shade guide are still based on the original description of the dimensions of color by Munsell.[1]

Overall, 67.5% of the respondents had good knowledge about shade selection, while 32.5% had poor knowledge. With regard to practice, 60.5% of the respondents utilized good practices on shade selection, while 39.5% had poor practices. Poor knowledge about shade selection was significantly associated with poor practices, while consultants and those that had poor knowledge had significantly poorer practices than other respondents. Capa et al.[45] have already shown that dental care professionals who routinely performed restorative procedures matched the shades better than other dental occupational groups together with laypeople. Research has shown that previous knowledge and experience in dental shade matching has a correlation with the esthetic outcomes of restorations. Some experts have emphasized the need for training, color teaching and experience proving their impact on color matching ability.[45] Research has shown that training programs increase the level of knowledge and shade-matching performance of dental practitioners.[46] Hence, there is a need for continuous retraining of all categories of dental personnel.

 Conclusion



Experienced dentists and restorative consultants appear to have adequate knowledge about shade selection and this had a significant impact on their practice. A need however exists to bridge the gap among other categories of dental personnel to improve the esthetic outcome of composite restorations.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Sproull RC. Color matching in dentistry. 3. Color control. J Prosthet Dent 1974;31:146-54.
2Sachdeva GS, Ballal S, Kandaswamy D. Evaluation of the color matching ability of three light cure composite materials, in variable thickness with their respective shade guides and the standard vitapan shade guide using CIE Lab spectroscopy: Anin vitro study. J Conserv Dent 2007;10:77.
3Nahsan FP, Mondelli RF, Franco EB, Naufel FS, Ueda JK, Schmitt VL, et al. Clinical strategies for esthetic excellence in anterior tooth restorations: Understanding color and composite resin selection. J Appl Oral Sci 2012;20:151-6.
4de Araujo EM Jr., Baratieri LN, Monteiro S Jr., Vieira LC, de Andrada MA. Direct adhesive restoration of anterior teeth: Part 2. Clinical protocol. Pract Proced Aesthet Dent 2003;15:351-7.
5Dietschi D. Optimising aesthetics and facilitating clinical application of free-hand bonding using the 'natural layering concept'. Br Dent J 2008;204:181-5.
6Dietschi D, Ardu S, Krejci I. A new shading concept based on natural tooth color applied to direct composite restorations. Quintessence Int 2006;37:91-102.
7Ozel E, Kazandag MK, Soyman M, Bayirli G. Two-year follow-up of fractured anterior teeth restored with direct composite resin: Report of three cases. Dent Traumatol 2008;24:589-92.
8Joiner A. Tooth colour: A review of the literature. J Dent 2004;32 Suppl 1:3-12.
9Fondriest J. Shade matching in restorative dentistry: The science and strategies. Int J Periodontics Restorative Dent 2003;23:467-79.
10Klemetti E, Matela AM, Haag P, Kononen M. Shade selection performed by novice dental professionals and colorimeter. J Oral Rehabil 2006;33:31-5.
11Dagg H, O'Connell B, Claffey N, Byrne D, Gorman C. The influence of some different factors on the accuracy of shade selection. J Oral Rehabil 2004;31:900-4.
12Ahmad S, Habib SR, Azad AA. Scientific and artistic principles of tooth shade selection: A review. Pak Oral Dent J 2011;31:222-6.
13Jasinevicius TR, Curd FM, Schilling L, Sadan A. Shade-matching abilities of dental laboratory technicians using a commercial light source. J Prosthodont 2009;18:60-3.
14Paravina RD. Critical appraisal. Color in dentistry: Improving the odds of correct shade selection. J Esthet Restor Dent 2009;21:202-8.
15Stevenson B. Current methods of shade matching in dentistry: A review of the supporting literature. Dent Update 2009;36:270-2, 274-6.
16Tin-Oo MM, Saddki N, Hassan N. Factors influencing patient satisfaction with dental appearance and treatments they desire to improve aesthetics. BMC Oral Health 2011;11:6.
17Zlatarić DK, Celebić A. Factors related to patients' general satisfaction with removable partial dentures: A stepwise multiple regression analysis. Int J Prosthodont 2008;21:86-8.
18Zorić EK, Žagar M, Zlatarić DK. Influence of gender on the patient's assessment of restorations on the upper anterior teeth. Acta Stomatol Croat 2014;48:33-41.
19Albashaireh ZS, Alhusein AA, Marashdeh MM. Clinical assessments and patient evaluations of the esthetic quality of maxillary anterior restorations. Int J Prosthodont 2009;22:65-71.
20Prevedello GC, Vieira M, Furuse AY, Correr GM, Gonzaga CC. Esthetic rehabilitation of anterior discolored teeth with lithium disilicate all-ceramic restorations. Gen Dent 2012;60:e274-8.
21Fedorowicz Z, Carter B, de Souza RF, Chaves CA, Nasser M, SequeiraByron P. Single crowns versus conventional fillings for the restoration of root filled teeth. Cochrane Database Syst Rev 2012;16:CD009109.
22Franco EB, Francischone CE, Medina-Valdivia JR, Baseggio W. Reproducing the natural aspects of dental tissues with resin composites in proximoincisal restorations. Quintessence Int 2007;38:505-10.
23Terry DA. Dimensions of color: Creating high-diffusion layers with composite resin. Compend Contin Educ Dent 2003;24:3-13.
24ten Bosch JJ, Coops JC. Tooth color and reflectance as related to light scattering and enamel hardness. J Dent Res 1995;74:374-80.
25Joiner A, Hopkinson I, Deng Y, Westland S. A review of tooth colour and whiteness. J Dent 2008;36 Suppl 1:S2-7.
26Beltrami R, Colombo M, Chiesa M, Bianchi S, Poggio C. Scattering properties of a composite resin: Influence on color perception. Contemp Clin Dent 2014;5:501-6.
27Zhu H, Lei Y, Liao N. Color measurements of 1,944 anterior teeth of people in southwest of China-discreption. Zhonghua Kou Qiang Yi Xue Za Zhi 2001;36:285-8.
28Zhao Y, Zhu J.In vivo color measurement of 410 maxillary anterior teeth. Chin J Dent Res 1998;1:49-51.
29Paul SJ, Peter A, Rodoni L, Pietrobon N. Conventional visual vs. spectrophotometric shade taking for porcelain-fused-to-metal crowns: A clinical comparison. Int J Periodontics Restorative Dent 2004;24:222-31.
30Douglas RD, Steinhauer TJ, Wee AG. Intraoral determination of the tolerance of dentists for perceptibility and acceptability of shade mismatch. J Prosthet Dent 2007;97:200-8.
31Wee AG, Lindsey DT, Kuo S, Johnston WM. Color accuracy of commercial digital cameras for use in dentistry. Dent Mater 2006;22:553-9.
32Hong G, Luo MR, Rhodes PA. A study of digital camera colorimetric characterization based on polynomial modeling. Color Res Appl 2001;26:76-84.
33Okubo SR, Kanawati A, Richards MW, Childress S. Evaluation of visual and instrument shade matching. J Prosthet Dent 1998;80:642-8.
34Cal E, Sonugelen M, Guneri P, Kesercioglu A, Kose T. Application of a digital technique in evaluating the reliability of shade guides. J Oral Rehabil 2004;31:483-91.
35Ayna B, Yılmaz BD, Izol BS, Ayna E, Tacir İH. Effect of different esthetic post-core materials on color of direct-composite restorations: A preliminary clinical study. Med Sci Monit 2018;24:4091-100.
36Wagenaar R, Smit R. Shade taking: Factoring out human error. Dent Lab 2004;29:26-9.
37Anderson CJ, Kugel G. Color Science and Shade Matching in Direct Composite Restorations. Available from: https://cdeworld.com/courses/4353-color-science-and-shade-matching-in-direct-composite-restorations. [Last accessed on 2019 Nov 05].
38Russell MD, Gulfraz M, Moss BW.In vivo measurement of colour changes in natural teeth. J Oral Rehabil 2000;27:786-92.
39Naik AV, Pai RC. Colour blindness in dental students and staff an obstacle in shade selection for restorations. Ann Essences Dent 2010;2:25-8.
40Bamise CT, Esan TA, Akeredolu PA, Oluwatoyin O, Oziegbe EO. Color vision defect and tooth shade selection amongst Nigerian dental practitioners. Rev Clín Pesq Odontol 2007;3:175-82.
41Sorensen JA, Torres TJ. Improved color matching of metal-ceramic restorations. Part I: A systematic method for shade determination. J Prosthet Dent 1987;58:133-9.
42Rosentiel Stephen F, Fujimoto J, Land Martin F. Cotemporary Fixed Prosthodontics. 2nd ed. USA: Mosby; 1995. p. 592.
43Kim HS, Um CM. Color differences between resin composites and shade guides. Quintessence Int 1996;27:559-67.
44Sidhu SK, Ikeda T, Omata Y, Fujita M, Sano H. Change of color and translucency by light curing in resin composites. Oper Dent 2006;31:598-603.
4545. Capa N, Malkondu O, Kazazoglu E, Calikkocaoglu S. Evaluating factors that affect the shade-matching ability of dentists, dental staff members and laypeople. J Am Dent Assoc 2010;141:71-6.
46Alkhudairy R, Tashkandi E. The effectiveness of a shade-matching training program on the dentists' ability to match teeth color. J Esthet Restor Dent 2017;29:E33-43.