Shade matching in restorative dentistry: the science and strategies

Comparative evaluation on the masking ability of different tooth colored restoration over blackish discoloration caused by 38% silver diamine fluoride: an in -vitro study

BACKGROUND

The application of Silver diamine fluoride is an effective approach in controlling dental caries. But the black discoloration caused by its application is unaesthetic and is of greater concern to the parents.

AIM

To assess the potential color masking ability of tooth colored restorative material over discoloration caused by 38% SDF using a UV‒VIS-NIR spectrophotometer.

MATERIAL AND METHODS

20 extracted teeth were taken and randomly divided into 4 groups: Group A: 38% SDF + GIC; Group B: 38% SDF + RMGIC; Group C: 38% SDF+ Composite; Group D: 38% SDF+ Cention N. Two readings were recorded, one on application of 38% SDF and second after application of test materials using a UV‒VIS-NIR spectrophotometer.

RESULT

The intragroup comparison for color masking ability (ΔE) for all four restorative materials revealed no statistically significant differences, with a test value of 1.168 and a p value of 0.353, and the highest mean was observed in Group A, i.e., 38% SDF + GIC (9.171966) Significant differences in color were observed, with more shifts toward yellow in group A (2.488 ± 2.957) and group D (1.686 ± 0.559) and more shifts toward green in groups B (-0.088 ± 0.34) and C (-0.062 ± 0.5). The mean lightness was greatest for Group C, i.e., the composite group (86.396 ± 3.741), and least for Group A, i.e., the GIC group (76.664 ± 8.213).

CONCLUSION

All 4 restorative materials were equally effective in terms of color masking over 38% SDF discoloration.

Visual evaluation of the color adjustment of single-shade and group shade resin composites in restorations with different cavity configurations

OBJECTIVE

To evaluate the influence of the tooth shade, type of resin composite and cavity configuration on the color adjustment of single-shade and group shade resin composites.

METHODS

Class I and V cavities were prepared in artificial acrylic mandibular right molars with different shades - A1, A2, A3, A3.5 and A4. Three single-shade (OMN, UNI, CHA) and two group shade (FIL, HAR) resin composites were evaluated. Seventy-five observers, including dentists, dental students and laypersons (n = 25), participated in the study. A psychophysical experiment based on visual assessments of the color matching between each tooth and each restoration was ranked from 0 (excellent match) to 4 (huge mismatch), and mean frequencies (%) were calculated. Visual color differences among composite materials and tooth shades were statistically tested (P < 0.05).

RESULTS

The results showed highest percentages of unacceptable color mismatches for class V compared to class I restorations, especially for more chromatic tooth shades (A3.5 and A4). The percentage of ratings of acceptability was higher for laypersons group. For class V, OMN presented significant difference only from UNI in tooth shades A1, A2, A3 and A4. However, for class I, OMN presented significant differences with CHA for A1, A2 and A4, and with HAR and FIL for A1.

CONCLUSIONS

Class I resin composite restorations exhibit superior color matching than Class V, with lighter and low chroma tooth shades demonstrating better color adjustment. The color matching of both cavity configurations is comparable for single and group shade resin composites.

CLINICAL SIGNIFICANCE

Cavity configuration and tooth shade may impact color matching of single and group shade resin composites. This study demonstrates superior color matching in class I configurations over class V for both single and group shade resin composites. Additionally, restorations placed in teeth with lighter shades exhibit more favorable color adjustment.

Changes in the Color and Brightness of White Spots Associated with Orthodontic Treatment 6 Months after the Application of Infiltrative Resins: Systematic Review and Meta-Analysis

One of the risks that we find after orthodontic treatment is the secondary appearance of white spot lesions (WLS) after the removal of fixed multi-bracket appliances. Today, there are several treatment methods, resin infiltration being the most used in the most serious cases. The objective of this study is to carry out a systematic review and meta-analysis to determine the efficacy and stability in the variables of color and gloss, six months after resin infiltration. A comprehensive search was performed in the following databases: PubMed, Embase, Google Scholar, Scopus, Medline, and Web of Science. Articles published in the last 10 years were selected, including in vivo studies with a six-month follow-up. PRISMA guidelines were followed to carry out this systematic review. All studies where the application of resin was performed on carious lesions were discarded. Once the inclusion and exclusion criteria were applied, a final sample of four articles was obtained, on which the review and meta-analysis were carried out. Once examined, all authors considered that there was an immediate improvement in both variables. However, statistically significant differences were obtained in the color change outcome, but not in the brightness outcome in the subgroup analysis after six months of icon resin infiltration.

An Overview of Shade Selection in Clinical Dentistry

The selection of an accurate tooth shade has always been a challenging task for dental practitioners in restoring the natural appearance of teeth. Various factors can influence shade selection, such as different lighting conditions, clearness and opaqueness of teeth, eye fatigue, aging and color vision problems. It is imperative to have a sound knowledge about the concept of shades and its selection protocol for obtaining good esthetics outcomes. To attain the best esthetics, four elementary contributing factors are essential: exact position, shape, surface texture and shade. The current analysis focuses on several features of shade, sensitivity of shades, optical properties of the teeth, visual and innovative instrumental techniques for shade selection, protocols for shade selection and factors affecting dental shade selection.

Development of a novel dental shade determination application

Determining the shade of dental materials is a challenging requirement for the restorative dentist. Improper shade selection is the second cause for laboratory remakes, resulting in inefficiency and additional cost, and unnecessary stress for the clinician and patient. The process of shade selection is somewhat subjective, with no consensus on the protocol. This research investigation aimed to develop a novel software application to provide an accurate, objective, and systematic approach to shade determination for teeth, soft tissues, and dental materials. An IOS software application was developed, termed Smile Shade, to facilitate a simple approach for dental shade determination. Smile Shade functions on a high-dynamic-range microcolor sensor with automatic temperature control and inter-device repeatability of <1.0 ∆E. The determination of shade is completed through the evaluation of color based on CMYK, RGB, and LAB, which are different techniques of storing colors. Further research is underway to compare this novel application to the traditional shade tab approach commonly practiced at most dental schools.