In vitro effects of two topical varnish materials and Er:YAG laser irradiation on enamel demineralization around orthodontic brackets

White Spot Lesions in Fixed Orthodontics: A Literature Review on Etiology, Prevention, and Treatment

White spot lesions (WSLs) are a common complication after treatment using fixed orthodontic appliances. Decalcification of enamel surrounding fixed orthodontic appliances, known as WSLs, poses a significant aesthetic difficulty during and after treatment, as the purpose of fixed orthodontic therapy is to improve facial and dental appearance. Modern dentistry utilizes remineralization therapies to non-invasively treat WSLs to prevent the progression of disease and enhance the strength, appearance, and functionality of the affected tooth. This review aims to identify and assess the etiology, formation, and risk factors, as well as current treatment approaches used in achieving WSLs remineralization, induced by fixed orthodontic appliances. An electronic search on the PubMed and ScienceDirect databases was performed using a selected keyword. A total of 172 studies (from 2013 to 2023) were retrieved. Their references were also checked to find other relevant studies. Duplicate copies were excluded. After the abstract and full-text screening, only 39 studies were included. Even though numerous studies address the different treatment modalities for managing post-orthodontic WSLs, such as antiseptics; fluorides such as dentifrices, mouthwash, and varnish, and remineralizing agents such as casein phosphopeptides amorphous calcium phosphate, biomimetic self-assembling peptides, lasers, bleaching, microabrasion, and resin infiltration. There is a lack of evidence-based studies that examine the long-term effects of WSL treatment. Further well-performed controlled clinical trials with long-term follow-up are needed to establish best clinical practice.

Effect of Dental Varnishes in Prevention of Enamel Demineralization Adjacent to Orthodontic Brackets

Aim

The aim of the current research was to assess the ability of different dental varnishes in averting enamel demineralization adjoining the orthodontic brackets.

Materials and Methods

Seventy-five premolars devoid of dental caries that were subjected to extraction for orthodontic purposes were employed in this research. The surface of enamel was etched with 37% phosphoric acid and subjected to primer application. Individual brackets were placed on the midregion of the buccal surfaces of the premolars with Transbond™ XT adhesive. Postbracket bonding, the dry premolar tooth samples were set aside cautiously. The samples were then allocated to three groups: Group I: Duraphat Varnish, Group II: Clinpro XT Varnish, and Group III: Profluorid Varnish. Every sample was independently subjected to immersion in demineralizing solution for a period of 96 h at 37°C in an incubator. Areas of demineralization were evaluated by documenting the microhardness along the severed surface using a microhardness tester equipped with a Vickers diamond.

Results

The highest surface microhardness was noted with Profluorid Varnish group at 328.48 ± 1.12 in pursuit by Clinpro XT Varnish group at 322.08 ± 0.04 as well as Duraphat Varnish group at 307.42 ± 0.28 with a statistically noteworthy dissimilarity amid the groups.

Conclusion

In conclusion, the three varnishes employed had an influence on the prevention of enamel demineralization surrounding the orthodontic brackets. Profluorid varnish however exhibited maximum efficiency in avoiding enamel demineralization versus Clinpro XT varnish as well as Duraphat varnish group.

Combined Effect of Fluoride Mouthwash and Sub-ablative Er:YAG Laser for Prevention of White Spot Lesions around Orthodontic Brackets

Background:

Development of white spot lesions (WSLs) around orthodontic brackets compromises esthetics and necessitates additional dental treatments.

Objectives:

This study aimed to assess the efficacy of fluoride mouthwash combined with Er:YAG laser irradiation for the prevention of WSLs around orthodontic brackets.

Methods:

Orthodontic brackets were bonded to 50 bovine incisors. The entire tooth surface was coated with acid-resistant varnish except for a margin around the brackets. The microhardness of the teeth was measured at the respective area using the Vickers hardness test. The teeth were then randomly divided into five groups (n=10) of control (Gc), Orthokin fluoride mouthwash (Gf), 100 mJ/cm2 Er:YAG laser (Gl), laser + mouthwash (Glf), and mouthwash + laser (Gfl). Then, the teeth underwent pH cycling according to the standard protocol for demineralization. The microhardness of the teeth was measured again, and the percentage of change in microhardness was calculated. The amount of calcium released during pH cycling was quantified using atomic absorption spectroscopy. Data were analyzed using one-way ANOVA and Tukey’s test.

Results:

Calcium release (indicative of demineralization) in the Gf, Gfl, and Glf groups was significantly lower than that in the Gc and Gl groups (P<0.05). The reduction in surface microhardness was also the same in the five groups with no significant difference (P>0.05).

Conclusion:

Fluoride mouthwash combined with Er:YAG laser or Er:YAG laser alone cannot decrease the incidence of WSLs around orthodontic brackets compared to fluoride mouthwash alone.

Effect of sodium fluoride plus tricalcium phosphate with and without CO2 laser on remineralization of white spot lesions

Objectives

The aim of this in vitro study was to evaluate the effect of NaF plus TCP with and without CO₂ laser irradiation on management of demineralized enamel using microhardness test and digital microscopy.

Methods

Eighty intact extracted human premolar teeth were randomly divided into 4 groups (20/each). Each group was subjected to a demineralizing solution to create white spot lesion. Group 1 was treated with 3M Vanish™. Group 2 was irradiated with CO₂ laser. Group 3 was subjected to CO₂ laser followed by 3M Vanish™. Group 4 was treated by 3M Vanish™ then CO₂ laser. The teeth were immersed in artificial saliva. Surface microhardness was measured for each tooth before demineralization at base line (M1 as a control), after demineralization (M2) and after management (M3). Comparison of microhardness values between groups was performed using one way ANOVA test with significant level (0.05) followed by multiple comparisons post-hoc Tukey test between groups. Enamel surface was photographed by digital microscope.

Results

All intervention methods used in the current study significantly increased microhardness values of demineralized enamel (P < 0.001). Little improvement of enamel appearance was observed in all groups meanwhile using CO₂ laser on demineralized enamel directly led to signs of white and black dots affecting the appearance of enamel surface.

Significance

The most effective intervention regarding microhardness was group 2 followed by group 3, group 4 and group 1. Coating the enamel surface with 3M Vanish™ before CO₂ laser irradiation acted as a protective layer from the undesirable effects of laser on the teeth with increasing enamel microhardness values more than using Vanish alone. So the promising intervention method regarding both microhardness and appearance was group 4.

Potential role of Er:YAG laser and fluoride in the dental enamel remineralization: a Raman spectroscopy preliminary <i>ex vivo</i> study

Background and aims: Dental caries are a widespread oral disease and a serious public health problem, starting by teeth demineralization, which is a loss of minerals such as calcium and phosphate. Modern caries treatment is aimed at preventing the disease progression by teeth remineralization which is a supply of minerals to the enamel. The most popular remineralization method is the treatment of teeth with fluoride. Er:YAG laser has also gained research attention as a method for improving the uptake of fluoride and phosphate by introducing chemical and morphological changes into the structure of enamel but, while some researchers described it as effective, others found no significant effect from its application. This work aimed to further study the effect of Er:YAG laser, alone or combined with fluoride, to dental enamel. Materials and Methods: Twenty upper central human incisors, extracted for periodontal reasons, were used in the study. Samples were demineralized by acetic acid and divided into four groups: a) control, b) fluoride + Er:YAG laser, c) Er:YAG laser alone and d) fluoride alone. The remineralization rate of teeth was estimated by Raman Spectroscopy. Results: In comparison with the control group, the phosphate peak’s intensity increased notably for the teeth treated by fluoride, but decreased slightly for the teeth treated with Er:YAG laser and with a combination of the laser and fluoride. Conclusions: With the limits of this study, due to the limited samples number, Er:YAG laser, alone and combined with fluoride, seems to be not effective, at the parameters used, for the enamel remineralization.

The effect of different re-mineralizing agents and diode laser irradiation on the microhardness of primary molar enamel: An in vitro study

Background and Aims

Dental caries is a global concern and different materials and methods were proposed for its prevention.The aim of this study was evaluation of the effect of different demineralizing agents with and without diode laser radiation on the microhardness of primary molars enamel.

Materials and Methods

48 primary molar teeth were used in this study. The enamel blocks were prepared. Primary microhardness values were also measured. All samples were demineralized, then demineralization was approved by a DIAGNOdent pen. The remineralization was done into the buccal and lingual surfaces of the samples as follows:Group 1: CPP-ACP, Group 2: CPP-ACPF, Group 3: MI varnish, Group 4: NaF varnish. The lingual surfaces received diode laser irradiation. Finally, a secondary microhardness test was performed on all samples. Statistical analyses were done and a P-value less than 0.05 was considered to be statistically significant.

Results

A comparison between the primary and the secondary microhardness values showed significant differences (P = 0.003). The highest secondary microhardness values belonged to the MI varnish +laser group.

Conclusion

Application of the agents, containing the combination of Ca, P, and F, was significantly better than others in increasing the microhardness of the enamel. Although the application of diode laser increased the hardness of the enamel.

Laser-assisted prevention of enamel caries: a 10-year review of the literature

Since the invention of lasers in dentistry, investigations in caries prevention by the use of laser radiation have been proposed. There are several mechanisms stated for this purpose such as photothermal and/or photochemical interaction processes with the enamel. Alone or in conjugation with topical fluoride application, this treatment modality may improve enamel acid resistance in high-caries-risk populations. Data collection was done by searching the keywords caries, prevention, and laser in PubMed, Embase, Web of Science, Cochrane Library, and Google Scholar. Lasing protocols of the collected literature and their effectiveness as well as examination methods used to verify treatment outcomes have been evaluated. One hundred eighteen publications were found for the last 10 years. The wavelengths investigated for caries prevention are mainly located in the near and the mid-infrared spectral range. In the evaluated period of time, investigations using CO₂; Er:YAG; Er,Cr:YSGG; Er:YLF; fundamental, second, and third harmonic generations of Nd:YAG; diodes; and argon ion lasers were found in the databases. Accounting for 39% of the literature, CO₂ laser was the most examined system for this purpose. Reviewing the literature in this narrative review showed that all laser systems presented a positive effect in varying degrees. Laser irradiation could be an alternative or synergistic to topical fluoridation for enamel caries prevention with longer lasting effect. Further research should be focused on selecting proper laser settings to avoid damage to enamel and developing effective evidence-based clinical protocols.

Decalcification prevention around orthodontic brackets bonded to bleached enamel using different topical agents

BACKGROUND

The present study was conducted to evaluate the effect of different topical agents utilized for prevention of enamel decalcification around orthodontic brackets bonded to bleached and non-bleached enamel.

METHODS

Human maxillary premolars (n = 120) were divided into two equal groups. Teeth in group I were left without bleaching while those in group II were bleached with Vivastyle gel. Metal brackets were bonded to all the teeth using light-cured adhesive. Each group was divided into six equal subgroups (A, B, C, D, E, and F). In subgroup A, no material was applied (control). In subgroups B, C, D, E, and F, the following materials were applied respectively: Profluorid varnish, Enamel Pro Varnish, Ortho-Choice Ortho-Coat, GC Tooth Mousse, and GC MI Paste Plus. All teeth were cycled in a demineralization solution/artificial saliva for 15 days. Laser fluorescence was used to measure the level of enamel mineralization. The data were statistically analyzed.

RESULTS

Regarding the non-bleaching subgroups, all studied material revealed significant demineralization reduction in comparison to the control subgroup (P < 0.05). Ortho-Choice Ortho-Coat revealed the highest significant effect while GC Tooth Mousse showed the least effect. In bleached subgroups, Profluorid varnish, Enamel Pro Varnish, and Ortho-Choice Ortho-Coat significantly reduced demineralization (P < 0.05) while either GC MI Paste Plus or GC Tooth Mousse had no significant effects (P > 0.05).

CONCLUSIONS

Ortho-Choice Ortho-Coat, and Profluorid and Enamel Pro varnishes could be utilized successfully to reduce enamel demineralization around brackets bonded to either bleached or non-bleached enamel. GC MI Paste Plus and GC Tooth Mousse were effective only in non-bleached enamel.