Effects of toothpastes on white spot lesions around orthodontic brackets using quantitative light-induced fluorescence (QLF) : An in vitro study

In-vitro and in-vivo comparative studies of treatment effects on enamel demineralization during orthodontic therapy: implications for clinical early-intervention strategy

OBJECTIVES

This study aimed to investigate if CPP-ACP / infiltrating resin was superior in treating enamel demineralization during orthodontic therapy compared with fluoride varnish, in order to provide early-intervention implications for dental professionals.

MATERIALS AND METHODS

In the in-vitro study, premolars were grouped into four: remineralization with fluoride varnish / CPP-ACP, sealing with infiltrating resin, and negative control. Experimental demineralization of enamel surfaces was analyzed using techniques of QLF, SEM, EDS and micro-hardness testing. An in-vivo intervention study was conducted on patients randomly assigned into three groups. At the baseline and every-3-month follow-up, QLF parameters were compared temporally and parallelly to yield potential implications for promotion in clinical practice.

RESULTS

The in-vitro study performed on 48 experimental tooth surfaces demonstrated that sealing with infiltrating resin reduced enamel surface porosity and increased surface micro-hardness significantly. In the in-vivo intervention study on 163 tooth surfaces, it was suggested that for those who meet the criteria of -10 < ΔF < -6 and - 1000 < ΔQ < -20 at the baseline, all these treatment methods could achieve acceptable outcomes; with the rising of absolute values of ΔF and ΔQ, sealing with infiltrating resin showed more evident advantages.

CONCLUSION

For enamel demineralization during orthodontic therapy, all the treatment methods involved in this study showed acceptable effectiveness but had respective characteristics in treatment effects. QLF parameters could be used as indicators for clinical early-intervention strategy with regards to this clinical issue.

CLINICAL RELEVANCE

With QLF parameters, clinical early-intervention strategy for enamel demineralization during orthodontic therapy could be optimized.

Comparison of therapies of white spot lesions: a systematic review and network meta-analysis

OBJECTIVE

White spot lesions (WSLs), the earliest evidence of enamel demineralization, are considered amenable to intervention to achieve a remineralized or arrested state of caries. The management of WSLs is quite challenging, and there is no definitive cure as yet. We performed a network meta-analysis to assess the efficacy of seven therapies for WSLs and gave a hierarchy of them.

MATERIALS AND METHODS

We systematically searched the PubMed, EMBASE, Cochrane, and Web of Science databases (last search: July 2022) to identify all relevant studies. We limited our search to studies published in English. Randomized controlled designed in vitro/clinical trials related to the efficacy of the seven therapies for WSLs were included. Data extraction was performed independently by two reviewers. The risk of bias (ROB) 2.0 tool from Cochrane and a previous in vitro methodological tool will be used for the quality assessment. Variations in quantitative light-induced fluorescence (QLF), laser fluorescence (LF), and lesions area were the primary outcome measures. Standard mean difference (SMD) was used as the effect size for the Network meta-analysis (NMA). Consistency and inconsistency tests were conducted. The hierarchy of 7 treatment effects was evaluated using surface probabilities under cumulative ranking (SUCRA). Publication bias was evaluated using a bias plot.

RESULTS

Forty-two articles were included in the systematic review. Thirty-one of them, with a total of 1906 participants, were included in the network meta-analysis. The studies owned a low and moderate risk of bias. This analysis does not suffer from significant inconsistency. The difference between 4 groups 'self-assembled peptide (SAP) P11-4', 'P11-4 + Fluoride Varnish (FV)', 'Resin Infiltration (RI)', 'casein phosphor peptides-amorphous calcium fluoride phosphate (CPP-ACFP)' and the 'Control' group was found to be statistically significant. Compared to the 'FV' and 'casein phosphor peptides-amorphous calcium phosphate (CPP-ACP)' groups, the 'P11-4 + FV" group and 'RI" group made a significant difference. The hierarchy was evident in the SUCRA values of 7 therapies. P11-4 + FV and RI were considered effective therapies compared to the control group or the FV group (gold standard group).

CONCLUSIONS

The available evidence suggests that resin infiltration and P11-4 in combination with fluoride varnish had advantages over gold standard (FV). The effect of tricalcium phosphate-based drugs and fluoride is not very noticeable. Overall, drugs based on P11-4 and resin infiltration will be better therapies. Using more than two drugs in combination also would increase efficacy.

Streptococcus mutans levels in patients who received orthodontic brackets bonded using probiotic impregnated resin composite - a randomized clinical trial

To evaluate the effect of impregnating an orthodontic resin composite with probiotic bacteria (Lactobacillus rhamnosus GG) on the levels of Streptococcus mutans (S. mutans) in patients undergoing orthodontic treatment. Thirty patients were randomly selected and allotted by block randomization to two groups: an experimental group, who received brackets bonded with probiotic impregnated resin composite and a control group, who received brackets bonded with conventional light cure resin composite. Plaque samples were collected before (ET0 and CT0) and two months (ET1 and CT1) after bonding. Levels of S. mutans were assessed using the colony count method. Two months after bonding of the brackets, the S. mutans levels had decreased with statistical significance in the experimental group (p = 0.001), but not in the control group (p = 0.137). Impregnation of resin composite with probiotic bacteria for the purpose of preventing formation of white spot lesions on enamel holds promise. Long-term evaluation would be necessary to provide confirmatory results.

Effectiveness of fluoride-containing toothpastes associated with different technologies to remineralize enamel after pH cycling: an in vitro study

BACKGROUND

To evaluate the efficacy of fluoride-containing toothpastes with different technologies to remineralize artificial caries lesions in enamel.

METHODS

Bovine enamel blocks were divided into three thirds: intact (untreated), demineralized (artificial caries lesion), and treated (caries lesion, pH cycling with dentifrices). Enamel blocks were randomly distributed into five groups (n = 12): Fluoride-free toothpaste, Colgate Oral Care (NC); Arginine-containing toothpaste, Colgate Total Daily Repair (PC); Silicate-based fluoride toothpaste: REFIX technology, regenerador + sensitive (RDC), NR-5 technology, Regenerate Enamel Science (RES), and NOVAMIN technology, Sensodyne Repair and Protect (SRP). The specimens were submitted to a pH cycling model for 6 days. The efficacy of the toothpastes was estimated by calculating the surface microhardness recovery (%SMHR) and the fluorescence recovery (ΔFRE) with quantitative light-induced fluorescence. The cross-sectional micromorphology of the enamel surface was also assessed using scanning electron microscopy. Elemental analyses (weight%) were determined with an energy-dispersive X-ray spectrometer (EDS). The results were compared to that of the control (NC). Data were statistically analyzed (5%).

RESULTS

%SMHR could be ranked as follows: RDC = PC = RES = SRP > NC. Significantly higher %SMHR and ΔFRE means were observed after enamel treatment with RDC (22.7 and 46.9, respectively). PC (%SMHR = 18.8) was as efficacious as RDC to recover the surface microhardness with a significantly lower mean of ΔFRE (19.5). Only RDC was able to promote the formation of a mineralized layer on the surface of enamel enriched with silicon on the surface.

CONCLUSIONS

The silicate-based fluoride toothpaste containing REFIX technology demonstrated greater efficacy in the remineralizing artificial caries than the other products.

Correlation of quantitative light-induced fluorescence and qualitative visual rating in infiltrated post-orthodontic white spot lesions

OBJECTIVES

The aim of this prospective, clinical single-centre study was to evaluate the masking efficacy of post-orthodontic resin infiltration after 12-month follow-up and correlate quantitative and qualitative outcome measures.

METHODS

Patients with completed fixed orthodontic treatment and the presence of one or more vestibular active non-cavitated white spot lesion/s (WSL) [ICDAS 1 or 2 (International Caries Detection and Assessment System)] were provided with resin infiltration 3-12 months after bracket removal. All patients (n = 31) participating before (t0) intervention were invited again and examined after 12 months (t2). Enamel demineralization was scored using quantitative light-induced fluorescence [QLF (DeltaF[flourescence], DeltaQ[lesion volume], White Spot Area)] and qualitative visual rating [11-point Likert-scale from 0 (no lesions visible on any tooth) to 10 (all teeth affected on the entire vestibular surface)].

RESULTS

In 17 patients (7 female and 10 male) 112 WSL (ICDAS 1: n = 1; ICDAS 2: n = 111) in 112 teeth were (re)examined. Before treatment (t0) a significant, weak (DeltaF), and moderate (DeltaQ, White Spot Area) correlation was observed between the quantitative and the qualitative rating (P < 0.002) [median DeltaF: -7.31 (-10.4/-6.58)%; DeltaQ:-2.25 (-10.8/-0.41)% mm2; White Spot Area: 0.34 (0.05/1.16) mm2; visual rating:3.7 ± 1.2]. Resin infiltration led to significantly increased fluorescence and decreased visual scores (P < 0.001) 7 days (t1) and 12 months (t2) after treatment. No significant changes based on DeltaF [-6.55 (-7.29/-6.08)%] and on visual ratings [1.0 ± 1.0] were observed between t1 and t2 (P = 1.000). After 7 days (t1) the correlation between the quantitative and the qualitative ratings remained significant, weak to moderate (P < 0.002). After 12 months (t2) the correlation was (non-)significant and weak for DeltaF, DeltaQ, and White Spot Area (P ≤ 0.097).

LIMITATIONS

Since the overall masking efficacy of resin infiltration has been shown previously, an untreated control group was omitted.

CONCLUSIONS

When assessing the masking efficacy of infiltrated post-orthodontic WSL only a weak to moderate correlation was found between QLF values and visual ratings. Furthermore, over time this correlation decreased. Thus, it remains unclear if QLF is a viable method to assess and quantify infiltrated post-orthodontic WSL over time.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS-ID:DRKS00005067).

Remineralisation capability of silver diamine fluoride in artificial enamel lesions on smooth surfaces using quantitative light-induced fluorescence measurements in-vitro

Enamel demineralisation can develop on smooth surfaces as an undesirable side effect during orthodontic treatment with fixed appliances. This study aimed to evaluate the ability of 38% silver diamine fluoride in remineralisation (as estimated by fluorescence gain) of artificial initial lesions in smooth surfaces of human enamel. The smooth surfaces of 50 human tooth samples were artificially demineralised and 45 samples were allocated randomly into three groups receiving a single treatment with a varnish: group I: Riva Star (silver diamine fluoride, SDF), group II: Bifluorid 12 (NaF, CaF₂), and group III: Cervitec F (CHX, CPC, NH₄F). Five samples were assigned as a negative control group without treatment. All samples were exposed to pH-cycling for 28 days. Fluorescence behavior was measured using Quantitative light-induced fluorescence before and after demineralisation and up to four weeks on a weekly basis. Analysis of variance (ANOVA) with Tukey–Kramer post-hoc tests and repeated measures ANOVA were used for statistical evaluation (α = 0.05). After demineralisation, all samples showed mean ΔF of − 16.22% ± 4.35, without significance differences between the fluorescence behaviour of the samples (p = 0.251). After 28 days group comparison showed a statistically significant difference (p = 0.034) for ΔF values: the lowest fluorescence values were found in group I (SDF, mean ΔF − 16.47 ± 6.08) with a significant difference compared to group III (Cervitec F, mean ΔF − 11.71 ± 4.83). In group II (Bifluorid 12) mean ΔF value was − 15.55 ± 2.15) without statistically significant differences to groups I and III. The fluorescence behaviour of SDF varnish on smooth surfaces with artificial initial enamel lesions was significantly lower compared to Cervitec F varnish after short time use.

Use of bioluminescence measurements for detection of artificial demineralization adjacent to orthodontic brackets

PURPOSE

Enamel demineralization can occur as a side effect during orthodontic treatment with fixed appliances and should be detected as early as possible. A new approach to assess demineralization is a system consisting of a photosensitive protein that binds to free calcium ions at the enamel surface. A camera is then used to visualize the bioluminescence spots. This in vitro study aimed to evaluate the ability of the bioluminescence technology to assess artificially demineralized enamel adjacent to various orthodontic brackets.

METHODS

In all, 108 human enamel samples were allocated randomly to groups with different orthodontic bracket material: stainless steel, titanium, ceramic. Initial lesions were created adjacent to the brackets. The samples were assessed by bioluminescence before and after demineralization. Images were assessed for presence of bioluminescence spots (yes/no). To quantify the bioluminescence measurements, the images' pixel values (P) were calculated within a defined area (F) adjacent to each bracket before and after demineralization. Quantitative light-induced fluorescence measurements (ΔF, ΔQ) were performed as the reference standard for demineralization.

RESULTS

After demineralization, bioluminescence spots were visible (yes/no decision) in 87% of the samples. The pixel analysis of the bioluminescence spots showed significantly higher pixel values after demineralization compared to baseline (p < 0.0001). The bracket material had no influence on the bioluminescence measurements. All samples showed fluorescence loss with a median ΔF of -9.52% (±3.15) and a median ΔQ of -1.01% × mm² (±3.34), respectively.

CONCLUSION

The bioluminescence technology is a promising tool to demonstrate demineralization adjacent to different orthodontic brackets in vitro.

Prevention of non-cavitated lesions with fluoride and xylitol varnishes during orthodontic treatment: a randomized clinical trial

OBJECTIVE

Fixed orthodontic appliances impair oral hygiene increasing the risk of non-cavitated lesions (NCLs) and tooth decay. The aim of this study was to compare the outcomes of fluoride and xylitol varnishes in preventing NCLs during comprehensive orthodontic treatment.

MATERIALS AND METHODS

The sample comprised 55 volunteers from 15 to 20 years of age under orthodontic treatment that were randomly divided into three groups: Fluoride Group (FG; n=17), Xylitol Group (XG; n=19), and Placebo Group (PG; n=19). The patients in each group received two applications of the following varnishes: Duraphat^TM (5% NaF), 20% xylitol, and placebo (no F/Xylitol) in the three groups, respectively. The varnishes were applied in the first appointment (T0) and 3 months later (T1). Clinical examinations were carried out at T0 and 6 months after (T2) using the ICDAS index and the QLF system (fluorescence difference). The intergroup comparisons were performed by ANOVA/Tukey's or Kruskal-Wallis/Dunn's tests (P<0.05).

RESULTS

There was no significant intergroup difference regarding ICDAS index changes from T0 to T2. Fluoride varnish produced significantly greater increase in fluorescence of NCLs (mean change of -0.65 +0.78 and -0.56 +0.83, for maxilla and mandible, respectively) in comparison to the other groups. The majority of non-cavitated lesions improved in the fluoride and xylitol varnish groups.

CONCLUSIONS

Fluoride varnish produced significantly greater increase in enamel fluorescence compared to xylitol and placebo varnishes. In short term, both fluoride and xylitol varnishes produced remineralization of NCLs in orthodontic patients.

CLINICAL RELEVANCE

Non-cavitated lesions can be effectively controlled in high-risk orthodontic patients by means of fluoride varnishes.

CLINICAL TRIAL REGISTRATION

ReBEC Identifier: RBR-6mdxfq; Date of Register: March 19th, 2020. Retrospectively Registered.

Impact of self-assembling peptides in remineralisation of artificial early enamel lesions adjacent to orthodontic brackets

Enamel demineralisation can occur as a side effect during orthodontic treatment with fixed appliances. This study aimed to evaluate the efficacy of the self-assembling peptide P11-4 for remineralisation combined with fluorides, compared to application of fluoride varnish alone. De- and remineralisation was assessed by Quantitative light-induced fluorescence (QLF). Orthodontic brackets were bonded on 108 human enamel samples and white spot lesions were created. The samples were allocated randomly into three groups: Group I received no treatment, group II had a single application of fluoride varnish (22,600 ppm), and group III was treated with P11-4 following a single application of fluoride varnish. Quantitative light-induced fluorescence (QLF) measurements were performed at baseline, after demineralisation and after storage in remineralisation solution for 7 and 30 days. Non-parametric tests (Kruskal-Wallis test and Friedman test) were used for further analysis. After demineralisation, all samples showed a median ΔF -9.38% ± 2.79. After 30 days median ΔF values were as followed: group I = -9.04% ± 2.51, group II = -7.89 ± 2.07, group III = -6.08% ± 2.79). The median ΔF values differed significantly between all groups at all investigation times (p < 0.00001). Application of P11-4 with fluoride varnish was superior to the use of fluorides alone for remineralisation of enamel adjacent to brackets.

Current treatment modalities of orthodontically induced white spot lesions and their outcome - a literature review

Introduction

White spot lesion is a demineralization of the enamel that appears as a white spot on the surfaces of the tooth. The cause of this spot is determined by the activity of the bacterial plaque and it represents the initial stage of a carious lesion. This lesion is a common side effect for patients with fixed orthodontic appliances mainly because of the brackets' position that favors the accumulation of plaque that ultimately leads to the formation of the white spot.

Methods

We conducted a search on a single database, PubMed. "Orthodontic", "white spot lesions", "enamel demineralization treatment" and "remineralization" were the search terms used. We found 324 articles, but we took in consideration only the ones from the last 10 years, which resulted in 223 articles.

Results

The first step after research was article selection: first by scrutinizing the title and secondly by reviewing the abstracts or full texts. The exclusion criteria were: meta-analysis, reviews, original articles regarding prevention of white spot lesions and their prevalence or incidence. We included the articles that seemed relevant for the treatment of white spot lesions, made either on extracted teeth either on orthodontic patients. We found 75 articles to be eligible for this research and we eliminated 5 because of the lack of an abstract or full text and a further 22 were rejected because they did not fit the aforementioned criteria.

Conclusion

Although some traditional methods for the treatment of white spot lesions seem to have undesirable results, nowadays with new technologies and thorough investigations in nanotechnology, the eradication of the lesion appears to be short term.