Streptococcus mutans counts in plaque adjacent to orthodontic brackets bonded with resin-modified glass ionomer cement or resin-based composite

Effect of calcium fluoride nanoparticles in prevention of demineralization during orthodontic fixed appliance treatment: a randomized clinical trial

BACKGROUND

White spot lesions (WSLs) are the most common complications of fixed appliance orthodontic treatment.

OBJECTIVES

To evaluate the effectiveness of calcium fluoride nanoparticles-containing orthodontic primer (nCaF2-primer) in preventing the incidence of WSLs during orthodontic treatment.

TRIAL DESIGN

Single-centre, double-blinded, split-mouth, randomized clinical trial.

METHODS

The sample involved 31 orthodontic patients (≥12 years). Participants were recruited using a simple nonstratified randomization. Data collection, measurements, and analysis were performed blindly. Outcome measures included comparing the effect of nCaF2-primer with control primer (Transbond) regarding the degree of demineralization (DIAGNOdent pen), Streptococcus mutans (S. mutans) bacterial counting [real-time polymerase chain reaction device (PCR)], and WSLs incidence (pre- and post-operative photographs). The measurements were performed before bonding, 1, 3, and 6 months after bonding and after appliance removal. A two-way repeated measure analysis of variance test (for DIAGNOdent pen scores), and Wilcoxon signed-rank test (for the difference between bacterial counting and WSLs incidence) were used (P < 0.05).

RESULTS

Thirty-one patients were recruited and randomized (mean age 17.9 ± 2.45 years). For the primary outcome (DIAGNOdent pen scores) and secondary outcome of S. mutans counting: 31 patients (310 teeth for each group) were included in scoring at T1 and T3, and 30 patients (300 teeth) were included at T6. While for the photographic scores, 26 patients were included after bracket bonding. The demineralization scores showed significant differences at all-time intervals within the 6 months after bracket bonding which was more noticeable after the first month. There was a significant difference in bacterial count between the two primer groups at the T1 only. Regarding photographic scores, there were no significant differences in the WSLs incidence between the two primers groups after brackets removal. No harm was detected during treatment, except the usual pain/gingival irritation.

CONCLUSIONS

nCaF2-primer effectively decreased demineralization scores within the 6 months after bracket bonding. Moreover, it significantly reduced S. mutans colonization after the first month. However, the tested primer did not have an extra advantage in preventing WSLs development at the clinical level after appliance removal.

TRIAL REGISTRATION

The trial was registered with ClinicalTrials.gov on 8 May 2021 (registration number: NCT04994314).

Prevention of white spot lesions around orthodontic brackets using organoselenium-containing antimicrobial enamel surface sealant

Objectives

To investigate the antimicrobial potential of organo-selenium compound when applied as enamel surface sealant or primer (DenteShield™ [DS]) around orthodontic brackets to prevent enamel demineralization.

Methods

Human teeth were randomly assigned to seven treatment groups (15/group): control (No primer or sealant), Leopard light primer (LLP), DS Primer (DS-P), DS Enamel Surface Sealant (DS-S), Pro Seal, Opal Seal and combined DS-P/DS-S (DS-PS). Following etching, the tooth surface was coated with their respective material (except control group) and a bracket was bonded on each treated surface. All samples were subject to cariogenic challenge in a continuous flow microbial caries model at 37 °C in an incubator for 28 days. Demineralization was evaluated with Transerse microradiography to determine mineral loss (Δz) and lesion depth (LD). Data was statistically analyzed using Bonferroni protected Mann-Whitney tests (α = 0.05).

Results

Demineralization was obsessrved only in Control and LLP groups. Control group had significantly (p < 0.001) greater mean LD (109.47 ± 34.22 μm) and mean Δz (2251.07 ± 514.26 vol%μm) when compared with the LLP with mean LD (44.98 ± 11.69 μm) and Δz (700.67 ± 310.66 vol%μm). All other groups did not develop any lesions.

Conclusions

Selenium-based primer and sealant used alone or in combination were effective in protecting enamel from demineralization around brackets. The combination of primer and enamel surface sealant has no added benefit.

Significance

DS-S and DS-P containing antimicrobial organo-selenium compound can prevent whitespot lesions development when applied on tooth surface during orthodontic treatment. Light primer applied alone on tooth surface may not provide adequate protection for the enamel around orthodontic appliances.

Self-ligating versus conventional metallic brackets on Streptococcus mutans retention: A systematic review

Objective:

The present study aimed to review the literature systematically and assess comparatively whether self-ligating metallic brackets accumulate less Streptococcus mutans biofilm than conventional metallic brackets.

Material and methods:

The systematic search was performed following PRISMA guidelines and registration in PROSPERO. Seven electronic databases (Google Scholar, LILACS, Open Grey, PubMed, SciELO, ScienceDirect, and Scopus) were consulted until April 2016, with no restriction of language and time of publication. Only randomized clinical studies verifying S. mutans colonization in metallic brackets (self-ligating and conventional) were included. All steps were performed independently by two operators.

Results:

The search resulted in 546 records obtained from the electronic databases. Additionally, 216 references obtained from the manual search of eligible articles were assessed. Finally, a total of 5 studies were included in the qualitative synthesis. In 1 study, the total bacterial count was not different among self-ligating and conventional brackets, whereas in 2 studies the amount was lower for self-ligating brackets. Regarding the specific count of S. mutans, 2 studies showed less accumulation in self-ligating than in conventional brackets.

Conclusion:

Based on the limited evidence, self-ligating metallic brackets accumulate less S. mutans than conventional ones. However, these findings must be interpreted in conjunction with particularities individual for each patient – such as hygiene and dietary habits, which are components of the multifactorial environment that enables S. Mutans to proliferate and keep retained in the oral cavity.

Do Products Preventing Demineralization Around Orthodontic Brackets Affect Adhesive Bond Strength?

Objective:

This study investigated the effects, on the shear bond strength of orthodontic brackets, of using an antimicrobial selenium-containing sealant (DenteShieldTM) to serve dual functions of priming enamel prior to bonding and as a protective barrier against whitespot lesion formation.

Materials and Methods:

A total of 150 extracted human premolars were randomly assigned into 10 groups (n=15/group). Stainless steel brackets were bonded with two adhesive systems (DenteShieldTM or Transbond XT) after the enamel was conditioned with a primer (DenteShieldTM or Assure Universal) or a filled resin sealant (DenteShieldTM, Pro SealTM or Opal SealTM). The specimens were stored in deionized water at 37 °C for 24 hours and debonded with a universal testing machine.

Results:

The use of DenteShieldTM adhesive to bond orthodontic brackets to the enamel surface resulted in a significantly lower (P<0.05), but clinically acceptable, shear bond strength (mean & SD: 14.5±1.6 MPa) as compared with Transbond XT group (mean & SD: 19.3±1.7 MPa). DenteShieldTM sealant used as primer resulted in shear bond strength values comparable to those of Pro SealTM and Opal SealTM. All adhesive-sealant and primer-sealant combinations tested in this study exhibited shear bond strength values greater than 9.6 MPa, sufficient for clinical orthodontic needs.

Conclusion:

DenteShieldTM sealant can serve as primer as well as anti-demineralization sealant during orthodontic treatment without adversely affecting the shear bond strength of the bracket.

Influence of resin-modified glass ionomer and topical fluoride on levels of Streptococcus mutans in saliva and biofilm adjacent to metallic brackets

Decalcification of enamel during fixed orthodontic appliance treatment remains a problem. White spot lesions are observed in nearly 50% of patients undergoing orthodontic treatment. The use of fluoride-containing orthodontic materials has shown inconclusive results on their ability to reduce decalcification. The aims of this investigation were to compare the levels of Streptococcus mutans (SM) in saliva and biofilm adjacent to orthodontic brackets retained with a resin-modified glass ionomer cement (RMGIC) (Fuji ORTHO LC) and a light cured composite resin (Transbond XT), and to analyze the influence of topical application of the 1.23% acidulated phosphate fluoride (APF) on SM counts. In a parallel study design, two groups (n=14/15) were used with random allocation and high salivary SM counts before treatment. Biofilm was collected from areas adjacent to the brackets on teeth 13, 22, 33, and 41. Both saliva and biofilm were collected on the 7th, 21st, 35th, and 49th days after appliance placement. Topical fluoride application was carried out on the 35th day. Bonding with RMGIC did not alter SM counts in saliva or biofilm adjacent to the brackets. On the other hand, the biofilm adjacent to brackets retained with composite resin showed a significant increase in SM counts along the trial period. Topical application of 1.23% APF did not reduce salivary or biofilm SM counts regardless of the bonding material. In conclusion, fluoride topical application did not show efficacy in reducing SM. The use of RMGIC as bonding materials allowed a better control of SM cfu counts in dental biofilm hindering the significant increase of these microorganisms along the trial period, which was observed in the biofilm adjacent to the composite material.

Prevention and Treatment of White Spot Lesions in Orthodontic Patients

Decalcification of enamel, appearing as white spot lesions (WSLs), around fixed orthodontic appliances is a major challenge during and after fixed orthodontic treatment by considering the fact that the goal of orthodontic treatment is to enhance facial and dental esthetic appearance. Banded or bonded teeth exhibit a significantly higher rate of WSLs compared to the controls with no braces as fixed appliances and the bonding materials promote retention of biofilms. These lesions are managed in the first step by establishing good oral hygiene habits and prophylaxis with topical fluorides, including high-fluoride toothpastes, fluoride mouthwashes, gels, varnishes, fluoride-containing bonding materials, and elastic ligatures. Recently, other materials and methods have been recommended, including the application of casein phosphopeptides-amorphous calcium phosphate, antiseptics, probiotics, polyols, sealants, laser, tooth bleaching agents, resin infiltration, and microabrasion. This article reviews the currently used methods to manage enamel demineralization during and after orthodontic treatment and the risk factors and preventive measures based on the latest evidence.

Assessment of the effectiveness of mouthwashes in reducing cariogenic biofilm in orthodontic patients: a systematic review

OBJECTIVES

The use of fixed orthodontic appliances makes it difficult to clean the teeth and accessories associated with it. For this reason, orthodontic patients have used oral antiseptics as coadjuvent means to reduce cariogenic plaque. The aim of this systematic review was to evaluate the effectiveness of oral antiseptics on the reduction of cariogenic plaque on orthodontic patients.

DATA

This review has been registered at PROSPERO--international prospective register of systematic reviews under the number CRD42013006857.

SOURCES

A systematic review of the literature was conducted in the following electronic databases: Scopus, PubMed, Web of Science, Medline, Embase and Cochrane, Grey literature and Clinical Trials, without limitations on the year of publication or language. Clinical studies in patients with fixed orthodontic appliances, who were making use of oral mouthwashes in order to reduce cariogenic plaque, were included. Articles with patients using systemic drugs, syndromic patients, those using mouthwashes for other purposes and/or using different cleaning techniques, and clinical cases were excluded. After selection by title and abstract, potentially eligible articles were read in full. The methodological quality and risk of biases of articles included were evaluated according to the characteristics of the study, measurements and statistical analyses of the study. The methodological quality was classified as high, moderate or low.

STUDY SELECTION

The search identified 2716 articles, of which 15 met the inclusion criteria. Of these, 8 analyzed chlorhexidine-based mouthwashes, while in 1 article Cetylpyridinium was used; 1 analyzed the mouthwash containing sanguinaria; 1 the use of NaF; 2 articles the use of AmF/SnF2; 2 the use of Listerine(®), 1 also analyzed the association between mouthwashes with octenidine and with PVP-I. Of the articles analyzed, 11 were classified as having high and 4 as having moderate methodological quality.

CONCLUSION

There is evidence of effectiveness of the use of oral mouthwashes in the control of cariogenic plaque in patients with fixed orthodontic appliances. The orthodontists may suggest the use of oral antiseptics in the oral hygiene of their patients as coadjuvent means to reduce cariogenic plaque.

CLINICAL SIGNIFICANCE

Given current evidence, orthodontists may prescribe mouthwash as an auxiliary method in the control of cariogenic biofilm in orthodontic patients.

Quantitative analysis of S. mutans and S. sobrinus cultivated independently and adhered to polished orthodontic composite resins

In orthodontics, fixed appliances placed in the oral cavity are colonized by microorganisms.

OBJECTIVE

The purpose of this study was to quantitatively determine the independent bacterial colonization of S. mutans and S. sobrinus in orthodontic composite resins.

MATERIAL AND METHODS

Seven orthodontic composite adhesives for bonding brackets were selected and classified into 14 groups; (GIm, GIs) Enlight, (GIIm, GIIs) Grengloo, (GIIIm, GIIIs) Kurasper F, (GIVm, GIVs) BeautyOrtho Bond, (GVm, GVs) Transbond CC, (GVIm, GVIs) Turbo Bond II, (GVIIm, GVIIs) Blugloo. 60 blocks of 4x4x1 mm of each orthodontic composite resin were made (total 420 blocks), and gently polished with sand-paper and ultrasonically cleaned. S. mutans and S. sobrinus were independently cultivated. For the quantitative analysis, a radioactive marker was used to codify the bacteria (³H) adhered to the surface of the materials. The blocks were submerged in a solution with microorganisms previously radiolabeled and separated (210 blocks for S. mutans and 210 blocks for S. sobrinus) for 2 hours at 37 ºC. Next, the blocks were placed in a combustion system, to capture the residues and measure the radiation. The statistical analysis was calculated with the ANOVA test (Sheffè post-hoc).

RESULTS

Significant differences of bacterial adhesion were found amongst the groups. In the GIm and GIs the significant lowest scores for both microorganisms were shown; in contrast, the values of GVII for both bacteria were significantly the highest.

CONCLUSIONS

This study showed that the orthodontic composite resin evaluated in the GIm and GIs, obtained the lowest adherence of S. mutans and S. sobrinus, which may reduce the enamel demineralization and the risk of white spot lesion formation.

The effect of two different bracket types on the salivary levels of S mutans and S sobrinus in the early phase of orthodontic treatment

OBJECTIVE

To determine the difference in the levels of Streptococcus mutans and S sobrinus in stimulated saliva in orthodontic patients with different bracket types (stainless steel and esthetic brackets) using polymerase chain reaction and cultivation method.

MATERIALS AND METHODS

Thirty-two patients, aged 13 to 30 years, were selected following these criteria: 1) orthodontic treatment indication, 2) systemic health, and 3) no tobacco and antibiotic consummation for three months prior to the commencement of the study. Patients were divided into two groups according to the bracket type; 16 patients formed the conventional bracket group (stainless steel brackets), and 16 patients formed the esthetic bracket group (plastic brackets). The levels of S mutans and S sobrinus in stimulated whole saliva samples were collected prior to fixed orthodontic appliance placement (T1) and 12 weeks after placement (T2), as were the Decayed, Missing, and Filled Surface Index (DMFS) and Oral Hygiene Index-Simplified (OHI-S). Mann-Whitney, Wilcoxon, and chi-square tests were used for statistical analysis.

RESULTS

Statistical analysis (chi-square test) showed no difference in S mutans and S sobrinus counts among patients with different brackets at either T1 or T2. There was no difference in total bacteria counts after fixed orthodontic appliance placement.

CONCLUSION

The number of colony-forming units of S mutans and S sobrinus in stimulated saliva samples does not seem to be significantly different between patients with stainless steel brackets and patients with plastic brackets.

Synthesis and characterization of dimethacrylates containing quaternary ammonium functionalities for dental applications

OBJECTIVES

The widespread incidence of recurrent caries highlights the need for improved dental restorative materials. The objective of this study was to synthesize low viscosity ionic dimethacrylate monomers (IDMAs) that contain quaternary ammoniums groups (antimicrobial functionalities) and are compatible with existing dental dimethacrylate-based monomers. Such monomers have the potential to copolymerize with other methacrylate monomers and produce antibacterial polymers.

METHODS

Two monomers (IDMA-1 and IDMA-2) were synthesized using the Menschutkin reaction and incorporated at 0-30% (by mass) into a 1:1 (by mass) bisphenol A glycerolate dimethacrylate (BisGMA):triethylene glycol dimethacrylate (TEGDMA) resin. Resin viscosity was quantified using rheology, and polymer degree of conversion (DC) and surface charge density were measured using Fourier transform infrared spectroscopy (FTIR) and fluorescein binding, respectively. Effects of IDMA-1 on initial attachment of Streptococcus mutans and on viability and metabolic activity (via reductase enzymes) of RAW 264.7 macrophage-like cells were quantified.

RESULTS

IDMA-1 and IDMA-2 were prepared and characterized. IDMA-1 was miscible with BisGMA:TEGDMA and slightly increased the resin viscosity and DC. As expected, polymeric surface charge density increased with increasing IDMA-1. Incorporation of 10% IDMA-1 into BisGMA:TEGDMA reduced bacterial colonization without affecting viability or metabolic activity of mammalian cells. Increasing IDMA-1 up to 30% had no additional effect on bacterial coverage, but ≥20% IDMA-1 significantly reduced macrophage density, viability, and metabolic activity. Leachables from polymers containing IDMA-1 were not cytotoxic.

SIGNIFICANCE

The Menschutkin reaction provides a facile, convenient means to synthesize new monomers with quaternary ammonium groups for dental and medical applications.