Periodontal and microbiologic evaluation of 2 methods of archwire ligation: ligature wires and elastomeric rings

The effect of surface roughening of orthodontic elastomers on hydrophobicity and in vitro adherence of Streptococcus gordonii

OBJECTIVES

Biofilm formation around orthodontic appliances causes gingivitis, enamel decalcification and caries. Bacteria adhere less readily to superhydrophobic surfaces. The aim of this study was to determine whether a superhydrophobic surface could be generated on orthodontic elastomers by surface modification in order to reduce bacterial adhesion.

MATERIALS AND METHODS

Orthodontic elastomers were modified with sandpapers of various grit sizes (80-600 grit). Surface roughness of the modified and unmodified surfaces was assessed qualitatively with scanning electron microscopy and quantitatively with confocal microscopy. Water contact angles were measured with a goniometer to quantify hydrophobicity. Measurements were performed on unextended elastomers (100% original length) and elastomers extended to 150%, and 200% of the original length. Adhesion of Streptococcus gordonii to saliva coated elastomers was measured by counting colony forming units on agar plates.

RESULTS

Abrasion with different sandpapers produced elastomers with surface roughness (Ra) ranging from 2 to 12 μm. Contact angles followed a quadratic trend with a maximum contact angle of 104° at an Ra of 7-9 μm. Average water contact angles, when viewed perpendicular to the direction of extension, decreased from 99° to 90° when the extension was increased from 100% to 200% and increased from 100° to 103° when viewed parallel to the direction of extension. Bacterial adhesion increased as roughness increased and this effect was more pronounced with elastomer extension.

CONCLUSION

The surface roughness of orthodontic elastomers influences both their hydrophobicity and bacterial adhesion. Superhydrophobicity of elastomers could not be achieved with sandpaper abrasion.

Effectiveness of a Combined Toothbrushing Technique on Cariogenic Dental Biofilm in Relation to Stainless Steel and Elastomeric Ligatures in Orthodontic Patients: A Randomized Clinical Trial

Increased dental biofilm commonly occurs during orthodontic treatment. The aim of this study was to evaluate the effect of a combined toothbrushing method on dental biofilm cariogenicity in patients with stainless steel (SSL) and elastomeric (EL) ligatures. At baseline (T1), 70 participants were randomized (1:1 ratio) to the SSL or EL group. Dental biofilm maturity was evaluated using a three-color-disclosing dye. The participants were instructed to brush their teeth using a combined horizontal-Charters-modified Bass technique. Dental biofilm maturity was reassessed at the 4-week follow-up (T2). We found that at T1, new dental biofilm was the highest, followed by mature and cariogenic dental biofilm in the SSL group (p < 0.05). In the EL group, cariogenic dental biofilm was highly observed, followed by mature and new dental biofilm (p < 0.05). After intervention, cariogenic dental biofilm significantly decreased in both groups (p < 0.05). Moreover, a marked decrease in cariogenic dental biofilm was observed in the EL group compared with the SSL group (p < 0.05). However, the change in mature dental biofilm in the groups was similar (p > 0.05). Our results demonstrated that the combined toothbrushing method reduced cariogenic dental biofilm in the SSL and EL groups.

Salivary pH changes under the effect of stainless steel versus elastomeric ligatures in fixed orthodontic patients: a single-center, randomized controlled clinical trial

BACKGROUND

Fluctuations in pH of saliva during a prolonged treatment course influences the enamel demineralization progress, which is one of the complications of fixed orthodontic treatment. This randomized clinical trial aimed to evaluate and compare the short-term effects of stainless steel (SS) versus elastomeric (EM) ligatures on salivary pH in patients scheduled for fixed orthodontic treatment.

METHODS

Seventy participants were enrolled in the study (54 female, 16 male) aged 19-36 years who met specific inclusion criteria. They were randomly selected and allocated into two equal groups through computer-generated randomization. All patients received fixed orthodontic treatment using conventional orthodontic brackets. Two commonly used archwire ligature methods were used: SS and EMs. An unstimulated (resting) salivary sample was collected before tying of the ligatures at T0 (baseline), 2 weeks, 6 (weeks), and 12 (weeks). Salivary pH was measured using a digital pH meter. The level of significance was set at p value < 0.05.

RESULTS

The salivary pH level was stable between T0 and T1 (6.72 ± 0.14), then significantly and progressively increased from T1 to T2 (6.78 ± 0.13) and from T2 to T3 (6.81 ± 0.14) with (p < 0.05) in the SS group. In the EM group, the salivary pH level was significantly decreased in all follow-up periods; T0 (6.77 ± 0.16), T1 (6.72 ± 0.14), T2 (6.67 ± 0.13) and T3 (6.64 ± 0.13).

CONCLUSION

The EM ligatures showed a significant decrease in salivary pH to an unfavorable level, which increased the risk of enamel demineralization. Therefore, EMs as ligature material is preferably should not be recommended in patients with high caries index or inadequate oral hygiene. Trial registration ANZCTR.org. (ACTRN12618001647224) http://www.anzctr.org.au/ACTRN12618001647224.aspx . Registration Date: 5/10/2018, "Retrospectively registered".

The effect of ligation methods on biofilm formation in patients undergoing multi-bracketed fixed orthodontic therapy - A systematic review

BACKGROUND

Many modifications to fixed orthodontic appliances have been introduced to manage biofilm formation. The aim of this review was to investigate elastomeric ligation in comparison with stainless steel ligation and self-ligation with regard to microbiological and clinical indicators of biofilm formation in patients wearing multi-bracketed fixed orthodontic appliances.

METHODS

The MEDLINE and the EMBASE databases were searched up to February 2021 and supplemented by additional manual searches of bibliographies. Parallel-group and split-mouth randomized controlled trials (RCTs) comparing different ligation methods were identified. The Cochrane Risk of Bias-2 tool was applied to assess the quality of evidence.

RESULTS

A total of 11 RCTs were included in this review. Nine RCTs compared self-ligation and elastomeric ligation; two compared elastomeric ligation and stainless steel ligation. The included studies had either some concerns or were at a high risk of bias. Qualitative assessment of the studies identified that there were no significant differences in biofilm formation between elastomeric ligation and self-ligation, but that stainless steel ligation was less susceptible to biofilm formation than elastomeric ligation.

CONCLUSIONS

There were no significant differences between self-ligation and elastomeric ligation for biofilm formation in patients wearing multi-bracketed fixed orthodontic appliances. Stainless steel ligation may accumulate less biofilm than elastomeric ligation; however, the clinical significance of the difference could not be evaluated. Further high-quality studies are required in order to determine which ligation method is better for managing biofilm formation in patients wearing multi-bracketed fixed orthodontic appliances.

The Oral Microbiota Changes in Orthodontic Patients and Effects on Oral Health: An Overview

Nowadays, there is a considerable interest to study the biological and microbiological changes that accompany orthodontic treatment. Growing knowledge on oral microbiota allows, day after day, to identify and characterize the microbial arrangements specifically associated with oral and extra-oral conditions. The aim of the present work is to highlight any further correlations between orthodontic appliances and the qualitative and quantitative modifications of the oral microbiota, such as predisposing factors for the onset of caries, periodontal diseases, and other infections, which can impact the oral and systemic health of the orthodontic patients. When compared with subjects without orthodontic appliances, orthodontic patients reported significant qualitative and quantitative differences in supra- and subgingival plaque during the entire treatment period. Certain components of fixed appliances (mainly bonded molar brackets, ceramic brackets, and elastomeric ligatures) showed high risks of periodontal disease and tooth decay for patients. An unclear prevalence of Candida spp. and the paucity of studies on viruses and protozoas in the oral microbiota of orthodontic patients need to be further investigated. The evidence emerging from this study could guide clinicians in modulating the timing of controls and enhance patient motivation to prevent the formation of mature plaque, thus reducing the risks of oral-plaque-related diseases.

Initial Bacterial Adhesion and Biofilm Formation on Aligner Materials

The present study aims to assess the initial bacterial adhesion and biofilm formation on different aligner materials. A total of four different aligner materials, CA-medium (CAM), copolyester (COP), Duran (DUR), Erkodur (ERK), were tested. Stimulated human saliva was obtained from six healthy volunteers. Salivary bacteria were harvested by centrifugation, and 1 mL of the salivary suspension was injected onto each sample surface for 2 h and 3 days, respectively. The samples were then washed twice with 5 mL 0.9% NaCl solution, and non-adherent bacteria were removed. The adherent microorganisms were dislodged from the sample surfaces after ultrasonication for 4 min in 1 mL 0.9% NaCl on ice. After the incubation of the adherent salivary bacteria under both aerobic and anaerobic conditions on Columbia blood agar plates at 37 °C and 5% CO₂ and in anaerobic jars overnight, several dilutions thereof were used for the determination of CFUs. This protocol was applied three times, obtaining an average of nine independent measurements for each material group. Overall, the differences between the tested aligner materials as well as between the materials and controls were not of statistical significance (p > 0.05). Regarding initial bacterial attachment and biofilm formation, the tested aligner materials are comparable to enamel and metal orthodontic brackets and can be therefore considered for clinical use. The four tested aligner materials CAM, COP, DUR, ERK showed no significant differences in initial microbial attachment and biofilm formation of aerobic and anaerobic species compared to enamel and conventional brackets.

A Simplified and Effective Method for Generation of Experimental Murine Periodontitis Model

Periodontitis, a common disease that can lead to bone destruction, periodontal attachment loss, and tooth loss, is the major cause for oral tissue engineering. Experimental periodontitis is a suitable disease-model for studying bone regeneration and the potential therapeutic role of biomaterials on periodontal tissue engineering, as this in vivo model could be employed to mimic the natural host response under bacteria-caused oral pathological environments. Although large animals with ligature-induced periodontitis have mostly been used for experiments, a mouse model is a better choice for several reasons. Inserting ligature threads through the interproximal space between the teeth is the key step in establishing a periodontitis model, and it is easy to achieve in large animals, but difficult in mice due to the limited operating space. In this work, we provide a new and proven approach for periodontitis induction in mice using C+ nickel-titanium root canal files and stainless-steel ligature wires. The validity of this method was assessed by evaluating alveolar bone loss via micro-CT and detecting periodontal inflammation by histological staining and qPCR after the treatments. Progressive alveolar bone loss was observed from day 3 after the ligature-placement. Infiltration and accumulation of F4/80+ macrophage was also detected. In accordance with the histological results, there was upregulation of the expression levels of the inflammatory genes Il1β, Tnf-α, and Il6 in gingival tissues isolated from the ligation sites. Our results suggest that this novel method could resolve the difficulty of ligature-placement in mice and consequently contribute to further use of mouse models for studying the pathological mechanisms of periodontitis and developing potential periodontal tissue regeneration strategies. C+ files, which are made of nickel-titanium, are tough, elastic, and sufficiently thin to pass through the interproximal space between the teeth after pre-bending to form an appropriate angle, thus providing an access for ligature wire insertion. As a common tool in the dental clinic, it is familiar to researchers of oral biology, and can provide the feasibility for wide application of our method.

Microbial profile in different orthodontic appliances by checkerboard DNA-DNA hybridization: An in-vivo study

INTRODUCTION

The design of the orthodontic bracket or appliance is 1 of the most important factors for creating retentive areas for biofilm formation. In orthodontics, this would be the first study to compare the microbial level changes in 3 different types of orthodontic appliances using checkerboard DNA-DNA hybridization technique. The purpose of this study was to evaluate and compare the extent of appearance of orange and red microbial complexes in patients undergoing orthodontic treatment using aligners, conventional metallic fixed labial appliances, and lingual fixed appliances.

METHODS

A total of 60 patients, of which 20 patients were undergoing treatment with aligners, 20 patients with labial fixed appliances, and 20 patients with lingual fixed appliances, were included in our study. After 30 days, debonded brackets and rinsed aligners were stored and processed for analysis with checkerboard DNA-DNA hybridization.

RESULTS

Most bacterial species showed moderate counts, with the exception of Treponema denticola, which showed a higher count in all 3 types of appliances. Fusobacterium nucleatum, Porphyromonas gingivalis, and T denticola were present in a higher percentage in the lingual appliance. Fusobacterium periodontium and Prevotella intermedia were present in a higher percentage in the labial fixed appliance. Campylobacter rectus, Tannerella forsythia, and Prevotella melaninogenica counts were moderate in all 3 appliances, with the first 2 microbes showing slightly higher counts in aligners. The association between all the microorganisms were statistically insignificant, with the exception of F nucleatum, which showed a strong statistically significant association in all 3 types of appliances.

CONCLUSIONS

The microbial contamination in metallic brackets was higher than that of aligners, when used for a month. Lingual fixed appliances showed more microbial contamination than labial fixed appliances followed by aligners.

Orthodontic, periodontal and prosthodontic treatment for a periodontally compromised patient with a deep overbite

Background

Periodontitis may result in displacement, overeruption and the tilting of teeth, which can lead to occlusal prematurities and accelerate the loss of periodontal structures. Orthodontic treatment is needed to correct displaced tooth positions, but inappropriate force and tooth movement can lead to further loss of supporting tissues.

Aim

To describe the treatment of a deep overbite in a 32-year-old male with a history of periodontitis, gingival recession and missing premolars.

Methods

After evaluation, fixed appliances applying light forces were chosen as the appropriate treatment approach. A segmental arch and a utility arch technique were applied. Periodontal therapy was conducted before and throughout orthodontic care.

Results

After 28 months of treatment, a normal overbite and overjet were restored. A displaced premolar was repositioned. Space needed for the prosthetic replacement of the missing teeth was obtained and dental implants were planned after orthodontic treatment. The height of the alveolar bone increased in some areas. After 18 months of retention, the attachment level of the upper left incisor increased approximately 1 mm.

Conclusion

For patients with a compromised periodontium, adequate management of the tissues is the basis of orthodontic care. Appropriate orthodontic treatment may be beneficial to periodontal health in the long term.

Photodynamic inactivation of planktonic cultures and Streptococcus mutans biofilms for prevention of white spot lesions during orthodontic treatment: An in vitro investigation

INTRODUCTION

This study evaluated the efficacy of photodynamic inactivation (PDI) with hematoporphyrin IX (H) and modified hematoporphyrin IX (MH) at 10 μmol/L, using a blue light-emitting diode (LED), fluence of 75 J/cm,² over planktonic cultures and biofilm of Streptococcus mutans (UA 159).

METHODS

Suspensions containing 107 cells/mL were tested under different experimental conditions: a) H and LED (H+L+), b) MH and LED (MH+L+), c) only LED (P-L+), d) only H (H+L-), e) only MH (MH+L-), and f) control group, no LED or photosensitizer treatment (P-L-). The study also evaluated the effect of PDI on S mutans biofilm on metallic or ceramic brackets bonded on specimens of human teeth. The strains were seeded onto Mitis salivarius-bacitracin-sacarose agar to determine the number of colony-forming units.

RESULTS

H and MH under LED irradiation were effective on planktonic cultures (P <0.0001). H and MH (H+L+ and MH+L+) caused a reduction of 3.80 and 6.78 log¹⁰ CFU/mL. PDI with the use of H or MH and LED exerted a strong antimicrobial effect over S mutans showing 54% and 100% reduction, respectively. PDI on S mutans biofilm on metallic and ceramic brackets with the use of H was not effective (P = 0.0162, P = 0.1669), however, MH caused a significant reduction of 44% and 53% of the cell count on metallic and ceramic brackets, respectively (P = 0.0020, P = 0.004).

CONCLUSIONS

In vitro planktonic cultures with the use of H or MH and LED exerted significant antimicrobial activity. No effect was observed on S mutans biofilm on either bracket type with the use of H, MH showed better results, suggesting a promising use against dental caries and white spot lesions.

Changes in oral microbiota due to orthodontic appliances: a systematic review

Background: Oral microbiota has been at the center of cultural attention in recent years. In daily clinical practice, orthodontic appliances may be associated with an increased cariogenic risk and a worsening of preexisting periodontal diseases. Objective: The purpose of this review is to investigate the available evidence regarding the association between orthodontic appliances and changes in the quality and quantity of the oral microbiota. Design: The research included every article published up to October 2017 featuring the keywords 'Orthodontic appliance* AND (microbiological colonization OR periodontal pathogen* OR Streptococcus mutans OR Lactobacillus spp. OR Candida OR Tannerella forsythia OR Treponema denticola OR Fusobacterium nucleatum OR Aggregatibacter actinomycetemcomitans OR Prevotella intermedia OR Prevotella nigrescens OR Porphyromonas gingivalis)' and was conducted in the major medical databases. The methodological quality of selected papers was scored using the 'Swedish Council on Technology Assessment in Health Care Criteria for Grading Assessed Studies' (SBU) method. Results: Orthodontic appliances influence the oral microbiota with an increase in the counts of S. mutans and Lactobacillus spp. and in the percentage of potentially pathogenic gram-negative bacteria. Conclusions: There is moderate/high evidence regarding the association between orthodontic appliances and changes in the oral microbiota. PROSPERO registration number CRD42018091589.

Evidence of variable bacterial colonization on coloured elastomeric ligatures during orthodontic treatment: An intermodular comparative study

Background

Besides, other factors, the choice of materials used as orthodontic ligatures could be one of the many tools to counter the effects of microbial adhesion, that culminates into dental ailments. Therefore, we assessed bacterial adhesion on elastomeric ligatures with special reference to coloured elastomeric rings during orthodontic treatment.

Material and Methods

A split mouth study, involving 240 samples of different elastomeric ligatures from forty orthodontic patients possessing good oral hygiene was carried out. The archwire was ligated to the brackets on both arches with elastomeric rings (superslick, clear transparent , blue and pink) at predetermined quadrants. After six weeks, ligatures from second premolars were removed and processed for bacterial enumeration using standard techniques. Bacterial counts were also determined for stimulated saliva samples taken at 0 and 6 weeks.

Results

A statistically significant difference in bacterial counts was obtained amongst different elastomeric modules used. Maximum bacterial counts were found on conventional pigmented elastomeric modules, followed by Superslick module and clear module. More number of bacteria associated with the conventional pink as compared to the conventional blue pigmented modules, however it was not statistically significant. The three bacterial genera Streptococcus Staphylococcus and Aerobic Lactobacilli adhered to elastomeric modules in following predominant pattern i.e. Conventional pink>Conventional Blue>Superslick>Clear.

Conclusions

The studies evidenced colour and material dependent bacterial colonization on orthodontic modules and could be an indicator of bacterial biofilm forming potential based on surface chemistries and a clinically efficacious tool to redesign conventional and modified elastomeric rings as orthodontic ligation accessories.

Key words:Bacterial colonization, biofilm, coloured elastomers, orthodontic ligatures.

Microbial Colonization on Elastomeric Ligatures during Orthodontic Therapeutics: An Overview

The current review focuses on the studies conducted on the colonization of microorganisms on orthodontic ligatures during orthodontic treatment. The fixed orthodontic appliances have long been associated with an increase in plaque accumulation, bacterial colonization, and resultant enamel decalcification. Voluminous research has been carried out on the microbial colonization of even newer orthodontic materials such as elastomeric ligatures with an evidence of variably increased microbial counts during orthodontic treatment. However, conclusive material-based data for minimal microbial colonization to establish acceptance criteria for the use of elastomeric ligatures are hardly available. Thus, there is a need for further studies with dual emphasis on exploring microbial associations based on surface chemistries of different elastomers and their requisite modifications for hampering microbial biofilms to evolve efficacious oral health friendly orthodontic ligatures.

Improving the efficacy of chlorhexidine-releasing elastomerics using a layer-by-layer coating technique

The aims of this study were to identify the optimal concentration of coated orthodontic elastomerics using a layer-by-layer technique that can release chlorhexidine (CHX) as an antimicrobial material, and to measure the physical properties and antimicrobial effects of the coated elastomerics. Ethyl cellulose (EC) was used as the polymer, and five study groups with various combinations of solvents (i.e., ethanol and dichloromethane [DCM]) were included. The coated elastomerics were evaluated with a spectrophotometer to confirm the release of CHX, and their surfaces were observed by SEM. The CHX+EC+DCM group sustained antimicrobial release for the longest period (168 h, p<0.001) and exhibited the largest antimicrobial effect in an inhibition zone test using S. mutans for 7 days (p<0.05). This group had most effective physical properties and antimicrobial effects of coated elastomerics produced using a layerby-layer technique, and so its composition should be considered for use in clinical applications in orthodontics.

The effect of bracket ligation on the periodontal status of adolescents undergoing orthodontic treatment. A systematic review and meta-analysis

INTRODUCTION/OBJECTIVES

This systematic review aimed to critically appraise the evidence regarding the effect of bracket ligation type on the periodontal conditions of adolescents undergoing orthodontic treatment.

DATA

Search terms included randomized controlled trial (RCTs), controlled clinical trials, ligation, bracket, periodontal, inflammation. Risk of bias assessment was made using the Cochrane risk of bias tool and the quality of evidence was assessed with GRADE.

SOURCES

Electronic Database search of published and unpublished literature was performed without language restriction in May 25, 2016 (MEDLINE via Pubmed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Clinical Trials.gov and National Research Register).

STUDY SELECTION

Of 140 articles initially retrieved, 8 were eligible for inclusion in the systematic review, while 4 RCTs with unclear risk of bias were included in the quantitative synthesis, all comparing self-ligating to conventional steel ligated brackets. Random effects meta-analyses were implemented. At 4-6 weeks after bracket placement there was no evidence to support the use of either type of bracket for achieving improved plaque- (PI) and gingival index (GI). At 3-6 months, there was scarce evidence of greater PI increase for conventional brackets. GI and pocket depth pooled estimates did not reveal significant differences between the two systems. The quality of the evidence was moderate according to GRADE for all outcomes.

CONCLUSIONS

Overall, non-significant differences on the periodontal status of adolescents undergoing orthodontic treatment with either conventional or self-ligating brackets were detected.

CLINICAL SIGNIFICANCE

The periodontal status of adolescents undergoing orthodontic treatment is of considerable importance. The synthesis of the available evidence on oral hygiene related factors will provide insights to best clinical practice during the course of orthodontic treatment.

Plaque accumulation and Streptococcus mutans levels around self-ligating bracket clips and elastomeric modules: A randomized controlled trial

Aim

To determine the effect of two different ligating systems that is, elastomeric modules and self-ligating (SL) bracket systems (Smartclip - 3M Unitek) with respect to harboring bacterial plaque in fixed orthodontic treatment.

Objectives

To assess, evaluate, and compare the amount of plaque accumulation and Streptococcus mutans colonization around elastomeric ligation and SL clips in the smart clip appliance.

Materials and Methods

A total of 111 orthodontic patients scheduled for fixed orthodontic treatments were selected for this split maxillary arch study. All the patients were bonded with smart-clip (3M Unitek) SL brackets, and the wire was placed into the bracket slots, on the randomly selected hemi arch, elastomeric modules were placed for the study to be conducted. Microbial and periodontal plaque accumulation was recorded at 3-time intervals post ligation. Plaque index-by Silness and Loe, modified Quigely Hein index, bleeding on probing were evaluated, and biofilm was collected from the tooth surface after 30 days and placed in petri dishes containing Mitis Salivarius agar for bacterial culturing.

Result

It was observed that the side where ligation was done with elastomeric modules accumulated more plaque and increase in S. mutans colony forming units as compared to the side without external ligation (P < 0.05).

Conclusion

Reduced bacterial colonization and better plaque control was seen with SL orthodontic bracket appliance system as compared to conventional ligation method.

Effect of bracket type on halitosis, periodontal status, and microbial colonization

OBJECTIVE

To determine the effect of bracket type on halitosis, periodontal status, and microbial colonization.

MATERIALS AND METHODS

Forty-six patients scheduled for fixed orthodontic treatment (age 11-16 years) were selected from the orthodontic department of Suleyman Demirel University. Patients were divided into two groups with random distribution of brackets; 23 patients were treated with self-ligating brackets (group SLBs), the others with conventional brackets (group CBs). Halitosis measurements and periodontal and microbial records were obtained before the placement of brackets (T0), 1 week later (T1), and 5 weeks after bonding (T2). Periodontal parameters, including plaque index (PI), gingival index (GI), and bleeding on probing index (BOP), were obtained from all the bonded teeth. Halitosis measurements were performed at the same time. Microbial samples were obtained from the buccal surfaces of all the bonded teeth. Data were analyzed by using a repeated-measurement analysis of variance test for the comparison of parameters between groups and times.

RESULTS

Periodontal parameters and halitosis results were higher in the CBs group than in the SLBs group (P<.05). In the SLBs group, halitosis and BOP values revealed no pronounced changes between T1 and T2 (P>.05). Intra- and intergroup comparisons showed that there were no statistically significant differences for microbial colonization between all the time intervals (P>.05).

CONCLUSION

Bracket type has an effect on halitosis and periodontal status. Therefore, self-ligating brackets may be advised in order to prevent patients from developing halitosis and to increase the likelihood of good oral hygiene during orthodontic treatment.

The influence of orthodontic fixed appliances on the oral microbiota: a systematic review

OBJECTIVE

To investigate whether there is scientific evidence to support the hypothesis that the presence of orthodontic fixed appliances influences the oral microbiota.

METHODS

The search for articles was conducted in PubMed; ISI Web of Knowledge and Ovid databases, including articles published in English until May 17th, 2012. They should report human observational studies presenting the following keywords: "fixed orthodontic appliance" AND "microbiological colonization"; OR "periodontal pathogens"; OR "Streptococcus"; OR "Lactobacillus"; OR "Candida"; OR "Tannerella forsythia"; OR "Treponema denticola"; OR "Fusobacterium nucleatum"; OR "Actimomyces actinomycetemcomitans"; OR "Prevotella intermedia"; OR "Prevotella nigrescens"; OR "Porphyromonas gingivalis". Articles were previously selected by title and abstract. Articles that met the inclusion criteria were analyzed and classified as having low, moderate or high methodology quality. A new detailed checklist for quality assessment was developed based on the information required for applicable data extraction for reviews. The study design, sample, follow-up period, collection and microbial analysis methods, statistical treatment, results and discussion were assessed.

RESULTS

The initial search retrieved 305 articles of which 33 articles were selected by title and abstract. After full-text reading, 8 articles met the inclusion criteria, out of which 4 articles were classified as having low and 4 as moderate methodological quality. The moderate methodological quality studies were included in the systematic review.

CONCLUSIONS

The literature revealed moderate evidence that the presence of fixed appliances influences the quantity and quality of oral microbiota.

Are self-ligating brackets related to less formation of Streptococcus mutans colonies? A systematic review

OBJECTIVE

To verify, by means of a systematic review, whether the design of brackets (conventional or self-ligating) influences adhesion and formation of Streptococcus mutans colonies.

METHODS

SEARCH STRATEGY

four databases (Cochrane Central Register of Controlled Trials, Ovid ALL EMB Reviews, PubMed and BIREME) were selected to search for relevant articles covering the period from January 1965 to December 2012.

SELECTION CRITERIA

in first consensus by reading the title and abstract. The full text was obtained from publications that met the inclusion criteria.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data using the following keywords: conventional, self-ligating, biofilm, Streptococcus mutans, and systematic review; and independently evaluated the quality of the studies. In case of divergence, the technique of consensus was adopted.

RESULTS

The search strategy resulted in 1,401 articles. The classification of scientific relevance revealed the high quality of the 6 eligible articles of which outcomes were not unanimous in reporting not only the influence of the design of the brackets (conventional or self-ligating) over adhesion and formation of colonies of Streptococcus mutans, but also that other factors such as the quality of the bracket type, the level of individual oral hygiene, bonding and age may have greater influence. Statistical analysis was not feasible because of the heterogeneous methodological design.

CONCLUSIONS

Within the limitations of this study, it was concluded that there is no evidence for a possible influence of the design of the brackets (conventional or self-ligating) over colony formation and adhesion of Streptococcus mutans.

Effects of 2 bracket and ligation types on plaque retention: a quantitative microbiologic analysis with real-time polymerase chain reaction

INTRODUCTION

The aim of this study was to evaluate the effects of self-ligating brackets and conventional brackets ligated with stainless steel ligatures on dental plaque retention and microbial flora.

METHODS

Twenty boys (mean age, 14.2 ± 1.5 years) underwent bonding with self-ligating bracket systems and conventional standard edgewise bracket systems ligated with stainless steel ligatures with a split-mouth design. Clinical measurements, including plaque index, probing pocket depth, and bleeding on probing, were obtained before bonding, 1 week after bonding, and 3 months after bonding. Supragingival plaque samples were obtained at baseline and 3 months after bonding for the detection of bacteria. A quantitative analysis for Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei, and Lactobacillus acidophilus was performed using real-time polymerase chain reaction. The Mann-Whitney U test and the Hotelling T(2) multivariate test were used for statistical comparisons of the groups.

RESULTS

The numbers of S mutans, S sobrinus, L casei, and L acidophilus were not statistically different between self-ligating brackets and conventional brackets ligated with stainless steel ligatures (P >0.05). The 2 archwire ligation techniques showed no statistically significant differences in plaque index, bleeding on probing, and probing pocket depth values of the bonded teeth (P >0.05). All clinical parameters and the numbers of all microorganisms showed statistically significant increases from baseline to 3 months after bonding in both groups (P <0.001).

CONCLUSIONS

Self-ligating brackets and conventional brackets ligated with stainless steel ligatures do not differ with regard to dental plaque retention.

Clinical and microbiological parameters in patients with self-ligating and conventional brackets during early phase of orthodontic treatment

OBJECTIVE

To determine the effect of different bracket designs (conventional brackets and self-ligating brackets) on periodontal clinical parameters and periodontal pathogens in subgingival plaque.

MATERIAL AND METHODS

The following inclusion criteria were used: requirement of orthodontic treatment plan starting with alignment and leveling, good general health, healthy periodontium, no antibiotic therapy in the previous 6 months before the beginning of the study, and no smoking. The study sample totaled 38 patients (13 male, 25 female; mean age, 14.6 ± 2.0 years). Patients were divided into two groups with random distribution of brackets. Recording of clinical parameters was done before the placement of the orthodontic appliance (T0) and at 6 weeks (T1), 12 weeks (T2), and 18 weeks (T3) after full bonding of orthodontic appliances. Periodontal pathogens of subgingival microflora were detected at T3 using a commercially available polymerase chain reaction test (micro-Dent test) that contains probes for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, and Treponema denticola.

RESULTS

There was a statistically significant higher prevalence of A actinomycetemcomitans in patients with conventional brackets than in patients with self-ligating brackets, but there was no statistically significant difference for other putative periodontal pathogens. The two different types of brackets did not show statistically significant differences in periodontal clinical parameters.

CONCLUSION

Bracket design does not seem to have a strong influence on periodontal clinical parameters and periodontal pathogens in subgingival plaque. The correlation between some periodontal pathogens and clinical periodontal parameters was weak.

Quantifying plaque during orthodontic treatment:

OBJECTIVE

To evaluate the literature on different methods of scoring plaque in patients with fixed orthodontic appliances.

MATERIALS AND METHODS

A systematic electronic and hand search using MEDLINE and PubMed was conducted.

RESULTS

Most orthodontic trials have used the original Silness and Löe plaque index. Indices vary in several potentially important aspects. Only two papers have reported reproducibility of methods of plaque scoring in orthodontic patients.

CONCLUSION

Some plaque indices are inappropriate for orthodontic patients. Newer digital planimetric methods are promising if more complex. There is a need to further assess the reproducibility and practicability of the advocated methods.

Adhesion of Porphyromonas gingivalis and Biofilm Formation on Different Types of Orthodontic Brackets

Objectives. To examine the interaction between Porphyromonas gingivalis and 3 different orthodontic brackets in vitro, focusing on the effect of an early salivary pellicle and other bacteria on the formation of biofilms. Material and Methods. Mono- and multi-species P. gingivalis biofilms were allowed to form in vitro, on 3 different bracket types (stainless steel, ceramic and plastic) with and without an early salivary pellicle. The brackets were anaerobically incubated for 3 days in Brain Heart Infusion Broth to form biofilms. Bacteria were quantified by trypsin treatment and enumeration of the total viable counts of bacteria recovered. Results. Saliva was found to significantly affect (P < 0.001) adhesion and biofilm formation of P. gingivalis, with higher numbers for the coated brackets. No significant effect was detected for the impact of the type of biofilm, although on stainless steel and plastic brackets there was a tendency for higher numbers of the pathogen in multi-species biofilms. Bracket material alone was not found to affect the number of bacteria. Conclusions. The salivary pellicle seems to facilitate the adhesion of P. gingivalis and biofilm formation on orthodontic brackets, while the material comprising the brackets does not significantly impact on the number of bacteria.

Effect of a self-etching adhesive containing an antibacterial monomer on clinical periodontal parameters and subgingival microbiologic composition in orthodontic patients

INTRODUCTION

The aims of this study were to evaluate the effect of a self-etching adhesive system containing an antibacterial monomer on periodontal health and subgingival microbiologic composition in orthodontic patients and to compare it with a conventional adhesive system.

METHODS

A split-mouth design was chosen, and 15 patients were included in the study. Brackets in contralateral quadrants were bonded with either a conventional adhesive system (control) or a self-etching adhesive system that contained an antibacterial monomer. Clinical periodontal parameters including plaque index, gingival index, probing depths, and bleeding on probing were determined. Subgingival plaque samples were collected before bracket placement (T0) and at the 6-month follow-up (T1). The real-time TaqMan polymerase chain reaction assay was used to determine the subgingival counts of Porphyromonas gingivalis, Tannerella forsythensis, Prevotella intermedia, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Campylobacter rectus. For clinical periodontal parameters, analysis of covariance (ANCOVA) and, for bacterial counts, Wilcoxon tests were used for statistical comparisons at the P <0.05 level.

RESULTS

Clinical periodontal parameters were not changed, and they were not different between the groups from T0 to T1. T forsythensis and F nucleatum increased during the treatment period in both groups (P <0.05). The majority of the bacteria were T nucleatum at T0 and T1 in both groups. Changes in bacterial load from T0 to T1 were not different between groups except for T forsythensis and F nucleatum (P <0.05).

CONCLUSIONS

The use of an antibacterial monomer did not have an additional positive effect on clinical periodontal parameters. When used in bonding orthodontic brackets, the antibacterial monomer failed to reduce periodontopathogenic bacteria when compared with the conventional adhesive system during a 6-month treatment period.

Comparative analysis of long-term biofilm formation on metal and ceramic brackets

OBJECTIVE

To test the null hypothesis that stainless steel and ceramic brackets show no differences in biofilm adhesion.

MATERIALS AND METHODS

Twenty adolescents (6 boys, 14 girls) who had received fixed orthodontic therapy for 18.9 ± 3.2 months were divided into a metal and a ceramic bracket group. Thirty brackets per group were taken from central incisors, canines, and second premolars and quantitatively analyzed for biofilm coverage with the Rutherford backscattering detection method. Five micrographs were obtained per bracket with views from the buccal, mesial, distal, gingival, and occlusal aspects, resulting in a total of 300 images. Biofilm formation between groups was compared using the Mann-Whitney U-test (α = .05).

RESULTS

Total biofilm formation was 12.5% ± 5.7% (3.3 ± 1.6 mm(2)) of the surface on metal and 5.6% ± 2.4% (1.5 ± 0.6 mm(2)) on ceramic brackets. Differences between groups were statistically significant (P < .05). A pairwise comparison of biofilm formation revealed significantly lower biofilm formation on ceramic brackets with respect to intraoral location (central incisor, canine, second premolar) and bracket surface (buccal, mesial, distal).

CONCLUSIONS

The hypothesis was rejected. The results indicate that ceramic brackets exhibit less long-term biofilm accumulation than metal brackets.

Short-term influence of lingual orthodontic therapy on microbial parameters and periodontal status. A preliminary study

OBJECTIVE

To perform a preliminary study of the short-term effect of fixed, customized lingual orthodontic appliances on periodontal and microbial parameters.

MATERIALS AND METHODS

The sample comprised 20 subjects (6 males and 14 females) with a mean age of 22.3 years +/- 8.6 years. Before (T(0)) and 4 weeks after placement (T(1)) of custom-made lingual appliances on the lower teeth only, plaque index (PI), probing pocket depth (PPD), and bleeding on probing (BOP) were measured. A 16S rRNA-based polymerase chain reaction (PCR) method was used to detect Aggregatibacter actinomycetemcomitans ( Aa ) and Porphyromonas gingivalis ( Pg ) in the crevicular fluid. To compare periodontal parameters on bonded lingual (testing) and unbonded palatal (control) and labial (control) sites between T(0) and T(1), the Wilcoxon test was applied.

RESULTS

On the lingual aspects of bonded teeth, a significant increase of BOP (T(0): 23.4 +/- 22.5%; T(1): 46.2 +/- 23.5%; P = .001) and PI (T(0): 0.3 +/- 0.3; T(1): 1.0 +/- 0.7; P = .001) was observed, but no significant changes for PPD (T(0): 2.1 +/- 0.4 mm; T(1): 2.2 +/- 0.3 mm; P = .286) were found. On control sites, no significant changes were recorded for any periodontal parameter. Aa was found in 25% of the patients at baseline (5 subjects) and in 35% of the patients at T(1) (2 additional positive subjects), whereas Pg was found in 5% of the cohort at T(0) and at T(1) (same patient).

CONCLUSIONS

Even in the short term, insertion of fixed lingual appliances induced a worsening of periodontal parameters restricted to bonded lingual sites.

[Reciprocal relationships between orthodontics and periodontics: relevance of a synergistic action]

The aim of this article is to review evidence on the reciprocal relationships between orthodontics and periodontics. Normal intra-arch and inter-arch relationships have long been considered as an anatomic prerequisite for the preservation of dental health and function. Certain malocclusion traits are associated with difficulties in maintaining good oral hygiene and as a consequence to poor periodontal condition. Therefore, proper alignment of the teeth provided by orthodontic treatment may promote good control of soft deposit and calculus and subsequent periodontal inflammation. The tendency of orthodontic appliances, particularly the brackets and bands to promote the accumulation of plaque and thus increasing the risk of developing localized periodontal disease must however be constantly emphasized. Periodontitis involves progressive loss of the alveolar bone around the teeth, pathological tooth migration and gingival recession with pathological tooth migration and gingival recession as a possible outcome. The effectiveness of orthodontics in conjunction with periodontics in the management of these esthetic and functional defects is highlighted in this review.