The effects of different orthodontic appliances upon microbial communities

Probiotics for maintaining oral health during fixed orthodontic treatment: A systematic review and meta-analysis

INTRODUCTION

To systematically review the effect of probiotics on oral health during treatment with fixed orthodontic appliances.

METHODS

PubMed, Embase and the Cochrane Library were searched up to August 2022 using broad MeSH terms and keywords. Randomized clinical trials comparing a probiotic with a control/no treatment; at least 10 patients/group undergoing fixed orthodontic therapy; and reporting at least one oral health-related parameter were included.

RESULTS

The most reported parameters in the 14 included studies were the microbiological counts of mutans streptococci and lactobacilli, microorganisms associated with white spot lesions (WSL). A meta-analysis of these showed a positive effect of probiotics on mutans streptococci. Probiotic treatment led to significantly less patients with high counts and significantly more with low counts of these bacteria. An effect on the lactobacilli counts was not seen. However, the sole clinical study investigating WSL could not demonstrate a clinical effect of probiotics on these lesions. Additionally, one study reported encouraging results of probiotics on bad breath and one on the occurrence of traumatic oral lesions. One study found reduced counts of Porphyromonas gingivalis in the probiotic group. The clinical results of probiotics on plaque index were ambiguous: one study reported that probiotics reduce the plaque and gingival index, and two that probiotics had no significant influence on plaque index.

CONCLUSION

Probiotics are a promising option to lower mutans streptococci counts in patients undergoing fixed orthodontic therapy. However, due to the heterogeneity of the studies, it is not possible to draw conclusions about one specific probiotic.

Microbial contamination profile on esthetic elastomeric ligatures through the checkerboard DNA-DNA hybridization technique : A randomized split-mouth study

OBJECTIVE

The aim of this study is to assess the microbial contamination of three different brands of esthetic elastomeric ligatures.

MATERIALS AND METHODS

Different brands of esthetic ligatures (Unistick Pearl [American Orthodontics, Sheboygan, WI, USA], Power Sticks Pearl [Ortho Technology, Tampa, FL, USA], and Ease [Obscure, 3M Unitek, Monrovia, CA, USA]) were randomly assigned to permanent canines of 25 patients (aged 11-18 years) undergoing corrective orthodontic treatment. After 30 days, the ligatures were removed, processed, and the biofilm composition was analyzed by checkerboard DNA-DNA hybridization for 40 bacterial species. The microbiological data were analyzed using a nonparametric mixed model.

RESULTS

The ligatures presented intense microbial contamination after 30 days, but no statistically significant differences were observed among the three groups (p > 0.05). The levels of the evaluated individual species and proportions of the microbial complexes showed no statistically significant differences among the ligature groups (p > 0.05).

CONCLUSIONS

Esthetic elastomeric ligatures became multicolonized by several bacterial species after 30 days of exposure to the oral cavity. However, no relevant differences were observed among the biofilm composition formed on the different ligature brands.

Impact of Clear Aligners on Oral Health and Oral Microbiome During Orthodontic Treatment

The demand for clear aligners has risen over the past decade because they satisfy patients' desire for less noticeable and more comfortable orthodontic appliances. Because clear aligners are increasingly used in orthodontics, there is a big push to learn more about the physiologic and microbial changes that occur during treatment. The present work highlighted further links between clear aligners and changes in oral health and the oral microbiome and provided plaque control methods for clear aligner trays. Existing literature revealed that clear aligners have no significant influence on the structure of the oral microbiome during orthodontic therapy. Clear aligner treatment demonstrated promising results in terms of controlling plaque index, gingival health, and the prevalence of white spot lesions. Nevertheless, grooves, ridges, microcracks, and abrasions on the aligner surface would provide a prime environment for bacterial adherence and the development of plaque biofilms. A combination of mechanical and chemical methods seems to be a successful approach for removing plaque biofilm from aligners whilst also preventing pigment adsorption.

Porphyrin-associated fluorescence spectroscopy (Photogen®) for the optical diagnosis of dental biofilm in orthodontic treatment: an observational clinical trial

OBJECTIVE

This study assessed the presence of dental biofilm with fluorescence spectroscopy associated with porphyrin (Photogen®) in users of orthodontic appliances.

METHODS

This cross-sectional observational clinical trial included 21 patients with metallic orthodontic fixed appliances. The presence of biofilm was evaluated by fluorescence spectroscopy (Evince-MMÓptics. São Carlos-SP, Brazil) with a porphyrin photo-evidence device (Photogen®). Digital images of the buccal surface of the upper anterior teeth (central and lateral incisors and canines) without and with porphyrin were analyzed using the histogram R (red) function in ImageJ software. The results were analyzed using the maximum and mode values of the red pixels from the histograms. The statistical analysis considered the significance level of 5%.

RESULTS

The maximum values and modes of the red pixels were significantly higher in biofilms analyzed by porphyrin-associated optical spectroscopy compared to optical spectroscopy alone.

CONCLUSIONS

Porphyrin-associated fluorescence spectroscopy was able to detect dental biofilm in the oral environment of patients with orthodontic treatment. This method better evidenced the presence of biofilm on the buccal surfaces of the upper teeth compared to that observed with fluorescence spectroscopy without porphyrin.

Dysbiotic changes of periodontal pathogens in patients wearing conventional and self-ligating orthodontic appliances

Objective: This study aimed to analyse dysbiotic changes of periodontal pathogenic bacteria and their relationship with different types of fixed orthodontic appliances in a population located in Northwestern Mexico.

Methods: Three groups of patients were identified: a control group without orthodontic appliances (C), a conventional-ligating appliance group (CLA), and a self-ligating appliance group (SLA). Periodontal biofilm samples were collected for DNA extraction to identify the presence and load of Treponema denticola, Prevotella intermedia, and Fusobacterium nucleatum, using a quantitative real-time PCR technique.

Results: A total of 92 patients were included. The results showed that F. nucleatum was present in all groups including the control patients (C 96%, CLA 100%, and SLA 67%, respectively). Female participants displayed a higher frequency of periodontal pathogens than males, but males were more affected by F. nucleatum. In addition, the presence of T. denticola and P. intermedia was time-dependent, being more frequent in patients in treatment for longer than 12 months whereas CLA showed 74% and 78% of positive samples and SLA showed 78% and 89%, respectively. F. nucleatum was present in 100% of CLA samples before and after 12 months of treatment and its load was higher in the SLA group after 12 months.

Conclusions: Dysbiotic changes that could affect the periodontal tissues were seen in patients wearing orthodontic appliances. The frequency of F. nucleatum was significantly higher in CLA and noted with a greater load in SLA. In addition, female participants showed a higher frequency of periodontal pathogens while male subjects were more affected by F. nucleatum. As expected, treatment for longer than 12 months correlated with a higher frequency of all periodontal pathogens. The results support the concept that dysbiosis leading to periodontal disease can be caused by the rise of a dominant species, instead of the appearance of a new species.

Effects of Laser Therapy on Periodontal Status in Adult Patients Undergoing Orthodontic Treatment

Orthodontic treatment with fixed devices should only be indicated in case of a stable, non-active periodontal disease status. Throughout orthodontic treatment, a careful assessment of the periodontal status is advised. Due to its anti-inflammatory and antimicrobial effects, laser therapy is frequently used as an adjunct to classic periodontal therapy. The aim of this study was to evaluate the advantages and limitations of the use of laser therapy on periodontal status during orthodontic treatment. Throughout the 9 months during which this placebo-controlled, single-blind clinical trial was conducted, 32 patients were included in the study, divided into two groups: microscope “+” (patients who observed the bacteria within the dental plaque-sample examination on the screen of a dark-field microscope in real time) and microscope “−” (patients who did not see the oral pathogens using a dark-field microscope). For all patients, using the split-mouth study design, laser therapy was applied to one hemiarch (HL), whereas the other hemiarch received treatment without active light (HC). After one month, by analyzing the main indicators of periodontal health status, we found that the plaque index (PI) and bleeding on probing (BOP) values were significantly decreased after receiving treatment (for PI: HL-p = 0.0005, HC-p = 0.0297; for BOP: HL-p = 0.0121, HC-p = 0.0236), whereas the probing-depth (PD) values remained almost the same as before treatment (HL-p = 1.5143; HC-p = 1.4762). Conclusions: The use of the dark-field microscope proved to be beneficial in sensitizing patients to the presence of bacteria in the oral cavity and motivated them to strictly follow the rules of oral hygiene. Laser treatment can be a valuable aid in periodontal therapy, but only in adjunction with mechanical therapy.

Salivary bacterial community profile in normal-weight and obese adolescent patients prior to orthodontic treatment with fixed appliances

OBJECTIVES

The aim of this study was to compare the intra-oral bacterial profile of normal-weight and obese adolescents prior to orthodontic treatment with fixed appliances.

MATERIALS AND METHODS

Nineteen adolescent patients were recruited into two groups based upon body mass index (BMI) and classified as normal-weight or obese. Unstimulated whole mouth saliva was obtained for 5 minutes. Bacterial DNA extraction was performed from saliva, and 16S rRNA gene sequencing of the V1-2 variable regions was undertaken followed by analysis using the mothur pipeline.

RESULTS

Saliva from a total of 19 adolescent patients with mean (SD) age 15.6 (1.8) years were divided into 10 normal-weight with mean BMI of 19.4 (2.2) kg/m² and 9 obese with mean BMI of 30.2 (3.5) kg/m² . A total of 156 783 sequences were obtained from the 19 samples with no significant differences in richness or diversity between sample groups by obesity status or gender (AMOVA). The bacterial community in both groups was dominated by bacterial genera characteristic of the human mouth, which included Streptococcus, Porphyromonas, Veillonella, Gemella, Prevotella, Fusobacterium and Rothia.

CONCLUSION

There were no differences in alpha or beta diversity of oral bacterial communities between normal-weight and obese orthodontic patients. Obese adolescents attending for orthodontic treatment had a similar microflora to their normal-weight counterparts.

Motivation of Adult Patients with Orthodontic Treatment in Maintaining Oral Hygiene

Background: In the last decades, adult patients require orthodontic treatment as a therapeutic method in an increasing percentage. This treatment has a lot of benefits, but unfortunately it also presents a number of complications and risks, among which favoring the accumulation of bacterial plaque is the most concerning.

Aim of the study: In this study we aimed to evaluate the effectiveness of using the dark-field microscope as a method of motivating adult patients with orthodontic treatment in maintaining a proper oral hygiene.

Material and methods: Thirty-six patients were selected based on the inclusion and exclusion criteria. At time T0, patients were divided into two groups: Group 1–microscope and Group 2 – control, in such a way that the groups were as homogeneous as possible. Dental plaque samples were collected and analyzed under a dark field microscope in the presence of the patient for subjects from Group 1 but not Group 2. All patients were then instructed on oral hygiene techniques. The following periodontal indices were recorded of each patient: plaque index (PI), index of bleeding on probing (BOP), probing depth (PD) – at T0 and T1 (after one month).

Results: Comparing the PI and BOP values before (T0) and after treatment (T1), statistically significant results were detected (PI: p = 0.0020, BOP: p = 0.0297), which denotes that patients who observed the bacterial load of their dental plaque in real time using the dark-field microscope had a better oral hygiene and lower values of periodontal health indices. Regarding the PD index, the difference between time T0 and T1 was not statistically significant (p = 1.4762).

Conclusions: During the orthodontic treatment, adult patients often present gingival inflammation caused by improper hygiene. The use of the dark-field microscope is effective in motivating patients regarding the rules of maintenance of a proper oral hygiene.

Effectiveness of the Human Oral Microbe Identification Microarray in Identifying Periodontal Pathogens: A Systematic Review

The aim of this review was to investigate the effectiveness of the Human Oral Microbe Identification Microarray (HOMIM) in identifying and quantifying bacterial species of the oral microbiome in periodontal disease. The search for articles was conducted in CENTRAL, CINAHL, MEDLINE and EMBASE by two reviewers, and included articles published in English between January 1990 and December 2021. The selected articles were human observational studies in adults between 18 and 65 years, presenting specific predefined keywords. Articles were initially selected by title and abstract; articles that met the inclusion criteria were analyzed for methodological quality using a detailed checklist for quality assessment. Data were extracted and reported using the PRISMA tool. The study design, sample, follow-up period, collection and microbial analysis methods, statistical treatment, results and discussion were quality assessed and risk of bias was evaluated using the Cochrane Risk-of-Bias tool. A narrative synthesis approach was used to synthesize and interpret the extracted data. From the initial search, 2931 articles were retrieved; 51 of these were then selected after screening by title and abstract. Subsequently, 8 articles met the inclusion after full-text reading and were classed according to methodological quality as high (2), moderate (3) or low (3). Studies included in this review were of high and medium quality. Data from the Human Oral Microbe Identification Microarray (HOMIM) provide much more robust results, showing major shifts between periodontal health and periodontal disease. Compared to earlier techniques such as Denaturing Gradient Gel Electrophoresis (DGGE), HOMIM represents a more effective approach for quantification due to its high sensitivity; thus, it is able to identify a high prevalence of periodontal pathogens and novel species in low abundance. The literature provides moderate evidence that the Human Oral Microbe Identification Microarray (HOMIM) is more effective in identifying and quantifying bacterial species of the oral microbiome in periodontal disease, compared to earlier molecular and non-molecular methods such as Denaturing Gradient Gel Electrophoresis (DGGE) and a culture-based approach with phenotypic tests.

Microbial colonisation associated with conventional and self-ligating brackets: a systematic review

Background:

Decalcification and gingivitis caused by plaque accumulation around brackets are common iatrogenic effects of fixed appliances. The influence of conventional versus self-ligating bracket design on microbial colonisation is unknown.

Objective:

To assess the levels of microbial colonisation associated with conventional and self-ligating brackets.

Search sources:

Three databases were searched for publications from 2009 to 2021.

Data selection:

Randomised controlled trials comparing levels of microbial colonisation before and during treatment with conventional and self-ligating brackets were assessed independently and in duplicate.

Data extraction:

Data were extracted independently by two authors from the studies that fulfilled the inclusion criteria. Risk of bias assessments were made using the revised Cochrane risk of bias tool for randomized trials. The quality of the included studies was assessed using the Critical Appraisal Skills Programme Checklist.

Results:

A total of 11 randomised controlled trials were included in this systematic review. Six of the studies were found to be at low risk of bias and five presented with some concerns. The studies were considered moderate to high quality. Five trials reported no statistically significant difference in microbial colonisation between bracket types. The remaining studies showed mixed results, with some reporting increased colonisation of conventional brackets and others increased colonisation of self-ligating brackets. The heterogeneity of study methods and outcomes precluded meta-analysis.

Conclusion:

Of the 11 studies included in this systematic review, five found no differences in colonisation between conventional and self-ligating brackets. The remaining studies showed mixed results. The evidence is inconclusive regarding the association between bracket design and levels of microbial colonisation.

Space Maintainers Used in Pediatric Dentistry: An Insight of Their Biosecurity Profile by Applying In Vitro Methods

Space maintainers have presented an increased interest due to their chemical composition which influences the electrochemical and electrolytic processes of the oral cavity, leading to important biological activity. The present study was purported to evaluate the biological in vitro activity of three types of space maintainers (S1, S2, and S3, differing from each other in terms of metal composition) used in pediatric dentistry, in terms of their antimicrobial effect and biosecurity profile using two types of keratinocytes (PGK: primary gingival keratinocytes, and HaCaT: human immortalized keratinocytes) by assessing the morphology, viability, cytotoxicity, and gene expression of the cells. Statistical differences were calculated by the one-way ANOVA test, followed by Tukey’s post-test. Antimicrobial screening highlighted a dilution-dependent influence that, in the case of all strains tested, did not show inhibition or stimulation of bacterial growth. The in vitro evaluations revealed that the test samples did not induce important cytotoxic potential on both keratinocyte cell lines (HaCaT and PGK), with the cells manifesting no morphological alteration, a good viability rate (above 90%: PGK–S1, * p < 0.05), and a low cytotoxic activity (less than 11%: PGK, S1 *** p < 0.001 and S3 * p < 0.05; HaCaT, S1 ** p < 0.01). The data obtained in this study highlight the fact that the samples analyzed are biocompatible and do not develop the growth of the studied bacteria or encode the gene expression of primary and immortalized keratinocytes.

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.

Evaluation and Comparison of the Effect of Elastomeric Chain and Stainless Steel Ligature Wire on Maxillary Orthodontic Miniscrew Failure

Context:

Orthodontic miniscrews are used for the purpose of conservation of anchorage.

Aims:

The aim of the study was to evaluate the orthodontic miniscrew failure between the elastomeric chain-supported retraction and stainless steel (SS) ligature-aided retraction.

Settings and Design:

This was a cross-sectional split mouth randomized controlled trial.

Materials and Methods:

The sample (30) was divided equally among the control group and the experimental group (15 each). Miniscrews were placed between second premolar and the first molar of maxilla. The experimental group was based on the split mouth technique wherein right or left side of the maxillary arch was treated using either an elastomeric power chain (EPC) engaged to the miniscrews directly (Group 1) or an EPC engaged indirectly to miniscrews with the help of SS ligature wire (Group 2). In control group, implants were placed in maxilla without any retraction force. Clinical signs of inflammation was assessed at the following interval; 7^th day, 14^th day, 1^st month, 2^nd month, and at the time of removal of implant.

Statistical Analysis Used:

Kruskal–Wallis ANOVA test was used.

Results:

Mean rank of gingival inflammation was 28.33 at the 1^st-month interval in Group 1 and inflammation remained high in the this group for all time intervals in comparison to Group 2. Group 2 showed highest mean rank of inflammation of 26.10 at 7^th day. In control group, the inflammation remained low at all the time intervals. Moreover, the difference noted was statistically significant.

Conclusions:

The gingival inflammation around the peri-implant tissue with the application of EPC at various interval remained high in comparison to the EPC with SS group. The gingival inflammation in the control group was very less, and it remained less throughout the different time periods.

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.

Salivary MRP-8/14 and the presence of periodontitis-associated bacteria in children with bonded maxillary expansion treatment

OBJECTIVES

The aim of this study was to investigate changes in saliva concentration of the inflammatory marker MRP-8/14 and the presence of some periodontitis-associated bacteria in patients with mixed dentition treated with a rigid acrylic, bonded maxillary expander.

METHODS

Fifteen patients in mixed dentition treated with a bonded palatal expander were enrolled in this longitudinal study. Saliva samples were taken before the therapy, as well as in 2 weeks and 3, 6, 9, and 12 months after the beginning of the therapy. In each sample, the levels of MRP-8/14 were determined by ELISA and the presence of 11 bacteria was detected by PCR followed by DNA-DNA hybridization.

RESULTS

Salivary concentration of MRP-8/14 and the amount of Tannerella forsythia, Treponema denticola, and Eikenella corrodens were significantly increased during treatment with bonded maxillary expander. These changes were transient and the maximal levels of MRP-8/14 and periodontitis-associated pathogens were observed 6-9 months after the beginning of the therapy.

CONCLUSION

Therapy with bonded maxillary results in higher MRP-8/14 levels and increased prevalence of some periodontitis-associated bacteria, namely T. forsythia, T. denticola, and E. corrodens. The results suggest the detection of salivary MRP-8/14 levels may be a potential tool to reflect the oral health status in children with fixed orthodontic treatment.

CLINICAL RELEVANCE

Our data suggest that the treatment with bonded maxillary expander might influence the oral health status and should be accompanied by the careful control of the oral health during the therapy.

Roughness and wettability of aligner materials

OBJECTIVE

The characterisation of surface roughness and energy of contemporary thermoplastic materials used in manufacturing of orthodontic aligners.

DESIGN

In vitro, laboratory study.

MATERIALS AND METHODS

Four commercially available thermoplastic materials were selected (CA-medium/CAM, Essix-copopyester/COP, Duran/DUR and Erkodur/ERK). Five disks from each, as received, material were tested and subjected to: (1) reflected light microscopy; (2) optical profilometry for the estimation of Sa, Sz, Sq, Sdr, Sc, Sv surface roughness parameters (n = 5); and (3) contact angle measurements with a Zisman series of liquids for the estimation of critical surface tension (γ_C), total work of adhesion (W^A), as well as the work of adhesion due to polar (W^P) and dispersion (W^D) components employing the Zisman method (n = 5/liquid). Thermoformed disks were prepared against a dental stone model and the roughness parameters were calculated again Statistical analysis was performed by one-way ANOVA/ Tukey multiple comparison test and t-test (a = 0.05).

RESULTS

Microscopic and profilometric analyses revealed a smooth surface texture in the as-received materials, but a very rough texture after thermoforming, with insignificant differences within each state. Significant differences in the as-received state were found in the surface energy parameters; CAM showed the lowest γ_C and the highest W^A, W^P, W^D, whereas ERK with the highest γ_C demonstrated lower W^A. COP and DUR were ranked in an intermediate group regarding γ_C, with a statistically significant difference in W^A between them, mainly attributed to the lower W^P of the former.

CONCLUSION

Given the differences in surface energy parameters and the lack of roughness differences within the as received or thermoformed groups, it may be concluded that variations in the plaque retaining capacity are anticipated, determined by γ_C, W^A and the W^P, W^D components.

Fluorescence image and microbiological analysis of biofilm retained around healthy and inflamed orthodontic miniscrews

INTRODUCTION

Peri-miniscrew inflammation is one of the causes of orthodontic miniscrew failure.

OBJECTIVE

The aim of this study was to correlate and quantify throughout autofluorescence images, PCR and microbiologic count of biofilm retained around orthodontic miniscrew and the presence of Porphyromonas gingivalis.

MATERIALS AND METHODS

Forty miniscrews used for orthodontic treatment were evaluated during orthodontic treatment, collected from patients and divided into two groups: healthy and inflamed miniscrews. To be considered inflamed, the samples should present: loss of stability checked by periotest®, clinical presence of mucositis, red aspect of the gum or bleeding around the miniscrew. Immediately after removal of the miniscrews, they were photographed using a macro 100 lens and a Pentax camera coupled to a fluorescent equipment - Qscan (AioBio - Korea) with 405 nm excitation wavelength and a blue band filter. A microbiologic sample was collected with a sterile microbrush scrubbed around the miniscrew tread. Fluorescent images were analyzed with ImageJ software to quantify fluorescent intensity and fluorescent area and microbiological samples were submitted to CFU count for total contamination and q-PCR assay to quantify Porphyromonas gingivalis.

RESULTS

The results showed a good correlation between CFU count and fluorescent intensity and PCR/fluorescent area. The healthy miniscrews presented less fluorescent intensity and lower CFU count when compared to inflamed miniscrews. q-PCR analysis showed a higher number of P. gingivalis contamination around inflamed miniscrews.

CONCLUSION

Quantification of biofilm retained by miniscrew by images of autofluorescence is a simple and reliable method with great potential for clinical use to monitory inflammation around miniscrew and risk of loss.

Orthodontic treatment as an adjunct to periodontal therapy

This study discusses the role of orthodontic treatment as an adjunct to the control and treatment of periodontal disease conditions, and describes a clinical case of severe anterior mandibular crowding and periodontal disease followed up for nine years and three months after orthodontic treatment completion. Malocclusion impaired proper dental hygiene, which led to bone loss and development of a periodontal abscess between mandibular canines and lateral incisors. After scaling and root planing, orthodontic treatment was initiated with extraction of the four second premolars, to correct the deficiency detected in cephalometric and model analysis. Treatment objectives were met, and facial and dental esthetics was satisfactory. Adequate periodontal management, hygiene control and tooth movement ensured ideal occlusion and facilitated the control of biofilm.

The Microflora Diversity and Profiles in Dental Plaque Biofilms on Brackets and Tooth Surfaces of Orthodontic Patients

Objective: Fixed orthodontic appliances may influence the oral environment through accumulation of plaque, decreased plaque pH, and increased gingival inflammation. These changes in the oral cavity can potentially lead to periodontal disease, demineralization, and other infectious diseases.

Materials and Methods: To investigate the changes in biofilm throughout the initial 2 weeks, we placed a stainless steel bracket on the upper second premolar and collected plaque samples on the bracket and on the tooth surface at different time points (0, 24, 48 h and 1 and 2 weeks) and plated on tryptic soy agar blood agar plate, and kept at 37°C in an anaerobic chamber for 5 days to determine the CFUs of bacteria. At the end of 2 weeks, we removed the bracket and elastomeric module, and we isolated genomic DNA from the bacterial biofilm for identification of bacteria by 16S rRNA PCR analysis. We also analyzed the morphology of biofilm on the bracket by scanning electron microscope.

Results: Our results show that the bacterial biofilm was significantly increased on the bracket in all the subjects, whereas on the tooth surface, the CFUs were not significantly increased. PCR assay showed that biofilm on orthodontic brackets from all subjects showed colonization by Streptococcus gordonii, Porphyromonas gingivalis and Streptococcus mutans were observed on some of the subjects after 48 h, whereas Aggregatibacter actinomycetemcomitans biofilm was observed in all the time points except 24 h.

Conclusion: This study demonstrated that both periodontal and cariogenic bacterial biofilms were formed on the bracket as early as 24 h.

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.

Profiling of subgingival plaque biofilm microbiota in female adult patients with clear aligners: a three-month prospective study

Background

Clear aligners are well known for facilitating oral hygiene maintenance and decreasing susceptibility to periodontal diseases as compared to conventional fixed appliances. However, few research studies focus on the subgingival microbial community during clear aligner treatment (CAT). Hence, this study investigates changes of the subgingival microbial community and its association with clinical characteristics during the first three months of CAT.

Methods

Ten female patients with clear aligners were enrolled in this study. Subgingival plaque samples were obtained at three time points: before orthodontic treatment (T0), one month after orthodontic treatment (T1) and three months after orthodontic treatment (T2). DNA was then extracted from plaque samples and analyzed by 16S rRNA gene sequencing. Periodontal examinations, including plaque index (PI) and gingival bleeding index (GBI) measurements were also recorded.

Results

The plaque indices (PIs) and gingival bleeding indices (GBIs) were slightly increased at T1 and T2, but no statistically significant difference was found. The alpha diversity indices, including the ACE, Chao1, Shannon indices, all showed a declining trend without significance, and a rising trend in the Simpson diversity index was observed. The weighted UniFrac distance was significantly higher at T1 and T2 compared with T0. Principal Coordinates Analysis (PCoA) demonstrated that the communities at T0 tended to cluster apart from the communities at T1 and T2. The relative abundance of the phylum Firmicutes and genus Mycoplasma was significantly increased at T0 compared with T2. There was no significant difference in the relative abundance of periodontal pathogens at the genus and species levels or core microorganisms at the genus level.

Conclusion

A slightly decreasing microbial diversity with a significant change of microbial structure was found during the first three-month clear aligner treatment (CAT). However, subjects receiving clear aligner treatment were free from periodontal diseases with relatively stable levels of periodontal microorganisms and core microorganisms. Thus, our preliminary findings indicated that clear aligners induced nonpathogenic changes of the subgingival microbiome in the first three-month treatment.

Microbial complexes levels in conventional and self-ligating brackets

OBJECTIVES

The aims were to evaluate the levels of bacterial species in saliva and in situ and to assess whether the design of brackets influences the risk of developing periodontal disease.

MATERIALS AND METHODS

Twenty patients (13.3 mean age) were bonded with self-ligating brackets and a conventional bracket. Saliva was collected before bonding and 30 and 60 days after bonding. One sample of each bracket was removed 30 and 60 days after bonding. The analysis was determined by checkerboard DNA-DNA hybridization. The data was evaluated by the non-parametric test.

RESULTS

A significant increase in the levels of bacterial species in the saliva occurred in 15 of the 22 analyzed species. The self-ligating brackets presented the highest incidence percentages for the orange and red complexes 60 days after bonding. In situ analyses showed different patterns according to the bracket design. The levels of Campylobacter rectus showed significant differences (p = 0.011) 60 days after bonding among the three brackets; the highest values were observed in the In-Ovation®R bracket.

CONCLUSIONS

The bracket design seems to influence the levels of bacterial species involved in periodontal disease. Considering the wide variety of bacterial species, additional studies are needed to aid in the establishment of effective protocols to prevent the development of periodontal disease during orthodontic treatment.

CLINICAL RELEVANCE

A dynamic alteration in the oral microbiota may lead to inflammatory reactions in the supporting soft and hard tissues. The different types of brackets interfere with bacterial adherence. Bracket design should be considered in orthodontic treatment.

Impact of Orthodontic Treatment on Periodontal Tissues: A Narrative Review of Multidisciplinary Literature

The aim of this review is to describe the most commonly observed changes in periodontium caused by orthodontic treatment in order to facilitate specialists' collaboration and communication. An electronic database search was carried out using PubMed abstract and citation database and bibliographic material was then used in order to find other appropriate sources. Soft and hard periodontal tissues changes during orthodontic treatment and maintenance of the patients are discussed in order to provide an exhaustive picture of the possible interactions between these two interwoven disciplines.

Effects of Fixed and Removable Space Maintainers on Plaque Accumulation, Periodontal Health, Candidal and Enterococcus Faecalis Carriage

OBJECTIVE

To evaluate the effects of space maintainers on plaque accumulation, periodontal health and oral microflora.

SUBJECTS AND METHODS

The study participants comprised 38 patients aged 4-10 years requiring either fixed or removable space maintainers. Plaque index, gingival index, bleeding on probing index, candidal colonization and Enterococcus faecalis were recorded just before the application of space maintainers (T0) and during treatment at the 1st (T1), 3rd (T2) and 6th (T3) month.

RESULTS

The gingival and bleeding on probing index scores increased significantly (gingival index from 0.20 ± 0254 to 0.54 ± 0417 and bleeding on probing index from 7.18 ± 9.946 to 18.07 ± 14.074) in the regions with fixed space maintainers at T3 (p < 0.01). The mean Candida counts also increased (for removable appliances from 1.90 ± 3.638 to 1.98 ± 3.318, p < 0.05, and for fixed appliances from 4.25 ± 4.587 to 4.52 ± 4.431, p < 0.001). The salivary E. faecalis counts at T3 also increased significantly with the use of fixed and removable appliances (for removable appliances from 5.93 ± 2.65 to 85.53 ± 34.1 and for fixed appliances from 4.95 ± 2.94 to 123.59 ± 29.51, p < 0.001). A positive correlation was found between the plaque (r = 0.67), gingival (r = 0.76) and bleeding on probing index scores (r = 0.76) and the candidal colonization for the fixed space maintainers (p < 0.01, p < 0.001).

CONCLUSIONS

In this study, both fixed and removable space maintainers led to an increase in the number of microorganisms in the oral cavity as well as to increases in the periodontal index scores. Patients should be informed that space maintainers may serve as a source of infection and that special attention must be given to their oral hygiene.

Periodontal health during clear aligners treatment: a systematic review

BACKGROUND

Clear aligner treatment (CAT) has been cited as a safe and comfortable orthodontic procedure for adult patients. However, the available evidence is scarce.

OBJECTIVE

To perform a systematic review of the existing literature in order to assess periodontal health during CAT.

SEARCH METHODS AND SELECTION CRITERIA

Pubmed, Pubmed Central, National Library of Medicine's Medline, Embase, Cochrane Central Register of Controlled Clinical trials, Web of Knowledge, Scopus, Google Scholar, and LILACS were searched from January 1945 to September 2014 to identify all peer-reviewed papers potentially relevant to the review.

DATA COLLECTION AND ANALYSIS

After duplicate selection and extraction procedures, the risk of bias was assessed according to the Centre for Reviews and Dissemination criteria, and a 3-point grading system, as described by the Swedish Council on Technology Assessment in Health Care (SBU), was used to rate the methodological quality of the selected papers. A PICOS table was used for data extraction.

RESULTS

Five relevant articles were selected from the 1247 identified articles. The level of evidence was moderate for all the studies. A significant improvement of the periodontal health indexes was revealed, in particular when CAT was compared to fixed appliances. No periodontal CAT adverse effects were observed in the selected studies.

CONCLUSIONS

Periodontal health indexes were significantly improved during CAT. The results of this review should be interpreted with some caution because of the number, quality, and heterogeneity of the included studies.

Axenic culture of a candidate division TM7 bacterium from the human oral cavity and biofilm interactions with other oral bacteria

The diversity of bacterial species in the human oral cavity is well recognized, but a high proportion of them are presently uncultivable. Candidate division TM7 bacteria are almost always detected in metagenomic studies but have not yet been cultivated. In this paper, we identified candidate division TM7 bacterial phylotypes in mature plaque samples from around orthodontic bonds in subjects undergoing orthodontic treatment. Successive rounds of enrichment in laboratory media led to the isolation of a pure culture of one of these candidate division TM7 phylotypes. The bacteria formed filaments of 20 to 200 μm in length within agar plate colonies and in monospecies biofilms on salivary pellicle and exhibited some unusual morphological characteristics by transmission electron microscopy, including a trilaminated cell surface layer and dense cytoplasmic deposits. Proteomic analyses of cell wall protein extracts identified abundant polypeptides predicted from the TM7 partial genomic sequence. Pleiomorphic phenotypes were observed when the candidate division TM7 bacterium was grown in dual-species biofilms with representatives of six different oral bacterial genera. The TM7 bacterium formed long filaments in dual-species biofilm communities with Actinomyces oris or Fusobacterium nucleatum. However, the TM7 isolate grew as short rods or cocci in dual-species biofilms with Porphyromonas gingivalis, Prevotella intermedia, Parvimonas micra, or Streptococcus gordonii, forming notably robust biofilms with the latter two species. The ability to cultivate TM7 axenically should majorly advance understanding of the physiology, genetics, and virulence properties of this novel candidate division oral bacterium.