Oral bacteria in plaque and invading buccal cells of young orthodontic patients

Telehealth Parenting Program and Salivary Epigenetic Biomarkers in Preschool Children With Developmental Delay: NIMHD Social Epigenomics Program

Importance

Children with developmental delays are at a heightened risk of experiencing mental health challenges, and this risk is exacerbated among racially minoritized children who face disproportionate adversity. Understanding the impact of parenting interventions on biological markers associated with these risks is crucial for mitigating long-term health disparities.

Objective

To examine the effect of 20 weeks of an internet-based parent-child interaction training (iPCIT) program on biomarkers associated with aging and chronic inflammation among preschoolers with developmental delay at 12-month follow-up.

Design, Setting, and Participants

An observational secondary analysis of data from a randomized clinical trial conducted from March 17, 2016, to December 15, 2020, to assess changes in salivary DNA methylation (DNAm)-derived biomarkers following iPCIT intervention. Participants were recruited from 3 Part C early intervention sites in a large southeastern US city. Eligible participants included children recruited within 3 months of their third birthday who had a Child Behavior Checklist Externalizing Problems T score greater than 60 and provided saliva in at least 1 study wave. Data analysis was conducted May 2023 to April 2024.

Intervention

Participants received either iPCIT (a telehealth therapeutic intervention focused on enhancing the parent-child relationship and addressing behavioral challenges in young children) or referrals as usual.

Main Outcomes and Measures

DNAm at the 12-month follow-up was assessed using the Infinium HumanMethylationEPIC Bead Chip Assay to derive biomarkers DunedinPACE, C-reactive protein (CRP), and interleukin-6 (IL-6). Analyses were intent-to-treat and used path analysis.

Results

A total of 71 children (mean [SD] age, 36.27 [0.61] months 51 male [71.8%] and 20 female [28.2%]) were analyzed, of whom 34 received iPCIT and 37 received referrals as usual. The iPCIT group had a slower pace of aging (β = 0.26; 95% CI, 0.06 to 0.50; P = .03) and less DNAm-derived CRP (β = 0.27; 95% CI, 0.05 to 0.49; P = .01) relative to the control condition at the 12-month follow-up. These associations remained significant after accounting for baseline DNAm score, child demographics, and symptom severity, and were independent of predicted buccal epithelial cell proportion for both DunedinPACE and CRP. There was no association with DNAm-derived IL-6 (β = 0.14; 95% CI, -0.08 to 0.36; P = .21).

Conclusions and Relevance

In this study of a parenting intervention, iPCIT, the association of intervention with decreased molecular markers of inflammation and biological aging suggests their potential to modify aspects of the biological embedding of stress. Understanding the systemic biological impact of such interventions offers insights into addressing health disparities and promoting resilience among vulnerable populations.

Trial Registration

ClinicalTrials.gov Identifier: NCT03260816.

The intriguing strategies of Tannerella forsythia's host interaction

Tannerella forsythia, a member of the "red complex" bacteria implicated in severe periodontitis, employs various survival strategies and virulence factors to interact with the host. It thrives as a late colonizer in the oral biofilm, relying on its unique adaptation mechanisms for persistence. Essential to its survival are the type 9 protein secretion system and O-glycosylation of proteins, crucial for host interaction and immune evasion. Virulence factors of T. forsythia, including sialidase and proteases, facilitate its pathogenicity by degrading host glycoproteins and proteins, respectively. Moreover, cell surface glycoproteins like the S-layer and BspA modulate host responses and bacterial adherence, influencing colonization and tissue invasion. Outer membrane vesicles and lipopolysaccharides further induce inflammatory responses, contributing to periodontal tissue destruction. Interactions with specific host cell types, including epithelial cells, polymorphonuclear leukocytes macrophages, and mesenchymal stromal cells, highlight the multifaceted nature of T. forsythia's pathogenicity. Notably, it can invade epithelial cells and impair PMN function, promoting dysregulated inflammation and bacterial survival. Comparative studies with periodontitis-associated Porphyromonas gingivalis reveal differences in protease activity and immune modulation, suggesting distinct roles in disease progression. T. forsythia's potential to influence oral antimicrobial defense through protease-mediated degradation and interactions with other bacteria underscores its significance in periodontal disease pathogenesis. However, understanding T. forsythia's precise role in host-microbiome interactions and its classification as a keystone pathogen requires further investigation. Challenges in translating research data stem from the complexity of the oral microbiome and biofilm dynamics, necessitating comprehensive studies to elucidate its clinical relevance and therapeutic implications in periodontitis management.

Manual vs. interactive power toothbrush on plaque removal and salivary Streptococcus mutans and Lactobacillus casei levels : Single-center, examiner-blinded, randomized clinical trial in orthodontic patients

INTRODUCTION

The purpose of this study was to compare efficacy of a manual and an interactive power toothbrush in orthodontic patients by assessing periodontal indexes and bacterial content of saliva samples.

METHODS

Forty patients (20 females, 20 males; age range 12-18 years) with fixed orthodontic appliances were included in the study. The patients were randomly divided into two groups in a 1:1 ratio using sealed envelopes: group 1: manual toothbrush (Oral‑B Ortho Brush, Procter&Gamble Company, Dublin, Ireland), group 2: interactive power toothbrush (Oral‑B Genius 8900, Procter&Gamble Company, Marktheidenfeld, Germany). All participants were given the same toothpaste (Colgate Triple Action, Colgate-Palmolive, New York, NY, USA). The brushing procedure for each patient was described in detail, both orally and visually, utilizing a video demonstration. Plaque and bleeding index scores were recorded for both the lower and upper arches at the beginning of the study (T0) and at weeks 6 (T1) and 12 (T2). In addition, the numbers of Streptococcus (S.) mutans, Lactobacillus (L.) casei, and Porphyromonas (P.) gingivalis bacteria were determined using a real-time polymerase chain reaction (PCR) analysis in saliva samples collected at T0, T1, and T2 times. Mann-Whitney U test and Student's t test were used to compare data between the groups, and one-way analysis of variance (ANOVA) and Friedman tests were used to compare data from different time intervals for each group.

RESULTS

Plaque index values were greater in group 1 at T1 and T2, although there was no difference between the groups at T0. The gingival index scores of both groups were similar at T0, T1, and T2. While group 2 had a larger number of salivary S. mutans at T0 and T2, there was no significant difference between the groups at T1. At all three time points, there was no significant difference in salivary L. casei levels between the groups.

CONCLUSIONS

Although the interactive power toothbrush was more effective at removing plaque than the manual toothbrush, the results of the gingival index did not reflect the plaque scores. The number of certain salivary bacteria and brush type did not appear to have a clear relationship.

Leveling and alignment time and the periodontal status in patients with severe upper crowding treated by corticotomy-assisted self-ligating brackets in comparison with conventional or self-ligating brackets only: a 3-arm randomized controlled clinical trial

INTRODUCTION

The lengthy period of time required is one of the main reasons patients refuse orthodontic treatment. In addition, treatment may have negative effects on periodontal tissues.

OBJECTIVE

This study aimed to evaluate the overall time needed for leveling and alignment and the periodontal indices in adult patients with severe crowding. Patients were treated using either self-ligating brackets associated with flapless corticotomy (SLBs + FC group), self-ligating brackets alone (SLBs group), or conventional brackets (CBs group) alone.

MATERIALS AND METHODS

A total of 57 adult patients (10 male patients, 47 female patients) referred to the Department of Orthodontics, the University of Damascus Dental School from August 2018 to March 2019, were enrolled in this trial. The patients were randomly allocated to 1 of 3 groups: CBs (mean age: 19.62 ± 2.42 years), SLBs (mean age: 19.98 ± 2.84 years), or SLBs + FC (mean age: 20.67 ± 2.59 years). The overall alignment time for the upper anterior teeth was calculated. The following periodontal parameters were measured at 5 assessment times: plaque index, gingival index, papillary bleeding index, and probing depth.

RESULTS

The average leveling and alignment time was 81.89 ± 9.49 days, 123 ± 10.69 days, and 165.25 ± 13.05 days for the SLBs + FC group, the SLBs group, and the CBs group, respectively. A significant reduction in the overall alignment duration was found in the SLBs + FC group by 50%, and in the SLBs group by 25%, compared to the control group, with a statistically significant difference among the 3 groups (P < 0.001). There were statistically significant differences in the periodontal indices (except probing depth) after 1 month, with values greater in the SLBs + FC group (P < 0.05).

CONCLUSIONS

Using self-ligating brackets in combination with flapless corticotomy may be effective in accelerating upper dental decrowding in adult patients, with a reduction of 50% of the normal treatment time using traditional brackets. Using self-ligating brackets alone reduced treatment time by 25%. The adjunctive flapless corticotomy did not cause clinically negative effects on the periodontal tissues.

Comparison of Subgingival and Buccal Mucosa Microbiome in Chronic and Aggressive Periodontitis: A Pilot Study

Periodontal microorganisms not only colonize subgingival pockets, but also are detected on various mucous membranes in patients with periodontitis. The object of this pilot study was, using the next-generation sequencing of 16S RNA gene, to characterize the microbiota in two oral habitats (buccal mucosas and subgingival pockets) in patients with different forms of periodontitis. Thirty-two buccal swab samples and 113 subgingival samples were obtained from eleven subjects with chronic periodontitis (ChP), twelve subjects with aggressive periodontitis (AgP), and nine periodontally healthy individuals (HP). Using Miseq Sequencing of 16S rRNA gene, we found that the subgingival and buccal mucosa microbiome of ChP and AgP patients both differed from HP. Meanwhile, Veillonella, Treponema, Filifactor, Fretibacterium, Peptostreptococcaceae_[XI][G-6], Peptostreptococcaceae_[XI][G-5], Bacteroidetes_[G-5], Bacteroidetes_[G-3], Peptostreptococcaceae_[XI][G-4], Peptostreptococcaceae_[XI][G-2] significantly increased both in buccal and subgingival plaque samples in periodontitis subjects (ChP and AgP) compared with HP. Moreover, the results based on the Unweighted UniFrac distance showed that buccal and subgingival plaque samples from the same individuals show higher community divergence than same habitats from different subject samples. This study demonstrated that the microbiome of buccal mucosa can be influenced by periodontitis. However, subgingival and buccal mucosa microbiome seem to be characterized by species-specific colonization patterns. This pilot study provides a glimpse at the changes of subgingival and buccal mucosa associated with periodontitis from a holistic view. Further studies should be taken to illuminate the interplay between these detected changes and periodontitis development.

Comparative Evaluation of Plaque Inhibitory and Antimicrobial Efficacy of Probiotic and Chlorhexidine Oral Rinses in Orthodontic Patients: A Randomized Clinical Trial

Background

Antimicrobial agents serve as an effective adjunct in plaque control, and chlorhexidine has been the gold standard. However, the philosophy that natural agents are better for children's oral health is on the rise. Probiotic technology represents a breakthrough approach to maintain oral health by utilizing natural beneficial bacteria commonly found in healthy mouths.

Aim and Objective

To compare efficacy of probiotic and chlorhexidine oral rinses in orthodontic patients.

Materials and Methods

30 healthy patients undergoing fixed orthodontic treatment were randomly selected for the study by block randomization and allocation concealment and were divided into three groups: group a, 0.2% chlorhexidine mouthwash; group b, probiotic mouthwash; and group c, a control group.

Results

Probiotic and chlorhexidine groups had significantly decreased plaque indices as compared to the control group. However, greater improvement was seen in the gingival indices than plaque indices with better results in the probiotic group than the chlorhexidine group. No statistical significance was observed in the streptococcus count of probiotic and chlorhexidine groups at the end of the intervention period.

Conclusion

The comparison of probiotics to chlorhexidine has proven that probiotics are as effective as chlorhexidine as an adjunctive chemical plaque control agent.

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.

Biofilm formation in Haas palatal expanders with and without use of an antimicrobial agent: an in situ study

Orthodontic appliances causes specific alterations in oral environment, including reduction of pH, increase of dental biofilm and elevation of salivary microbial levels, causing an increased risk for dental caries. This study evaluated, using microbial culture and scanning electron microscopy (SEM), the in situ contamination by mutans streptococci (MS) of different surfaces of Haas palatal expanders with and without use of chlorhexidine gluconate mouthrinses (CHX). Thirty-four patients were randomly assigned to two groups (n = 17/group), using placebo (Group I) and 0.12% CHX (Group II-Periogard^® ) mouthrinses twice a week. After 4 months, appliances were submitted to microbiological processing and after fragments were analyzed by SEM. Mann-Whitney U test (α = 5%) was used to assess differences between groups on the appliances' different surfaces and to compare the contamination on the free and nonfree surfaces of these components. There was no difference (p = 0.999) between groups regarding the number of MS colonies/biofilms on the nonfree surfaces, which showed intense contamination. However, free surfaces of Group II presented less contamination (p < 0.001) than those of Group I in all appliances' components. Results of the microbial culture were confirmed by SEM. Use of 0.12% CHX was effective in reducing the formation of MS colonies/biofilms on free surfaces of Haas expanders, in situ.

In vitro evaluation of microbial contamination of orthodontic brackets as received from the manufacturer using microbiological and molecular tests

OBJECTIVE

To test the null hypothesis that orthodontic brackets as supplied by manufacturers do not have microbial contamination.

MATERIALS AND METHODS

The sample comprised 140 brackets of four different commercially available brands, used directly from the manufacturer's packaging, divided into 14 groups (n  =  10 brackets each). Of the 140 pieces, 60 were full cases and 80 were replacement brackets. Materials were tested to detect bacterial growth, analyze types of bacteria present (biochemical test), and identify bacteria (molecular test with polymerase chain reaction [PCR]).

RESULTS

In two of 12 groups the brackets showed microbial contamination: group 1, Morelli full case brackets, and group 12, Abzil-3M Unitek replacement brackets. Staphylococcus aureus and Staphylococcus epidermidis were the bacteria identified in groups 1 and 12, respectively (suggested by the biochemical test and confirmed by PCR).

CONCLUSIONS

Brackets of two brands (Morelli and Abzil-3M Unitek) were found to be contaminated by bacteria in the original packages supplied by the manufacturers, which suggests a risk for patient contamination. These data suggest that the manufacturers of these materials should improve the quality control of the packaging used, including sterilization, for the security of patient health.

Combined effects of repeated oral hygiene motivation and type of toothbrush on orthodontic patients: a blind randomized clinical trial

OBJECTIVE

To investigate the effects on plaque index (PI) scores of manual or electric toothbrush with or without repeated oral hygiene instructions (OHI) and motivation on patients wearing fixed orthodontic appliances.

MATERIALS AND METHODS

One month after the orthodontic fixed appliance bonding on both arches, 60 patients were randomly assigned to four groups; groups E1 (n  =  15) and E2 (n  =  15) received a powered rotating-oscillating toothbrush, and groups M1 (n  =  15) and M2 (n  =  15) received a manual toothbrush. Groups E1 and M1 received OHI and motivation at baseline (T0) and after 4, 8, 12, 16, and 20 weeks (T4, T8, T12, T16, and T20, respectively) by a Registered Dental Hygienist; groups E2 and M2 received OHI and motivation only at baseline. At each time point a blinded examiner scored plaque of all teeth using the modified Quigley-Hein PI.

RESULTS

In all groups the PI score decreased significantly over time, and there were differences among groups at T8, T12, T16, and T20. At T8, PI scores of group E1 were lower than those of group E2, and at T12, T16, and T20, PI scores of groups M1 and E1 were lower compared to those of groups M2 and E2. A linear mixed model showed that the effect of repeated OHI and motivation during time was statistically significant, independently from the use of manual or electric toothbrush.

CONCLUSIONS

The present results showed that repeated OHI and motivation are crucial in reducing PI score in orthodontic patients, independent of the type of toothbrush used.

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.

Microbial changes in subgingival plaque and polymicrobial intracellular flora in buccal cells after fixed orthodontic appliance therapy: a preliminary study

The oral ecosystem is strictly related to a balance maintained by specific niches recognized as sites, where oral bacteria can metabolize avoiding the immune system response. The oral bacteria species that colonize the ecological niches vary during fixed orthodontic treatment, with a prevalence of periodontal bacterial species. Qualitative analysis of five periodontal pathogens was used to investigate the microbial colonization rate in the crevice and buccal epithelial cells. The presence of inadequate oral hygiene was considered as a modulation variable for microbial colonization. Statistical analysis was performed by Fisher's exact test, ANOVA, and Pearson correlation. A P value lower than 0.05 was assumed as statistically significant. Tannerella forsythia was the only periodontal pathogen detected with a statistically admissible frequency. The positivity for Tannerella forsythia was correlated to sampling time and oral hygiene motivation. In buccal epithelial cells, both factors contributed to microbial decrease (P < 0.05), whereas, in crevice, oral hygiene motivation promoted a decrease in the microbial colonization rate (P < 0.05). According to microbiological findings, it is possible to identify how correct motivation for oral hygiene is more than enough to modulate or to avoid an upset of the oral ecosystem balance in early stages of orthodontic treatment.

Periodontal health and relative quantity of subgingival Porphyromonas gingivalis during orthodontic treatment

OBJECTIVE

To examine periodontal changes and the relative quantity of subgingival Porphyromonas gingivalis during orthodontic treatment.

MATERIALS AND METHODS

The study subjects were recruited consecutively among malocclusion patients seeking orthodontic treatment. Group A comprised 28 subjects (17.6 ± 5.68 years of age) at the beginning of orthodontic treatment, and group B comprised 20 subjects (17.8 ± 4.49 years of age) at the end of orthodontic treatment. Plaque index (Pl.I), gingival index (GI), and probing pocket depth (PPD) were measured before and after appliance placement in group A and before and after appliance removal in group B. Real-time quantitative polymerase chain reaction was used to quantify P. gingivalis in subgingival plaque at each time point.

RESULTS

There was a significant increase in Pl.I and GI during the first 3 months of appliance placement but a significant decrease in Pl.I, GI, and PPD during the first 6 months after appliance removal. The carriage and relative quantity of subgingival P. gingivalis were high at the end of orthodontic treatment, and they decreased significantly after appliance removal. The amount of subgingival P. gingivalis after appliance removal (for a period of 6 months) was higher than the amount measured before appliance placement.

CONCLUSIONS

Fixed orthodontic treatment is conducive to dental plaque accumulation and gingival inflammation. In our study, after removal of orthodontic appliances, periodontal health improved, and the carriage and amount of subgingival P. gingivalis decreased. Nevertheless, the amount of subgingival P. gingivalis remained high for 6 months after appliance removal, and this finding might imply a potential risk to periodontal health in certain patients.

Streptococcus Mutans and Streptococcus Sobrinus are Able to Adhere and Invade Human Gingival Fibroblast Cell Line

Streptococcus mutans and Streptococcus sobrinus, the principal etiologic agents of caries decay of teeth, are generally acquired in oral cavity at the moment of tooth eruption. However, as S. mutans has been detected in oral cavity of predentate children, the eruption of teeth seems not to be a necessary prerequisite, suggesting that this species may be not confined to dental plaque. Here, we evaluate the ability of S. mutans and S. sobrinus in planktonic and biofilm lifestyle to adhere, invade and survive within human gingival fibroblast (HGF-1) cells. Planktonic and biofilm streptococci adhered and invaded host cells to different extents, showing higher efficiencies of biofilm than planktonic counterparts. Moreover, planktonic and biofilm streptococci showed the same percentage of survival within host cells. Transmission electron and confocal microscopy observations confirmed intracellular localization of planktonic and biofilm bacteria. The adhesion, invasion and survival abilities within human oral cells may be considered S. mutans and S. sobrinus virulence mechanisms to colonize and persist in the oral cavity in the absence of tooth surface.

The oral microbiota: living with a permanent guest

The oral cavity of healthy individuals contains hundreds of different bacterial, viral, and fungal species. Many of these can associate to form biofilms, which are resistant to mechanical stress or antibiotic treatment. Most are also commensal species, but they can become pathogenic in responses to changes in the environment or other triggers in the oral cavity, including the quality of an individual's personal hygiene. The complexity of the oral microbiome is being characterized through the newly developed tools of metagenomics. How the microbiome of the oral cavity contributes to health and disease is attracting the interest of a growing number of cell biologists, microbiologists, and immunologists.

Diminished treatment response of periodontally diseased patients infected with the JP2 clone of Aggregatibacter (Actinobacillus) actinomycetemcomitans

This longitudinal study evaluated the response to periodontal treatment by subjects infected with either JP2 (n = 25) or non-JP2 (n = 25) Aggregatibacter (Actinobacillus) actinomycetemcomitans. Participants were treated during the first 4 months by receiving (i) scaling and root planing, (ii) systemic antibiotic therapy, and (iii) periodontal surgery. Probing depth (PD), clinical attachment level (CAL), and gingival and plaque indices (GI and PI, respectively) were monitored at baseline and at 12 months, along with DNA-PCR-based subgingival detection of JP2 or non-JP2 A. actinomycetemcomitans. At baseline, PD, CAL, and GI scores were statistically higher in the JP2 strain-positive group than the non-JP2-strain-positive group. At 12 months, PD, CAL, and GI scores had decreased significantly for both groups, but the reduction rates of PD and CAL were higher in the non-JP2-strain-positive group. Among JP2-strain-positive patients in the baseline, patients who remained JP2 strain positive at 12 months showed significantly higher GIs than did the patients who had lost the detectable JP2 clone. Patients who remained JP2 strain positive at 12 months appeared to be more resistant to mechanical-chemical therapy than did those who were still non-JP2 strain positive, while the elimination of JP2 A. actinomycetemcomitans remarkably diminished gingival inflammation. Early identification and elimination of the JP2 clone of A. actinomycetemcomitans will enable practitioners to effectively predict the outcome of treatments applied to periodontal patients.

Orthodontic Attachments and Chlorhexidine-Containing Varnish Effects on Gingival Health

Objective: To compare the severity of clinical inflammation parameters and the level of the inflammatory mediator interleukin (IL)–1β during orthodontic treatment by using brackets and bands. In addition, the effect of a chlorhexidine-containing varnish was investigated.

Materials and Methods: This prospective randomized controlled trial included 40 healthy children who required an orthodontic treatment of mild crowding. Either brackets or bands were randomly allocated to the premolars with a split-mouth design. Twenty of the children received a chlorhexidine-containing varnish during the treatment (0, 12, 24 weeks), while the remaining children served as a control group. Prior and until 24 weeks after the insertion, data were recorded regarding the pocket depth (PD), the gingival appearance (gingival index [GI]), and the plaque accumulation (plaque index [PI]). Gingival crevicular fluid was collected as well. A quantitative enzyme-linked immunoassay technique was used to detect differences in IL-1β.

Results: The PDs and the gingival index of teeth with brackets showed significantly lower values in comparison with teeth treated with bands (P = .0001). The IL-1β levels confirmed these findings. In contrast, the PI showed higher values for the teeth with brackets (P = .0001). The teeth that received a chlorhexidine-containing varnish showed significantly lower values in the follow-ups for most of the evaluated parameters (PDBand, PIBand, PIBracket, GIBand, GIBracket; P &lt; .015).

Conclusion: The clinically observed parameters as well as the IL-1β levels reflected the higher impact of bands on gingival health. These values showed a significant decrease after application of a chlorhexidine-containing varnish. However, the PI showed higher values for the teeth with brackets.