Effect of fixed orthodontic appliances on salivary microbial parameters at 6 months: a controlled observational study

Changes in the pH and the Flow Rate of Saliva During Orthodontic Treatment with Fixed Orthodontic Appliances: A Systematic Review

This systematic review aimed to assess salivary flow and pH changes at various stages of orthodontic treatment with fixed appliances. A comprehensive searches in electronic databases, including Medline, ResearchGate, Web of Science, SAGE Journals, Cochrane Oral Health Group's Trials Register, and ScienceDirect, without any publication date restrictions until January 2022 was conducted. The Pre-ferred Reporting Items for Reporting Systematic Reviews and Meta Analyses (PRISMA 2020 version) protocol was adopted and the risk of bias assessments were performed using the Cochrane ROBINS-I tool for non-randomized studies. Out of 4902 articles, 25 were fully evaluated, and seven studies that met the inclusion criteria were included in the review. The results showed that orthodontic treatment with fixed orthodontic appliances increased the stimulated salivary flow rate during various stages of treatment. However, the unstimulated salivary flow rate showed different changes. Furthermore, stimulated salivary pH increased, whereas unstimulated salivary pH significantly decreased, depending on the specific period of orthodontic treatment. Overall, fixed orthodontic appliances have an impact on salivary flow rate and pH during different stages of treatment. Nevertheless, the current literature is insufficient to draw definitive conclusions. More well-designedrandomized studies with larger sample sizes are necessary to confirm these findings.

Potential Uses of Adhatoda Vasica in Orthodontics

Plaque control, pain control, and modulation of inflammatory mediators to accelerate or stabilize tooth movements are hot issues in orthodontics. The recent advent of phytochemicals as biological mediators has opened new vistas in the aforementioned areas of orthodontics. Adhatoda vasica has caught the attention of investigators due to multiple properties related to orthodontics. This study addresses the potential areas of use of A. vasica in orthodontics, which provide ideas for further investigations. A. vasica possesses antibacterial activity, antifungal activity, anti-oxidant effect, anti-inflammatory activity, analgesic effect, osteogenic, and osteoclastic activities. A. vasica has huge potential in orthodontics, whereas all these vistas need careful and methodical testing before use in clinical orthodontics. In the future, investigators can focus on these aspects of the use of A. vasica to develop products.

Pre-treatment oral microbiome analysis and salivary Stephan curve kinetics in white spot lesion development in orthodontic patients wearing fixed appliances. A pilot study

BACKGROUND

White spot lesions (WSLs) are a formidable challenge during orthodontic treatment, affecting patients regardless of oral hygiene. Multifactorial in nature, amongst potential contributors to their development are the microbiome and salivary pH. The aim of our pilot study is to determine if pre-treatment differences in salivary Stephan curve kinetics and salivary microbiome features correlate with WSL development in orthodontic patients with fixed appliances. We hypothesize that non-oral hygiene determined differences in saliva could be predictive of WSL formation in this patient population through analysis of salivary Stephan curve kinetics, and that these differences would further manifest as changes in the oral microbiome.

METHODS

In this prospective cohort study, twenty patients with initial simplified oral hygiene index scores of "good" that were planning to undergo orthodontic treatment with self-ligating fixed appliances for at least 12 months were enrolled. At pre-treatment stage, saliva was collected for microbiome analysis, and at 15-minute intervals after a sucrose rinse over 45 min for Stephan curve kinetics.

RESULTS

50% of patients developed a mean 5.7 (SEM: 1.2) WSLs. There were no differences in saliva microbiome species richness, Shannon alpha diversity or beta diversity between the groups. Capnocytophaga sputigena exclusively and Prevotella melaninogenica predominantly were found in WSL patients, while Streptococcus australis was negatively correlated with WSL development. Streptococcus mitis and Streptococcus anginosus were primarily present in healthy patients. There was no evidence to support the primary hypothesis.

CONCLUSIONS

While there were no differences in salivary pH or restitution kinetics following a sucrose challenge and no global microbial differences in WSL developers, our data showed change in salivary pH at 5 min associated with an abundance of acid-producing bacteria in saliva. The results suggest salivary pH modulation as a management strategy to inhibit the abundance of caries initiators. Our study may have uncovered the earliest predecessors to WSL/caries development.

Effect of fixed orthodontic appliances on gingival status and oral microbiota: a pilot study

Background

This pilot study aimed to investigate how fixed orthodontic appliances simultaneously applied on the upper and lower arches affect the oral environment in the medium term.

Methods

The oral status of 30 orthodontic patients was evaluated using the number of decay-missing-filled teeth (DMFT), plaque (PI), and gingival indices (GI) before bonding of fixed orthodontic appliances (T0) and during the therapy (T1). Besides, the gingival crevicular fluid (GCF) and a dental plaque were collected. Samples were analyzed for selected Candida sp. and for 10 selected oral bacteria using mass spectroscopy and multiplex polymerase chain reaction, respectively.

Results

In 60% of patients, deterioration of the oral status (demonstrated by the increase in PI) was recorded (p < 0.05). Moreover, the changes in PI correlated with those of GI (p < 0.001). At the T1 time point, the mean representation of Actinomyces sp. in the total prokaryotic DNA in GCF and dental plaque of individual patients increased compared to T0 (p < 0.05). The probability of finding any of the 7 selected periodontal bacteria combined with Candida sp. was 10 times higher in patients in whom PI deteriorated between T0 and T1 (p < 0.01).

Conclusions

Changes in the oral microbial diversity and an increase in PI were observed in the medium term after bonding of orthodontic appliance. Our study highlights the importance of a complex approach in this type of research as the association between clinical characteristics and combined microbial parameters is higher than when evaluated separately.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02511-9.

Clinical evaluation of periodontal status in subjects with multibracket appliances and the role of age and gender during initial months of fixed orthodontic treatment

Background

During fixed orthodontic treatment, the presence of various fixed appliances like brackets in the oral cavity for a long period leads to various changes in the oral microflora, ultimately affecting the periodontal health of the teeth. Hence, the current study was performed to clinically assess the periodontal status of the subjects undergoing fixed orthodontic treatment and to evaluate the role of age and gender during the first 6 months of treatment.

Materials and Methods

Forty-one subjects (26 females and 15 males) in the age range of 12-28 years scheduled for fixed orthodontic treatment were included in the study. Twenty-eight subjects were adolescents with a mean age of 13.96 years and 13 were adults with a mean age of 22.38 years. Plaque index (PI) and gingival index (GI) were recorded at the beginning and the end of 1, 2, 3, and 6 months of the treatment, and pocket probing depth (PPD) was evaluated at the start and after 6 months of fixed orthodontic treatment.

Results

The study showed a statistically significant increase in the mean values of PI (1.10 ± 0.264) and GI (0.929 ± 0.220) over a period of 6 months when compared with the baseline mean values, i.e., 0.557 ± 0.224 and 0.423 ± 0.329, respectively (P < 0.001). The mean PPD values exhibited no significant change. Effect of orthodontic treatment on adolescents/adults and between genders did not statistically differ.

Conclusions

Fixed orthodontic treatment with multibracket appliances significantly increases plaque accumulation leading to significant inflammatory changes in the gingival tissues without any significant changes in the clinical probing depths of the pockets regardless of age and gender.

Screening of biochemical parameters in the orthodontic treatment with the fixed appliances: A follow-up study

The aim of this study was to assess the changes in vital salivary parameters such as calcium, phosphorous, alkaline phosphatase, buffering capacity, pH, flow-rate and Oral Hygiene Index (OHI) in fixed orthodontic treatment patients during the retention period. In this study, saliva samples were collected from 35 patients before de-bonding (T₀) and after 4 to 5 weeks of de-bonding or on retention period (T₁). The biochemical parameters such as calcium, phosphorous and alkaline phosphatase levels were measured with saliva samples. Additionally, flow-rate, buffering capacity, pH and OHI levels was also measured. The current study results showed reduction in calcium, alkaline phosphatase, pH, flow-rate and OHI levels during T₁ (p < 0.05). However, phosphorous and buffering capacity levels were increased at T₁. The phosphorous levels showed non statistically significant difference when compared between T₀ and T₁ (p = 0.42). The remaining salivary parameters showed statistically significant difference when compared between T₀ and T₁ (p < 0.05). The present study concludes that there was a statistically significant decrease in the calcium, alkaline phosphatase, pH, flow rate and OHI values a month after de-bonding and increased in the buffering capacity values.

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".

Physiological and Immunological Changes Associated with Oral Microbiota When Using a Thermoplastic Retainer

Background: The study examined the oral microbiota, physiological and immunological changes in patients using thermoplastic retainers during three months of use. Methods: The study included several steps. Firstly, 10 swabs were collected from the buccal and palatal surfaces of the teeth of the patients, approximately 2 mL of saliva was collected from the same patients and 2 mL of saliva was collected from 10 healthy people to measure the pH and secretory IgA level. This was followed by the isolation and identfication of the bacterial isolates in the patient samples. Then, isolate susceptibility toward chlorhexidine (CHX) and their adhesion ability to thermoplastic retainer surfaces was measured. In addition to that the study estimated the numbers of Lactobacillus and Streptooccus mutans colonies during three months and finally, a comparsion of pH acidity and IgA level between the patients and healthy people was performed. The results showed the predominant bacteria during the three months were Lactobacillus spp. and Streptococcus spp. followed by different rates of other bacteria. Raoultella ornithinolytica showed more resistance to CHX while Lactobacillus spp. showed more sensitivity. Streptococcus mutans colony levels were higher than Lactobacillus spp. colonies during the three months, also S. mutans had the highest value in adherence to retainer thermoplastic. Finally, pH acidity showed a highly significant difference (p ≤ 0.05) in the third month, like IgA levels (p ≤ 0.05). Conclusions: According to the results obtained from the current study, the researchers noted that the thermoplastic retainers helped change the oral cavity environment.

Salivary microbial changes during the first 6 months of orthodontic treatment

Background

Orthodontic treatment is widely used to treat malocclusion. However, the influence of treatment on the oral microbiome remains unclear. In this study, we investigated salivary microbial changes in patients undergoing orthodontic treatment.

Methods

In total, 19 orthodontic patients participated in this study. Saliva samples were collected at the following three timepoints: before (T0) and 3 months (T1) and 6 months (T2) after the placement of orthodontic appliances. High-throughput sequencing was performed based on the 16S rRNA gene V4 region.

Results

The phyla of Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria and Fusobacteria were predominant. Observed Species, Chao1 and ACE, which represent α diversity, were significantly decreased at T1 and subsequently increased at T2. In addition, the β diversity at T1 based on the Bray-Curtis distances differed from T0 and T2. The relative abundances of Prevotella, Porphyromonas and Peptostreptococcus were decreased with treatment, whereas those of Capnocytophaga and Neisseria exhibited the opposite results. In total, 385 of 410 operational taxonomic units were shared at T0, T1 and T2. The co-occurrence networks with hub nodes at T1 were the most complex.

Conclusion

Orthodontic treatment temporarily affected the saliva microbial community. This dynamic alteration in species did not induce deterioration in oral health. Oral hygiene instructions were necessary and should be emphasized during each visit. Further studies with longer observation periods and more participants are required.

The effect of incorporation Nano Cinnamon powder on the shear bond of the orthodontic composite (an in vitro study)

Objectives

One of the causes of dental caries that occurs due to orthodontic treatment is the lack of antibacterial properties in orthodontic adhesive. This study was designated to investigate the effect of orthodontic resin modified by incorporating Nano Cinnamon powder on the shear bond strength of orthodontic brackets.

Materials and methods

Heliosit Orthodontic Resin, a photo-activated light cure resin was modified by the addition of Cinnamon in the form of Nano particle powder. Twenty uniform disks were made, 5 as a control and 5 for each concentration of the 1%, 3% and 5% wt/wt Cinnamon modified resin. Their antimicrobial activity against Streptococcus Mutans was tested using the disk diffusion method. Then, the most effective concentration of the modified resin was used to bond metal orthodontic brackets to human extracted premolars. The universal testing machine was used to record the shear bond strength of the control and the modified resin. Also, the adhesive remnant index was measured.

Results

Disc diffusion method showed that the 3% wt/wt Cinnamon powder modified resin was more effective than 1% with a larger bacterial inhibition zone. Shear bond strengths of the control were 8.50 MPa and 7.20 MPa for the 3% Cinnamon modified resin with no significant difference between them. Also, no significant difference was recorded in the adhesive remnant index scores between the control and the modified resin groups.

Conclusion

Findings of this study revealed that the incorporation of 3% Cinnamon Nano particles in orthodontic resin produced an antibacterial effect against Streptococcus mutans without compromising the shear bond strength.

Clinical relevance

Incorporation of Cinnamon Nano particles in orthodontic resin may reduce caries formation around brackets during treatment course.

Real-time polymerase chain reaction quantification of the salivary levels of cariogenic bacteria in patients with orthodontic fixed appliances

Aim

The aim was to investigate the salivary detection frequencies and quantities of caries‐associated bacteria from patients with orthodontic brackets.

Methods

Patients wearing orthodontic brackets (n = 40, mean age = 26 years) and healthy controls without brackets (n = 40, mean age = 17 years) were enrolled in the study. Saliva samples from each patient was collected. After DNA purification, target species comprising streptococci and a Lactobacillus species were detected and quantified from the samples using polymerase chain reaction (PCR) and real‐time quantitative PCR.

Results

Detection frequencies did not differ between the orthodontic patients and the control subjects for any target species except for Streptococcus sobrinus, which showed significantly lower detection rates in orthodontic patients (p < .05). Lactobacillus casei and Streptococcus gordonii were found at the highest detection frequencies with both species being detected in 38 (95%) of the saliva samples of orthodontic patients. Similarly, L. casei and Streptococcus salivarius were the species with highest detection frequencies (35, 87.5%) in the control subjects. Real‐time PCR revealed that Streptococcus mutans and S. salivarius quantities were significantly higher in orthodontic patients than in the control subjects (p < .05).

Conclusions

Application of orthodontic brackets for 12 months leads to increased salivary levels of cariogenic bacteria and may serve as a potential risk factor for caries initiation.

Effects of orthodontic treatment and different fluoride regimens on numbers of cariogenic bacteria and caries risk: a randomized controlled trial

Background

Caries is an undesirable side-effect of treatment with fixed orthodontic appliances. Therefore, it is crucial to understand how orthodontic treatment and different fluoride regimens affect caries risk and individual risk factors.

Objective

To evaluate the effects of orthodontic treatment and different fluoride regimens on caries risk and caries risk factors, including cariogenic bacteria.

Trial design

Three-armed, parallel group, randomized, controlled trial.

Methods

Patients referred to the Specialist Clinic of Orthodontics, Mölndal Hospital, Sweden, were distributed randomly into the following groups: group I (Control group), 1450 ppm fluoride (F) toothpaste; group II, 1450 ppm F toothpaste plus 0.2 per cent sodium fluoride (NaF) mouth rinse; and group III, 5000 ppm F toothpaste. The inclusion criteria were: age 12-20 years; and bimaxillary treatment with fixed appliances. The primary outcome variables were: caries risk; and the numbers of cariogenic bacteria. Radiographs were taken before treatment to determine the caries status. Data were collected before treatment and after 1 year with a fixed appliance. The variables were compiled into a Cariogram to assess the caries risk. Comparisons were made over time within and between the groups. The generation of randomization sequence was performed in blocks of 30. Blinding was employed during the data analysis and the caries registration.

Recruitment

The clinical study duration was from October 2010 to December 2012.

Results

Overall, 270 patients were randomized, of which 15 were excluded from the study. Therefore, 255 patients were included in the analyses. The caries risk increased significantly during orthodontic treatment in group I (P < 0.0001), whereas groups II and III had unchanged caries risks. All the groups showed statistically significant increases in the numbers of cariogenic bacteria.

Harms

No harms were reported during the trial.

Conclusions

To avoid an increased risk of caries during orthodontic treatment, everyday use of high-fluoride toothpaste (5000 ppm F) or mouth rinse (0.2% NaF) in combination with ordinary toothpaste is recommended.

Registration

The trial was not registered.

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.

Effect of fixed orthodontic appliances on nonmicrobial salivary parameters

OBJECTIVES:

To examine possible changes in the levels of salivary antioxidants, C-reactive protein (CRP), cortisol, pH, proteins, and blood in patients treated with fixed orthodontic appliances.

MATERIALS AND METHODS:

Salivary samples from 21 orthodontic patients who met specific inclusion criteria were collected before the beginning of orthodontic treatment (T0; baseline), 1 hour after bonding (T1), and 4-6 weeks after bonding (T2). Oxidant-scavenging ability (OSA) was quantified using a luminol-dependent chemiluminescence assay. Cortisol and CRP levels were measured using immunoassay kits. pH levels and presence of proteins and blood in the samples were quantified using strip-based tests.

RESULTS:

A significant decrease in salivary pH was observed after bonding ( P = .013). An increase in oxidant-scavenging abilities during orthodontic treatment was detected, but the change was not statistically significant. Cortisol and CRP levels slightly increased after bonding, but the difference was small without statistical significance. Changes in the presence of proteins and blood were also insignificant.

CONCLUSIONS:

Exposure to fixed orthodontic appliances did not show a significant effect on salivary parameters related to inflammation or stress, with the exception of a significant but transient pH decrease after bonding.

Microbiological Changes and Caries-Preventive Effect of an Innovative Varnish Containing Chlorhexidine in Orthodontic Patients

The aim of this study was to investigate the effects of Cervitec Plus® on the level of mutans streptococcus (SM) and lactobacillus (LB) colonies and the development of white spot lesions (WSLs) in patients with fixed orthodontic appliances. Informed consent was obtained from 32 volunteers (age 16.5 ± 2.75 years). At baseline, levels of the bacterial colonies were determined in saliva and plaque using a chairside test (CRT Bacteria, Ivoclar-Vivadent, Schaan, Liechtenstein), and the number of WSLs was registered. After placing the fixed appliance, Cervitec Plus® or placebo varnishes (Ivoclar-Vivadent, Schaan, Liechtenstein) were applied monthly around the brackets and tubes, randomly in the right or left (test and placebo) quadrants of the same dental arch. SM and LB colonies in saliva and the SM colonies in plaque were determined on 11–21, 13–23, 15–25, and 16–26 teeth monthly over a 6-month period. At the sixth month, the number of new WSLs was determined. By the end of the study, compared with baseline, the ratio of saliva samples belonging to the low-risk category was significantly higher (p ≤ 0.01) from the 2nd month regarding the SM (76 vs. 52%) and LB (69 vs. 52%); reduction of SM in plaque was significantly greater on the test than placebo sides (6.69 ± 1.71 and 4.45 ± 1.60, respectively; p ≤ 0.01). The mean number of new WSLs was significantly lower in the test (0.06 ± 1.60) than in the placebo quadrants (1.13 ± 1.50, p ≤ 0.01). Conclusion: Monthly use of Cervitec Plus® could result in a significant improvement in oral health of orthodontic patients.

Influence of salivary parameters in the caries development in orthodontic patients-an observational clinical study

BACKGROUND

Previous studies have shown during the orthodontic treatment, the prevalence of active caries lesions (ACL) in 30 to 70% of patients.

AIM

To evaluate the effect of orthodontic treatment on salivary properties considering caries development.

DESIGN

Twenty two individuals (11-22 years) were assessed regarding caries, oral hygiene, sugar exposure, salivary flow rate (SFR), buffering capacity, pH, carbonic anhydrase VI (CA VI) and amylase activity, at baseline, 1, 3 and 6 months after the orthodontic appliances placement. Caries index was determined by Nyvad criteria. CA VI and amylase activities were performed by zymography and ELISA, respectively.

RESULTS

Buffering capacity decreased after 3 months (P < 0.0001) and showed positive correlation with pH at baseline and after 1 month in individuals who did not develop active caries lesions. Amylase activity decreased after 1 and 6 months (P = 0.0003) and presented positive correlation with CA VI in patients who developed ACL. SFR increased after 1 month (P = 0.0283) and showed positive correlation with CA VI activity after 3 months in individuals who did not develop ACL. Salivary pH showed negative correlation with CA VI after 1 month in patients who did not develop ACL. ACL were firstly diagnosed after 3 months.

CONCLUSIONS

The present study demonstrated that saliva of individuals under orthodontic treatment is subjected to changes in properties that have implications on the onset of ACL.

Cytomorphometric Analysis on the Effects of Components of Orthodontic Appliances on the Epithelial Cells of the Buccal Mucosa

Aim:

The aim of the present study was to evaluate the effect of fixed orthodontic appliances on the epithelial cells of buccal mucosa in patients undergoing orthodontic treatment.

Materials and Methods:

The study group included 30 healthy patients who were advised orthodontic treatment. Applying sterile cement spatula, scrapping of exfoliated buccal epithelial cells was performed from the middle part of the inner cheeks before starting the orthodontic treatment and at 1^st week, 2^nd week, 1 month, and 45 days after the treatment, followed by smearing and staining with Papanicolaou stain. Light microscope was used to score micronuclei, and independent two-tailed t-test was used for statistical analysis.

Results:

Micronuclei were assessed during the various stages of treatment and were recorded accordingly. At 1 week, there was increase in micronuclei number compared to before starting the treatment (day 0) and at 15^th day; 30^th day showed decrease in number compared to 1 week but increase compared to day 0. The results of day 45 were almost equal to day 0 with a significant P value (P < 0.001).

Conclusion:

Fixed orthodontic appliances induce increased micronuclei frequency, especially in the first weeks of treatment, however, these genotoxic effects tend to approach baseline levels in later period.

Evaluation of the antibacterial activity of a conventional orthodontic composite containing silver/hydroxyapatite nanoparticles

Background

One of the most important complications of fixed orthodontic treatment is the formation of white spots which are initial carious lesions. Addition of antimicrobial agents into orthodontic adhesives might be a wise solution for prevention of white spot formation. The aim of this study was to evaluate the antibacterial properties of a conventional orthodontic adhesive containing three different concentrations of silver/hydroxyapatite nanoparticles.

Methods

One hundred and sixty-two Transbond XT composite discs containing 0, 1, 5, and 10 % silver/hydroxyapatite nanoparticles were prepared and sterilized. Antibacterial properties of these composite groups against Streptococcus mutans, Lactobacillus acidophilus, and Streptococcus sanguinis were investigated using three different antimicrobial tests. Disk agar diffusion test was performed to assess the diffusion of antibacterial agent on brain heart infusion agar plate by measuring bacterial growth inhibition zones. Biofilm inhibition test showed the antibacterial capacity of composite discs against resistant bacterial biofilms. Antimicrobial activity of eluted components from composite discs was investigated by comparing the viable counts of bacteria after 3, 15, and 30 days.

Results

Composite discs containing 5 and 10 % silver/hydroxyapatite nanoparticles were capable of producing growth inhibition zones for all bacterial types. Results of biofilm inhibition test showed that all of the study groups reduced viable bacterial count in comparison to the control group. Antimicrobial activity of eluted components from composite discs was immensely diverse based on the bacterial type and the concentration of nanoparticles.

Conclusions

Transbond XT composite discs containing 5 and 10 % silver/hydroxyapatite nanoparticles produce bacterial growth inhibition zones and show antibacterial properties against biofilms.

Evaluation of changes in Streptococcus mutans colonies in microflora of the Indian population with fixed orthodontics appliances

BACKGROUND

Orthodontic therapy has oral ecological changes causing increased numbers of mutans streptococci in saliva and plaque. The purpose of this study was to estimate counts and colonization pattern of Streptococcus mutans after application of fixed orthodontic appliances.

MATERIALS AND METHODS

Plaque samples of randomly selected sixty patients were collected before placement of orthodontic appliances from buccal and labial aspects of the anterior teeth and four first molars and readings were recorded as T0. After placement of appliances (0.22 MBT preadjusted Gemini), i.e., 2(nd) and 3(rd) month, the plaque samples were collected again from same site and readings were recorded as T1 and T2, respectively. Counts of S. mutans in these patients were determined by using DM Strips (Orion Diagnostic, Espoo, Finland). Kruskal-Wallis test and Mann-Whitney U-test were used to find out significant differences between different time interval for Dentocult score for S. mutans in orthodontic patients (P < 0.001).

RESULTS

Prior to the treatment, 46 patients (76%) showed mild and 14 patients (24%) showed moderate colonization of S. mutans. After treatment, the severity of colonization increased showing fifty patients (84%) moderate and six patients (10%) showing severe colonization of S. mutans at T1, which further increased in severity at T2 with 54 patients (90%) showing severe colonization with S. mutans.

CONCLUSION

Results showed that fixed orthodontic appliance increases colonization of S. mutans during orthodontic treatment.