[Study on the sterilization effect of plasma jet and plasma activated water on Streptococcus mutans]

To explore the effects of plasma jet (PJ) and plasma activated water (PAW) on the sterilization of Streptococcus mutans ( S. mutans) and compare the advantages and disadvantages of the two methods, so as to provide a basis for plasma treatment of dental caries and to enrich the treatment means of dental caries, an atmospheric pressure plasma excitation system was built, and the effects of PJ and PAW on the sterilization rate of S. mutans and the changes of temperature and pH during treatment were studied under different excitation voltage ( U e ) and different excitation time ( t e ). The results showed that in the PJ treatment, the difference in the survival rate of S. mutans between the treatment group and the control group was statistically significant ( P = 0.007, d=2.66) when U e = 7 kV and t e = 60 s, and complete sterilization was achieved at U e = 8 kV and t e = 120 s in the PJ treatment. In contrast, in the PAW treatment, the difference in the survival rate of S. mutans between the treatment group and the control group was statistically significant ( P = 0.029, d = 1.71) when U e = 7 kV and t e = 30 s, and complete sterilization was achieved with PAW treatment when U e = 9 kV and t e = 60 s. Results of the monitoring of temperature and pH showed that the maximum temperature rise during PJ and PAW treatment did not exceed 4.3 °C, while the pH value after PAW treatment would drop to a minimum of 3.02. In summary, the optimal sterilization parameters for PJ were U e =8 kV and 90 s < t e ≤ 120 s, while the optimal sterilization parameters for PAW were U e = 9 kV and 30 s< t e ≤ 60 s. Both treatment methods achieved non-thermal sterilization of S. mutans, where PJ required only a smaller U e to achieve complete sterilization, while at pH < 4.7, PAW only required a shorter t e to achieve complete sterilization, but its acidic environment could cause some chemical damage to the teeth. This study can provide some reference value for plasma treatment of dental caries.

Anaesthesia and Caries Treatment by Dental Hygienists: A Worldwide Review

OBJECTIVES

This study aimed to summarise the competencies and legal position of the dental hygienist (DH) regarding local anaesthesia and caries treatment through a worldwide review.

METHODS

A structured and peer-reviewed online questionnaire consisting of 27 questions was developed and emailed to all DH associations that are members of the International Federation of Dental Hygienists or European Dental Hygienists Federation. After obtaining the data, all responding associations were contacted to confirm that the data were summarised in the correct order and were asked to provide further clarification of answers if necessary. A descriptive analysis was performed to summarise the data.

RESULTS

Thirty-one countries were approached and 26 responded, resulting in a response rate of 84%. In 62% of the countries, the DH can administer local anaesthesia via infiltration and/or block anaesthesia. In 23% of the countries, the DH can indicate the placement of a caries restoration. In 15% of the countries, the DH can place caries restorations. In 81% of the countries, the DH can apply sealants.

CONCLUSIONS

Considerable variation exists amongst countries regarding the extended scope of DH practice. Overall, independently administering local anaesthesia appears to be more accepted as being within the scope of DH practice than caries removal and the placement of restorations.

Investigating changes in salivary microbiota due to dental treatment: A metagenomic analysis study for forensic purposes

The advent of next generation sequencing techniques as well as the existing traditional culture methods has enabled metagenomic studies on the usability of microbiomes for the forensic identification of individuals to gain momentum. However, before the utilization of microbiomes as a potential technique for real forensic case resolutions, it is necessary to understand the stability of the microbiota compositions in an individual's biological samples and the factors responsible for their variations. In the present study, we compared the microbiota compositions present in the saliva of individuals with active dental caries before and after treatment from a forensic and clinical perspective using an approach based on the sequencing of all the variable regions (V1-V9) of the bacterial 16 S rRNA gene. For this purpose, 10 individuals were included in the study comprising of 8 individuals between the ages of 18-50 years with at least 3 deep dentin caries as patients and 2 healthy individuals without any dental or gingival diseases as controls. Saliva samples were collected from the patients at two timepoints, before and after treatment, as well as from the healthy individuals (before and after control) at an interval of 1 month. The collected 20 saliva samples were subjected to metagenomic analysis using the MinION device, which was developed by Oxford Nanopore Technologies (ONT Oxford, UK). Bioinformatic analyses were performed on the obtained data and the results were evaluated using statistical comparison methods and alpha/beta diversity analyses within the scope of the study objective. On evaluation using the distance metrics, it was observed that the microbial compositions in the saliva of individuals with active caries remained relatively stable after treatment. However, the relative abundance levels of bacteria of 28 genera and species showed statistically significant differences before and after treatment (p < 0.05). As a result, although the composition of salivary microbiome remained relatively stable after caries treatment, there were significant changes in many types of bacteria, especially at the species level, between the BT and AT samples. Our results provide a framework for further forensic and clinical investigations regarding the factors that affect human salivary microbiome diversity.

Evaluation of success of stainless steel crowns placed using the hall technique in children with high caries risk: A randomized clinical trial

Objective

This study aimed to compare the clinical efficacy and survival rates of the hall technique (HT), and conventional restoration (CR) for the management of occlusoproximal carious lesions in primary molars.

Materials and Methods

This clinical study observed 35 children (aged 4-8 years). Exclusion criteria included symptoms of pulpal or periradicular pathology or systemic conditions requiring special dental considerations. For each child, at least one tooth was treated with HT and one with CR. The primary outcome measures were minor and major clinical failure rates. Plaque and gingival scores of the teeth were also evaluated. Friedman test and Wilcoxon signed ranks test were used to compare the plaque and gingival index scores for each arm. Chi-square tests were used for comparisons of clinical outcomes, plaque-gingival index, and distribution of ICDAS categories among treatment arms (P < 0.05).

Results

Thirty-three of 35 (94.2%) participants returned for 1-year follow-up. HT showed statistically significantly higher treatment survival rate and fewer minor failures than CR (P = 0.040). The rate of major failures was minimal (2 of 84 teeth) and did not differ between treatments (P = 0.092). In both treatment groups, the gingival score and plaque score were significantly decreased at the 1-year follow-up (P < 0.05).

Conclusion

HT was a more successful method for managing caries in primary molars than CR, both for symptoms of pulpal disease and longevity of the restorations. HT is a simplified method of managing carious primary molars using SSCs cemented with no local anesthesia, caries removal, or tooth preparation.

Antibacterial silver-containing mesoporous bioglass as a dentin remineralization agent in a microorganism-challenged environment

OBJECTIVES

To provide a suitable material capable of treating dentin hypersensitivity with simultaneous active antibacterial activity.

METHODS

We developed silver-containing mesoporous bioglass (MBG-Ag) using the sol-gel technique, which loaded silver nanoparticles as promising bacteriostatic agents. The MBG-Ag with a powder-to-liquid ratio of 0.5 g: 0.01 mL were uniformly mixed with 20 %, 30 %, and 40 % phosphoric acid for 5, 10 and 20 min, respectively. Furthermore, we evaluated the occlusion efficiency, depth of penetration, and antibacterial activity of dentin specimens by simulating a Streptococcus mutans (S. mutans) infection on dentin. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the powders and assess tubule occlusion. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the MBG-Ag against S. mutans were determined via time-killing curves and colony formation assays.

RESULTS

The MIC ranged from 2.5 to 5 mg/mL, and the MBC ranged from 5 to 10 mg/mL. The highest dentinal tubule occlusion efficiency was over 90 %. The colony formation assay confirmed that 5 mg/mL MBG-Ag mixed with phosphoric acid reached the bactericidal concentration.

CONCLUSION

The MBG-Ag 40PA achieved a good occlusion efficiency and deep apatite precipitation in a short time, implying its superiority in clinical applications.

CLINICAL RELEVANCE

The MBG-Ag formed in this study is a promising candidate for the treatment of demineralized dentin and confers antibacterial effects on the remineralized dentin surface against S. mutans.

How to Intervene in the Caries Process in Older Adults: A Joint ORCA and EFCD Expert Delphi Consensus Statement

AIM

To provide recommendations for dental clinicians for the management of dental caries in older adults with special emphasis on root caries lesions.

METHODS

A consensus workshop followed by a Delphi consensus process were conducted with an expert panel nominated by ORCA, EFCD, and DGZ boards. Based on a systematic review of the literature, as well as non-systematic literature search, recommendations for clinicians were developed and consented in a two-stage Delphi process.

RESULTS

Demographic and epidemiologic changes will significantly increase the need of management of older adults and root caries in the future. Ageing is associated with a decline of intrinsic capacities and an increased risk of general diseases. As oral and systemic health are linked, bidirectional consequences of diseases and interventions need to be considered. Caries prevention and treatment in older adults must respond to the patient's individual abilities for self-care and cooperation and often involves the support of caregivers. Systemic interventions may involve dietary counselling, oral hygiene instruction, the use of fluoridated toothpastes, and the stimulation of salivary flow. Local interventions to manage root lesions may comprise local biofilm control, application of highly fluoridated toothpastes or varnishes as well as antimicrobial agents. Restorative treatment is often compromised by the accessibility of such root caries lesions as well as the ability of the senior patient to cooperate. If optimum restorative treatment is impossible or inappropriate, long-term stabilization, e.g., by using glass-ionomer cements, and palliative treatments that aim to maintain oral function as long and as well as possible may be the treatment of choice for the individual.

Effects of casein phosphopeptide-amorphous calcium phosphate crème on nicotine-induced Streptococcus mutans biofilm in vitro

OBJECTIVES

The aim of this study was to test the effects of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) crème, or MI Paste™ (MIP), on nicotine-induced Streptococcus mutans biofilm. The experiment utilized S. mutans biofilm assays with varying concentrations of nicotine and MIP aqueous concentrate levels. First hand exposure to nicotine has been demonstrated to significantly increase S. mutans biofilm formation, while the active component, CPP-ACP, in MIP has been shown to reduce S. mutans biofilm formation.

MATERIALS AND METHODS

A 24-h culture of S. mutans UA159 in microtiter plates were treated with varying nicotine concentrations (0-32 mg/ml) in Tryptic Soy Broth supplemented with 1% sucrose (TSBS) with or without MIP aqueous concentrate. A spectrophotometer was used to determine total growth absorbance and planktonic growth. The microtiter plate wells were washed, fixed, and stained with crystal violet dye and the absorbance measured to determine biofilm formation.

RESULTS

The presence of MIP aqueous concentrate inhibits nicotine-induced S. mutans biofilm formation at different concentrations of nicotine (0-32 mg/ml).

CONCLUSION

The results demonstrated nicotine-induced S. mutans biofilm formation is decreased in the presence of MIP. This provides further evidence about the cariostatic properties of CPP-ACP, the active soluble ingredient in the MIP, and reconfirms the harmful effects of nicotine.

CLINICAL SIGNIFICANCE

Smokers may gain dual benefits from the use of MIP, as a remineralization agent and as a cariostatic agent, by inhibiting nicotine-induced S. mutans biofilm formation.

How to Intervene in the Caries Process in Children: A Joint ORCA and EFCD Expert Delphi Consensus Statement

This paper provides recommendations for dentists for the treatment of dental caries in children, with an emphasis on early childhood caries (ECC), primary teeth, and occlusal surfaces in permanent teeth. A consensus workshop followed by an e-Delphi consensus process was conducted with an expert panel nominated by the European Organization for Caries Research (ORCA) and European Federation of Conservative Dentistry (EFCD)/German Association of Conservative Dentistry (DGZ) boards. Based on 3 systematic reviews and a nonsystematic literature search, recommendations were developed. The caries decline has led to a more polarized disease distribution in children and adolescents along social gradients which should be taken into account when managing the caries process at all levels, such as the individual, the group, or a population. The control or reduction of caries activity is the basis for successful caries management. In children, caries management requires adequate daily oral hygiene and fluoride application via toothpaste, ensured by caregivers, and especially for ECC prevention an emphasis on sugar intake reduction is needed. These noninvasive interventions are also suitable to arrest or control initial or even cavitated dentine caries lesions in the absence of irreversible pulpitis. Fluoride varnish or silver diammine fluoride can be added as supplementary agents. In pits and fissures, composite resin materials can be used as preventive sealants and for defect-oriented minimally invasive restorations. In primary molars, preformed metal crowns are more successful than multisurface fillings, especially in caries-active patients. With persisting high caries activity, multiple lesions, and limited cooperation, caries control should consist of robust measures with high success rates, even including extraction in selected cases. This applies especially to treatments performed under general anesthesia.

Cost-effectiveness of child caries management: a randomised controlled trial (FiCTION trial)

BACKGROUND

A three-arm parallel group, randomised controlled trial set in general dental practices in England, Scotland, and Wales was undertaken to evaluate three strategies to manage dental caries in primary teeth. Children, with at least one primary molar with caries into dentine, were randomised to receive Conventional with best practice prevention (C + P), Biological with best practice prevention (B + P), or best practice Prevention Alone (PA).

METHODS

Data on costs were collected via case report forms completed by clinical staff at every visit. The co-primary outcomes were incidence of, and number of episodes of, dental pain and/or infection avoided. The three strategies were ranked in order of mean cost and a more costly strategy was compared with a less costly strategy in terms of incremental cost-effectiveness. Costs and outcomes were discounted at 3.5%.

RESULTS

A total of 1144 children were randomised with data on 1058 children (C + P n = 352, B + P n = 352, PA n = 354) used in the analysis. On average, it costs £230 to manage dental caries in primary teeth over a period of up to 36 months. Managing children in PA was, on average, £19 (97.5% CI: -£18 to £55) less costly than managing those in B + P. In terms of effectiveness, on average, there were fewer incidences of, (- 0.06; 97.5% CI: - 0.14 to 0.02) and fewer episodes of dental pain and/or infection (- 0.14; 97.5% CI: - 0.29 to 0.71) in B + P compared to PA. C + P was unlikely to be considered cost-effective, as it was more costly and less effective than B + P.

CONCLUSIONS

The mean cost of a child avoiding any dental pain and/or infection (incidence) was £330 and the mean cost per episode of dental pain and/or infection avoided was £130. At these thresholds B + P has the highest probability of being considered cost-effective. Over the willingness to pay thresholds considered, the probability of B + P being considered cost-effective never exceeded 75%.

TRIAL REGISTRATION

The trial was prospectively registered with the ISRCTN (reference number ISRCTN77044005) on the 26th January 2009 and East of Scotland Research Ethics Committee provided ethical approved (REC reference: 12/ES/0047).

Sealing or infiltrating proximal carious lesions

OBJECTIVES

Micro-invasive treatment (sealing, infiltration) seems more efficacious to arrest early (non-cavitated) proximal carious lesions than non-invasive treatment (NI). Uncertainty remains as to the efficacy of sealing versus infiltration and the robustness of the evidence. We aimed to review and synthesize this evidence using pairwise and network meta-analysis (NMA) and to perform trial sequential analysis (TSA).

SOURCES

Searching three electronic databases (Medline, Embase, Cochrane Central) was complemented by hand searches and cross-referencing.

STUDY SELECTION

Randomized controlled trials comparing micro-invasive strategies against each other, NI or placebo for managing proximal carious lesions were included. The primary outcome was radiographically assessed lesion progression. Pairwise and Bayesian network meta-analyses as well as TSA were used for synthesis.

DATA

Thirteen split-mouth studies (486 participants, mean age 15 years) were included. Mean follow-up was 25 months (min/max 12/36 months). Firm evidence on the superior efficacy of sealing/infiltration over NI (OR; 95% CI: 0.25; 0.18-0.32) was reached. Firm evidence was also reached on the superior efficacy of sealing (OR; 95% CI: 0.29; 0.18-0.46, 7 studies) and infiltration (OR; 95% CI: 0.22; 0.15-0.33, 7 studies) over NI. One study compared infiltration versus sealing and found no significant difference (0.70; 0.34-1.47). Based on Bayesian NMA, infiltration was ranked first in 80% of the simulations (sealing 20%, NI 0%). The surface-under-the-cumulative-ranking (SUCRA) values were 0.90 for infiltration, 0.60 for sealing and 0.00 for NI. We did not detect significant inconsistency (p = 0.89, node-split).

CONCLUSIONS

Sealing or infiltration are likely to be more efficacious for arresting early (non-cavitated) proximal lesions than NI.

CLINICAL SIGNIFICANCE

Practitioners should strive to perform micro-invasive treatment instead of NI for early proximal lesions. The decision between sealing or infiltration should be guided by practical concerns beyond efficacy.

Surface Roughness of Initial Enamel Caries Lesions in Human Teeth After Resin Infiltration

BACKGROUND

Low viscosity resin infiltration of initial caries lesions is a modern microinvasive method to treat initial cries lesions. However, only scarce information is available about the long-term surface alterations of infiltrated lesions.

METHODS

Twenty-eight premolar teeth exhibiting non-cavitated initial caries lesions (International Caries Detection and Assessment System (ICDAS code 1&2)) were divided into two groups, one of which was infiltrated with resin, and the other remained untreated. The teeth underwent two thermocycling procedures. The surface roughness was determined quantitatively, and the results were evaluated statistically. In addition, the surfaces of the lesions were investigated by scanning electron microscopy (SEM), and the surface was analyzed visually with respect to surface irregularities.

RESULTS

The results showed a reduction in the surface roughness that was significant after 2500 thermocycles compared to the untreated surface. In the control specimens, no change in the surface roughness was found. The qualitative SEM data also showed a smooth surface after thermocycling, which supported the statistical findings.

CONCLUSION

After thermocycling, resin-infiltrated enamel surfaces become smoother and had no additional risk for plaque accumulation.

Atraumatic Restorative Treatment compared to the Hall Technique for occluso-proximal cavities in primary molars: study protocol for a randomized controlled trial

Background

In many parts of the world, school-age children have high dental treatment needs; however, there is often low, or no, dental care provision. Although Atraumatic Restorative Treatment (ART) was developed to address this, its survival rate in occluso-proximal lesions is low. An alternative, the Hall Technique (HT) has shown better relative outcomes for occluso-proximal lesions, but has not been directly compared to ART or tested in field settings. This trial will compare ART and the HT for the most clinically- and cost-effective strategy for managing occluso-proximal lesions in primary molars, in a school setting, using low-technology and child-friendly dental techniques.

Methods/Design

This two-arm, parallel group, patient-randomized controlled, superiority trial will have treatment provided in schools. Schoolchildren (n = 124, age 6–8) with at least one occluso-proximal carious primary molar lesion will have random allocation to treatment with ART or HT. Baseline measures and outcome data will be assessed through participant report, clinical examination and parent report/questionnaires. The primary outcome is survival rate, a composite measure of absence of Minor Failures (a defect in the restoration/crown, but not interfering with tooth health) and Major Failures (signs or symptoms of irreversible pulp damage, such as dental fistula/abscess, tooth fracture or failures that cannot be repaired). Secondary outcomes are: (1) child-reported discomfort, (2) childrens’ and (3) parents’ concerns around dental appearance and (4) acceptability of treatments, (5) occlusal-vertical dimensions (OVD) changes, (6) plaque index, (7) gingival health, (8) decayed, missing, filled teeth in permanent teeth (DMFT)/decayed, missing, filled teeth in primary teeth (dmft), (9) oral health-related-quality of life, reported by children and parents/caregivers, (10) the incremental cost-effectiveness, and (11) operator effect. A trained and calibrated examiner will evaluate the treated teeth after 1 week, then 1, 6, 12, 24 and 36 months post treatment. Kaplan-Meier and Cox regression tests will be used to investigate the primary outcome. The Mann-Whitney or t test, Friedman test, paired t test or Wilcoxon test and Ordinal Logistic Regression Analysis will be used to analyze the secondary outcomes.

Discussion

The results of this trial will support decision-making by clinicians and policy-makers for managing occluso-proximal lesions in settings with constrained resources and limited dental access.

Trial registration

www.clinicaltrials.gov, NCT02569047, registered 5 October 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1270-z) contains supplementary material, which is available to authorized users.