The caries environment: saliva, pellicle, diet, and hard tissue ultrastructure

TGF-β1 maintains the developmental potential of embryonic submandibular gland epithelia separated with mesenchyme

Objective

The objective of this study was to investigate the impact of transforming growth factor β1 (TGF-β1) on epithelial development using an ex vivo model of submandibular gland (SMG) epithelial-mesenchymal separation.

Materials and methods

The ex vivo model was established by separating E13 mouse SMG epithelia and mesenchyme, culturing them independently for 24 h, recombining them, and observing branching morphogenesis. Microarray analysis was performed to evaluate the transcriptome of epithelia treated with and without 1 ng/ml TGF-β1. Differential gene expression, pathway enrichment, and protein-protein interaction networks were analyzed. Quantitative real-time polymerase chain reaction, Western blot, and immunofluorescence were employed to validate the mRNA and protein levels.

Results

Recombined SMGs using separated epithelia and mesenchyme that were cultured for 24 h showed a significant inhibition of epithelial development compared to SMGs recombined immediately after separation. The level of TGF-β1 decreased in the SMG epithelia after epithelia-mesenchyme separation. Epithelia that were separated from mesenchyme for 24 h and pretreated with 1 ng/ml TGF-β1 continued to develop after recombination with mesenchyme, while epithelia without 1 ng/ml TGF-β1 treatment did not. Microarray analysis suggested pathway enrichment related to epithelial development and an upregulation of Sox2 in the 1 ng/ml TGF-β1-treated epithelia. Further experiments validated the phosphorylation of SMAD2 and SMAD3, upregulation of SOX2 and genes associated with epithelial development, including Prol1, Dcpp1, Bhlha15, Smgc, and Bpifa2. Additionally, 1 ng/ml TGF-β1 inhibited epithelial apoptosis by improving the BCL2/BAX ratio and reducing cleaved caspase 3.

Conclusions

The addition of 1 ng/ml TGF-β1 maintained the developmental potential of embryonic SMG epithelia separated from mesenchyme for 24 h. This suggests that 1 ng/ml TGF-β1 may partially compensate for the role of mesenchyme during the separation phase, although its compensation is limited in extent.

Remineralization potential of varying concentrations of two plant-based extracts of Cocos nucifera on white spot lesions using SEM and EDAX analysis: An in vitro study

Aim

To evaluate the remineralization potential of varying concentrations of two plant-based extracts of Cocos nucifera on white spot lesions using SEM and EDAX in vitro testing methods.

Materials and Methods

The pulp was freshly obtained from coconut and divided into two. Then, coconut milk was obtained by blending, while the next portion was freeze-dried and lyophilized. Third molar teeth were processed into tooth slabs (N = 40) and split equally into five groups by block randomization. After demineralization, one tooth slab was taken from each, and SEM analysis was done. Remineralization was then performed among the various groups that included Group 1, which acted as a control and consisted of the remineralization solution. Groups 2 and 3 comprised 1:1 and 2:1 concentrations of the coconut milk, whereas Groups 4 and 5 consisted of 1:1 and 2:1 concentrations of the lyophilized extract. SEM and EDAX testing were done post-remineralization. Ca and phosphate values were tabulated, and statistical significance was determined for the obtained values using ANOVA.

Results

Among the control and treatment groups, surface remineralization was better observed in 1:1 coconut milk and 2:1 coconut milk than in the 2:1 lyophilized coconut, control, and 1:1 lyophilized coconut. Between the control and treatment groups, Ca and phosphate percentages (P < 0.001) showed statistical differences. The lowest value of 2.3% was noted in the 2:1 lyophilized coconut group.

Conclusion

Coconut extracts exhibit remineralization potential on the artificial carious lesion. Coconut milk exhibited significant improvement in the surface properties than lyophilized coconut.

Prevalence of white spot lesions and gingival index during orthodontic treatment in an academic setting

INTRODUCTION

The objective of this study was to determine the prevalence of white spot lesions (WSL) in orthodontic patients in an academic setting. Specific aims include using a novel combination to measure plaque accumulation (PA) and detect the association between WSL and PA and the associations between multiple independent variables.

METHODS

Cross-sectional data were collected on 111 patients. To enhance standardization, a combination of plaque-disclosing agents and standardized intraoral photographs was used to analyze plaque index (PI) and WSL for all teeth except molars. Factors including time in fixed appliances (FA), number of teeth, location of the lesions, and demographic information were reported. A multiple linear regression model was used to detect associations between the PI and WSL and the independent variables (P <0.05).

RESULTS

Approximately 79.3% of participants had at least one WSL, with a mean of 4 affected teeth per patient. A significant association was found between time in FA and the more severe PI reporting (P <0.001). There was no significant association between WSL and PI or the other variables. WSL was greater in the maxilla than in the mandible. PI was greater on the left than on the right side. Interexaminer reliability was assessed for PI and WSL (κ = 0.93 and 0.92).

CONCLUSIONS

The prevalence of WSL for orthodontic patients treated at this institution was greater than previously reported in the literature. In addition, the severity of PI was associated with increased time in FAs. Combining the proposed method of reporting PA facilitates standardization, calibration, and documentation in an academic environment.

Streptococcus mutans membrane vesicles inhibit the biofilm formation of Streptococcus gordonii and Streptococcus sanguinis

Streptococcus mutans, whose main virulence factor is glucosyltransferase (Gtf), has a substantial impact on the development of dental caries. S. mutans membrane vesicles (MVs), which are rich in Gtfs, have been shown to affect biofilm formation of other microorganisms. Streptococcus gordonii and Streptococcus sanguinis are initial colonizers of tooth surfaces, which provide attachment sites for subsequent microorganisms and are crucial in the development of oral biofilms. S. mutans and S. gordonii, as well as S. mutans and S. sanguinis, have a complex competitive and cooperative relationship, but it is unclear whether S. mutans MVs play a role in these interspecific interactions. Therefore, we co-cultured S. mutans MVs, having or lacking Gtfs, with S. gordonii and S. sanguinis. Our results showed that S. mutans MVs inhibited biofilm formation of S. gordonii and S. sanguinis but did not affect their planktonic growth; contrastingly, S. mutans ΔgtfBC mutant MVs had little effect on both their growth and biofilm formation. Additionally, there were fewer and more dispersed bacteria in the biofilms of the S. mutans MV-treated group than that in the control group. Furthermore, the expression levels of the biofilm-related virulence factors GtfG, GtfP, and SpxB in S. gordonii and S. sanguinis were significantly downregulated in response to S. mutans MVs. In conclusion, the results of our study showed that S. mutans MVs inhibited biofilm formation of S. gordonii and S. sanguinis, revealing an important role for MVs in interspecific interactions.

Effect of Exo/Endogenous Prophylaxis Dentifrice/Drug and Cariogenic Conditions of Patient on Molecular Property of Dental Biofilm: Synchrotron FTIR Spectroscopic Study

(1) Objectives: This study is the first one to investigate the molecular composition of the dental biofilm during the exogenous and endogenous prophylaxis stages (use of dentifrice/drug) of individuals with different cariogenic conditions using molecular spectroscopy methods. (2) Materials and Methods: The study involved 100 participants (50 males and 50 females), aged 18–25 years with different caries conditions. Biofilm samples were collected from the teeth surface of all participants. The molecular composition of biofilms was investigated using synchrotron infrared microspectroscopy. Changes in the molecular composition were studied through calculation and analysis of ratios between organic and mineral components of biofilm samples. (3) Results: Based on the data obtained by synchrotron FTIR, calculations of organic and mineral component ratios, and statistical analysis of the data, we were able to assess changes occurring in the molecular composition of the dental biofilm. Variations in the phosphate/protein/lipid, phosphate/mineral, and phospholipid/lipid ratios and the presence of statistically significant intra- and inter-group differences in these ratios indicate that the mechanisms of ion adsorption, compounds and complexes arriving from oral fluid into dental biofilm during exo/endogenous prophylaxis, differ for patients in norm and caries development. (4) Conclusions: The conformational environment and charge interaction in the microbiota and the electrostatic state of the biofilm protein network in patients with different cariogenic conditions play an important role. (5) Clinical Significance: Understanding the changes that occur in the molecular composition of the dental biofilm in different oral homeostasis conditions will enable successful transition to a personalised approach in dentistry and high-tech healthcare.

Biofilm accumulation and sucrose rinse modulate calcium and fluoride bioavailability in the saliva of children with early childhood caries

This study aimed at investigating the combined effect of biofilm accumulation and 20% sucrose rinse on the modulation of calcium (Ca²⁺), phosphate (P_i), and fluoride (F^-) bioavailability in the saliva of children with early childhood caries (ECC). Fifty-six preschoolers of both genders were evaluated according to caries experience and activity: caries-free (CF, n = 28) and with ECC (n = 28) and then, submitted to biofilm intervention (biofilm accumulation). In each situation, saliva samples were collected before and five minutes after a 20% sucrose rinse to determine the concentrations of Ca²⁺, P_i, and F^-. Calcium concentration was significantly lower in the biofilm accumulation situation compared to the situation of biofilm mechanical control (p ≤ 0.01), except for CF children after sucrose rinse. Biofilm accumulation increased salivary calcium concentration in children with ECC after sucrose rinse (p = 0.04), whereas mechanical biofilm control reduced it in both groups (p = 0.000). Phosphate concentration was influenced by mechanical control of biofilm in CF children (p = 0.03). The fluoride bioavailability was reduced by sucrose rinse and biofilm accumulation in CF and ECC children (p ≤ 0.002). In conclusion, the combined effect of biofilm accumulation and sucrose rinse modifies the bioavailability of calcium and fluoride in the saliva of children with early childhood caries.

Bioinspired caries preventive strategy via customizable pellicles of saliva-derived protein/peptide constructs

Dental caries has been the most widespread chronic disease globally associated with significant health and financial burdens. Caries typically starts in the enamel, which is a unique tissue that cannot be healed or regrown; nonetheless, new preventive approaches have limitations and no effective care has developed yet. Since enamel is a non-renewable tissue, we believe that the intimate overlaying layer, the acquired enamel pellicle (AEP), plays a crucial lifetime protective role and could be employed to control bacterial adhesion and dental plaque succession. Based on our identified AEP whole proteome/peptidome, we investigated the bioinhibitory capacities of the native abundant proteins/peptides adsorbed in pellicle-mimicking conditions. Further, we designed novel hybrid constructs comprising antifouling and antimicrobial functional domains derived from statherin and histatin families, respectively, to attain synergistic preventive effects. Three novel constructs demonstrated significant multifaceted bio-inhibition compared to either the whole saliva and/or its native proteins/peptides via reducing biomass fouling and inducing biofilm dispersion beside triggering bacterial cell death. These data are valuable to bioengineer precision-guided enamel pellicles as an efficient and versatile prevention remedy. In conclusion, integrating complementary acting functional domains of salivary proteins/peptides is a novel translational approach to design multifunctional customizable enamel pellicles for caries prevention.

The predictive power of saliva electrolytes exceeds that of saliva microbiomes in diagnosing early childhood caries

Early childhood caries (ECC) is one of the most prevalent chronic diseases affecting children worldwide, and thus its etiology, diagnosis, and prognosis are of particular clinical significance. This study aims to test the ability of salivary microbiome and electrolytes in diagnosing ECC, and their interplays within the same population. We here simultaneously profiled salivary microbiome and biochemical components of 331 children (166 caries-free (H group) and 165 caries-active children (C group)) aged 4-6 years. We identified both salivary microbial and biochemical dysbiosis associated with ECC. Remarkably, K⁺, Cl^-, NH₄⁺, Na⁺, SO₄^2-, Ca²⁺, Mg²⁺, and Br^- were enriched while pH and NO₃^- were depleted in ECC. Moreover, the dmft index (ECC severity) positively correlated with Cl^-, NH₄⁺, Ca²⁺, Mg²⁺, Br^-, while negatively with pH and NO₃^-. Furthermore, machine-learning classification models were constructed based on these biomarkers from saliva microbiota, or electrolytes (and pH). Unexpectedly, the electrolyte-based classifier (AUROC = 0.94) outperformed microbiome-based (AUROC = 0.70) one and the composite-based one (with both microbial and biochemical data; AUC = 0.89) in predicting ECC. Collectively, these findings indicate ECC-associated alterations and interplays in the oral microbiota, electrolytes and pH, underscoring the necessity of developing diagnostic models with predictors from salivary electrolytes.

High-throughput sequencing identifies salivary microbiota in Chinese caries-free preschool children with primary dentition

OBJECTIVES

The study aimed at identifying salivary microbiota in caries-free Chinese preschool children using high-throughput sequencing.

METHODS

Saliva samples were obtained from 35 caries-free preschool children (18 boys and 17 girls) with primary dentition, and 16S ribosomal DNA (rDNA) V3-V4 hypervariable regions of the microorganisms were analyzed using Illumina MiSeq.

RESULTS

At 97% similarity level, all of these reads were clustered into 334 operational taxonomic units (OTUs). Among these, five phyla (Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Candidate division TM7) and 13 genera (Streptococcus, Rothia, Granulicatella, Prevotella, Enterobacter, Veillonella, Neisseria, Staphylococcus, Janthinobacterium, Pseudomonas, Brevundimonas, Devosia, and Gemella) were the most dominant, constituting 99.4% and 89.9% of the salivary microbiota, respectively. The core salivary microbiome comprised nine genera (Actinomyces, Capnocytophaga, Gemella, Granulicatella, Lachnoanaerobaculum, Neisseria, Porphyromonas, Rothia,and Streptococcus). Analysis of microbial diversity and community structure revealed a similar pattern between male and female subjects. The difference in microbial community composition between them was mainly attributed to Neisseria (P=0.023). Furthermore, functional prediction revealed that the most abundant genes were related to amino acid transport and metabolism.

CONCLUSIONS

Our results revealed the diversity and composition of salivary microbiota in caries-free preschool children, with little difference between male and female subjects. Identity of the core microbiome, coupled with prediction of gene function, deepens our understanding of oral microbiota in caries-free populations and provides basic information for associating salivary microecology and oral health.

A retrospective study of the Hall technique for the treatment of carious primary teeth in Sydney, Australia

Objectives

The aim of this retrospective study was to evaluate the outcome of preformed metallic crowns (PMC) utilizing the HT in carious primary molars for children treated within public dental clinics across the Sydney region.

Materials and Methods

A retrospective cohort study was designed, whereby two investigators evaluated 113 primary molars treated with HT PMCs involving 71 participants (aged between 5 and 11 years) after a minimum of 6 months post treatment. The mean time elapsed between crown placement (treatment) and the review was 1.42 years (17 months). The outcome of the HT was assessed by clinical and radiographic criteria.

Results

One hundred thirteen HT PMCs were reviewed from 71 participants. The overall success rate of PMCs placed utilizing the HT was 99%, with only one case presenting with confirmed failure.

Conclusions

HT PMCs have an overall high success rate as a treatment option in carious primary molars.

Factors Affecting High Caries Risk in Children With and Without Cleft Lip and/or Palate: A Cross-Sectional Study

OBJECTIVE

The aim of the study was to analyze the caries protective factors, salivary parameters, and microbial counts in high caries risk children with cleft lip and/or palate (CL/P).

DESIGN

This was a cross-sectional study.

SETTING

This study was conducted in a tertiary health care teaching hospital in New Delhi, India.

PARTICIPANTS

The study was conducted in 40 children, 20 with CL/P and 20 without aged between 5 and 12 years.

METHODS

Children with 2 or more caries lesions in both groups were included in this study. Demographic details, dental caries of affected teeth (World Health Organization criteria for Decayed Missing Filled Teeth [WHO-DMFT] and International Caries Detection and Assessment System [ICDAS II]), caries protective factors, salivary parameters, and microbial counts were recorded by one calibrated investigator.

MAIN OUTCOME MEASURES

Caries protective factors, salivary parameters, and microbial profile.

RESULTS

The Chi-square (χ²) test and Pearson correlation were used for statistical analysis. All the children participating in the study brushed their teeth only once in a day and consumed sweets more than twice a day. None of the children had ever received fluoride varnish. Resting saliva had a low buffering capacity in 80% of children with CL/P and 95% of children without CL/P. Microbial assessment of stimulated saliva showed that with the increases in the numbers (DMFT scores ≥4) and severity (ICDAS codes from 1-2 to 5-6) of caries lesions, both Streptococci and Lactobacilli counts were ≥10⁵ colony-forming units/mL of saliva in the both groups.

CONCLUSIONS

Children with CL/P showed limited access to caries protective measures and low buffering capacity in resting saliva, along with elevated levels of salivary Streptococci and Lactobacilli in stimulated saliva.

The Concept of Sustainable Development of Modern Dentistry

This paper concerns the assessment of the current state of dentistry in the world and the prospects of its sustainable development. A traditional Chinese censer was adopted as the pattern, with a strong and stable support on three legs. The dominant diseases of the oral cavity are caries and periodontal diseases, with the inevitable consequence of toothlessness. From the caries 3.5–5 billion people suffer. Moreover, each of these diseases has a wide influence on the development of systemic complications. The territorial range of these diseases and their significant differentiation in severity in different countries and their impact on disability-adjusted life years index are presented (DALY). Edentulousness has a significant impact on the oral health-related quality of life (OHRQoL). The etiology of these diseases is presented, as well as the preventive and therapeutic strategies undertaken as a result of modifying the Deming circle through the fives’ rules idea. The state of development of Dentistry 4.0 is an element of the current stage of the industrial revolution Industry 4.0 and the great achievements of modern dental engineering. Dental treatment examples from the authors’ own clinical practice are given. The systemic safety of a huge number of dentists in the world is discussed, in place of the passive strategy of using more and more advanced personal protective equipment (PPE), introducing our own strategy for the active prevention of the spread of pathogenic microorganisms, including SARS-CoV-2. The ethical aspects of dentists’ activity towards their own patients and the ethical obligations of the dentist community towards society are discussed in detail. This paper is a polemic arguing against the view presented by a group of eminent specialists in the middle of last year in The Lancet. It is impossible to disagree with these views when it comes to waiting for egalitarianism in dental care, increasing the scope of prevention and eliminating discrimination in this area on the basis of scarcity and poverty. The views on the discrimination of dentistry in relation to other branches of medicine are far more debatable. Therefore, relevant world statistics for other branches of medicine are presented. The authors of this paper do not agree with the thesis that interventional dental treatment can be replaced with properly implemented prophylaxis. The final remarks, therefore, present a discussion of the prospects for the development of dentistry based on three pillars, analogous to the traditional Chinese censer obtaining a stable balance thanks to its three legs. The Dentistry Sustainable Development (DSD) > 2020 model, consisting of Global Dental Prevention (GDP), Advanced Interventionist Dentistry 4.0 (AID 4.0), and Dentistry Safety System (DSS), is presented.

The potential of Streptococcus salivarius oral films in the management of dental caries: An inkjet printing approach

The use of probiotics, which can be administered in oro-dispersible films (ODFs) and have prolonged activity in the mouth, was explored. ODFs made of xylitol and containing Streptococcus salivarius were formulated using inkjet printing and tested against Streptococcus mutans - a causative organism of dental caries. The testing of the prepared ODFs involved co-incubating an ink-jetted formulation of S. salivarius and xylitol with S. mutans and monitoring the microbial growth kinetics in real-time using isothermal microcalorimetry and colony plate counts. Cell-free supernatants (CFS) of S. salivarius were also tested against S. mutans. The phosphate solubilisation potential of S. salivarius was also determined and found to be negative, an indication that the species will not deplete phosphate from teeth. From the tests, it was observed that the formulation reduced the S. mutans population from 7.9 to 5.04 Log CFU/mL post-calorimetry (approximately 3 Log reduction) which was comparable to the 99.9% reduction expected during antimicrobial activity testing. A gradual decrease in S. mutans population was also observed with increasing of CFS of S. salivarius volumes indicative of pathogen suppression. This study demonstrates that S. salivarius can be useful in managing dental caries and ODFs of S. salivarius can be formulated easily using ink-jetting for such management.

A Comparative Evaluation of Remineralizing Potential of Three Commercially Available Remineralizing Agents: An In Vitro Study

Aim

An in vitro study to evaluate and compare the remineralization potential of commercially available remineralizing agents containing silver diamine fluoride (SDF), casein sucrose phosphate (CSP), casein phospho peptide-amorphous calcium phosphate (CPP-ACP) using DIAGNOdent.

Materials and methods

Thirty freshly extracted premolars for orthodontic treatment were collected. Specimens were randomly divided into 3 groups of 10 each: group I: SDF, group II: CSP, group III: CPP-ACP. The samples were subjected to DIAGNOdent analysis for recording the baseline values. Specimens were placed in demineralizing solution incubated at 37°C for 72 hours. DIAGNOdent values were recorded after demineralization. Following this, remineralization procedure was carried out using 3 different remineralizing agents: group I samples with SDF, group II with CSP, and group III with CPP-ACP. The remineralization procedure was performed to group I once and repeated for 14 days for group II and group III and storage solution was changed every 24 hours. The samples were subjected to DIAGNOdent analysis after 72 hours, 7 days, and 14 days and values were recorded.

Results

The data were analysed using Statistical Package for the Social Sciences (SPSS) with analysis of variance (ANOVA) and post hoc test. Intragroup comparison of DIAGNOdent readings showed a highly significant difference between baseline, postdemineralization, and postremineralization values. Among intergroup comparison, SDF showed maximum remineralization values followed by CSP and CPP-ACP, respectively.

Conclusion

Silver diamine fluoride, CSP, and CPP-ACP are proven to possess remineralization potential.

Clinical significance

A comparative evaluation of these three remineralizing agents will aid in identifying most potent and effective agent in treating initial caries lesions in an effective noninvasive and child-friendly manner.

How to cite this article

Vinod D, Gopalakrishnan A, Subramani SM, et al. A Comparative Evaluation of Remineralizing Potential of Three Commercially Available Remineralizing Agents: An In Vitro Study. Int J Clin Pediatr Dent 2020;13(1):61–65.

Dental Caries Preventive Considerations: Awareness of Undergraduate Dental Students

The aim of this study was to assess awareness and knowledge of undergraduate dental students of common caries-related preventive considerations and to highlight these factors in a concise manner to act as a guide for dental practitioners. A sample of 118 undergraduate students at a local government dental school was included. An interactive survey that contains questions related to common preventive strategies against dental caries was presented to the students. The survey contained 22 questions concerning dietary and therapeutic strategies. Students casted their votes using their mobile cellphones. The correct answer for each question was shown to the students, and further discussion was held. Data was collected, and the statistical analysis was conducted using one-sample z- and chi-squared tests at 0.05 significance level. The students answered the questions related to oral hygiene practices, xylitol, and the common knowledge regarding fluoride. The questions related to the use of chlorhexidine, dietary factors, and fluoride formulations were answered mostly incorrectly. The students seemed to grasp details of important concepts of flossing, brushing, reducing frequency of sugar exposure, and the use of fluoride products. Still, more emphasis should be given to increase students’ awareness of dietary guidelines for caries prevention, since adequate knowledge of these modalities is paramount for graduating dentists.

Combined Effect of Enamel Deproteinization and Intermediate Bonding in the Retention of Pit and Fissure Sealants in Children: A Randomized Clinical Trial

OBJECTIVE

This manuscript shows if enamel deproteinization along with an intermediate layer of bonding enhances the retention of pit and fissure sealants..

STUDY DESIGN

Two hundred six mandibular first permanent molars were allocated to Group I (n=103) and Group II (n=103). Group I underwent deproteinization, acid etching, bonding agent application and pit & fissure sealant placement while Group II treated with acid etching followed by pit & fissure sealant application only. Clinical analysis of all the teeth in the two groups was performed at 1, 3, 6, 9 and 12 months respectively. Pearson's chi - square test was utilized to evaluate the success of both treatment procedures (p<0.05).

RESULTS

At 12 months follow up the differences between the groups pertaining to Marginal integrity, Marginal discoloration and Anatomical form were statistically significant suggesting enhanced retention in Group I.

CONCLUSIONS

Enamel deproteinization along with the use of intermediate bonding layer significantly enhances the retention of pit and fissure sealants in terms of enhanced marginal integrity, decreased marginal discoloration and preserving the anatomical form.

Deproteinization Effectiveness on Occlusal Enamel Surfaces and Resultant Acid Etching Patterns: An in vitro Study

PURPOSE

The goal of this in vitro study was to identify whether occlusal enamel deproteinization is effective in the removal of organic material in order to obtain quality etching patterns using phosphoric acid (H₃PO₄) and sodium hypochlorite (NaOCl) compared to phosphoric acid alone.

STUDY DESIGN

Nine extracted third permanent molars were polished with pumice and water. Every pit and fissure was evaluated as a unit, resulting in 40 individual units and then these were divided into five treatment groups. The occlusal enamel surface of each group was subjected to the following treatments: Group 1 (C) Control: No treatment; Group 2 (P): Polish and rinse; Group 3 (PD): Polish, rinse, and sodium hypochlorite (NaOCl) 5.25% for 60 seconds; Group 4 (PA): Polish, rinse, and acid etching with H₃PO₄ 37% for 15 seconds; and Group 5 (PDA): Polish, rinse, sodium hypochlorite (NaOCl) 5.25% for 60 seconds, and acid etching with H₃PO₄ 37% for 15 seconds. Results showed no significant statistical difference in the organic material present between groups 1 (C) (30.18%) and 2 (P) (36.61%), but there was a statistical difference (p <0.002) between Groups 1 and 2, and Group 3 (PD) (16.50%). In the acid etching group, the undesirable Type-III pattern (discussed later) was found in Group 4 (PA) (33.54%), while this was only 7.70% in Group 5, nearly five times more than Group 4, with a significant statistical difference (0.05). When differences were sought for Types I and II etch patterns (discussed later) for Groups 4 and 5, Group 4 (PA) obtained 26.29% (Type I) and 1.75% (Type II) etch patterns, compared to Group 5 (PDA) with 33.4% (Type I) and 38.97% (Type II) etch patterns.

CONCLUSIONS

The enamel deproteinization technique is an effective way to remove organic material on the occlusal surfaces of teeth, obtaining after phosphoric acid application, up to 72.38% of Types I and II etch patterns. Etching Types I or II can also be determined by the removal of organic material in between enamel crystals.

Randomised in situ clinical trial investigating self-assembling peptide matrix P11-4 in the prevention of artificial caries lesions

The aim was to investigate the ability of self-assembling Peptide P11-4 Matrix (SAPM) to remineralize artificial initial caries lesions compared to the use of fluoride varnish. Volunteers were recruited for this randomised, cross-over in situ trial. Bovine specimens, half including orthodontic brackets, were recessed on the buccal aspects of mandibular appliances. Specimens included internal sound enamel control, a demineralised control and a part exposed during the in situ phase. Each phase lasted four weeks, followed by a one-week washout. Treatment groups were: A: negative control, no treatment,B: positive control, 22,600 ppm fluoride varnish,C: test group, 1,000 ppm SAPM. Laser fluorescence values (LF) were measured before/after demineralisation, and after the in situ period. Micro-CT analysis was used to assess mineral changes within the specimens after the in situ phase. In specimens without brackets, ΔLF values after in situ phase were: A: +5.28, B: +0.85, C: −2.89. Corresponding ΔLF for specimens with brackets were: A: +5.77, B: +1.30, C: −3.15. LF-values between groups significantly differed from each other (p < 0.0001) after the in situ phase. Micro-CT analysis yielded no significant difference among groups for specimens without brackets. For specimens with brackets, the test group showed significantly more remineralisation than the negative (p = 0.01) and positive control (p = 0.003). Within the limitations of the study, SAPM showed prevention of caries and remineralisation of enamel around orthodontic brackets.

The Bioarchaeology of Health Crisis: Infectious Disease in the Past

Beginning some 10,000 years ago, humans began a dramatic alteration in living conditions relating especially to the shift in lifeway from foraging to farming. In addition to the initiation of and increasing focus on the production and consumption of domesticated plant carbohydrates, this revolutionary transformation in diet occasioned a decline in mobility and an increased size and agglomeration of populations in semipermanent or permanent settlements. These changes in life conditions presented an opportunity for increased transmission of pathogenic microbes from host to host, such as those that cause major health threats affecting most of the 7.5 billion members of our species today. This article discusses the bioarchaeology of infectious disease, focusing on tuberculosis, treponematosis, dental caries, and periodontitis, all of which continue to contribute to high levels of morbidity and mortality among the world's populations today.

Salivary functions in mastication, taste and textural perception, swallowing and initial digestion

Saliva exerts multiple functions in relation to the initial digestive processes taking place in the upper parts of the gastrointestinal tract. Ingestion of food and beverages, in turn, is a strong stimulus for secretion of saliva with a differential composition depending on the neuronal stimulation pattern. This review paper provides insight into the mechanisms by which saliva acts in relation to taste, mastication, bolus formation, enzymatic digestion and swallowing. Also, the protective functions of saliva including maintenance of dental and mucosal integrity will be discussed as they indirectly influence the digestive process. The final part of this study focuses on the implications of xerostomia and salivary gland dysfunction on gastrointestinal functions.

The proteomic profile of the acquired enamel pellicle according to its location in the dental arches

OBJECTIVE

This study evaluated the variation in the protein profile of the acquired enamel pellicle (AEP) formed in vivo according to its location in the dental arches.

DESIGN

The AEP was formed for 120min in 9 volunteers. Pellicle formed at upper+lower anterior facial (ULAFa; teeth 13-23 and 33-43), upper anterior palatal (UAPa; teeth 13-23), lower anterior lingual (LALi; teeth 33-43), upper+lower posterior facial (ULPFa; teeth 14-17 24-27, 34-37 and 44-47), upper posterior palatal (UPPa; teeth 14-17 and 24-27) and lower posterior lingual (LPLi; teeth 34-37 and 44-47) regions were collected separately and processed for analysis by label-free LC-ESI-MS/MS.

RESULTS

Three-hundred sixty three proteins were identified in total, twenty-five being common to all the locations, such as Protein S100-A8, Lysozyme C, Lactoferrin, Statherin, Ig alpha-2, ALB protein, Myeloperoxidase and SMR3B. Many proteins were found exclusively in the AEP collected from one of the regions (46-UAPa, 33-LALi, 59-ULAFa, 31-ULPFa, 44-LPLi and 39-UPPa).

CONCLUSIONS

The protein composition of the AEP varied according to its location in the dental arches. These results provide important insights for understanding the differential protective roles of the AEP as a function of its location in the dental arches.

Dental caries

Dental caries is a biofilm-mediated, sugar-driven, multifactorial, dynamic disease that results in the phasic demineralization and remineralization of dental hard tissues. Caries can occur throughout life, both in primary and permanent dentitions, and can damage the tooth crown and, in later life, exposed root surfaces. The balance between pathological and protective factors influences the initiation and progression of caries. This interplay between factors underpins the classification of individuals and groups into caries risk categories, allowing an increasingly tailored approach to care. Dental caries is an unevenly distributed, preventable disease with considerable economic and quality-of-life burdens. The daily use of fluoride toothpaste is seen as the main reason for the overall decline of caries worldwide over recent decades. This Primer aims to provide a global overview of caries, acknowledging the historical era dominated by restoration of tooth decay by surgical means, but focuses on current, progressive and more holistic long-term, patient-centred, tooth-preserving preventive care.

Oral health in transition: The Hadza foragers of Tanzania

Conventional wisdom holds that a decline in oral health accompanies the transition from hunting and gathering to agriculture, given increased consumption of carbohydrates. This widely touted example of the mismatch between our biology and modern lifestyle has been intuited largely from the bioarchaeological record of the Neolithic Revolution in the New World. Recent studies of other populations have, however, challenged the universality of this assertion. Here, we present the first comprehensive study of oral health among a living population in transition from the bush to village life, the Hadza hunter-gatherers of Tanzania, to test the hypothesis that the shift from foraging to farming, or agricultural intensification, inevitably leads to increased periodontal disease, caries, and orthodontic disorders. Our results showed that women living in villages consuming a mostly agricultural diet exhibited more caries and periodontal disease than those living in the bush consuming a mostly wild-food diet. Furthermore, men living in the bush consuming mostly a wild-food diet had more than those living in the village consuming a mostly agricultural diet. These findings are explained by the high incidence of maize consumption in village settings, along with previously recognized variation in rate of caries between men and women. The unexpected discovery of high caries incidences for men in the bush is likely explained by heavy reliance on honey, and perhaps differential access to tobacco and marijuana. These data support the notions that mechanisms of cariogenesis are multifactorial and that the relationships between oral health and the shift from a predominantly wild-food diet to one dominated by cultigens are nuanced.

A Polymorphism in the MTRR Gene Is Associated with Early Childhood Caries and Underweight

Polymorphisms in genes encoding the enzymes involved in the metabolism of homocysteine, such as methionine synthase (MTR) and methionine synthase reductase (MTRR), play an important function in the metabolism of folic acid and vitamin B12. The present study aimed to evaluate the association of polymorphisms in genes MTR (rs1805087) and MTRR (rs1801394) with susceptibility of early childhood caries (ECC) and with body mass index alterations. A cross-sectional study was performed in 488 children aged from 2 to 6 years from 25 public day care centers in Rio de Janeiro, Brazil. Demographic data and oral health habits were obtained through a questionnaire. Anthropometric measurements and caries experience data were collected by 2 examiners (κ = 0.80). Genotyping of the selected polymorphisms was carried out by TaqMan real-time PCR using genomic DNA extracted from buccal cells. Allele and genotype frequencies were compared between groups with and without disease. The t test, χ2 test, odds ratio, Pearson correlation tests, and logistic regression analysis were used (p ≤ 0.05). The mean white spot lesion score was 1.18 (±2.57) in normal weight children and 2.50 (±3.87) in underweight children (p = 0.05). For MTRR polymorphisms, significant differences were observed for allele and genotype frequency distributions between caries-free and caries-affected children (p = 0.03 and 0.04 for allele and genotype frequencies, respectively) and in the genotype frequencies between normal weight and underweight children (p = 0.04). Our results suggest an association between underweight and ECC; in addition it is suggested that MTRR is a common genetic risk factor for ECC and underweight.

Salivary Proteins-A Barrier on Enamel Demineralization: An in vitro Study

AIM

The aim of this study is to evaluate the protective effect of the salivary proteins on the demineralization of enamel.

MATERIALS AND METHODS

Twenty freshly extracted human molar teeth were used in this study. Enamel samples (2 mm thickness) were prepared from the buccal and lingual surfaces of the teeth selected. An acid-resistant nail varnish was used to cover every aspect of the sample, except an area of 5 * 5 mm limited by an adhesive tape. After drying, the adhesive tape was removed, exhibiting a rectangular area on the enamel surface. Samples were divided into two groups: Group I (10 samples): Each sample was coated by 100 μg of albumin for 2 hours at 37°C. Group II (10samples): Each sample was exposed to 100 μL of deionized water.Samples were washed by dipping once in deionized water. They were then disposed into individual tubes containing demineralization solution for 1, 2, 3, and 4 minutes at 37°C with gentle agitation. The demineralization solution was utilized to determine the calcium loss from specimens at 1, 2, 3, 4 minutes using an ultraviolet-visible spectrophotometer.

RESULTS

Calcium loss was less from the albumin-coated samples than control group at all times and was statistically significant (p < 0.05). Also, calcium loss was maximum at the end of 1 minute, and it decreased as time interval increased and was statistically significant (p < 0.001).

CONCLUSION

Albumin has provided a strong protection against enamel demineralization at all times compared to the one without it.

HOW TO CITE THIS ARTICLE

Hegde MN, Sajnani AR. Salivary Proteins-A Barrier on Enamel Demineralization: An in vitro Study. Int J Clin Pediatr Dent 2017;10(1):10-13.

Demineralization-remineralization dynamics in teeth and bone

Biomineralization is a dynamic, complex, lifelong process by which living organisms control precipitations of inorganic nanocrystals within organic matrices to form unique hybrid biological tissues, for example, enamel, dentin, cementum, and bone. Understanding the process of mineral deposition is important for the development of treatments for mineralization-related diseases and also for the innovation and development of scaffolds. This review provides a thorough overview of the up-to-date information on the theories describing the possible mechanisms and the factors implicated as agonists and antagonists of mineralization. Then, the role of calcium and phosphate ions in the maintenance of teeth and bone health is described. Throughout the life, teeth and bone are at risk of demineralization, with particular emphasis on teeth, due to their anatomical arrangement and location. Teeth are exposed to food, drink, and the microbiota of the mouth; therefore, they have developed a high resistance to localized demineralization that is unmatched by bone. The mechanisms by which demineralization-remineralization process occurs in both teeth and bone and the new therapies/technologies that reverse demineralization or boost remineralization are also scrupulously discussed. Technologies discussed include composites with nano- and micron-sized inorganic minerals that can mimic mechanical properties of the tooth and bone in addition to promoting more natural repair of surrounding tissues. Turning these new technologies to products and practices would improve health care worldwide.

Effect of the antimicrobial photodynamic therapy on microorganism reduction in deep caries lesions: a systematic review and meta-analysis

This study aimed to perform a systematic review to assess the effectiveness of antimicrobial photodynamic therapy (aPDT) in the reduction of microorganisms in deep carious lesions. An electronic search was conducted in Pubmed, Web of Science, Scopus, Lilacs, and Cochrane Library, followed by a manual search. The MeSH terms, MeSH synonyms, related terms, and free terms were used in the search. As eligibility criteria, only clinical studies were included. Initially, 227 articles were identified in the electronic search, and 152 studies remained after analysis and exclusion of the duplicated studies; 6 remained after application of the eligibility criteria; and 3 additional studies were found in the manual search. After access to the full articles, three were excluded, leaving six for evaluation by the criteria of the Cochrane Collaboration’s tool for assessing risk of bias. Of these, five had some risk of punctuated bias. All results from the selected studies showed a significant reduction of microorganisms in deep carious lesions for both primary and permanent teeth. The meta-analysis demonstrated a significant reduction in microorganism counts in all analyses (p<0.00001). Based on these findings, there is scientific evidence emphasizing the effectiveness of aPDT in reducing microorganisms in deep carious lesions.

Quantification and Correlation of Oral Candida with Caries Index Among Different Age Groups of School Children: A Case-Control Study

Background:

Dental caries is the most common infectious disease affecting humans and is the predominant cause of tooth loss in children. Although Candida's role in dental caries has been studied extensively, limited homogenous studies have been conducted and none have been found, that associate Candida with dental caries, while correlating it to different age groups.

Aim:

The study aimed to quantify oral Candida in school children and correlate candidal carriage to the caries index and further analyze an age association.

Subjects and Methods:

Decayed-Filled teeth/Decayed-Missing-Filled Teeth (dft/DMFT) index scores of 150 subjects were evaluated, and concentrated oral rinse samples were collected from each participant for mycologic investigation. Based on the age and caries activity, the participants were categorized into three groups consisting of 50 each such as Group-I (caries active participants of 6–12 years age), Group-II (caries active participants in 13–18 years age), and Group-III (caries-free participants in 6–18 years age); CHROMagar™ was used as a primary culture medium for candidal growth. The data was statistically analyzed using Unpaired t-test, Chi-square test and Spearman's rank order.

Results:

The results demonstrated that as age increases, the dft/DMFT scores as well as the candidal growth decreased. In addition, the oral candidal carriage levels were found to be low in caries-free group (Group-III) when compared to the study groups.

Conclusion:

The presence of Candida was directly related to the caries status and inversely proportional to the age.

Caries management by risk assessment: A review on current strategies for caries prevention and management

The current trend in treating dental caries is using nondestructive risk-based caries management strategies rather than focusing on the restorative treatment alone. Currently, there have been many changes in understanding of the multifaceted nature of caries process and its management. Caries Management by Risk Assessment (CAMBRA) which is an evidence-based approach focuses on determining many factors causing the expression of disease and take corrective action. The clinicians can ascertain what behaviors are increasing a patient's risk for disease and disease progression by evaluating the current caries risk of a patient. With this modern CAMBRA protocol, a novel treatment plan can be designed to arrest dental caries thereby decreasing the chance of cavitation. After the recognition of the multi factorial nature of caries involving the biofilm, the contemporary approaches focused mainly on the various options to cope with the locally out-of-balance oral biofilm and stop the progression of the disease. The initial caries lesions can be diagnosed with modern diagnostic aids and with the help of CAMBRA, reestablishment of the integrity of the tooth surface early on in the caries process will bring great rewards for patients. This review focuses on the repair of hard tooth tissues using noninvasive strategies.

Antibacterial activity of gold-titanates on Gram-positive cariogenic bacteria

Objective: Gram-positive cariogenic bacteria are etiological agents in dental caries; therefore, strategies to inhibit these bacteria to reduce the incident of this disease have intensified. In this study, we investigated antibacterial activities of titanates and gold-titanates against Lactobacillus casei (Lc) and Streptococcus mutans (Sm).

Materials and methods: Monosodium titanate (MST), nanomonosodium titanate (nMST) and amorphous peroxo-titanate (APT), which are inorganic compounds with high-binding affinity for specific metal ions, were used. Total bacterial proteins were measured to represent bacterial cell mass after 24 h incubation with gold-titanates. We further examined the effect of nMST-Au(III) concentrations (10,200,400 mg/L) on Lc and Sm cell viability over time via Live/Dead fluorescent staining and colony forming units (CFUs). Transmission electron microscopy (TEM) was used to determine specific locations on the bacterial cells affected by the nMST-Au(III).

Results: We found all gold-titanates and APT alone reduced bacterial protein for Lc (p value <0.001) while only MST-Au(III) and nMST-Au(III) affected Sm growth (p value <0.001). Overall, nMST-Au(III) showed the most effectiveness against both Lc and Sm at 400 mg/L. The Live/Dead staining showed all concentrations of nMST-Au(III) affected Lc growth but only 200 and 400 mg/L nMST-Au(III) interrupted Sm growth. The growth curves based on CFUs/mL showed all nMST-Au(III) concentrations affected growth of both Lc and Sm. TEM images showed nMST-Au(III) attached to Lc and Sm cell wall and were internalized into both cells.

Conclusions: nMST-Au(III) demonstrated potential antimicrobial activity against Gram-positive cariogenic bacteria. These results support further development of nMST-Au(III) as a potential novel material to prevent dental caries.

Effect of antibacterial dental adhesive on multispecies biofilms formation

Antibacterial adhesives have favorable prospects to inhibit biofilms and secondary caries. The objectives of this study were to investigate the antibacterial effect of dental adhesives containing dimethylaminododecyl methacrylate (DMADDM) on different bacteria in controlled multispecies biofilms and its regulating effect on development of biofilm for the first time. Antibacterial material was synthesized, and Streptococcus mutans, Streptococcus gordonii, and Streptococcus sanguinis were chosen to form multispecies biofilms. Lactic acid assay and pH measurement were conducted to study the acid production of controlled multispecies biofilms. Anthrone method and exopolysaccharide (EPS):bacteria volume ratio measured by confocal laser scanning microscopy were performed to determine the EPS production of biofilms. The colony-forming unit counts, scanning electron microscope imaging, and dead:live volume ratio decided by confocal laser scanning microscopy were used to study the biomass change of controlled multispecies biofilms. The TaqMan real-time polymerase chain reaction and fluorescent in situ hybridization imaging were used to study the proportion change in multispecies biofilms of different groups. The results showed that DMADDM-containing adhesive groups slowed the pH drop and decreased the lactic acid production noticeably, especially lactic acid production in the 5% DMADDM group, which decreased 10- to 30-fold compared with control group (P < 0.05). EPS was reduced significantly in 5% DMADDM group (P < 0.05). The DMADDM groups reduced the colony-forming unit counts significantly (P < 0.05) and had higher dead:live volume ratio in biofilms compared with control group (P < 0.05). The proportion of S. mutans decreased steadily in DMADDM-containing groups and continually increased in control group, and the biofilm had a more healthy development tendency after the regulation of DMADDM. In conclusion, the adhesives containing DMADDM had remarkable antimicrobial properties to serve as "bioactive" adhesive materials and revealed its potential value for antibiofilm and anticaries clinical applications.

Comparison of the effect of two sugar-substituted chewing gums on different caries- and gingivitis-related variables: a double-blind, randomized, controlled clinical trial

OBJECTIVE

The aim of this study was to compare the effect of two sugar-substituted chewing gums besides toothbrushing on different clinical, microbiological, and biochemical caries- and gingivitis-related variables.

MATERIALS AND METHODS

The study was designed as a double-blind, randomized, controlled trial with three parallel arms. A total of 130 dental students, who volunteered after signing an informed consent, were randomly allocated to receive one of the following interventions: hexitol-sweetened gum containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), pentitol-sweetened gum containing no CPP-ACP, and control group with no gum. Subjects within the experimental groups chewed two gum pellets for 20 min three times a day after meals. The daily consumption level of both polyols was 6.0 g. Clinical examinations and salivary samplings were conducted at baseline and after 30 days of gum use. Pre- and post-intervention stimulated whole saliva samples were quantified for calcium/phosphate ionic concentration, total facultative bacterial load, Streptococcus mutans/Lactobacillus spp. counts, and Gram-negative percentage.

RESULTS

A statistically significant reduction in visible plaque score was displayed in the hexitol/CPP-ACP gum group after the intervention when compared with baseline, but the order of the effect was in the same order as the differences between the groups at baseline. A similar tendency was seen in both the pentitol/non-CPP-ACP gum and control groups regarding total salivary facultative bacterial load and S. mutans count, but median values of these parameters were more significantly reduced in the pentitol/non-CPP-ACP gum group in comparison with those of the control group. Alterations of salivary Lactobacillus spp. were demonstrated only in the pentitol/non-CPP-ACP gum group.

CONCLUSION

Although these findings might indicate that a 30-day protocol of daily chewing of pentitol-sweetened gum containing no CPP-ACP might have some a reducing effect on the salivary levels of facultative bacteria, S. mutans and Lactobacillus spp., there was only a marginal, if any, benefit from the chewing gums under study on some microbiological caries- and gingivitis-related variables.

CLINICAL RELEVANCE

Taking into account that for transferring results into clinically relevant conclusions the findings need to be strong and consistent, adhering to single significant differences appears not appropriate. Hence, the clinical significance of chewing gums as an adjunctive tool for daily oral care remained questionable.

Expertise regarding dental management of oral cancer patients receiving radiation therapy among Western Australian dentists

OBJECTIVES

Dental care forms an important part of the multidisciplinary management of oral cancer patients. The aim of this study was to examine actual and self-perceived knowledge and clinical expertise regarding dental management of oral cancer patients receiving radiation therapy among Western Australian general dentists.

MATERIALS AND METHODS

An invitation to participate in a web-based questionnaire was emailed to 1095 dentists registered with the Australian Dental Association (ADA), WA branch. To assess dentists' knowledge and expertise, actual and perceived knowledge was investigated. Information regarding type of practice, practice location, year of graduation and number of oral cancer patients treated in the preceding 12 months was also obtained.

RESULTS

One hundred and ninety one dentists responded to the survey. General dentists who took part in the study appeared to possess some knowledge regarding dental management of oral cancer patients treated with radiation therapy. The majority of responders however identified deficiencies in their knowledge and willingness to participate in continuing education programs.

CONCLUSION

In view of the rising incidence of oral cancer in Western Australia, efforts should be made to provide more clinically relevant training to dentists in this area.

Science behind human saliva

Saliva is a complex fluid, which influences oral health through specific and nonspecific physical and chemical properties. The importance of saliva in our everyday activities and the medicinal properties it possesses are often taken for granted. However, when disruptions in the quality or quantity of saliva do occur in an individual, it is likely that he or she will experience detrimental effects on oral and systemic health. Often head and neck radiotherapy has serious and detrimental side effects on the oral cavity including the loss of salivary gland function and a persistent complaint of a dry mouth (xerostomia). Thus, saliva has a myriad of beneficial functions that are essential to our well-being. Although saliva has been extensively investigated as a medium, few laboratories have studied saliva in the context of its role in maintaining oral and general health.

New Insights into the Composition and Functions of the Acquired Enamel Pellicle

The acquired enamel pellicle (AEP) is a thin acellular film that forms on tooth surfaces upon exposure to the oral environment. It consists predominantly of salivary proteins, but also includes non-salivary-derived proteins, carbohydrates, and lipids. Since it is the interface between teeth and the oral environment, the AEP plays a key role in the maintenance of oral health by regulating processes including lubrication, demineralization, and remineralization and shaping the composition of early microbial flora adhering to tooth surfaces. Knowledge of the 3D structure of the AEP and how that correlates with its protective functions may provide insight into several oral pathological states, including caries, erosion, and periodontal disease. This review intends to update readers about the latest discoveries related to the formation, ultrastructure, composition, and functions of the AEP, as well as the future of pellicle research, with particular emphasis on the emerging role of proteomic and microscopy techniques in oral diagnosis and therapeutics.

Hyperglycemia and xerostomia are key determinants of tooth decay in type 1 diabetic mice

Insulin-dependent type 1 diabetes mellitus (DM) and oral diseases are closely interrelated. Poor metabolic control in diabetics is associated with a high risk of gingivitis, periodontitis and tooth loss. Salivary flow declines in diabetics and patients suffer from xerostomia. Reduced saliva predisposes to enamel hypomineralization and caries formation; however, the mechanisms that initiate and lead to progression of tooth decay and periodontitis in type 1 DM have not been explored. To address this issue, we analyzed tooth morphology in Akita ⁻/⁻ mice that harbor a point mutation in the Ins2 insulin gene, which leads to progressive hyperglycemia. Mandibles from Akita ⁻/⁻ and wild-type littermates were analyzed by microCT, scanning EM and histology; teeth were examined for amelogenin (Amel) and ameloblastin (Ambn) expression. Mice were injected with pilocarpine to assess saliva production. As hyperglycemia may alter pulp repair, the effect of high glucose levels on the proliferation/differentiation of cultured MD10-F2 pulp cells was also analyzed. Results showed that Akita ⁻/⁻ mice at 6 weeks of age showed chalky white incisors that correlated with marked hyperglycemia and impaired saliva production. MicroCT of Akita ⁻/⁻ teeth revealed excessive enamel wearing and hypomineralization; immunostaining for Amel and Ambn was decreased. A striking feature was invasion of dentinal tubules with Streptococcus mitis and microabcesses that originated in the coronal pulp and progressed to pulp necrosis and periapical periodontitis. High levels of glucose also inhibited MD10-F2 cell proliferation and differentiation. Our findings provide the first evidence that hyperglycemia in combination with reduced saliva in a model of type1 DM leads to decreased enamel mineralization/matrix proteins and predisposes to excessive wearing and decay. Importantly, hyperglycemia adversely affects enamel matrix proteins and pulp repair. Early detection and treatment of hyperglycemia and hyposalivation may provide a useful strategy for preventing the dental complications of diabetes and promoting oral health in this population.

In vivo remineralization of acid-etched enamel in non-brushing areas as influenced by fluoridated orthodontic adhesive and toothpaste

This study aimed to evaluate the in vivo remineralization of acid-etched enamel in non-brushing areas as influenced by fluoridated orthodontic adhesive and toothpaste. One hundred and twenty teeth from 30 volunteers were selected. The teeth were assigned to four treatments: no treatment (negative control); 37% phosphoric acid-etching (PAE) (positive control); PAE + resin-modified glass ionomer cement (RMGIC); and, PAE + composite resin. Patients brushed teeth with fluoridated (n = 15) or non-fluoridated (n = 15) toothpastes, so that etched enamel was protected with screens and it was not in contact with the brush bristles. Remineralization was evaluated by means of laser fluorescence (LF), environmental scanning electronic microscopy, and energy dispersive spectrometry after extraction. The LF means were compared by means of Wilcoxon and Mann Whitney tests. Environmental scanning electron microscopy scores were compared among the groups using a Kruskal Wallis test, whereas the Ca/P ratio was evaluated by means of an Analysis of Variance with subparcels (treatments) and Tukey's post-hoc test. There were no statistically significant differences between the tooth pastes and between the orthodontic adhesives evaluated. Most teeth presented only partial enamel remineralization. Therefore, the fluoride released by the RMGIC was not enough to cause increased crystal regrowth in the acid-etched enamel. The use of fluoridated toothpaste did not provide positive additional effect.

The investigation of genetic polymorphisms in the carbonic anhydrase VI gene exon 2 and salivary parameters in type 2 diabetic patients and healthy adults

The aim of this study was to investigate carbonic anhydrase (CA) VI Exon 2 single nucleotide polymorphism (SNP) and its possible association with salivary parameters in type 2 diabetic patients compared to healthy adults. Caries status was measured by using the DMFT (number of decayed, missing, and filled teeth) index. Unstimulated whole saliva and blood samples were taken. SNPs of CA gene exon 2 were determined by PCR and DNA sequencing. Salivary CA activity and buffering capacity were determined by the method of Verpoorte and Ericson, respectively. Furthermore, salivary pH was measured with pH paper and salivary flow rate was calculated. Salivary buffering capacity and pH were significantly lower in diabetic patients than those of healthy subjects (P < 0.05). Salivary flow rate, CA activity and DMFT levels did not differ between groups (P > 0.05). Four SNPs were detected; their pubmed database number are rs2274327 (C/T), rs2274328 (A/C), rs2274329 (G/C) and rs2274330. While first three of those were responsible for amino acid changes, the last one was not. The frequencies of SNPs were not significant between groups (P > 0.05). Positive significant correlation was found between CA activity and the frequency of SNPs. There was no correlation between the SNPs frequencies and pH or buffering capacity. SNPs found in this study may be related to salivary CA activity in diabetics.

Oral ecosystem alterations in celiac children: a follow-up study

OBJECTIVE

The aims of this work were (1) to assess the oral health status of children with celiac disease (CD) with or without compliance with a gluten-free diet and in non-celiac children in a follow-up study and (2) to identify oral ecosystem changes that could be used as non-invasive monitoring methods for CD patients.

STUDY DESIGN

An 18-month follow-up study in children of both genders, who were 4-12 years old during the study period, was performed. Decayed-missing-filled in temporary (dmft) and permanent teeth (DMFT), enamel alterations, oral hygiene, and gingival index were measured. Oral smears were collected by brushing. Flow rate, calcium, phosphate, pH, buffer capacity, fluoride, and Ca/P ratio were measured in saliva. Salivary protein profiles were performed.

RESULTS

Most CD patients (80%) presented typical symptoms between 12 and 24 months old. Children with CD had a significantly low frequency of enamel alterations (30%) (p=0.0001). A high percentage of patients (63.15%) reported having had aphthous ulcers at several times. The celiac group showed significantly more polymorphonuclear neutrophils (PMNs) in smears (20% PMNs per area, p=0.0459) than the control group (0% PMNs per area) at baseline. In CD children, 90% of the samples that showed PMNs at baseline did not present them after 18 months. However, 10% of the smears of CD patients presented PMNs at the end of this study. Compliance with the gluten-free diet was controlled to detect the maintenance or worsening of signs and symptoms during the medical controls.

CONCLUSIONS

The main differences amongst CD children who did or did not comply with a gluten-free diet and control children are the presence of PMNs in oral mucosa and protein salivary patterns; these findings could be considered as markers for CD, in conjunction with other signs and symptoms.