Remineralization of Demineralized Enamel and Dentine Using 3 Dentifrices-An InVitro Study

[The effect of vitamin D deficiency on the content of some soluble signaling molecules in the oral fluid in individuals with dental caries]

OBJECTIVE

The aim of the sthudy is to sthudy the level of soluble Immune Checkpoint Molecules (B7.2, CTLA-4, Tim-3, Lag-3, PD-1) in the oral fluid during dental caries with the background of a lack and/or deficiency of 25-hydroxy-vitamin D in body.

MATERIALS AND METHODS

During the research 3 groups of people were formed, each one of them included 17 people aged from 20 to 24 years. The first group included students with high-intensity caries (above 9 DMFt index) and 25-hydroxy-vitamin D levels in blood serum >30 ng/ml, the second included students with high caries intensity and 25-hydroxy-vitamin D levels <30 ng/ml. The control group consisted of students with an average DMFt index of 1.5 (from 0 to 3) and a level of 25(OH)D in the blood more than 30 ng/ml. To determine the content of B7.2 (CD86), CTLA-4, Tim-3, Lag-3, PD-1, the Human Vascular Inflammation Panel 1 multiplex analysis kit from Biolegend (USA) was used.

RESULTS

The results of the research showed that during dental caries with a normal level of 25-hydroxy-vitamin D there are no significant changes in the content of Immune Checkpoint Molecules. With the background of deficiency and lack of 25-hydroxy-vitamin D there is a decrease in the amount of B7.2, LAG-3, Tim-3 and PD-1. These changes are being aggravated with an increase of the caries intensity.

CONCLUSION

Vitamin D deficiency leads to a decrease in mucosal immunity of the oral cavity, the multiplication of pathogenic microorganisms, which in turn, releasing various metabolites, including cytokine-like substances, aggravate the pathological process and intensify carious lesions.

An In-Vitro Comparative Study of Fluoride Varnish and Two Calcium-Containing Fluoride Products on the Remineralization of Primary Teeth Enamel

Objectives: To compare the effectiveness of fluoride varnish and two calcium-based fluoride products on the remineralization of primary teeth enamel. Materials and Methods: Surface-microhardness (SMH) of 36 extracted anterior primary teeth was measured by Vickers test (50gr/5 seconds) to provide a baseline for later comparisons. All teeth were immersed in demineralizing solution for 96 hours to create caries-like lesions and SMH was determined for the artificially-induced caries. The teeth were randomly assigned to three groups consisting of 5% fluoride varnish once daily/10 seconds, Clinpro™ 5000 toothpaste once daily/2 minutes, and Remin Pro cream once daily/3 minutes for 28 days. All specimens were kept in artificial saliva with pH cycling during the study period. After remineralization, SMH was evaluated for the last time. Data were analyzed by one-way ANOVA, Mauchly's sphericity, and RM-ANOVA with Bonferroni correction for inter-and- intra-group comparisons at the three stages of the study. Results: Neither the baseline SMH nor the SMH of the artificially created caries showed significant differences among the samples (P>0.05). The post-treatment SMH was highest in the Clinpro group (296.4±73.1kgf/mm2), followed by Remin Pro (283.8±119.3kgf/mm2), and varnish (270.9±78.3 kgf/mm2). There was no significant difference among the groups after treatment (P>0.05). We also did not observe a significant difference among the three different study stages (P>0.05). Conclusion: Within the limitations of this in-vitro study, daily application of low fluoride-calcium compound seems to be as effective as the professional use of fluoride varnish or high-content fluoride toothpaste in remineralizing initial caries of primary teeth.

Evaluation of shear bond strength and enamel remineralizing effect of experimental orthodontic composite containing nano-hydroxyapatite: An in vitro study

OBJECTIVE

The purpose of this study was to prepare an orthodontic composite containing hydroxyapatite nanoparticles to prevent demineralization and create a suitable environment for mineral deposition around orthodontic brackets, and to investigate the mechanical and remineralizing properties of the experimental adhesive composite.

METHODS

Experimental orthodontic composite were formulated using varying percentages of nano-hydroxyapatite particles. Assessments were based on four groups: a control group (3M™ Transbond™ XT) and experimental composites containing 2% (HA2), 5% (HA5) and 10% (HA10) hydroxyapatite. Vickers Microhardness test was performed to investigate the remineralizing effect in 3 stages: initial stage, after demineralization and after 4 weeks of exposure to artificial saliva. Scanning electron microscopy with energy dispersive X-ray spectroscopy analyser (SEM/EDAX) was used to evaluate hydroxyapatite precipitation and elemental composition of enamel surface. Shear Bond Strength tests were carried out using a universal testing machine and the debonding pattern was assessed using Adhesive Remnant Index (ARI).

RESULTS

All groups showed clinically acceptable SBS values. The highest SBS was achieved in the HA2 group, followed by Transbond™ XT, HA5 and HA10. There was no significant difference in the ARI scores. In terms of microhardness properties, HA5 and HA10 demonstrated a significant increase after 4 weeks. The results of SEM analysis showed the precipitation of hydroxyapatite crystals and EDAX analysis indicated the increase of calcium and phosphate ion peaks compared to the demineralized sample. The data were analysed using one-way ANOVA and Tukey's Post-hoc test.

CONCLUSIONS

Addition of hydroxyapatite nanoparticles to orthodontic composite can increase the mineral content and microhardness of the adjacent enamel. However, increasing the amount of nanoparticles reduces shear bond strength in a decreasing trend. The above-mentioned findings showed that incremental increase of nanoparticles of HA can be incorporated in composite to a certain extent and limitations are determined by mechanical properties (SBS) required for bracket bonding.

Nano-Hydroxyapatite (nHAp) in the Remineralization of Early Dental Caries: A Scoping Review

(1) Background: Nano-hydroxyapatite (nHAp) has been reported to have a remineralizing effect on early carious lesions. The objective of this scoping review was to analyze the remineralization potential of nano-hydroxyapatite (nHAp)-containing dentifrices, by mapping the existing literature. (2) Methods: This review was performed using the PRISMA-ScR Checklist, which is an extension of the PRISMA Checklist for Systematic Reviews and Meta-Analyses. In this study, the population, concept, and context (PCC) framework was used to find relevant papers published between 2010 and 2021. Nano-hydroxyapatite (nHAp) and dentifrices containing nHAp as one of the ingredients were the two main concepts of the research question. MeSH phrases, keywords, and other free terms relevant to nano-hydroxyapatite and dentifrices were used to search the literature databases. (3) Results: Preliminary searches yielded 59 studies; the title and abstract screening results excluded 11 studies. The remaining studies were thoroughly reviewed by two reviewers on the basis of the inclusion and exclusion criteria. Finally, 28 studies were included, and 20 studies were excluded. Most of the studies that were included reported that when nHAp was used alone, it had many different effects, such as remineralization, caries prevention, less demineralization, brighter teeth, less pain, and remineralization of enamel after orthodontic debonding. (4) Conclusions: Dentifrices that contain nHAp offer a variety of therapeutic and preventative effects. Currently, there is insufficient evidence to support the efficacy of nHAp dentifrices in primary teeth. Additional long-term investigations using standardized protocols are required to reach decisive conclusions about the effects of nHAp dentifrices on primary and permanent dentitions.

Comparative Evaluation of Influence of Nd:YAG Laser (1064 nm) and 980 nm Diode Laser on Enamel around Orthodontic Brackets: An In Vitro Study

(1) Background: The prevention of demineralizing lesions at the enamel structure level continues to represent a challenge in daily dental practice. When bacteria influence the pH level, this will decrease below the threshold for remineralization and the dissociation of hydroxyapatite will occur with a high percentage of phosphate and calcium loss. These elements continue to be studied by many authors in order to obtain a working protocol that will lead to their stabilization at the level of the enamel structure, thus preventing the demineralization process. The aim of this study is to evaluate and compare the influence of two types of laser wavelengths on the surface morphology and mineral components of the enamel through an examination with scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDX). (2) Methods: Thirty permanent human incisors extracted for periodontal reasons from patients aged 25−40 years old were selected for this study. Metallic brackets (SS Standard 022 Slot, OC Orthodontics, McMinnville, OR, 97128, USA) were bonded onto each tooth. The buccal surface was randomly assigned three sections: Section A—negative control (no treatment), section B—treated with 980 nm Gallium−Aluminum−Arsenide diode laser (a 300 µm optic fiber was used with 0.8 W output power, energy density of 5.33 J/mm2, in continuous mode, for 30 s, oriented perpendicularly to the enamel surface in contact mode) (KaVo GENTLEray 980 Diode Laser, Kaltenbach & Voigt GmbH, Biberach, Germany), and section C—treated with Nd:YAG laser (a 300 µm fiber was carried out at a 1 mm distance from the enamel surface with 0.75 W power, 75 mJ pulse energy, pulse repetition rate of 10 Hz, 5 J/mm2 fluency, average exposure time of 30 s, and water cooling assisted) (LIGHTWALKER AT S, M021-5AF/1 S, Fotona d.o.o, Ljubljana, Slovenia). The elements evaluated in this study were calcium (Ca), phosphate (P), oxygen (O), and carbon (C). A one-way analysis of variance, paired t-tests, and independent t-tests were carried out to evaluate the results using the SPSS 19 IBM Statistical package software for Microsoft. (3) Results: The evaluation of the data indicated that both wavelengths produced an increase in Ca wt% (for diode laser the mean of Ca wt% before irradiation was 21.06, while that after treatment reached 28.24; and for Nd:YAG laser, the mean of Ca wt% before irradiation was 21.31, while that after treatment reached 33.88); as well, the 980 nm diode laser decreased P wt% (from 17.20 before irradiation to 16.92 after irradiation) and the Nd:YAG laser increased P wt% (from 17.46 before irradiation to 18.28 after irradiation). These results showed a statistically significant difference at the p < 0.05 level. (4) Conclusions: It can be concluded that the best improvement of enamel chemical composition was obtained with Nd:YAG irradiation.

Bionic effects of nano hydroxyapatite dentifrice on demineralised surface of enamel post orthodontic debonding: in-vivo split mouth study

BACKGROUND

Orthodontic debonding procedure produces inevitable enamel surface alterations, sequelae to which are enamel demineralization, sensitivity and retention of pigments. Several agents have been employed to counterbalance the same. The purpose of this study was (1) To evaluate the hypothesis that no significant difference exists in the remineralising potential of nano hydroxyapatite (NanoHAP) dentifrice and fluoridated dentifrice after orthodontic debonding, (2) To estimate the enamel topographic parameters following use of nano HAP dentifrice, post orthodontic debonding.

METHODS

Sixty upper first bi-cuspids (30 subjects) planned for therapeutic extraction for the orthodontic treatment were bonded with a light cured adhesive. Envelope method of randomisation was followed in this prospective in-vivo study. In each subject, one of the first premolar brackets was debonded using a debonding plier and polished following standard protocols. Envelope method of randomisation was used to determine the side of the premolar to be debonded first. Patient was advised to use fluoridated (Group I) dentifrice for the first 15 days, then the first premolar was covered with a heavy-bodied putty cap, extracted and subjected to atomic force microscopy (AFM). Contralateral first premolar was then debonded and polished using similar protocol, and patient was advised to use nano hydroxyapatite dentifrice (Group II) for next 15 days. The premolar was then extracted and analyzed for surface roughness using AFM. The remineralizing potential of dentifrices was assessed by evaluating surface roughness parameters of the two groups and were compared using a two-sample t test.

RESULTS

A significant difference was found amongst Group I (Fluoridated dentifrice) and Group II (NanoHAP dentifrice) (p > 0.001***) for enamel surface roughness variables which reflect remineralising potential of dentifrices. Group II showed significantly lesser value of surface roughness characteristics.

CONCLUSIONS

NanoHAP dentifrice was shown, after 15 days, to be superior to fluoridated dentifrice in remineralising enamel post orthodontic debonding.

Decision tree protocol for demineralized gingival margin extension in class II composite cavity preparations

This study proposed the development of a protocol for class-II preparations with demineralized gingival margins for the improvement of the longevity of restorations. Evidence sources such as location/color/surface hardness/width of demineralized gingival margin with enamel/demineralized enamel (DE)/dentin/cementum were reviewed based on methodological studies and systematic reviews. A decision tree protocol was developed with criteria (i) lesion location: demineralized gingival margins in enamel must be removed, but if close to cementoenamel-junction, color should be evaluated. (ii) Color: yellow/brown lesions must be removed, but if white/opaque, then the surface hardness should be evaluated. (iii) Surface hardness: soft/demineralized gingival margin must be removed, but if adequately hard, width should be evaluated. (iv) Width: lesions less than half-enamel thickness and impenetrable by an explorer, remineralization is possible and the lesion does not need to be removed. A decision tree protocol was set up with the current available literature. Further continued investigations will be needed for the appropriate protocol updates.

Molar Incisor Hypomineralization in Children with Intellectual Disabilities

The aim of the study is to compare the frequency and the distribution of molar incisor hypomineralization (MIH) in children with intellectual disabilities.

METHODS

Seventy-two children with intellectual disabilities and 72 healthy children were included in the study. They ranged in age from 5 to 18 years with the same distribution by age and sex. Standard clinical examination was performed, at a dental clinic or in the institution where the children lived, by using a dental mirror and a probe, according the European Academy of Paediatric Dentistry judgment criteria for MIH.

RESULTS

Among the 72 children with intellectual disabilities, eight children (11.1%) presented MIH with 19 affected teeth. In the control group, one child (1.4%) presented MIH with two affected teeth. The difference was statistically significant (p = 0.033). There were no statistically significant differences between boys and girls. The molars, especially the first right molars were the most affected tooth. Brown defects were less common than white defects.

CONCLUSION

Children with MIH should be identified because this condition is a common problem in children with intellectual disabilities.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

This comprehensive review of the 2019 restorative dental literature is offered to inform busy dentists regarding remarkable publications and noteworthy progress made in the profession. Developed by the Scientific Investigation Committee of the American Academy of Restorative Dentistry, each author brings discipline-specific expertise to 1 of 8 sections of the report: (1) prosthodontics; (2) periodontics, alveolar bone, and peri-implant tissues; (3) implant dentistry; (4) dental materials and therapeutics; (5) occlusion and temporomandibular disorders; (6) sleep-related breathing disorders; (7) oral medicine and oral and maxillofacial surgery; and (8) dental caries and cariology. The report targets important information likely to influence day-to-day dental treatment decisions. Each review is not intended to stand alone but to update interested readers so that they may visit source material when greater detail is desired. As the profession moves toward evidence-based clinical decision-making, an incredible volume of potentially valuable dental literature continues to increase. It is the intention of this review and its authors to provide assistance in negotiating the extensive dental literature published in 2019. It is our hope that readers find this work useful in the clinical management of dental patients.

The role of salivary contents and modern technologies in the remineralization of dental enamel: a narrative review

Human enamel once formed cannot be biologically repaired or replaced. Saliva has a significant role in remineralization of dental enamel. It not only has a buffering capacity to neutralize the oral cavity’s low pH generated after acidic encounters, but also acts as a carrier of essential ions, such as fluoride, calcium and phosphate, which have a positive role in enamel’s remineralization. This review discusses how salivary contents, like proteins and enzymes, have a natural role in enamel’s mineralization. In addition, the presence of ions, such as fluoride, calcium and phosphate, in saliva further enhances its capability to remineralize the demineralized enamel surface. The review further examines modern innovative technologies, based on biomimetic regeneration systems, including dentin phosphoproteins, aspartate-serine-serine, recombinant porcine amelogenin, leucine-rich amelogenin peptide and nano-hydroxyapatite, that promote enamel remineralization. Fluoride boosters like calcium phosphates, polyphosphates, and certain natural products can also play an important role in enamel remineralization.

The role of salivary contents and modern technologies in the remineralization of dental enamel: a narrative review

Human enamel once formed cannot be biologically repaired or replaced. Saliva has a significant role in remineralization of dental enamel. It not only has a buffering capacity to neutralize the oral cavity's low pH generated after acidic encounters, but also acts as a carrier of essential ions, such as fluoride, calcium and phosphate, which have a positive role in enamel's remineralization. This review discusses how salivary contents, like proteins and enzymes, have a natural role in enamel's mineralization. In addition, the presence of ions, such as fluoride, calcium and phosphate, in saliva further enhances its capability to remineralize the demineralized enamel surface. The review further examines modern innovative technologies, based on biomimetic regeneration systems, including dentin phosphoproteins, aspartate-serine-serine, recombinant porcine amelogenin, leucine-rich amelogenin peptide and nano-hydroxyapatite, that promote enamel remineralization. Fluoride boosters like calcium phosphates, polyphosphates, and certain natural products can also play an important role in enamel remineralization.