Effect of black tea and matrix metalloproteinase inhibitors on eroded dentin in situ

Polyphenols for Preventing Dental Erosion in Pre-clinical Studies with in situ Designs and Simulated Acid Attack

Dental erosion is a chemical process characterized by acid dissolution of dental hard tissue, and its etiology is multifactorial. Dietary polyphenols can be a strategy for dental erosion management, collaborating to preserve dental tissues through resistance to biodegradation. This study describes a comprehensive review to interpret the effects of polyphenols on dental erosion of pre-clinical models with in situ designs and simulated acid attacks on enamel and dentin samples. We aim to evaluate evidence about Polyphenols' effects in the type of dental substrate, parameters of erosive cycling chosen in the in situ models, and the possible mechanisms involved. An evidence-based literature review was conducted using appropriate search strategies developed for main electronic databases (PubMed, Scopus, Web of Science, LILACS, EMBASE, LIVIVO, CINAHL, and DOSS) and gray literature (Google Scholar). The Joanna Briggs Institute checklist was used to evaluate the quality of the evidence. From a total of 1900 articles, 8 were selected for evidence synthesis, including 224 specimens treated with polyphenols and 224 control samples. Considering the studies included in this review, we could observe that polyphenols tend to promote a reduction in erosive and abrasive wear compared to control groups. However, as the few studies included have a high risk of bias with different methodologies and the estimated effect size is low, this conclusion should not be extrapolated to clinical reality.

Erosive potential of ice tea beverages and kombuchas

OBJECTIVES

Kombuchas and other tea-based beverages are often perceived as healthy products despite the lack of knowledge on their effects on oral health. This in vitro study determined the erosive potential of commercial kombuchas, and ice teas compared to cola drinks.

MATERIALS AND METHODS

The pH and fluoride content of 7 kombuchas and 18 tea drinks were measured with ion-selective electrodes. Calcium dissolution from hydroxyapatite grains was quantified by atomic absorption spectroscopy after beverage exposure. The effect of beverages on the enamel surface was visualized by scanning electron microscopy (SEM). Distilled water, and cola drinks were used as negative and positive controls.

RESULTS

The kombuchas exhibited lower pH values (2.82-3.66) than the ice teas (2.94-4.86), but still higher than the cola drinks (2.48-2.54). The fluoride concentration varied between 0.05 and 0.46 ppm and for 7 beverages the concentration was below the detection limit. The calcium release for kombuchas was 198-746 mg/l, for ice teas 16.1-507 mg/l, and for cola drinks 57.7-71.9 mg/l. Twenty-two beverages had a significantly greater calcium release than the cola drinks (p = .009-.014). The surface etching of the enamel was seen in the SEM analysis after beverage exposure.

CONCLUSIONS

Tea-based beverages have even higher erosive potential than cola drinks. Kombuchas especially, displayed a considerable erosive potential.

Effects of the application timing of anti-erosive agents on dentin erosion

This in vitro study aimed to evaluate the effects of the application timing of anti-erosive agents on dentin erosion. Eighty dentin specimens with dimensions of 2 × 2 × 2 mm were prepared and randomly divided into 4 groups based on the treatment solutions: 1.23 × 104 μg/ml sodium fluoride (NaF), 120 μg/ml chlorhexidine (CHX), 300 μg/ml quercetin (QUE), and deionized water (DW, negative control). The specimens in each group were further divided into 2 subgroups according to the application timing of the treatment solutions (n = 10): before the erosive challenges (PRE) and after the erosive challenges (POST). All specimens were submitted to 4 daily erosive challenges for 5 d. For each erosive challenge, the specimens in the subgroup PRE were treated with the respective solutions for 2 min and then immersed in cola drinks for 5 min, while the specimens in the subgroup POST were immersed in cola drinks for 5 min followed by treatment with the respective solutions for 2 min. The erosive dentin loss (EDL) was measured using a contact profilometer, and the surface morphology of the dentin specimens was evaluated by scanning electron microscopy at the end of the experiment. The data were statistically analyzed using two-way analysis of variance (ANOVA) and Bonferroni's test (α = 0.05). Significantly less EDL was observed in the groups NaF, CHX, and QUE than in the group DW (all P < 0.001). Significantly lower EDL was observed in the groups CHX and QUE than in the group NaF (P = 0.001 and P < 0.001, respectively). For CHX, subgroup POST exhibited significantly less EDL than subgroup PRE (P < 0.001). Regarding QUE, subgroup PRE showed significantly less EDL than subgroup POST (P < 0.001). Furthermore, a relatively greater number of obliterated dentinal tubules was visible in the subgroup POST rather than in the subgroup PRE of the group CHX, while in the group QUE, narrower dentinal tubules were observed in the subgroup PRE than those in subgroup POST. In conclusion, CHX and QUE showed the best performance in controlling dentin erosion. CHX was more effective in reducing EDL when applied after erosive challenges, whereas QUE worked more effectively when used before erosive attacks. The application timing should be considered when evaluating the effects of anti-erosive agents because it may determine their effectiveness.

Topical Agents for Nonrestorative Management of Dental Erosion: A Narrative Review

A nonrestorative approach to the management of dental erosion is the foremost option: controlling dental erosion. The objectives of this study are to provide an overview and to summarise the effects and properties of topical anti-erosive agents as a nonrestorative treatment of dental erosion. A literature search was conducted on five databases of peer-reviewed literature—Cochrane Library, EMBASE, PubMed, Scopus and Web of Science—to recruit articles published between 1 January 2000 and 31 December 2021. The literature search identified 812 studies; 95 studies were included. Topical anti-erosive agents can be broadly categorised as fluorides, calcium phosphate-based agents, organic compounds and other anti-erosive agents. In the presence of saliva, fluorides promote the formation of fluorapatite on teeth through remineralisation. Calcium phosphate-based agents supply the necessary minerals that are lost due to the acid challenge of erosion. Some organic compounds and other anti-erosive agents prevent or control dental erosion by forming a protective layer on the tooth surface, by modifying salivary pellicle or by inhibiting the proteolytic activity of dentine collagenases. Topical anti-erosive agents are promising in managing dental erosion. However, current evidence shows inconsistent or limited results for supporting the use of these agents in clinical settings.

Influence of periodic polyphenol treatment on the anti-erosive potential of the acquired enamel pellicle-A qualitative exploratory study

OBJECTIVE

The aim of the present study was to investigate the impact of periodic polyphenol treatment on the ultrastructure and anti-erosive potential of an in-situ formed pellicle.

METHODS

Subjects wore intraoral appliances with buccally and palatally fixed bovine enamel specimens. During 6 h of intraoral pellicle formation, 100 ml black tea or tannic acid was applied ex-vivo every 25 min for 5 min. Untreated pellicles served as control. After the trial, specimens were immersed in 0.1% or 1% citric acid for 60 s and analysed for calcium release with atomic adsorption spectrometry and ultrastructure with transmission electron microscopy.

RESULTS

Specimens covered by pellicles treated with black tea or tannic acid released less calcium than untreated pellicles. Ultrastructural analyses reveal an increase in pellicle's thickness and density after treatment with polyphenols.

CONCLUSIONS

Periodic polyphenol treatment of the pellicle modify its ultrastructure and increase its anti-erosive potential.

CLINICAL SIGNIFICANCE

Consumption of polyphenolic beverages can enhance the anti-erosive potential of the enamel pellicle.

Novel bioactive adhesive containing dimethylaminohexadecyl methacrylate and calcium phosphate nanoparticles to inhibit metalloproteinases and nanoleakage with three months of aging in artificial saliva

OBJECTIVES

The objectives of this study were to: (1) develop a multifunctional adhesive via dimethylaminohexadecyl methacrylate (DMAHDM) and nanoparticles of amorphous calcium phosphate (NACP); and (2) investigate its ability to provide metalloproteinases (MMPs) deactivation and remineralization for long-term dentin bonding durability.

METHODS

DMAHDM and NACP were incorporated into Adper™ Single Bond 2 Adhesive (SB2) at mass fractions of 5% and 20%, respectively. Degree of conversion and contact angle were measured. Endogenous MMP activity of the demineralized dentin beams, Masson's trichrome staining, nano-indentation, microtensile bond strength and interfacial nanoleakage analyses were investigated after 24 h and 3 months of storage aging in artificial saliva.

RESULTS

Adding DMAHDM and NACP did not compromise the degree of conversion and contact angle of SB2 (p > 0.05). DMAHDM and NACP incorporation reduced the endogenous MMP activity by 53 %, facilitated remineralization, and increased the Young's modulus of hybrid layer by 49 % after 3 months of aging in artificial saliva, compared to control. For SB2 Control, the dentin bond strength decreased by 38 %, with greater nanoleakage expression, after 3 months of aging (p < 0.05). However, DMAHDM+NACP group showed no loss in bond strength, with much less nanoleakage, after 3 months of aging (p > 0.05).

SIGNIFICANCE

DMAHDM+NACP adhesive greatly reduced MMP-degradation activity in demineralized dentin, induced remineralization at adhesive-dentin interface, and maintained the dentin bond strength after aging, without adversely affecting polymerization and dentin wettability. This new adhesive has great potential to help eliminate secondary caries, prevent hybrid layer degradation, and increase the resin-dentin bond longevity.

Spectroscopic and microscopic examination of teeth exposed to green tea at different temperatures

Tea is a popular beverage consumed at different temperatures. The effect of tea on teeth at different temperatures has not been studied previously. The present study used an in vitro green tea immersed tooth model at different tea temperatures (hot and cold) compared to an in vivo tea administration model allowing rats to drink tea over the course of a week. The elements present in tea leaves were identified by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and compared to the elements in teeth (enamel surface) using Laser-Induced Breakdown Spectroscopy (LIBS). Here, LIBS demonstrated in vivo and in vitro green tea treatments resulted in a significant increase in the mineral elements found in enamel. For the in vitro assessment, elements in enamel varied based on cold-tea and hot-tea treatment; however, hot water reduced the elements in enamel. Atomic force microscopy found the in vivo tea group had a higher roughness average (RA) compared with the in vivo water group. Cold tea and hot tea in vitro groups demonstrated lower RA than in vitro water controls. Scanning electron microscopy found hot water induced cracks more than 1.3μm in enamel while cold tea and hot tea promoted the adhering of extrinsic matter to teeth. Overall, teeth treated to high temperature lost the mineral phase leading to demineralization. Our results indicate that green tea protects enamel, but its protective action in dental structures is enhanced at cold temperature.