Acids with an equivalent taste lead to different erosion of human dental enamel

Scent of relief: Mastic resin scent recovers salivation in chronic dry mouth patients

BACKGROUND

Olfactory stimulation with mastic resin, derived from the Pistacia lentiscus tree, demonstrated a bona fide sialagogic effect in healthy volunteers [1]. Its main volatile compound, α-pinene, also showed this effect. The current study aimed to validate the effect of mastic resin volatiles in chronic dry mouth patients with confirmed decreased saliva secretion.

METHODS

41 chronic dry mouth patients with decreased unstimulated saliva secretion (<0.25 mL/min) were exposed to mastic resin volatiles as part of the diagnostic routine at the Saliva Clinic of Academic Centre for Dentistry Amsterdam. During their visit, dry-mouth questionnaires were conducted and samples of unstimulated whole saliva, chew-stimulated saliva, acid-stimulated saliva and mastic resin stimulated saliva were collected. Saliva flow rate, spinnbarkeit, pH, ion composition, MUC5B and MUC7 levels in all samples were analyzed.

RESULTS

Salivary flow rates increased by all stimuli when compared to the baseline unstimulated saliva (P<0.001). During olfactory mastic resin stimulation, the salivary spinnbarkeit (P<0.001) and sodium concentration (P<0.01) were increased compared to unstimulated saliva. MUC5B and MUC7 levels were increased during olfactory mastic resin stimulation compared to chew-stimulated saliva (P=0.016 and P<0.001, respectively). Spinnbarkeit correlated positively with MUC5B (R=0.399, P=0.002) and MUC7 levels (R=0.375, P=0.004). Results of dry-mouth questionnaires indicated reduced posterior palate dryness shortly after olfactory mastic resin stimulation (P=0.04).

CONCLUSIONS

Olfactory mastic resin stimulation increased mucous saliva secretion and reduced posterior palate dryness in a group of chronic dry mouth patients. These findings, validated in patients, underscore mastic resin scent as a beneficial and non-invasive sialagogic treatment for clinical applications.

The dynamic interplay of dietary acid pH and concentration during early-stage human enamel and dentine erosion

Dental erosion continues to be a significant global health concern affecting nearly 30% of adults world-wide. With increasing soft drink consumption predominantly driving its prevalence, strategies for prevention and control are often implemented when erosion is severe, or rates are high in the populace. While factors affecting dental erosion such as pH on enamel has received much attention, the effect of dietary acid concentration when factored out to a commercially available pH has yet to be determined. Furthermore, understanding these effects on dentine, which is known to be more susceptible to erosion than enamel can unravel structure property relationships between acid characteristics and hard tissue types. This study aimed to develop structure-property relationships between dietary acid concentration, and pH, on the nano-textural and nano-mechanical properties of human enamel and dentine during short-term simulated drinking. To achieve this, a novel sample preparation methodology and analysis approach was developed by applying atomic force microscopy (AFM) in quantitative imaging mode. This enabled simultaneous measurement of enamel and dentine morphology and mechanical properties. Flow-cells were used to simulate drinking, exposing polished and smear layer free human enamel and dentine to 30 s repeated cycles of unbuffered citric acid 6% (pH = 1.88) and 1% (w/v) (pH = 2.55) and commercially available buffered pH = 3.8 states, for up to 180 s. The same 50 µm × 50 µm area of specimen morphology was analysed using in-house developed nanotextural analysis using the bearing area curve (BAC) with a focus on roughness (Ra), normalised peak (PA) and valley areas (VA). Mechanical properties were simultaneously measured for stiffness (N/m) after each 30 s. While all studies agree pH is a major factor in the erosion of enamel, here its dominance over the treatment time varied, with concentration surpassing the importance of pH after initial acid contact. Conversely, dentine erosion showed concentration-dependent changes in morpho-mechanical properties only. These results not only highlight the dynamic process of erosion, but how the interplay between acid characteristics and dental tissue type impact the progression of very early-stage erosion.

Effects of prolonged use of over-the-counter bleaching agents on enamel: An in vitro study

This study evaluated the effects of four over-the-counter (OTC) bleaching products on the properties of enamel. Extracted human molars were randomly assigned into four groups (n = 5): PD: Poladay (SDI), WG: White Teeth Global (White Teeth Global), CW: Crest3DWhite (Procter & Gamble), and HS: HiSmile (HiSmile). The hydrogen peroxide (H₂ O₂ ) content in each product was analyzed via titration. Twenty teeth were sectioned into quarters, embedded in epoxy resin, and polished. Each quarter-tooth surface was treated with one of the four beaching times: T0: control/no-bleaching, T14: 14 days, T28: 28 days, and T56: 56 days. Materials were applied to enamel surfaces as recommended. Enamel surfaces were examined for ultramicrohardness (UMH), elastic modulus (EM), superficial roughness (Sa), and scanning electron microscopy (SEM). Ten additional teeth were used to evaluate color and degree of demineralization (DD) (n = 5). Data were statistically tested by two-way ANOVA and Tukey's tests (α = 5%). Enamel surfaces treated with PD and WG presented UMH values significantly lower than the controls (p < .05). Elastic modulus (E) was significantly reduced at T14 and T28 for PD, and at T14 for HS (p < .05). A significant increase in Sa was observed for CW at T14 (p < .05). Color changes were observed in the PD and WG groups. Additionally, DD analysis showed significant demineralization at T56 for CW. Overall, more evident morphological alterations were observed for bleaching products with higher concentrations of H₂ O₂ (p < .05), PD, and WG. Over-the-counter bleaching products containing H₂ O₂ can significantly alter enamel properties, especially when application time is extended.

Effectiveness of Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) Compared to Fluoride Products in an In-Vitro Demineralization Model

The goal of this study was to evaluate the effectiveness of the toothpaste Tooth Mousse compared to conventional fluoride-based versions in the prevention of enamel and dentin demineralization. Human enamel and dentin samples (n = 120 each) were exposed to artificial demineralization at pH 4.92. During the demineralization process, the samples in the test groups were periodically treated with Tooth Mousse (TM) containing casein-phosphopeptide -amorphous-calcium-phosphate (CPP-ACP) and Tooth Mousse Plus (TMP) containing amorphous-calcium-fluoride-phosphate (CPP-ACPF) to evaluate their protective properties. Fluoride toothpastes containing 1400 ppm amine fluoride (AmF) and 1450 ppm sodium fluoride (NaF) were applied in the positive control groups. Treatment with distilled water (group C-W) or demineralization without treatment (group C-D) served as negative controls. After the demineralization and treatment process, all samples were cut longitudinally and lesion depths were determined at six locations using polarized light microscopy. In TM/TMP groups (enamel: 80/86 µm, dentin: 153/156 µm) lesion depths were significantly smaller compared to the negative control groups C-W/C-D (enamel: 99/111 µm, dentin: 163/166 µm). However, TM and TMP compared to the positive controls AmF/NaF (enamel: 58/63 µm, dentin: 87/109 µm) showed higher lesion depths. The application of TM/TMP (89%/78%) during demineralization led to a reduced number of severe lesions compared to the negative controls C-W/C-D (100%/95%). In this study we demonstrate that Tooth Mousse is less effective regarding prevention of enamel and dentin demineralization compared to fluoride containing toothpastes.

Surface degradation evaluation of different self-adhesive restorative materials after prolonged energy drinks exposure

AIM

To evaluate the effects of energy drinks and soft beverages on the surface degradation of different self-adhesive materials.

MATERIALS AND METHODS

A 156 disc shaped specimens of each of the following materials were prepared: Alkasite (Cention N, CN), High viscozity glass ionomer (Equia Forte, EF), Glass Carbomer (GCP Fill, GC) (n = 52). After specimen preparations, baseline surface roughness measurements were done using a 3D non-contact optical profilometer. Then, specimens were subdivided into 4 subgroups (n = 13) and stored in petri dish containing Red Bull; Burn; Coca-Cola and Distilled water. The surface roughness of the specimens were measured after 1-day, 1-week, and 1-month of immersion in beverages.

RESULT

It was observed that 1-month Red Bull immersion revealed the highest roughness difference (ΔRa) for each self-adhesive restorative material and this was followed by Burn. Whereas, the lowest ΔRa values were observed after 1-day coke and distilled water immersion in all tested material groups (P < 0.05). Coke and distilled water presented the energy drinks' 1-day immersion affect, after 1-week immersion (P < 0.05).

CONCLUSION

The energy drinks have a substantially damaging effect on roughness of self adhesive materials compared with soft drinks and distilled water; and this effect is increasing with exposure duration.

Prevention of erosive tooth wear: targeting nutritional and patient-related risks factors

This article provides an overview of the nutritional and patient-related risk factors involved in the aetiology of erosive tooth wear (ETW) and the preventive strategies to counteract them. The first step is to diagnose clinical signs of ETW and to recognise causal factors. Low pH and high buffer capacity of foods/drinks are the major risk factors, while the calcium concentration is the main protective factor. Reduction of frequency of consumption and contact time of erosive foods/drinks with the teeth, use of straws appropriately positioned and consumption of dairy products are advisable. Oral hygiene has a role in the development of ETW, however, postponing toothbrushing is not clinically advisable. In cases of drug abuse, chronic alcoholism, GERD or bulimia, the patient must be referred to a doctor. Immediately after vomiting, patients might be advised to rinse the mouth. Saliva has an important protective role and patients with reduced salivary flow can benefit from the use of chewing gum. Recent studies have focused on improving the protective capacity of the acquired pellicle as well as on the role of protease inhibitors on dentine erosion. However, the degree of evidence for these preventive measures is low. Clinical trials are necessary before these measures can be recommended.

Prevalence and Extrinsic Risk Factors for Dental Erosion in Adolescents

OBJECTIVE

This manuscript examined the prevalence and extrinsic risk factors for dental erosion (DE) in early and middle adolescents in Pasto, Colombia.

STUDY DESIGN

Dental erosion was evaluated in a random sample of 384 individuals aged 10-15 years attending three primary and high schools in this cross-sectional study. Clinical dental assessment for DE was done using O'Sullivan index. Data on general sociodemographic variables and extrinsic risks factors were obtained. Descriptive and univariate binary logistic regression analyses were performed.

RESULTS

Dental erosion was observed in 57.3% of individuals. The univariate binary logistic regression analysis showed that frequency of drinking natural fruit juices (OR 2.670, 95% CI 1.346 - 5.295, P=0.004) and their pH (OR 2.303, 95% CI 1.292 - 4.107, P=0.004) were more associated with the odd of DE in early adolescence. However, a high SES (OR 10.360, 95% CI 3.700 - 29.010, P<0.001) and frequency of snacks with artificial lemon taste (OR 3.659, 95% CI 1.506 - 8.891, P=0.003) were highly associated with the risk of DE in middle adolescence.

CONCLUSIONS

The results suggest that DE is a prevalent condition in adolescents living in a city in southern Colombia. The transition from early to middle adolescence implies new bio-psychosocial changes, which increase the risk for DE.

Novel Dental Cement to Combat Biofilms and Reduce Acids for Orthodontic Applications to Avoid Enamel Demineralization

Orthodontic treatments often lead to biofilm buildup and white spot lesions due to enamel demineralization. The objectives of this study were to develop a novel bioactive orthodontic cement to prevent white spot lesions, and to determine the effects of cement compositions on biofilm growth and acid production. 2-methacryloyloxyethyl phosphorylcholine (MPC), nanoparticles of silver (NAg), and dimethylaminohexadecyl methacrylate (DMAHDM) were incorporated into a resin-modified glass ionomer cement (RMGI). Enamel shear bond strength (SBS) was determined. Protein adsorption was determined using a micro bicinchoninic acid method. A dental plaque microcosm biofilm model with human saliva as inoculum was used to investigate metabolic activity, colony-forming units (CFU) and lactic acid production. Incorporating 3% of MPC, 1.5% of DMAHDM, and 0.1% of NAg into RMGI, and immersing in distilled water at 37 °C for 30 days, did not decrease the SBS, compared to control (p > 0.1). RMGI with 3% MPC + 1.5% DMAHDM + 0.1% NAg had protein amount that was 1/10 that of control. RMGI with triple agents (MPC + DMAHDM + NAg) had much stronger antibacterial property than using a single agent or double agents (p < 0.05). Biofilm CFU on RMGI with triple agents was reduced by more than 3 orders of magnitude, compared to commercial control. Biofilm metabolic activity and acid production were also greatly reduced. In conclusion, adding MPC + DMAHDM + NAg in RMGI substantially inhibited biofilm viability and acid production, without compromising the orthodontic bracket bond strength to enamel. The novel bioactive cement is promising for orthodontic applications to hinder biofilms and plaque buildup and enamel demineralization.

Effect of acidity upon attrition-corrosion of human dental enamel

Attrition-corrosion is a synthesized human enamel wear process combined mechanical effects (attrition) with corrosion. With the rising consumption of acidic food and beverages, attrition-corrosion is becoming increasingly common. Yet, research is limited and the underlying mechanism remains unclear. In this study, in vitro wear loss of human enamel was investigated and the attrition-corrosion process and wear mechanism were elucidated by the analysis of the wear scar and its subsurface using focused ion beam (FIB) sectioning and scanning electron microscopy (SEM). Human enamel flat-surface samples were prepared with enamel cusps as the wear antagonists. Reciprocating wear testing was undertaken under load of 5N at the speed of 66 cycle/min for 2250 cycles with lubricants including citric acid (at pH 3.2 and 5.5), acetic acid (at pH 3.2 and 5.5) and distilled water. All lubricants were used at 37°C. Similar human enamel flat-surface samples were also exposed to the same solutions as a control group. The substance loss of enamel during wear can be linked to the corrosion potential of a lubricant used. Using a lubricant with very low corrosion potential (such as distilled water), the wear mechanism was dominated by delamination with high wear loss. Conversely, the wear mechanism changed to shaving of the softened layer with less material loss in an environment with medium corrosion potential such as citric acid at pH 3.2 and 5.5 and acetic acid at pH 5.5. However, a highly corrosive environment (e.g., acetic acid at pH 3.2) caused the greatest loss of substance during wear.

Possible ways of reducing dental erosive potential of acidic beverages

Frequent consumption of acidic beverages is related to excessive tooth wear, namely dental erosion. Preventive measures may involve reduction or elimination of acidic drink consumption. However, the success of this approach is difficult to achieve as it is highly dependent on patient compliance. Therefore, a practical way of minimizing the erosive potential of popular acidic drinks may be their chemical modification. The aim of this article was to review the different methods of modification and their shortcomings. The available literature demonstrates that the erosive potential of most acidic beverages could be reduced. To date, the effectiveness of soluble calcium salts supplementation is the best established. However, modification can reduce the sensorial quality of the drink and shorten its shelf-life. There is also a need to evaluate the lowest effective and safe dose of the additive.

Tooth surface loss: tools and tips for management

Tooth surface loss is becoming increasingly prevalent. Many cases can be managed with preventive measures, although there remain a number of patients for whom restorative intervention is indicated. Traditional treatment modalities have entailed extensive 'full-mouth' indirect restoration, although this approach has a number of disadvantages. Contemporary restorative techniques allow for a broader range of treatment options: this paper presents an overview of common issues and clinical techniques to overcome these.

CLINICAL RELEVANCE

Treatment options and guidance for managing patients who present with tooth surface loss.