Influence of five neutralizing products on intra-oral pH after rinsing with simulated gastric acid

Anti-erosive effect of calcium carbonate suspensions

Background

This study aimed to investigate the ability of different concentrations of calcium carbonate (CaCO3) suspensions to control enamel surface loss.

Material and Methods

Seventy-five enamel slabs were embedded, ground and polished in a pneumatic grinder-polisher machine. Reference areas were created with UPVC tape and the specimens were randomly allocated into five groups (n = 15) for exposure to hydrochloric acid solution to simulate gastric juice (0.01 M, pH 2) for 2 minutes. The samples were then exposed to suspensions containing 0.0001, 0.001, 0.01 or 0.1 mmol/L CaCO3 for 1 minute. Artificial saliva was used as control. The samples were subjected to a total of five erosive cycles followed by treatment with CaCO3 suspension. Surface loss was measured (in µm) using optical profilometry.

Results

One-way ANOVA (p = 0.009) and Tukey's test showed a significant reduction in surface loss when compared to the group not exposed to CaCO3 (0.74, +/- 0.23 µm), and the 0.01 mmol/L (0.40; +/- 0.23 µm) and 0.1 mmol/L suspensions (0.37; +/- 0.26 µm).

Conclusions

The lower concentrated suspensions were incapable of significantly reducing enamel surface loss. Rinsing with 0.01 and 0.1 mmol/L calcium carbonate suspensions was revealed as a potentially promising strategy to prevent enamel erosion. Key words:Tooth erosion, gastric acid, calcium carbonate, prevention and control.

Rinsing with antacid suspension reduces hydrochloric acid-induced erosion

OBJECTIVE

Mouthrinsing with antacids, following erosive episodes, have been suggested as a preventative strategy to minimize tooth surface loss due to their neutralizing effect. The purpose of this in situ study was to evaluate the effect of an antacid suspension containing sodium alginate, sodium bicarbonate and calcium carbonate in controlling simulated erosion of enamel of intrinsic origin.

DESIGN

The experimental units were 48 slabs (3×3×2mm) of bovine enamel, randomly divided among 12 volunteers who wore palatal appliances with two enamel slabs. One of them was exposed extra-orally twice a day to 25mL of a hydrochloric acid (HCl) solution (0.01M, pH 2) for 2min. There were two independent phases, lasting 5 days each. In the first phase, according to a random scheme, half of the participants rinsed with 10mL of antacid suspension (Gaviscon(®), Reckitt Benckiser Healthcare Ltd.), while the remainder was rinsed with deionized water, for 1min. For the second phase, new slabs were inserted and participants switched to the treatment not received in the first stage. Therefore, the groups were as follows: (a) erosive challenge with HCl+antacid suspension; (b) erosive challenge with HCl+deionized water (DIW); (c) no erosive challenge+antacid suspension; (d) no erosive challenge+DIW. Specimens were assessed in terms of surface loss using optical profilometry and Knoop microhardness. The data were analyzed using repeated measures two-way analysis of variance and Tukey's tests.

RESULTS

Compared to DIW rinses, surface loss of enamel was significantly lower when using an antacid rinse following erosive challenges (p=0.015). The Knoop microhardness of the enamel was significantly higher when the antacid rinse was used (p=0.026).

CONCLUSIONS

The antacid suspension containing sodium alginate, sodium bicarbonate and calcium carbonate, rinsed after erosive challenges of intrinsic origin, reduced enamel surface loss.

Prosthetic Rehabilitation of a Patient With Gastroesophageal Reflux Disease: Five-Year Follow-up

Tooth wear is a multifactorial process that is a growing concern in dentistry. This phenomenon can be caused by mechanical (attrition, abrasion, or abfraction) or chemical (erosion) processes. Etiologic factors in dental erosion can be due to changes in behavior, an unbalanced diet, or gastrointestinal disorders such as acid regurgitation, which may influence the salivary flow rate and buffering capacity of saliva. This case report describes an esthetic rehabilitation of a patient with gastroesophageal reflux and dental erosion, with a treatment rationale that includes the use of a diagnostic template and five-year follow-up. This technique, presented here in a clinical case with moderate enamel loss, integrates an additive wax-up and a direct intraoral bis-acryl resin mock-up. Lithium disilicate glass-ceramic (IPS e.max Press, Ivoclar Vivadent) laminate veneers were fabricated with the heatpress technique. They were veneered with a layering ceramic (IPS e.max Ceram, Ivoclar Vivadent) to improve the appearance of the incisal edge. The case demonstrated the success of veneers as an effective, conservative, and esthetic treatment for patients with this pathology.

Systematic review of potential health risks posed by pharmaceutical, occupational and consumer exposures to metallic and nanoscale aluminum, aluminum oxides, aluminum hydroxide and its soluble salts

Abstract Aluminum (Al) is a ubiquitous substance encountered both naturally (as the third most abundant element) and intentionally (used in water, foods, pharmaceuticals, and vaccines); it is also present in ambient and occupational airborne particulates. Existing data underscore the importance of Al physical and chemical forms in relation to its uptake, accumulation, and systemic bioavailability. The present review represents a systematic examination of the peer-reviewed literature on the adverse health effects of Al materials published since a previous critical evaluation compiled by Krewski et al. (2007) . Challenges encountered in carrying out the present review reflected the experimental use of different physical and chemical Al forms, different routes of administration, and different target organs in relation to the magnitude, frequency, and duration of exposure. Wide variations in diet can result in Al intakes that are often higher than the World Health Organization provisional tolerable weekly intake (PTWI), which is based on studies with Al citrate. Comparing daily dietary Al exposures on the basis of "total Al"assumes that gastrointestinal bioavailability for all dietary Al forms is equivalent to that for Al citrate, an approach that requires validation. Current occupational exposure limits (OELs) for identical Al substances vary as much as 15-fold. The toxicity of different Al forms depends in large measure on their physical behavior and relative solubility in water. The toxicity of soluble Al forms depends upon the delivered dose of Al(+3) to target tissues. Trivalent Al reacts with water to produce bidentate superoxide coordination spheres [Al(O2)(H2O4)(+2) and Al(H2O)6 (+3)] that after complexation with O2(•-), generate Al superoxides [Al(O2(•))](H2O5)](+2). Semireduced AlO2(•) radicals deplete mitochondrial Fe and promote generation of H2O2, O2 (•-) and OH(•). Thus, it is the Al(+3)-induced formation of oxygen radicals that accounts for the oxidative damage that leads to intrinsic apoptosis. In contrast, the toxicity of the insoluble Al oxides depends primarily on their behavior as particulates. Aluminum has been held responsible for human morbidity and mortality, but there is no consistent and convincing evidence to associate the Al found in food and drinking water at the doses and chemical forms presently consumed by people living in North America and Western Europe with increased risk for Alzheimer's disease (AD). Neither is there clear evidence to show use of Al-containing underarm antiperspirants or cosmetics increases the risk of AD or breast cancer. Metallic Al, its oxides, and common Al salts have not been shown to be either genotoxic or carcinogenic. Aluminum exposures during neonatal and pediatric parenteral nutrition (PN) can impair bone mineralization and delay neurological development. Adverse effects to vaccines with Al adjuvants have occurred; however, recent controlled trials found that the immunologic response to certain vaccines with Al adjuvants was no greater, and in some cases less than, that after identical vaccination without Al adjuvants. The scientific literature on the adverse health effects of Al is extensive. Health risk assessments for Al must take into account individual co-factors (e.g., age, renal function, diet, gastric pH). Conclusions from the current review point to the need for refinement of the PTWI, reduction of Al contamination in PN solutions, justification for routine addition of Al to vaccines, and harmonization of OELs for Al substances.

Gastroesophageal reflux, dental erosion, and halitosis in epidemiological surveys: a systematic review

In published studies, it has been suggested that dental wear is associated with gastroesophageal reflux disease (GERD). This systematic review was carried out to evaluate the association of GERD, dental erosion, and halitosis and to compare the indices adopted in epidemiological surveys. The Medline database (until October, 2011) was searched systematically to identify studies evaluating the prevalence of oral alterations, such as dental erosion and halitosis, in patients with GERD symptoms. Two reviewers analyzed all reports and the selected studies were evaluated according to the quality of evidence, using the validated Newcastle-Ottawa Quality Assessment Scale. Full-text copies of a total of 32 publications were obtained in duplicate. Sixteen publications were identified among the citations in the Bibliographic lists of studies that fulfilled the exclusion/inclusion criteria and quality of evidence. The relationship between dental erosion and GERD patients was significant in only seven studies. According to three studies, halitosis could be one of several extraesophageal symptoms or manifestations in GERD patients. In one study, it was found that the mucosa of GERD patients was significantly more acidic in comparison with that of the control group. This systematic review showed that there is a relationship between GERD and oral diseases (dental erosion and halitosis). The epidemiological surveys used different indices to analyze GERD and dental erosion. Further research could investigate the best method for assessing the two diseases.

Counteractive effect of antacid suspensions on intrinsic dental erosion

This in vitro study aimed to investigate the anti-erosive effect of antacid suspensions applied to enamel after exposure to hydrochloric acid (HCl). Ninety bovine enamel slabs were embedded, flattened, and polished. Reference areas were created and specimens were divided into six groups. They were exposed to 0.01 M HCl (pH 2) for 2 min, followed by immersion for 1 min in one of the following test suspensions: magnesium hydroxide, aluminum hydroxide, magnesium hydroxide/aluminum hydroxide, sodium alginate/sodium bicarbonate/calcium carbonate, or hydrated magnesium aluminate. Artificial saliva was used as a negative control. Specimens were subjected to a total of five cycles of erosion/antacid treatment. Enamel surface loss was measured (in micrometers) by optical profilometry. In addition, baseline and final surface microhardness (SMH) values of enamel were obtained. It was found that antacid suspensions significantly reduced enamel loss, and that similar protection was afforded by all formulations. No differences were observed between the final enamel SMH values among groups. Antacid suspensions counteracted HCl-induced enamel loss, although they were not effective in reducing enamel softening. Mouth rinsing with antacid suspensions after vomiting can potentially represent a promising strategy to counteract enamel loss caused by erosion.

Dental erosion and its growing importance in clinical practice: from past to present

Since the mid-1990s, the focus of studies on tooth wear has steadily shifted from the general condition towards the more specific area of dental erosion; equally, a shift has occurred from studies in adults to those in children and adolescents. During this time, understanding of the condition has increased greatly. This paper attempts to provide a critical overview of the development of this body of knowledge, from earlier perceptions to the present. It is accepted that dental erosion has a multifactorial background, in which individual and lifestyle factors have great significance. Notwithstanding methodological differences across studies, data from many countries confirm that dental erosion is common in children and young people, and that, when present, it progresses rapidly. That the condition, and its ramifications, warrants serious consideration in clinical dentistry, is clear. It is important for the oral healthcare team to be able to recognize its early signs and symptoms and to understand its pathogenesis. Preventive strategies are essential ingredients in the management of patients with dental erosion. When necessary, treatment aimed at correcting or improving its effects might best be of a minimally invasive nature. Still, there remains a need for further research to forge better understanding of the subject.