Journal of Dental Research and Review

: 2019  |  Volume : 6  |  Issue : 4  |  Page : 88--91

Evaluation of the effectiveness of olive oil on the prevention of dental erosion: An In vitro study

Alaa Osman Ayoub, Elhadi Mohieldin Awooda 
 Department of Restorative Dentistry, Faculty of Dentistry, University of Medical Sciences and Technology, Khartoum, Sudan

Correspondence Address:
Elhadi Mohieldin Awooda
Department of Restorative Dentistry, Faculty of Dentistry, University of Medical Sciences and Technology, 12810, Khartoum


Aim: The aim of this study was to explore the anti-erosive effect of olive oil against citric acid on bovine teeth and to compare the effectiveness with that of fluoride varnish. Materials and Methods: An observational analytical cross-sectional study among forty recently extracted bovine incisor teeth. From each tooth, a cubic of 4 mm × 4 mm was cut. Five surfaces of the cubic were coated by nail varnish leaving only the enamel window uncovered. The specimen was divided into four groups randomly: Group 1: five teeth (control group) nothing used, Group 2: five teeth immersed in olive oil for 6 h, Group 3: five teeth immersed in olive oil for 48 h, and Group 4: 10 teeth immersed in fluoride varnish 48 h. Then, each specimen was immersed in citric acid (pH: 2.3) for 15 and 30 min. The amount of calcium dissolved was measured by atomic absorption spectrophotometer. Different variables were statistically compared by t-test and ANOVA test with the level of significant set at P≤ 0.05. Results: The mean of calcium dissolution among the control group at 15 min was 2.8 mg/dl, while dissolution in 30 min was 6.1 mg/dl. When comparing the effect of exposure time duration of all specimens in citric acid, it was found that calcium dissolution increased in 30 min exposure than in 15 min exposure. Emersion of teeth in olive oil for 6 h was effective in reducing enamel erosion when exposed to citric acid 1% at 15 min, while in 30-min exposure to citric acid was less effective and to a lesser degree than fluoride varnish (sodium fluoride). Conclusion: Bovine teeth immersed in olive oil for 6 h resist the erosive effect of citric acid exposure for 15 min. Olive oil has less effect on the prevention of erosive tooth wear when compared to fluoride varnish.

How to cite this article:
Ayoub AO, Awooda EM. Evaluation of the effectiveness of olive oil on the prevention of dental erosion: An In vitro study.J Dent Res Rev 2019;6:88-91

How to cite this URL:
Ayoub AO, Awooda EM. Evaluation of the effectiveness of olive oil on the prevention of dental erosion: An In vitro study. J Dent Res Rev [serial online] 2019 [cited 2020 Feb 18 ];6:88-91
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Dental erosion is defined as the loss of dental hard tissue through chemical etching and dissolution by acids of nonbacterial origin.[1],[2] The prevalence of dental erosion has been globally increasing in recent years,[3] leading to the impairment of esthetics and function, which affect the patient's quality of life.[4] Dental erosion frequency results from the exposure of acid to the tooth surface. The acids may be either intrinsic (gastric acids) which are regurgitated into the mouth or extrinsic acids which are commonly found in foods and drinks.[5] The critical pH values for enamel dissolution are <4.5 causing dissolution of hydroxyapatite and fluoroapatite in the dental enamel.[6]

The successful management of extensive tooth wear can be challenging and expensive. When diagnosed early, a preventive method could be applied to reduce the rate of loss of tooth substances and to maintain the integrity, esthetic, and function of dental structure.[7]

Many studies assessed the effectiveness of topical fluoridation in reducing enamel demineralization and in increasing remineralization or microhardening of the enamel to resist acid-softened tooth surface.[8] The total prevention of enamel erosion by the use of topical fluorides with daily dosages is difficult.[9]

Natural oils are commonly used by traditional medicine and dental practitioners in prevention and management of many diseases. Vegetable oils have been studied in preventive dentistry because they come from a natural, edible, low-cost, and worldwide accessible source.[10] Olive oil's chemical composition depends on both geographical and botanical origin of olives.[11] The promising data from studies regarding olive oil in view of its favorable composition of bioactive compounds motivate researchers to synthesize evidence of its potential role in the prevention and management of many diseases.[12] Few studies have been carried out to investigate the effect of olive oil on the prevention of dental erosion,[13],[14],[15] without a conclusive result. It is justified in this study to evaluate its effectiveness as an alternative approach when changing the duration of immersion of teeth in it and the duration of immersion in citric acid (1%). The objectives of this study were to explore the anti-erosive effect of olive oil on bovine teeth when subjected to citric acid (1%) for 15 and 30 min and to compare the effectiveness when immersing a group of bovine teeth in olive oil for 48 h and another group for 6 h. Also to evaluate the antierosive effect of olive oil in comparison to the effect of fluoride varnish.

 Materials and Methods

An observational analytical cross-sectional study design conducted on Environment, Natural Resources and Desertification Research Institute (ENDRI), National Centre for Research (NCR), Sudan, during the period from March 2017 to May 2017. Ethical approval for conducting the study was obtained from the University of Medical Sciences and Technology Ethical Committee, as well as from the National Centre for Research Laboratories, Khartoum, Sudan.

Six bovine mandibular jaws were collected from a local butcher, from claves raised in similar conditions and of the same age. Forty sound anterior teeth were extracted successfully by mandibular anterior forceps. The teeth were then cleaned with running water and polished to remove any debris and remnant of the periodontal ligament. Then, they were stored in deionized water till the time of the experiment. A 4 x 4 mm area was cut using a fine separating porcelain cutting disc forming a cubic shape with six surfaces. The cubic specimens were coated by nail polishing acid-resistant leaving only enamel window uncovered. The specimens were stored in deionizing water until experiment time.

The specimens were divided into four groups randomly: Group 1: 5 specimens nothing used (control group), Group 2: 5 specimens immersed in olive oil for 48 h, Group 3: 5 specimens immersed in olive oil for 6 h, and Group 4: 10 specimens immersed in fluoride varnish for 48 h. Each block was placed in 5 ml plain tube and labeled if control or using fluoride or olive oil. Then after immersion, the specimens were cleaned and immersed in 1% citric acid (pH 2.3) for 15 min and then 30 min. The buffer solution was added to cocentered citric acid powder, and pH meter was used to calibrate 2.21 pH. For each tube containing specimen, a 3 ml of citric acid was added using a micropipette. Tubes for different groups were coded for identification.

The pH meter was used to calibrate 6.47 pH of pure olive oil (100%), the amount of acid was found to be 0.0429, and the total acidity was 0.00958.

An atomic absorption spectrophotometer (210 VGP, Buck Scientific, Inc. East Norwalk, CT) was used to measure the amount of calcium dissolved (mmol/L) in each sample at different times. Wear rates were quantified by comparing the final calcium concentration.

The Statistical Package for the Social Sciences program version 17 (SPSS Inc., Chicago, IL, USA) was used to analyze the data. Multiple comparison between means of dissolved calcium in different groups was determined by one-way ANOVA. The level of statistical significance was set at PP = 0.004) when comparing means of calcium ions dissolved between groups and within groups. Comparing calcium dissolution between the groups; when immersed in citric acid for 30 min, revealed statistical significant difference (P = 0.001).{Table 2}


This study aimed to find a simple approach to prevent dental erosion, as its prevalence is increasing globally.[3],[16] The acid is a common cause of enamel decalcification, and erosion alone is not a big issue, but the consequence (sensitivity, dental caries, pain, change in occlusion, and poor esthetic) is constituted a big problem.

The challenges in controlling the causes of dental erosion make its prevention difficult and expensive. Many studies were carried out using medicinal plants to decrease the risk of dental erosion consequences. They have effects similar to or even better than conventional clinical treatment, such as fluoride varnish.[13],[14],[15] One of these materials is olive oil.

This study was In vitro in bovine teeth, when consideration in vivo; saliva buffering action, concentration and frequency of acid exposure to natural teeth, may represent factors that can play a role in the outcome of anti-erosive effect of olive oil. The erosive wear is complex and depends on the interaction of biological, chemical, and behavioral factors.[16] Salivary flow and overnight exposure to acid are important factors for erosive tooth wear.[17] In this study, the immersion of teeth in pure olive oil at different times was tested for the effect on enamel acid resistance. The citric acid (1%) of a pH 2.3 was used to test the erosive challenge which is the most common acidic source that humans are subjected to. The design of this study was in vitro in bovine teeth, which makes it difficult to simulate the human oral environments, thus drawing a conclusion from this study is impractical. An ex vivo study on the extracted human teeth is more justified, as the structure of this teeth and concentration of different minerals and saliva role may differ greatly from the bovines one. This could be considered as a baseline data, and future in vivo experiments are recommended.

Mechanism of action against erosive tooth wear according to emulsion duration, composition, types of olive oil, and its concentration is not clearly understood. It is assumed that the adhesion properties of olive oil might be increased when applied as emulsion leading to a protective coating of the enamel surface; it might act as a diffusion barrier during acid exposure.[18] Other factors such as tooth structure (enamel or dentin) and demineralization process may affect the process of erosion. Also salivary flow rate, its buffering capacity and pellicle formed by salivary mucins played a role in resistance of acid dissolution.[19] The 6-h immersion period was selected owing to the possibility of home use by using a nightguard as in home bleaching,[20] while the 48 h was taken from a previous research which used sodium fluoride.[21]

In consistent with the result obtained by Buchalla et al.,2003 fluoride has better anti-erosive effect when compared to olive oil.[14] In spite of that, there is a significant effect on immersion of 100% olive oil for 6 h after exposure to a citric acid, while immersion for 48 h was not effective. This result concluded that there is no need for immersion of olive oil for 48 h. The mechanism of prevention of acid dissolution by olive oil at 6 h is unclear yet, but it may be due to a short time (6 h) of immersion of olive oil which may simulate the real oral environment, while in case of 48 h, other factors might be contributed.

The result by Vivek et al., in 2018, revealed that 2% olive oil mouth rinse showed the least protection against erosion on the enamel.[15] Their findings contradict our results and Wiegand et al. results who reported that 100% pure olive oil is not effective against erosion, but 2% application of olive oil with fluoridated mouth rinse was effective against erosion, but to a lesser degree than the fluoride varnish.[13]


Immersion of bovine teeth in olive oil for 6 h and then exposure to citric acid for 15 min offer protection against dental erosion, more than when teeth immersed in olive oil for 48 h, but lesser than when treated with fluoride varnish for 48 h in different times' exposure to citric acid.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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