ORIGINAL SCIENTIFIC ARTICLE Are grape juices more erosive than orange juices? A. P. C. A. Beltrame 1 • R. A. T. Noschang 1 • D. P. Lacerda 1 • L. C. Souza 2 • I. C. S. Almeida 1 Received: 3 November 2016 / Accepted: 8 July 2017 Ó European Academy of Paediatric Dentistry 2017 Abstract Aims To evaluate the chemical characteristics of grape and orange juices, and their erosive potential in the decrease of microhardness and the loss of enamel structure. Methods Five grape and orange juices were evaluated for pH, titratable acidity, calcium, phosphate, and fluoride concentration. De-ionised water and Cola soft drink were used as a negative and positive control, respectively. Twelve specimens of bovine enamel were immersed in beverages for 10 min at 37 °C, 3 times/day for 7 days. Erosive potential was quantified using microhardness and loss of enamel structure. Anova One Way, Student’s t test, Multiple Regression and Spearman Correlation (p \ 0.05) were used to analyse the results. Results Powdered grape juice showed the lowest pH (3.18 ± 0.03) and pure grape juice presented the highest titratable acidity (5.48 ± 0.06 mL NaOH/100 mL). Fresh orange juice and soya-based grape juice revealed the lowest calcium (0.77 ± 0.12 mmol/L) and phosphate concentra- tions (0.35 ± 0.06 mmol/L), respectively. Among juices, powdered orange juice caused the greatest decrease in sur- face microhardness (SMH) (127.99 ± 40.47 DSMH) and grape juice from concentrate caused the greatest loss of enamel structure (13.30 ± 3.56 lm). Conclusions All of the evaluated juices contributed to dental erosion. Grape juices presented greater erosive potential than orange juices. Pure, powdered and concen- trated grape juices showed similar loss of enamel structure to the Cola soft drink. The erosive potential of beverages was statistically correlated to pH, titratable acidity, cal- cium, phosphate and fluoride concentrations. Keywords Dental erosion Á Chemical properties Á Fruit juices Introduction Dental erosion is defined as the dissolution of dental tissue by a chemical process without bacteria (Imfeld 1996). Epidemiological studies show a prevalence up to 79% in 5-year-old children (Mantonanaki et al. 2013) and 75% in 12-year-old teenagers (Zhang et al. 2014). High con- sumption of soft drinks is the most important aetiological factor (Corre ˆa et al. 2011; Murakami et al. 2011; Chrysanthakopoulos 2012; Kumar et al. 2013), but high consumption of citric fruits (Abu-Ghazaleh et al. 2013; Kumar et al. 2013) and fruit juices (Okunseri et al. 2011; Chrysanthakopoulos 2012; Nayak et al. 2012; Zhang et al. 2014; Kitasako et al. 2015) is also related with dental erosion. In vitro studies have shown high erosive potential of soft drinks in enamel (Sales-Peres et al. 2007; Borjian et al. 2010), with a loss of microhardness of up to 78% (Sales- Peres et al. 2007). Besides soft drinks, fruit juices also have a high erosive potential. Some studies have shown that these juices can be more erosive than soft drinks because they have a higher titratable acidity (Edwards et al. 1999; Jensdottir et al. 2005) and a higher loss of microhardness in enamel (Lussi et al. 1995). On the other hand, other studies have shown soft drinks with a higher titratable acidity & A. P. C. A. Beltrame anapaulabel@gmail.com 1 Dentistry Department, Federal University of Santa Catarina, Prof. Walter de Bona Castelan 502, Floriano ´polis, Santa Catarina 88037-300, Brazil 2 Clinical Analysis Department, Federal University of Santa Catarina, Floriano ´polis, Santa Catarina, Brazil 123 Eur Arch Paediatr Dent DOI 10.1007/s40368-017-0296-6