title: Comparison of the microhardness of primary and permanent teeth after immersion in two types of carbonated beverages.
abstract: OBJECTIVE
  The consumption of carbonated beverages is one of the etiological factors that cause dental erosion. The purpose of this research was to compare changes in the microhardness of permanent and primary teeth after immersion in two types of carbonated beverages.
  
  
  METHODS
  This investigation was done on 30 healthy permanent molars and 30 healthy primary canines. Each group of primary and permanent teeth was subdivided into three groups of 10 teeth. The teeth was immersed in 40 ml of each of the three beverages for 5 min. One subgroup was immersed in water (as a control). The next was immersed in Lemon Delster and the last subgroup was immersed in Coca-Cola. The microhardness of enamel was measured using the Vickers method before and after immersion. Finally, the data was analyzed by paired t-test, one-way analysis of variance, and t-test.
  
  
  RESULTS
  Microhardness reduction in the primary teeth was significant in both the Lemon Delster and Coca-Cola groups (P < 0.05). This reduction was also statistically significant in the permanent teeth (P < 0.05). A comparison of the enamel changes in the primary teeth with permanent teeth after immersion in both beverages showed a greater microhardness reduction in the primary teeth in both the experimental groups.
  
  
  CONCLUSIONS
  Coca-Cola and Lemon Delster caused a significant reduction of microhardness in tooth enamel. This reduction was greater in primary teeth than in permanent teeth, and was also greater after immersion in Coca-Cola than after immersion in Lemon Delster.
authors: Department of Material and Energy, Research Center of Material and Energy, Tehran, Iran.
authors: Hamid R
authors: HR
authors: Haghgou
authors: Department of Pediatric Dentistry, Shahed University, Tehran, Iran.
authors: Roza
authors: R
authors: Haghgoo
authors: Department of Pediatric Dentistry, Shahid Beheshty University, Tehran, Iran.
authors: Fatemah Molla
authors: FM
authors: Asdollah
keywords: Carbonated beverages; deciduous tooth; hardness; permanent tooth; tooth erosion