# An Evaluation of the Demineralizing Effects of Various Acidic Solutions
## 4 Conclusions  
The present study aimed to compare six different acidic solutions with respect to enamel demineralization. These acidic solutions were in liquid form (lactic acid, orthophosphoric acid; formic acid; and an acid solution that contains calcium chloride, sodium phosphate and acetic acid) and gel form (hydrochloric acid and orthophosphoric acid). The results of this in vitro research showed that acids in liquid state can penetrate the dental structures and demineralize them to a deeper extent than the gels. Orthophosphoric acid solution was the most efficient in dissolving the enamel, while the acetic acid solution affected only the superficial part of the enamel. The SEM aspects of etched teeth presented different types of enamel and dentine demineralization depending on the acidic solution used. Radio translucency was not observed, as the acids eroded the surface of the enamel completely. The present study could contribute to an initial understanding of enamel demineralization and the effect of acid erosion on HAP crystals. However, more research should be performed to further investigate the effects of different concentrations of acids on dental structures. Figure 10: The radiologic aspect of the teeth before and after demineralization for 24 h with (**a**) hydrochloric acid gel; (**b**) orthophosphoric acid solution; (**c**) orthophosphoric gel. **Author Contributions:** Conceptualization, A.K. and M.M. ; methodology, I.A.T. ; statistics, S.C.; writing--original draft preparation, A.K. ; writing--review and editing, I.C. and M.B. ; supervision, M.E.B. ; funding acquisition, A.K. All authors have read and agreed to the published version of the manuscript. This research was funded by Iuliu Hatieganu University of Medicine and Pharmacy, Department of Dental Medicine, Cluj-Napoca, Romania, grant number 7690/62. The study was conducted according to the guidelines of the Declaration of Helsinki and approved by the Ethics Committee of U.M.F. [PERSON] CLUJ-NAPOCA (271/30 July 2019). Informed Consent Statement: Informed consent was obtained from all subjects involved in the study. The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results. References  
[PERSON]; [PERSON]; [PERSON] The consumption of processed sugar- and starch-containing foods, and dental caries: A systematic review. _Eur. J. Oral Sci._**2020**, _128_, 467-475. [CrossRef] [PubMed]  
[PERSON]; [PERSON]; [PERSON] Dental caries. _Lancet_**2007**, _369_, 51-59. [CrossRef]  
[PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] Dental plaque microbiota profiles of children with caries-free and caries-active dentition. _J. Dent._**2021**, _104_, 103539. [CrossRef] [PubMed]  
[PERSON]; [PERSON]; [PERSON] A Review of the Role of Probiotic Supplementation in Dental Caries. _Probiotics Antimicrob. Proteins_**2020**, _12_, 1300-1309. [CrossRef]  
[PERSON]; [PERSON]; [PERSON] _Dental Caries: The Disease and Its Clinical Management_, 2 nd ed. ; Blackwell Munksgaard: Ames, IA, USA, 2008. [PERSON]; [PERSON] Understanding the chemistry of dental erosion. _Monogr. Oral Sci._**2006**, _20_, 66-76. [CrossRef] [PubMed]  
[PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] Mimicking the Self-Organized Microstructure of Tooth Enamel. _J. Phys. Chem. C_**2008**, _112_, 5892-5899. [CrossRef]  
[PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] Nano-hydroxyapatite and its applications in preventive, restorative and regenerative dentistry: A review of literature. _Ann. Stomatol._**2014**, \(5\), 108-114. [CrossRef]  
[PERSON]; [PERSON]; [PERSON] Preparation and Solubility of Hydroxyapatite. _J. Res. Natl. Bur. Stand. A Phys. Chem._**1968**, _72_, 773-782. [CrossRef]  
[PERSON]; [PERSON]; [PERSON] Synthesis of Hydroxyapatite from Oyster Shell via Precipitation. _Energy Procedia_**2014**, _56_, 112-117. [CrossRef]  
[PERSON]; [PERSON] Cariologie si odontoterapie restauratoare. _Ed. Med. Buc._**2006**, \(1\), 31-57.