Dental erosion is becoming increasingly prevalent in the primary dentition. The aims of the thesis, therefore, were to determine the prevalence of erosion in a birth cohort at 24, 36, and 48 months and to evaluate the associations between erosion and oral hygiene behaviour, medical conditions, and dietary habits that were reported at various time points. In addition, the thesis aimed to examine the effectiveness of a 10% casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste in protection against erosion. The present thesis also aimed to investigate the erosive potential of paediatric over-the-counter (OTC) medications in vitro, and to assess the change of the erosive potential in the presence of remineralising agents such as CPP-ACP.
The cohort study comprised of data collected as part of a larger longitudinal investigation on the general oral health in children. For this thesis, the results are focused on the clinical presentation of erosion. The birth cohort was recruited from public birthing and community health clinics located in a low socio-economic area of South-East Queensland, Australia. All mothers were instructed to brush their child’s teeth with 0.304% sodium monofluorophosphate toothpaste (My First Toothpaste, Colgate Oral Care, Sydney, Australia). In addition, all participants were randomised into three groups to receive once daily 10% CPP-ACP paste (Tooth Mousse®, GC Corporation, Tokyo, Japan), or 0.12% chlorhexidine gel (Curasept®, Curaden Swiss, Saranno, Switzerland), or no product (control) from the time of first tooth eruption. All children were examined in the community dental clinics at 24, 36, and 48 months and validated questionnaires on the child’s sociodemographic factors, oral hygiene behaviour, medical conditions, and dietary habits were collected. The prevalence of erosion and associations with risk factors were determined in a longitudinal fashion from the examinations of 154 children from the control group who used toothpaste only. Furthermore, the effectiveness of CPP-ACP was determined by comparing presence of erosion in all three treatment groups of children in a randomised controlled trial.
In the in vitro study, a range of paediatric OTC medications and commercially available drinks were examined for pH and titratable acidity (TA). Detailed testings of pH and TA were performed on representative drinks after the addition of remineralising agents to the drinks. The remineralising agents included Tooth Mousse® (TM, GC Corporation, Tokyo, Japan), Tooth Mousse Plus® (TMP, GC Corporation, Tokyo, Japan), ClinproTM (3M, Minnesota, USA), 1.23% neutral sodium fluoride (NaF), and artificial saliva (AS). Descriptive and analytical approaches were used in the data analysis. The Chi-square test, Fisher’s Exact test, Mann-Whitney U test, multiple logistic regression, student’s t-test (two-tailed), Dunnett multiple comparisons test, and one-way ANOVA were used (where appropriate) to compare groups. An alpha value of 0.05 was employed. Statistical analysis was carried out using SPSS v21 (IBM Corp, Armonk, NY, USA).
Of the 154 children examined in the control group of the cohort study, 0% (0/154), 7% (11/154), and 28% (40/154) had erosion detected for the first time at 24, 36, and 48 months, respectively (p<0.001). A cumulative total of 51 (33%) children and 256 (8%) teeth had erosion by the age of 48 months. There were no significant associations between erosive lesions first detected at 36 months and oral hygiene behaviour, medical conditions, or dietary habits reported at the 24- or 36-month examinations (all p>0.05). In contrast, erosive lesion first detected at 48 months was positively associated with the use of a feeding bottle reported at the 36-month examination (p=0.026).
In the randomised controlled trial, the prevalence of erosion was not influenced by the use of CPP-ACP or chlorhexidine (p≥0.05) when compared to the control group at 36 or 48 months. Therefore, all children were combined together for further analysis of possible risk factors associated with erosion. It was found that erosion at 36 months was significantly related to brushing less than once-per-day at 36 months (odds ratio, OR, 4.91, 95% CI: 1.49–16.19, p=0.009), while erosion at 48 months was significantly associated with breastfeeding at 24 months (adjusted odds ratio, AOR, 4.56, 95% CI: 1.43–14.53, p=0.010) and the consumption of acidic drinks at 36 months (AOR 3.09, 95% CI: 1.51–6.33, p=0.002).
In the in vitro study, paediatric OTC medications exhibited pH values of less than 5.5, which were comparable to commercial fruit juices and carbonated soft drinks. The TA values of OTC medications were similar to commerical fruit juices and carbonated soft drinks and ranged between 0.9mL to 25.9mL/ 20mL of 0.1M sodium hydroxide. The addition of TM, TMP, neutral NaF, and AS to the paediatric OTC medication increased the pH significantly compared to the control (PBS; p<0.001). The addition of TM, TMP, neutral NaF, and AS to the paediatric OTC medication decreased the TA significantly compared to the control (PBS; p<0.001-p<0.05), but not consistently.
The prevalence of dental erosion in young children increased with age, with clinically detectable lesions forming between 24 and 36 months of age. Brushing less than once-per-day and dietary factors including the use of a feeding bottle, breastfeeding, and the consumption of acidic drinks, were positively associated with erosion. In addition, as an intervention at a community level, daily use of 10% casein phosphopeptide-amorphous calcium phosphate paste did not protect young children’s teeth against erosion. Furthermore, paediatric over-the-counter medications have erosive potential that were comparable to commercially available drinks, and the erosive potential can be modified by the addition of Tooth Mousse®, Tooth Mousse Plus®, neutral sodium fluoride, and artificial saliva, but not ClinproTM.