Table 2.

Description of individual study

Authors, year, country	Sample size	Caries index	Type of saliva	Salivary parameters	Data analysis	Results
Nascimento et al., 2009, USA	45	DMFT	Whole unstimulated saliva	Arginine and urea	ANOVA	This study supports the theory that increased caries risk is associated with reduced alkali-generating capacity of the bacteria colonizing the oral cavity[8]
Kaur et al., 2012, India	60	DMFT	Stimulated and unstimulated	Flow rate, pH, buffering capacity, relative viscosity, calcium, phosphorus, and alkaline phosphatase levels	Chi-square statistical analysis	The results of the study showed that with an increase in salivary flow, pH, buffering capacity, there will be a decrease in caries incidence leading to good oral health and a reduced caries incidence. Increased salivary viscosity, salivary biochemical indicators such as calcium, phosphorus, and alkaline phosphatase also play their respective role in determining caries susceptibility of an individual[9]
Mithra et al., 2013, India	100	DMFT	Resting salivaStimulated saliva	Antioxidant level	ANOVA	There is a correlation between antioxidant level and dental caries as the antioxidant level increases the severity of dental caries also increases[10]
Mithra et al., 2013, India	12,500	DMFT	Unstimulated saliva	SOD activity, copper and zinc levels	Student t-test	SOD activity, as well as copper and zinc levels, increased in the caries-active group and the results were statistically significant[11]
Joana et al., 2013, Seattle	1763	Decayed, missing, or filled permanent teeth; visible cavitation; and visible interproximal enamel carious lesions	Stimulated and unstimulated	ConsistencyFlowpHBuffering capacity	Log-linear regression	The results of the study showed that there was no significant correlation between the salivary flow, pH and buffering capacity, and dental caries[2]
Pavitra et al., 2013, India	39	DMFT	Unstimulated	Total protein levels	Pearson’s correlation test	The total salivary proteins levels show a linear increase with the DMFT index[12]
Mithra et al., 2014, India	80	DMFT	Unstimulated	Salivary albumin levels	One-way ANOVAPearson’s correlation test	Increase in the levels of caries with decrease in the levels of albumin[13]
Halina et al., 2014	27	DMFT	Unstimulated	MUC1MUC5B	Mann-Whitney nonparametric’ U test	The levels of MUC1 and MUC5B were increased in individuals with high dental caries[14]
Teng-Yu et al., 2015, China	128	DMFT	Unstimulated, whole saliva	PR3	ANOVA	The protease PR3 is associated with the severity of dental caries, with low levels being associated with a greater severity of caries[15]
Nireeksha et al., 2017, India	80	DMFT	Unstimulated	PRPs	One-way ANOVA Post hoc Tukey’s test	Proline-rich protein bands were present in 95% of the caries-free group, whereas caries active group showed 65% proline-rich protein bands[16]
Monica et al., 2018	142	Visual detection of dental caries based on the following scores: 0 - Absence of caries 1 - Change in enamel aspect 2 - Enamel breakdown but no dentin alteration 3 - Presence of underlying dark dentin 4 - Presence of a distinct cavity 5 - Presence of a large cavity	Unstimulated	AlphaAmylase	Mann-Whitney test	The results showed that caries active children had higher levels of salivary enzyme which was statistically significant[17]

SOD: Superoxide dismutase, MUC: Mucin, PR3: Proteinase 3, PRPs: Proline-rich proteins, DMFT: Decayed, Missing, and Filled Teeth