Oral Bacterial Acid–Base Metabolism in Caries Screening: A Proof-Of-Concept Study

Abstract

The objective of this cross-sectional study was to clinically validate an array of biochemical tests for oral acid/alkali generation as caries screening instruments. 185 adult subjects (mean 33.6±10.6 years) were examined clinically for dental caries using the ICDAS criteria. Bitewing radiographs were used to confirm interproximal surfaces of posterior teeth. For the purposes of this study, subjects were classified as “caries-active” if they had at least one untreated caries lesion with ICDAS 4 or higher. Pooled supragingival plaque and unstimulated saliva samples were collected and assayed for pH changes from sucrose and urea metabolism using colorimetric tests. The validity of each test to discriminate between “caries-inactive” and “caries-active” subjects was assessed and compared to a commercial bacteriological caries-screening test using roc regression and logistic regression models. The AUCs of the plaque-urea (PU: 0.59 (0.51, 0.67)), plaque-urea-glucose (PUG: 0.59 (0.51, 0.67)) and saliva-urea-glucose (SUG: 0.59 (0.51, 0.67)) tests did not differ significantly from the bacteriological tests (CRT-mutans: 0.62 (0.54, 0.70); CRT-lactobacillus: 0.63 (0.56, 0.71) (P>0.05), but the plaque-glucose (SG), saliva-glucose (SG), saliva-urea (SU) and saliva-plaque-glucose (SPG) tests had significantly smaller AUCs (P<0.05). The AUCs for the PU, PUG, SUG, and the CRT-mutans tests were higher in subjects who had no existing dental restorations (PU: 0.90 (0.77, 1.04); PUG: 0.90 (0.79, 1.01); SUG: 0.89 (0.69, 1.08); CRT-mutans: 0.90 (0.73, 1.08)). The incorporation of the biochemical tests into a multidimensional bacteriological/psychosocial caries screening model significantly increased its diagnostic values (Se+Sp: 160.6, AUC: 0.846). In conclusion, as a proof of concept, the results of this study indicate that measuring the ability of dental plaque and saliva to metabolize urea together with the ability to generate acid from sugars may have a promising role in caries screening either independently, or as part of a multidimensional biological test.

Causal Relationship Study Between Basal Metabolic Rate and the Risk of Dental Caries: Evidence from Genome-Wide Association Analysis

“…These acidic byproducts may translocate to the oral cavity via the bloodstream, thereby perturbing the oral pH equilibrium. Such acidi cation of the oral microenvironment is conducive to the proliferation of cariogenic bacteria, consequently elevating the risk of dental caries [25]. Simultaneously, a heightened basal metabolic rate may induce compositional alterations in saliva, attenuating its antimicrobial e cacy and amplifying the susceptibility to dental caries.…”

Caries reporting in studies that used the International Caries Detection and Assessment System: A scoping review

“…Studies differed in their grouping of caries scores. For example, nine different caries surfaces measures and seven caries teeth measures were identified in this review. Some studies grouped them to classify caries as dentin and enamel lesions while others classified them as initial/early, moderate/established and severe/extensive lesions .…”

Antibacterial activity and synergistic effects between Machilus thunbergii ethanol extract and antibiotics against oral pathogens

“…There are more than 750 bacteria in the oral cavity, many of which are related to oral diseases [6]. The development of dental caries includes acidogenic and aciduric gram-positive bacteria, mainly mutans streptococci (Streptococcus mutans and S. sobrinus), lactobacilli and actinomycetes, which metabolize sucrose into organic acids that dissolve the calcium phosphate in teeth, causing decalcification and eventual decay [6][7][8]. In contrast, periodontal disease is subgingival and gum diseases associated with anaerobic gram-negative bacteria such as Porphyromonas gingivalis, Actinobacillus sp., Prevotella sp., and Fusobacterium sp.…”