Role of Streptococcus mutans in human dental decay.

Biology, immunology, and cariogenicity of Streptococcus mutans

This article reviews the mechanisms of bacterial adhesion to biomaterial surfaces and the factors affecting the adhesion The process of bacterial adhesion includes an initial physicochemical interaction phase (phase one) and a late molecular and cellular interaction phase (phase two), which is a complicated process affected by many factors, including the characteristics of the bacteria themselves, the target material surface, and the environmental factors, such as the presence of serum proteins or bactericidal substances

Concise review of mechanisms of bacterial adhesion to biomaterial surfaces.

Background and Overview Dental caries is a bacterially based disease. When it progresses, acid produced by bacterial action on dietary fermentable carbohydrates diffuses into the tooth and dissolves the carbonated hydroxyapatite mineral—a process called demineralization. Pathological factors including acidogenic bacteria (mutans streptococci and lactobacilli), salivary dysfunction, and dietary carbohydrates are related to caries progression. Protective factors—which include salivary calcium, phosphate and proteins, salivary flow, fluoride in saliva, and antibacterial components or agents—can balance, prevent or reverse dental caries. Conclusions Caries progression or reversal is determined by the balance between protective and pathological factors. Fluoride, the key agent in battling caries, works primarily via topical mechanisms: inhibition of demineralization, enhancement of remineralization and inhibition of bacterial enzymes. Clinical Implications Fluoride in drinking water and in fluoride-containing products reduces caries via these topical mechanisms. Antibacterial therapy must be used to combat a high bacterial challenge. For practical caries management and prevention or reversal of dental caries, the sum of the preventive factors must outweigh the pathological factors.

The science and practice of caries prevention

Dental caries is a bacterially based disease that progresses when acid produced by bacterial action on dietary fermentable carbohydrates diffuses into the tooth and dissolves the mineral, that is, demineralization. Pathological factors including acidogenic bacteria (mutans streptococci and lactobacilli), salivary dysfunction, and dietary carbohydrates are related to caries progression. Protective factors which include salivary calcium, phosphate and proteins, salivary flow, and fluoride in saliva can balance, prevent or reverse dental caries. Fluoride works primarily via topical mechanisms which include (1) inhibition of demineralization at the crystal surfaces inside the tooth, (2) enhancement of remineralization at the crystal surfaces (the resulting remineralized layer is very resistant to acid attack), and (3) inhibition of bacterial enzymes. Fluoride in drinking water and in fluoride-containing products reduces tooth decay via these mechanisms. Low but slightly elevated levels of fluoride in saliva and plaque provided from these sources help prevent and reverse caries by inhibiting demineralization and enhancing remineralization. The level of fluoride incorporated into dental mineral by systemic ingestion is insufficient to play a significant role in caries prevention. The effect of systemically ingested fluoride on caries is minimal. Fluoride "supplements" can be best used as a topical delivery system by sucking or chewing tablets or lozenges prior to ingestion.

Prevention and reversal of dental caries: role of low level fluoride.

Preventive measures in mothers influence the establishment of the bacterium Streptococcus mutans in their infants

Effect of caries preventive measures in children highly infected with the bacterium streptococcus mutans

— The aim of the study was to find out if any of the following factors, alone or in combination, could be used for prediction of caries activity: salivary) S. mutans, salivary lactobacilli, buffer capacity, saliva secretion rate, salivary pH, the amount of plaque and the caries freguency. The patient material consisted of 300 children between 9 and 12 years old. The increment of caries after 1 and 2 years was compared with all the above factors registered at baseline. Only the factors caries frequency and S. mutans showed a significant correlation to caries activity. In one of the tests the lactobacillus count approached significance. The combination of high numbers of incipient smooth surface lesions, S. mutans and lactobacilli gave a mean value of caries activity almost three times that of the whole group (8.4 versus 3. I).

A comparison between different methods for prediction of caries activity.

The role of specific microorganisms in dental caries is reviewed. A considerable amount of evidence supports the association between organisms of the Streptococcus mutans group and caries incidence and prevalence. The cariogenic potential of S. mutans is probably due to the unique combination of properties with which this microorganism is endowed. The pathogenic potential can be modified by changes in the environment. Lactobacilli play a major role in the development of a lesion. The specific plaque hypothesis has important implications because the association between S. mutans, lactobacilli and dental caries can be used in diagnosis, treatment and prevention of the disease in groups of subjects as well as in the individual case.

Support for and implications of the specific plaque hypothesis

– The prevalence of S. mutans and lactobacilli, the salivary secretion rate, and salivary pH and buffer capacity were examined in 655 children 9–12 years old. Some of these factors were correlated with the frequency of caries. Positive correlations were ob served between for example S. mutans and lactobacilli, between S. mutans and incipient smooth surface caries, and between lactobacilli and open carious lesion. A high proportion of the children showed large numbers of S. mutans and lactobacilli

Bo Krasse

Papers

Preventive measures in mothers influence the establishment of the bacterium Streptococcus mutans in their infants

Effect of caries preventive measures in children highly infected with the bacterium streptococcus mutans

A comparison between different methods for prediction of caries activity.

Support for and implications of the specific plaque hypothesis

Microbial and salivary conditions in 9- to 12-year-old children.