Effects of stabilized stannous fluoride dentifrice on dental calculus, dental plaque, gingivitis, halitosis and stain: A systematic review.

OBJECTIVES: The aim of the present systematic review was to examine the scientific evidence for the efficacy of stabilized stannous fluoride (SnF2) dentifrice in relation to dental calculus, dental plaque, gingivitis, halitosis and staining. DATA AND SOURCES: Medline OVID, Embase.com, and the Cochrane Library were searched from database inception until June 2017. Six researchers independently selected studies, extracted data, and assessed methodological quality. A meta-analysis of the 6-month gingivitis studies was done. Risk of bias was estimated using a checklist from the Swedish Agency for Health Technology Assessment (SBU, 2018). STUDY SELECTION: Two studies on dental calculus, 21 on dental plaque and gingivitis, 4 on halitosis, and 5 on stain met the inclusion criteria. Risk of bias was high for the studies on dental calculus, halitosis, and stain, and varied for the dental plaque and gingivitis studies. Significant reductions in dental calculus and in halitosis were reported for the SnF2 dentifrice; no differences in stain reduction were noted. A meta-analysis on gingivitis found better results for the SnF2 dentifrice compared to other dentifrices, though the results of the individual trials in the meta-analyses showed a substantial heterogeneity. CONCLUSIONS: The present review found that stabilized SnF2 toothpaste had a positive effect on the reduction of dental calculus build-up, dental plaque, gingivitis, stain and halitosis. A tendency towards a more pronounced effect than using toothpastes not containing SnF2 was found. However, a new generation of well conducted randomized trials are needed to further support these findings. CLINICAL RELEVANCE: Adding a SnF2 toothpaste to the daily oral care routine is an easy strategy that may have multiple oral health benefits.

Potential efficacy of chlorhexidine against mutans streptococci and human dental caries.

Chemotherapeutic agents have been considered as having potential for the prevention of dental caries. Several substances have been evaluated as possible candidates, but no antimicrobial agent, with the exception of fluoride, has received as much experimental attention as the bisbiguanide chlorhexidine. This substance represents, so far, the most effective and best-documented agent. To be effective against caries, therapeutic dosages of the antimicrobial agent have to be given for a sufficient but finite time period to sites with established cariogenic plaque. In studies where this principle has been used, the aim has been to eliminate or strongly suppress the population of mutans streptococci. Of various antimicrobial agents and methods tested, the most persistent reduction of mutants streptococci has been achieved by chlorhexidine varnishes, followed by gels and mouthwashes. The best clinical effect resulting in a considerable caries reduction has been obtained when persons highly colonized with mutans streptococci have been treated with gels and when the results of the antimicrobial measures have been verified by microbiological examination.

Distribution and prevalence of mutans streptococci in the human dentition.

The prevalence of mutans streptococci was determined in 14,859 samples of plaque from all available tooth surfaces in 114 subjects. The clinical examination included location of incipient caries lesions, fillings, and crowns. Mutans streptococci were detected on 40% of all tooth surfaces. The frequency distribution of mutans streptococci and the level of colonization showed a decreasing gradient from molars to incisors for buccal, lingual, occlusal, and approximal surfaces. The location and number of approximal restorations were closely related to the colonization level of mutans streptococci except for second and third molars. Restored surfaces tended to be more colonized by mutans streptococci than sound surfaces, except for occlusal surfaces. A high prevalence of mutans streptococci was found in plaque samples from tooth-colored fillings, especially on buccal and lingual surfaces.

Recolonization of human tooth surfaces by Streptococcus mutans after suppression by chlorhexidine treatment.

In eight subjects who were initially highly colonized with Streptococcus mutans and who used a 1% chlorhexidine gel, the numbers of this organism were suppressed in both plaque and saliva. Bacterial plaque samples were obtained from all tooth surfaces, and the recolonization pattern of S. mutans was studied over a 26-week period. At baseline, 83% of all surfaces harbored S. mutans with buccal surfaces colonized in higher frequency than the others. After chlorhexidine treatment, the proportion of tooth surfaces colonized by S. mutans was reduced to a low level. Re-appearance was slow. S. mutans was first recovered from the most posterior teeth in the mouth, the molar surfaces were recolonized earlier than were those of pre-molars and anterior teeth, and the buccal surfaces were recolonized more readily than were the other tooth surfaces. The data show that there is a specific recolonization pattern of S. mutans after chlorhexidine treatment, and that the re-emergence of S. mutans is most probably due to regrowth of bacteria which have not been eradicated.

Colonization and cariogenic potential in hamsters of the bacterium Streptococcus sanguis isolated from human dental plaque.

Strains of Strep. sanguis, freshly isolated from human dental plaque, were successfully implanted into albino hamsters. Transmission of the organisms from infected to uninfected animals occurred naturally. The transfer was as effective between unrelated hamsters as between dams and their offspring. Three of the strains tested did not cause caries in hamsters. Laboratory strains of Strep. sanguis did not colonize the hamsters. Two morphological variants of Strep. sanguis with different abilities to adhere to whale dentine in vitro, could infect hamsters; the more adhering phenotype was detected earlier and more frequently.

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

The number of Strep. mutans in saliva samples was examined in 101 13-14-year-old children, 53 in a control and 48 in the test group. All in the test group with 2.5 X 10(5) Strep. mutans per ml saliva were treated with 1 per cent chlorhexidine gel, once a day, for 14 days when the number of Strep. mutans was greatly reduced. Saliva samples were then examined in the test group every 4th month and all children with Strep. mutans levels above 2.5 X 10(5) were treated. A few selected children had fissure sealants applied to the occlusal surfaces. After 3 years, the mean number of new carious lesions was 9.6 in the control group and 4.2 in the test group. In the children with 10(6) Strep. mutans at the start of the study, the corresponding figures were 20.8 compared with 3.9. Thus a reduction in caries activity can be achieved by controlled antimicrobial treatment.

The influence of saliva on infection of the human mouth by mutans streptococci.

The relationship between oral implantation of Streptococcus mutans IB1600 (serotype c) and Streptococcus sobrinus OMZ65 (serotype g), the aggregating activity of saliva, and its influence on the adherence of these bacterial strains in vitro was examined in seven human subjects. All the saliva samples aggregated strain IB1600 but not strain OMZ65 cells. Whole saliva from subjects with low levels of infection by Strep. mutans aggregated strain IB1600 to a greater degree than did whole saliva from those who were readily infected. Whole saliva from subjects most resistant to infection supported the adsorption of the highest number of either strain IB1600 or OMZ65 to hydroxyapatite surfaces. Thus the ability of whole saliva to aggregate Strep. mutans may influence the ability of these microorganisms to infect the mouth.

Fluoride release in vitro from various glass ionomer cements and resin composites after exposure to NaF solutions.

The release of fluoride from 1) discs made from five glass ionomer cements and two composites, and 2) the same discs after exposure to different NaF solutions, were studied. The specimens were placed in distilled water for 10 wk. After 24 h and then once a week, the specimens were transferred to fresh distilled water. After 5 wk, the specimens were divided into four groups and exposed to 0, 0.02, 0.2 and 2% NaF solutions for 5 min. The fluoride release was highest during the first week after preparation, after which it decreased sharply and then more slowly. The amount of fluoride released was ordered: liner/base > restorative glass ionomer > composites. The composites released significantly less fluoride than the glass ionomer cements. After exposure to NaF, the fluoride release was significantly higher for the silver cermet material than for the other glass ionomers tested. From a clinical point of view, the results from this study imply that glass ionomer restorations may act as intraoral devices for the controlled slow release of fluoride at sites at risk for recurrent caries.

Microbial conditions and caries increment 2 years after discontinuation of controlled antimicrobial measures in Swedish teenagers.

The purpose of the present study was to examine the long-term effect of a special caries preventive program in teenagers. Over a 3-yr period directed and controlled antimicrobial treatment using Streptococcus mutans as an indicator organism resulted in a remarkable caries reduction especially in children with greater than 10(6) S. mutans per ml of saliva at the start of the study. Two years after discontinuation of the special preventive program 83 out of 101 subjects, 18-19 yr old, were reexamined. All the children had followed the same basic preventive program in the Dental Health Service. The number of S. mutans and lactobacilli per ml of saliva within and between control and test groups was with few exceptions practically the same as 5 yr earlier. During the posttreatment period the caries activity was similar in the control and test groups and lower than during the experimental years especially in the control group. Subjects with initial S. mutans level of greater than 10(6) CFU per ml of saliva continued to show incremental caries scores higher than those subjects with lower S. mutans levels.

Streptococcus mutans, lactobacilli and dental health in 13-14-year-old Swedish children.

The dental health and the prevalence of Streptococcus mutans and lactobacilli were examined in 101 13-114-year-old children. The average number of decayed (incipient caries) and filled surfaces (DFS) was 10.1 and 12.8, respectively. S. mutans was not detected in 11% of the children while 21% had 10(6) or more S. mutans per ml saliva. Lactobacilli were not found in 21% of the children whereas 11% had 10(5) or more lactobacilli per ml saliva. Statistically significant correlations were found between S. mutans and lactobacilli, S. mutans and DFS, lactobacilli and DFS and S. mutans plus lactobacilli and DFS. Increasing numbers of S. mutans and lactobacilli, alone and in combination, were associated with an increased caries frequency.

Effect of mechanical and chemical plaque control measures on oral microflora in schoolchildren.

The incidence of S. sanguis, S. salivarius, S. mutans, total streptococci and lactobacilli was examined in highly caries active 13-14-year-old schoolchildren participating in a prophylactic program. After 1 year of trial, professional toothcleaning once every second week markedly reduced the frequency of gingivitis and the caries increment. Bimonthly topical applications of a 0.5% chlorhexidine gel with or without subsequent rinsing with 2% NFP had no effect on plaque score and gingivitis but tended to reduce the caries activity. No significant changes were found in the groups with regard to the salivary number of total streptococci and S. sanguis. A reduction of the population of S. salivarius, S. mutans and lactobacilli was observed in the chlorhexidine group. In the group where chlorhexidine was combined with MFP, only S. mutans was reduced.

Dental caries and salivary and microbial conditions in 50-60-year-old persons.

In a group of 124 persons, 50-60 yr old, the prevalence at baseline of mutans streptococci (MS) and lactobacilli and the salivary secretion rate and buffer capacity were examined. The mean secretion rate was 1.58 mL/min with a flow rate below 1 mL/min found in 20% of the persons. A buffer capacity below end pH 5.5 was observed in 64% of the subjects. MS was not detected in 5% of the persons whereas 17% had 10(6) or more MS per ml saliva. Lactobacilli were not found in 10% of the persons while 21% had counts in excess of 10(5) CFU mL. A new examination 5 yr later in 1986 revealed no significant changes in secretion rate and buffer capacity or in the population of lactobacilli, whereas markedly elevated levels of salivary MS were found. S. sobrinus was detected in 35-37% of the persons at the two examinations. Persons with both S. mutans and S. sobrinus had more MS than persons with only S. mutans.

Evaluation of an intraoral controlled release delivery system for fluoride in primates.

An intraoral delivery system designed to release 0.5 mg of fluoride per day was evaluated in short-term studies in primates. This fluoride-releasing device, bonded to the buccal surface of the maxillary right central incisor of each of six monkeys (Macaca fascicularis), produced marked elevations in saliva and plaque fluoride concentrations without increases in serum fluoride concentrations. No changes were observed in the plaque and gingival scores or the populations of various species of plaque bacteria.

Prediction of caries activity in children with today's low caries incidence.

One hundred 14-yr-old children were observed over 1 yr to find out if caries incidence and caries progression could be predicted in a low prevalence child population by means of well-known caries related factors. The mean caries incidence was low (0.45, SD 0.70) but, on the other hand, 32% of the children developed at least one new lesion during the test period. In only eight out of 35 children progressing lesions were demonstrated. Independent variables at baseline examination were caries prevalence, sucrose intake, fluoride exposure, oral hygiene, saliva secretion rate, and salivary concentrations of mutans streptococci and lactobacilli. A weak but statistically significant correlation was demonstrated between caries incidence and caries prevalence. No other significant correlations were shown. It was concluded that caries activity could not be predicted in this population. Low disease prevalence was a major reason for the weak correlations.

Clinical evaluation of an intraoral device for the controlled release of fluoride.

An intraoral-releasing device designed to release 0.5 mg of fluoride per day was evaluated in a one-month trial. The results showed that the 11 men who wore the fluoride-releasing device on their maxillary first molars had significantly elevated levels of fluoride in their saliva and plaque compared with baseline levels. No significant changes were observed in mean serum or urine fluoride levels or in the gingival or plaque indexes during the study. The prevalence of S mutans in whole saliva did not change during the study and the relative proportion of S. mutans, S. sanguis, and A viscosus and A naeslundii in plaque also remained relatively stable. The elevated fluoride levels in saliva and plaque are presumptive evidence that the intraoral fluoride-releasing device could exert a cariostatic effect in humans. However, long-term clinical trials are needed to determine the cariostatic potential of this fluoride releasing system.

Antibacterial activity of dentinal bonding agents.

The susceptibility of five bacterial species to seven dentinal bonding agents was examined in vitro. Agar diffusion tests using filterpaper disks containing 10 microL each of conditioner, primer, or resin were performed on blood agar and mitis salivarius bacitracin agar. Chlorhexidine (0.2%) was used as a positive control. After incubation, zones of inhibited bacterial growth were measured. Of all the compounds tested, Gluma cleanser and Gluma etchant showed the strongest growth inhibition for all bacterial strains. No antibacterial effect was noted for Prisma Universal Bond 2 and Superlux Universal Bond 2 systems. The primers of Gluma, Denthesive, and Scotchbond 2 displayed antibacterial activity that, in some cases, was comparable to that of 0.2% chlorhexidine. Zones of inhibition were seen for the resin materials of Scotchbond 2 and Tripton with Streptococcus mutans, Streptococcus sanguis and Actinomyces viscosus. No inhibition was seen after these resins were cured, whereas the antibacterial effect of XR-Bond on S sanguis and A viscosus was not affected by light curing.

Results with the caries activity test "Cariostat" compared to prevalence of mutans streptococci and lactobacilli.

The colorimetric test, Cariostat (Sankin, Japan), for measuring the caries activity, based on the presence of acidogenic microorganisms, was evaluated. The results were compared with the prevalence of mutans streptococci and lactobacilli in the samples. Pure cultures of S. mutans and lactobacilli were inoculated into the test medium. A maximum color change from blue to yellow was not obtained not even when large numbers of bacteria were used. Samples of stimulated saliva and plaque samples from people with different salivary levels of mutans streptococci and lactobacilli were inoculated into the test medium. Samples with very low or very high numbers of cariogenic bacteria were found in all score groups indicating that the Cariostat test did not satisfactorily differentiate samples with low or high numbers of microorganisms associated with dental caries.

Fluoride release in vitro from a resin-modified glass ionomer after exposure to NaF solutions and toothpastes.

The aims of the present investigation were: (i) to study the release of fluoride from a resin-modified glass ionomer cement (Vitremer) after exposing ("recharging") the material with NaF toothpastes and NaF solutions with different fluoride concentrations, and (ii) to study the effect of covering the material with a sealant layer (glaze) in this respect. Totally 160 specimens were made, which were placed in water for 13 weeks to receive a low fluoride release value. The specimens were then randomly divided into 10 groups with 16 discs each. Five of the groups were exposed once a day for 7 days to one of the following fluoride agents: 0.05, 0.2 or 2% NaF solutions and slurries of two NaF toothpastes (Acta and Pepsodent). The other five groups received the same treatment twice a day. All treatments had a recharging effect. However, the 2% NaF solution resulted in significantly more fluoride release than the other solutions and toothpastes. Treatment twice a day gave higher total release than once a day, but the difference were only significant for the 0.2 and 2% NaF solutions. With glaze material covering the specimens, almost no fluoride release was observed. However, when the glaze was removed, a burst of fluoride occurred.

Efficacy of sealing the mesial surfaces of first permanent molars with respect to the status of the distal surfaces of the second primary molars in children at high caries-risk.

AIM: This study aimed at evaluating the efficacy of sealants at preventing caries development or arresting the progression of non-cavitated mesial carious lesions in first permanent molars (6m) with respect to the status of the distal surfaces of the second primary molars (05d). METHOD: The study population comprised 121, 8- to 10-year-old schoolchildren in a high-caries community in Valparaiso, Chile. They were examined clinically and radiographically and screened for caries-related risk factors using the risk-assessment software program Cariogram. The children were divided into three groups: Group A, with no caries lesions on adjacent surfaces of 05d-6m, served as a control group. Group B, with caries on 05d, received a preventive sealant on the caries-free 6m after temporary separation, and Group C, with carious 05d, received a therapeutic sealant on a 6m with initial lesions. Standardised follow-up radiographs were taken in 110 children after 12-14 months. RESULTS: In group A, with no treatment, the mean percentage of sound surfaces that developed caries lesions was 3.8%. In group B, the mean percentage of sound 6m surfaces that developed caries lesions was 4.9% for sealed and 22.0% for unsealed surfaces (p < 0.05). In group C, the progression of therapeutically sealed carious lesions on 6m was 3.0% compared with 41.2% for unsealed carious control surfaces (p < 0.05). CONCLUSIONS: These results suggest that sealing sound surfaces and non-cavitated caries in the proximal mesial surfaces of permanent molar teeth effectively prevents or reduces the progression of caries adjacent to lesions on the distal surfaces of the second primary molars.