Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2015-03-09, 08:10:19 | version 1.33.01
hygiene tribune Dental Tribune Middle East & Africa Edition | March-April 20152B < Page 1B > Page 4B rial cohesion and adhesion.15-17 The Plaque Glycolysis and Re- growth Model (PGRM) is an in situ method that allows evalu- ation of a formulation’s biologi- cal activity, based on its effects on plaque metabolism. Using a PGRM, White et al. found a statistically significant reduc- tion in acidogenicity associated with the use of stannous fluo- ride dentifrice versus a standard sodium fluoride control denti- frice.18,19 Using the same meth- odology, Liang et al. found that a stannous fluoride dentifrice, as compared to a control placebo, greatly reduced the amount of plaque acid and also inhibited plaque regrowth.20 Comparable results have been obtained in studies of the anti- bacterial action of this SFSH for- mula. Ramji et al. carried out a series of in vitro and in vivo stud- ies of this new formulation.21 In a Live/Dead assay21 they found that the new SFSH dentifrice had killed over 90% of the salivary bacteria 16 hours after a single exposure, thus showing strong and lasting antibacterial activity (Figure 2). In a second study, using PGRM, the SFSH dentifrice produced statistically significant reduc- tions in plaque acid production and plaque regrowth at 15 and 45 minutes after brushing ver- sus a standard sodium fluoride control dentifrice.21 Other re- search demonstrated the pres- ence of soluble tin, which serves as a marker for the active stan- nous fluoride, at levels above the minimum concentration re- quired for the inhibition of sali- vary bacterial activity.21 Another related value of stan- nous fluoride is its effect on inflammatory markers, inde- pendent of its action on bacte- ria. In vivo, antibacterial activity also helps reduce inflammation sincetheinflammatoryresponse should diminish with reduced levels of pathogenic bacteria. A study was conducted with 16 healthy subjects to measure inhibition of several host and bacterial pro-inflammatory en- zymes by stannous fluoride.22 Following a one-week period of using a standard sodium fluo- ride paste and manu al brush, a baseline supragingival plaque sample was collected from sub- jects. Subjects then rinsed with a slurry of stannous fluoride/ sodium hexametaphosphate dentifrice; plaque samples were taken immediately post-rinsing and 12 hours later. An analy- sis of the samples showed that stannous fluoride inhibited sev- eral pro-inflammatory enzymes, including mammalian matrix metalloproteinase subtypes and bacterial gingipain. These en- zymes can break down proteins (e.g., collagen) and are involved in processes such as pocket for- mation. At the 12-hour analysis, enough stannous fluoride was retained to inhibit about 40% of most enzymes measured. These studies demonstrate the sustained antibacterial and an- ti-inflammatory effects of this SFSH dentifrice, supporting its antiplaque and antigingivitis ef- ficacy. Anti-plaque and Anti-gingivi- tis Efficacy Many studies have investigated the effects of stannous fluoride on gingivitis and plaque. These evaluations have involved a wide range of trial durations, subject populations and modes of application (Table 1).23-34 The majority of these trials report significant reductions in plaque and gingivitis, supporting the agent’s ability to improve gin- gival health when used twice daily. In addition, long-term research has been conducted to evaluate stannous fluoride among special populations.35 A 2-year study in- vestigated the periodontitis pre- vention efficacy of a dual-phase stabilized 0.454% SFSH denti- frice compared to a positive con- trol (sodium fluoride/triclosan dentifrice) in a population of over 330 subjects with medica- tion-induced xerostomia. The study also evaluated the prod- uct’s ability to remineralize root caries lesions. Results showed that twice daily use of stannous fluoride/sodium hexametaphos- phate dentifrice demonstrated comparable benefits to the positive control, which was a sodium fluoride/triclosan den- tifrice, in reducing periodontal pocket depth, attachment loss and bleeding on probing as well as remineralizing root caries.35 Recent studies have evaluated the antigingivitis efficacy of SFSH dentifrice.24,30-32 One such six-month trial found statistical- ly significant reductions of 22% in gingivitis, 57% less bleeding and 7% less plaque relative to a negative control.24 In a second 6-month trial with 128 subjects, Mallatt et al. found a 17% re- duction in gingivitis (p ≤ 0.001), a 41% reduction in gingival bleeding (p ≤ 0.001) and an 8% reduction in plaque (p ≤ 0.001) with the SFSH dentifrice versus a negative control dentifrice.30 The SFSH dentifrice also dem- onstrated significant reductions in gingivitis (26%) and gingival bleeding (27%) relative to a tri- closan/copolymer control.31 In a follow-up to this study, Archila et al. chose subjects who had used the triclosan/copolymer den- tifrice twice a day but who had proved unresponsive to it, and still had high bleeding scores at the end of the six-month study period.32 After three months use of the stannous fluoride/sodium hexametaphosphate dentifrice both gingivitis and bleeding had decreased significantly, by 54% and 55% respectively. These re- sults showed that, even for those who have persistent problems with gingival disease, the SFSH dentifrice can offer significant health benefits when compared to other dentifrices. In a three-phase study involv- ing use of digital plaque imaging analysis (Figure 3), White et al. investigated the longer term ef- ficacy of the SFSH formula in the control of plaque.36 In Phase 1, subjects brushed twice daily us- ing a standard sodium fluoride dentifrice; in Phase 2 brushing frequency was reduced to once a day using the same dentifrice; in Phase 3 the daily brushing regi- men was continued using the antimicrobial stannous fluoride/ sodium hexametaphosphate dentifrice. Morning plaque cov- erage was 13% during Phase 1, increased to 18% in Phase 2, but decreased significantly in Phase 3 showing a 17% reduction as compared with the sodium fluo- ride dentifrice control. This sup- ports the sustained antibacterial effects reported by Ramji et al.21 Results of multiple, independ- ent clinical trials using the SFSH dentifrice mirror those investi- gating earlier stannous fluoride dentifrices; the recent formu- lation also shows benefits in the control of gingival disease where it is significantly more ef- ficacious than sodium fluoride based dentifrices. Dentinal Hypersensitivity Reports indicate that dentinal hypersensitivity affects more than 40 million people in the U.S. annually,37 or up to 30% of adults at some time during their lifetime.38 Hypersensitivity is characterized by a short, sharp pain arising from exposed den- tin in response to a stimulus that cannot be ascribed to any other form of dental defect or pathol- ogy;39 it arises from exposure of the dentinal tubuli to the stimu- lus. Unlike potassium nitrate, which alleviates sensitivity by acting on the nerve synapse, stannous fluoride reacts with enamel or dentin surfaces to produce solid complexes or in- soluble precipitates which whol- ly or partially occlude the tubuli, as has been shown by means of scanning electron microscopy (Figure 4).40 This action is thought to pro- duce the clinical efficacy of stan- nous fluoride in the prevention and control of dentinal hyper- sensitivity.41-44 Schiff and his col- laborators carried out two stud- ies to assess the efficacy of the SFSH formula in reducing hy- persensitivity on a sample popu- lation of 77.45,46 The first used an eight-week randomized trial to compare the effects on dentinal sensitivity of twice-daily brush- ing with the stannous fluoride/ sodium hexametaphosphate dentifrice and with a sodium fluoride-based, negative control dentifrice.45 Outcomes were as- sessed at 4 and 8 weeks with tests of tactile sensitivity (Yeaple Probe Index) and thermal sen- sitivity (Schiff Air Index). On all assessments, the SFSH dentifrice produced a significant decrease in sensitivity (p ≤ 0.0001) as com- pared to the control dentifrice. In the second study which used essentially the same procedures, results were similar, with the stannous fluoride/sodium hex- ametaphosphate group (n=45) producing significant reduc- tion in sensitivity compared to the control (n=45) (Figure 5).46 At 8 weeks, the SFSH showed improvements of 71% and 44% versus the negative control for tactile and thermal measure- ments, respectively. These studies support that the SFSH dentifrice shares the anti- sensitivity characteristics of pre- vious stannous fluoride formu- lations. Anti-caries Effects The anticaries effects of stan- nous fluoride have been recog- nized for over 50 years and in the 1960s, the stannous fluoride- containing dentifrice, Crest® with Fluoristan™, received a Seal of Acceptance by the ADA’s Council on Dental Therapeu- tics. Fluoride, in various forms, is well-recognized for its abil- ity to foster remineralization of partially demineralized tooth enamel using the calcium and phosphate present in saliva. In addition to these remineraliza- tion effects, stannous fluoride has been shown to react with enamel to form a tin fluoro- phosphate complex which coats and protects the surface of the enamel.48,49 The antibacterial ac- tivity of stannous fluoride, which was discussed above, provides further protection by suppres- sion of bacteria, particularly Streptococci mutans, which are one of the primary pathogens associated with dental caries.50,51 The anti-caries benefits of stan- nous fluoride are therefore due both to physical chemistry and its bacteriological effects. Before the introduction of this SFSH dentifrice, a large num- ber of clinical trials had been carried out that demonstrated the efficacy of stannous fluoride in the control of dental caries.52 More recently, Stookey et al. car- ried out a large-scale clinical trial with 955 subjects compar- ing the anticaries efficacy of a dual-phase early prototype SFSH dentifrice with a positive control standard sodium fluoride denti- frice, and also a high-dose (2800 ppm F) and a low-dose (500 ppm F) sodium fluoride formula- tion.53 Visual-tactile examination was supplemented with a radio- graphic examination at baseline, after 12 months and at the end of the trial at 24 months. Both ex- aminers found that there was significantly less caries in the SFSH (17% and 25%) and high dose (2800 ppm) sodium fluo- ride groups (13% and 23%) than in the positive control group treated with 1100 ppm fluoride. In an in situ study of minerali- zation-demineralization, Wefel et al. reported that a dual-phase stannous fluoride/sodium hex- ametaphosphate dentifrice pro- duced anticaries activity which Volume 83 Issue II Spring 2009 The Journal of Dental Hygiene 3 plaque samples were taken immedi- ately post-rinsing and 12 hours later. An analysis of the samples showed that stannous fluoride inhibited sev- eral pro-inflammatory enzymes, including mammalian matrix met- analysis, enough stannous fluoride was retained to inhibit about 40% of most enzymes measured. These studies demonstrate the sustained antibacterial and anti- inflammatory effects of this SFSH tions.35 A 2-year study investigated the periodontitis prevention efficacy of a dual-phase stabilized 0.454% SFSH dentifrice compared to a posi- tive control (sodium fluoride/triclo- san dentifrice) in a population of Table 1. Long-term clinical trials examining the effect of stabilized stannous fluoride on reduction of plaque, gingivitis and gingival bleeding. Reference No. of Subjects % SnF2 Mode of Delivery Treatment Frequency Length of Trial Plaque Reduction % Reduction Gingivitis : Bleeding Archila et al.31 186 adults 0.45 Dentifrice Twice daily 6 months ND 25.8%** : 27.4%** Archila et al.32 38 adults resistant to NaF treatment 0.45 Dentifrice Twice daily 12 weeks ND 54%** : 55%** Boyd et al.28 23 adolescent orthodontic 0.4 Brush-on gel Twice daily 18 months 50% ** 55%** : 50%** Beiswanger et al.9 140 adults 0.45 Dentifrice Twice daily 6 months 3% ns 19%* : 31% ns Ciancio et al.27 28 adults 0.1 Mouth rinse Twice daily 3 weeks 28% ** ND Chitke et al.26 26 handicapped children 0.2 Spray Twice daily 3 weeks 48% * 52%* : ND Mallatt et al.30 128 adults 0.45 Dentifrice Twice daily 6 months 8%** 17%** : 41%** Mankodi et al.23 104 adults 0.45 Dentifrice Twice daily 6 months 20%** 21%** : ND Mankodi et al.24 130 adults 0.45 Dentifrice Twice daily 6 months 7% ** 22%** : 57%** Perlich et al.29 154 adults 0.45 Dentifrice Twice daily 6 months 3% ns 21%* : 33%* Tinanoff et al.25 31 adults, partial denture 0.4 Brush-on Twice daily 6 months 55% *1 48%* : 69%* Williams et al.10 112 adults 0.45 Dentifrice Twice daily 6 months 23% ** 22%** : ND All reductions are versus control except for Archila32 and Chitke26 which were relative to baseline values. 1 Significant difference for abutment teeth. * p ≤ 0.05 ** p ≤ 0.01 ND-no data ns-non significant Table 1. Long-term clinical trials examining the effect of stabilized stannous fluoride on reduction of plaque, gingivitis and gingival bleeding. Figure 4. Left: Scanning electron microscopy images showing open tu- buli after treatment with a sodium fluoride toothpaste (left) and closed tubuli after treatment with a SFSH dentifrice (right). From Baig and He.5 Figure 3. Plaque imaging system Beiswanger et al.9140 adults 0.45 Dentifrice Twice daily 6 months 3% ns 19%* : 31% ns