Statistical vs Clinical Significance in Product Testing: Can They Be Designed to Satisfy Equivalence?

Statistical issues associated with demonstrating significance between treatment groups (efficacy or superiority) and nonsignificance (equivalence) are presented and discussed. Methodologies for demonstrating efficacy of a product are proposed and contrasted, incorporating clinical and statistical criteria, with emphasis on situations in which placebo groups are precluded from the study design. Distinctions are drawn between study designs for demonstrating superiority and those for equivalence, including the determination of sample sizes needed for the different approaches. The "at least as good as" criterion is proposed as a reasonable alternative to that of equivalence in active control equivalence studies for demonstrating that dental product modifications or new products are efficacious.     

不同含漱液控制菌斑和消除牙龈炎症效果的比较

目的：研究护齿含漱剂、口泰含漱液、万宝林牙齿、口腔清洁液在控制菌斑和牙龈炎的作用．方法：选择２０３例牙龈炎患者，随机分为护齿含漱剂组、口泰含漱液组、万宝林牙齿、口腔清洁液组、多贝尔氏液组和蒸馏水组，用药前后检查牙龈指数（ＧＩ）、牙龈出血指数（ＳＢＩ）、菌斑指数（ＰＬＩ）．结果：用药后护齿含漱剂、口泰含漱液、万宝林牙齿、口腔清洁液组的ＧＩ、ＳＢＩ、ＰＬＥ均比用药前有明显降低（ｐ＜０．０１），且优于多贝尔氏液和蒸馏水组．结论：护齿含漱剂、口泰含漱液、万宝林牙齿、口腔清洁液能有效控制菌斑及牙龈炎     

Effects of triclosan/copolymer dentifrice on dental plaque and gingivitis in a 3-month randomized controlled clinical trial: influence of baseline gingivitis on observed efficacy

Triclosan is a broad-spectrum antimicrobial agent widely used in oral care products. In recent studies, a triclosan/pyrophosphate dentifrice has shown efficacy against dental plaque but not gingivitis. Further, experimental gingivitis studies on triclosan itself and in combination with other dentifrice ingredients demonstrate only moderate antimicrobial activity. In contrast, there are a number of other studies in the literature reporting the antigingivitis efficacy of triclosan/copolymer and triclosan/zinc citrate dentifrices. These dentifrices possess similar effects on dental plaque to triclosan/pyrophosphate, thus the lack of effect on gingivitis from triclosan/pyrophosphate was unexpected since comparable effects on dental plaque from similar formulations may infer similar antimicrobial activity and duration of action within the oral cavity. Therefore, the objective of this research was to understand the clinical variables important to observe the reported effects for triclosan dentifrice so this clinical model could in turn be used to test the effects of the triclosan/pyrophosphate dentifrice on gingivitis. To achieve this objective, it was determined that a suitable approach was to duplicate the methodology of previous successful clinical trials on triclosan/copolymer dentifrice in order to better understand the study design used to demonstrate the antigingivitis efficacy of triclosan-containing dentifrices. To this end, a prospective trial was conducted employing the same active product, clinical site, investigator and gingivitis/plaque examiner previously used. The study was a randomized, blinded, placebo-controlled, parallel group 3-month trial, which recruited subjects with L?e-Silness Gingival Index (GI) scores > or = 1.0 and Turesky Plaque Index (PI) scores of > or = 1.5. The study population consisted of 160 adults who brushed twice daily with either triclosan/copolymer or placebo control (containing copolymer) following a prophylaxis. Gingivitis and plaque were measured using the GI and PI, respectively, and scores were analyzed using a one-way analysis of covariance. There was no evidence that 3-month gingivitis or plaque scores (whole mouth or severity index) for the triclosan/copolymer group were different from the placebo group. Additional analyses were conducted on study population subgroups with increasing intervals of baseline GI bleeding sites to gauge the effect of baseline bleeding on the treatment effect. For subjects in the > or = 40 bleeding sites subset, triclosan/copolymer demonstrated a 4.2% GI and 15% gingivitis severity index reduction versus placebo at 3 months (0.10 < p < 0.20). These findings suggest that a study design which includes subjects with greater numbers of gingival bleeding sites at baseline may have the required sensitivity to demonstrate treatment benefits for triclosan/copolymer. However, additional experimental parameters remain to be fully articulated in order to replicate previously successful trials. The overall results of this trial are consistent with the experimental gingivitis results, and indicate that, even when formulated with the copolymer, triclosan as an oral antimicrobial agent possesses limited activity as an antigingivitis ingredient.     

Clinical efficacy of a dentifrice and oral rinse containing sanguinaria extract and zinc chloride during 6 months of use

The efficacy of combined use of toothpaste and oral rinse containing sanguinaria extract and zinc chloride was compared to placebo products in a 6-month clinical trial. Sixty subjects with moderate levels of plaque and gingivitis were randomly assigned to active and placebo groups. Noninvasive measures of plaque and gingivitis were assessed at baseline and at 2, 6, 8, 14, 20, and 28 weeks. Bleeding on probing was measured at baseline and 6, 14, and 28 weeks. Active group scores were significantly lower (P less than .0001) than placebo scores at each post-baseline time point for all indices, with the exception of plaque at 2 weeks. The 28 week active group scores were 21% lower than the placebo group for plaque, 25% lower for gingivitis, and 43% lower for bleeding on probing. No dental staining or taste alteration was reported in the active group. Three of 30 active group subjects exhibited minor soft tissue irritations that resolved spontaneously without discontinuation of product use. Results indicate that the test products showed good levels of safety and efficacy when administered in a combined use regimen for 6 months.     

Clinical and microbiological efficacy of an antimicrobial mouth rinse containing 0.05% cetylpyridinium chloride in patients with gingivitis

To cite this article:
Int J Dent Hygiene 10 , 2012; 98–106
DOI: 10.1111/j.1601‐5037.2011.00523.x Rioboo M, García V, Serrano J, O’Connor A, Herrera D, Sanz M. Clinical and microbiological efficacy of an antimicrobial mouth rinse containing 0.05% cetylpyridinium chloride in patients with gingivitis. Abstract: Objectives: the aim of this study was to evaluate the effects of the use of a mouth rinse and dentifrice with cetylpyridinium chloride (CPC) in patients with gingivitis. Methods: the study was designed as a 1‐month, double‐blind, parallel, randomized clinical trial comparing a negative control regimen (minus active ingredients dentifrice and mouth rinse) with the test products (dentifrice and mouth rinse with 0.05% CPC) in terms of plaque and gingival indexes (PI, GI), patient‐based and microbiological outcome variables. The comparisons in relation to the main outcome variables (PI and GI) were made by means of the t‐test, either unpaired or paired for the intergroup and intragroup comparisons, respectively. Results: no differences were detected at baseline. Both groups showed statistically significant decreases in GI (0.17–0.19), without intergroup differences. The PI demonstrated a significant decrease of ?0.12 in the test group and minor changes in the negative control group (increase of +0.01). Differences between groups showed a tendency towards statistical significance. A limited impact was observed for microbiological variables in both groups. Conclusion: the results of this study show limited benefits of the evaluated formulations as adjuncts to unsupervised oral hygiene in reducing plaque accumulation, and no effect on gingivitis.     

李施德林漱口水辅助治疗牙龈炎的疗效观察

目的:观察李施德林漱口水辅助治疗牙龈炎的疗效。方法:选择18～60岁的符合纳入标准的牙龈炎病人60例,随机分为试验组和对照组,试验组在牙周基础治疗后含漱李施德林漱口水,对照组行牙周基础治疗后清水含漱,分别于治疗后1、2周,观察病人的菌斑指数和牙龈指数,进行统计学分析。结果:治疗后1、2周,试验组的菌斑指数和牙龈指数明显低于对照组。结论:李施德林漱口水可作为牙龈炎病人牙周基础治疗后的辅助局部用药。     

Efficacy and safety of BrushPicks, a new cleaning aid, compared to the use of Glide floss

The objective of this double-blind, four-week clinical study was to evaluate the efficacy of BrushPicks, a new cleaning aid, and Glide floss on the reduction of plaque area, gingivitis and bleeding on probing, and to monitor safety when these products were used in addition to toothbrushing with an ADA-Accepted toothbrush (Oral-B P35) and an ADA-Accepted fluoride-containing dentifrice (Crest Regular). No special instructions on or supervision of product use was conducted, other than requesting twice-a-day (morning and evening) use of the assigned products. Following a baseline examination, 63 qualifying adult male and female subjects from the Philadelphia, Pennsylvania area were randomized into two groups. Subjects were also told to use their assigned dental aid after each toothbrushing. Examinations for efficacy and safety were repeated after two and four weeks' use of the products. Sixty-two subjects completed all aspects of the study. There were no untoward side effects attributed to product use, reported or observed, at the two- or four-week examination times. At baseline, there were no significant differences in plaque, gingivitis or bleeding on probing mean scores between the BrushPicks and Glide floss groups. At the two- and four-week evaluation times, both the BrushPicks and Glide floss had numerically lower plaque scores compared to baseline levels. The only statistically significant reduction (p < 0.01) was in the BrushPicks group, comparing the week two mean with the baseline value. Gingivitis (GI) at four weeks was statistically (p < 0.05) lower in the BrushPicks group as compared to the Glide floss mean value. When the changes in scores from baseline to two weeks and to four weeks were assessed, the mean GI score for the Glide floss group was significantly lower at two weeks (p < 0.01) compared to baseline, and also from two weeks to four weeks (p < 0.001). The change in mean GI score for the Glide floss group from baseline to four weeks was also significant statistically (p < 0.001). When the changes in mean GI scores for the BrushPicks group were assessed, there was a significant decrease from baseline to two weeks (p < 0.001), from two weeks to four weeks (p < 0.001), and from baseline to four weeks (p < 0.001). For bleeding on probing, when the baseline to two- and four-week mean values were compared, only the BrushPicks produced significant (p < 0.001) decreases. At two and four weeks, the BrushPicks group mean bleeding on probing scores were significantly (p < 0.05-0.01) lower than the Glide floss group scores. At the end of this four-week study, the BrushPicks product was significantly more effective than Glide floss in the reduction of gingivitis and bleeding on probing, important attributes of soft-tissue health.     

口腔综合防治措施对正畸儿童龋病和牙龈炎的影响

目的 :本实验通过对年龄 13～ 15岁 ,均为矫治仅 1周的患者进行口腔防治措施及口腔健康教育。方法 :防治措施包括氟制剂和绿茶多酚制剂的应用。对对照组儿童不采取任何防治措施。结果用团体T检验的方法进行统计。结果 :实验组无新龋发生 ,对照组龋均比实验前有所上升 ,但两组之间无统计学上的显著性差异。而实验组儿童口腔内GI、SBI、PLI指数明显降低 ,与对照组相比有显著性差异。结论 :对正畸儿童在矫治期间进行龋病和牙龈炎的防治非常必要 ,它可以防止龋病和牙龈炎的发生。     

Four years of monthly professional toothcleaning and topical fluoride application in Brazilian schoolchildren.

The effect on gingivitis of monthly professional toothcleaning, without oral hygiene instruction, was evaluated in 103, 7- to 11-year-old Brazilian children. Plaque and gingivitis (PlI and GI) were recorded initially and after 1, 2, 3 and 4 years. The baseline examination showed a similar high level of plaque (PlI approximately 1.55) and low level of gingivitis (GI approximately 0.32) around permanent teeth of both test and control groups. The test children were given monthly professional toothcleaning followed by topical application of fluoride gel (APF), totaling 32 sessions. At all annual follow-up examinations, the mean PlI in the test group was significantly lower than in the control group. However, even in the test group, at least 80% of the tooth surfaces harbored plaque. In spite of this, no child in the test group showed overt gingivitis (mean individual GI greater than or equal to 1.0) and the distribution of "GI score = 2" was very low. In the control group the percentage of children with overt gingivitis increased from 3% at the baseline to 20% at the final examination and areas scoring GI = 2 doubled in number. It is suggested that for young children, monthly thorough removal of plaque is sufficient to prevent the development of gingivitis.     

A clinical methods study of the effects of triclosan dentifrices on gingivitis over six months

The basic design for human clinical trials which examine prevention of gingivitis recurrence is well known. However, the anti-gingivitis efficacy of triclosan-containing dentifrices has not been routinely demonstrated using this design, regardless of formulation. In an effort to better understand the subtleties of design which show triclosan efficacy, a study was undertaken to prospectively test how subjects with a range of baseline disease levels (which encompassed the range of gingivitis severity documented in the triclosan literature) benefit from a triclosan dentifrice. This trial was a randomized, double-blind, parallel group, six-month study where subjects brushed twice daily with either triclosan/pyrophosphate, triclosan/copolymer, triclosan placebo or sodium fluoride control (NaF) dentifrice following a prophylaxis. Both gingivitis and bleeding were measured using the L?e-Silness Gingival Index (GI) and plaque was measured using the Turesky Plaque Index. Comparisons between treatments were performed using an analysis of covariance. At month 3, the triclosan/pyrophosphate group had a relative mean plaque benefit of 14.4% versus the triclosan placebo group (with an associated p-value of 0.004), and subjects using triclosan/copolymer had a mean reduction in GI bleeding sites of 16.2% relative to those brushing with the NaF control (with an associated p-value of 0.031). The overall results did not demonstrate a treatment effect for gingivitis or plaque for either triclosan-containing dentifrice at month 6. There was evidence of modest anti-gingivitis efficacy in the triclosan placebo. In an effort to better understand how baseline disease severity may have impacted the trial outcome, additional analyses were performed to investigate whether the magnitude of a triclosan effect was related to baseline gingivitis levels. An analysis of covariance model incorporating a baseline group interaction effect indicated that the magnitude of the treatment differences depended on the baseline scores The effect was most pronounced for GI bleeding sites. Further analysis showed that differences between triclosan dentifrices and the NaF control dentifrice were only present for subjects with more than 33 to 63 bleeding sites, depending on the specific comparison. These findings were illustrated through a series of subset analyses on subjects with > or = 20 (entire study population), > or = 31, > or = 40 and > or = 45 baseline GI bleeding sites. The magnitude of the treatment effect for both GI and GI bleeding sites increased with each succeeding subset. Unlike that required for other antimicrobial agents used in oral care products, these findings suggest that a study design which includes subjects with more severe gingivitis at baseline has the required sensitivity to demonstrate treatment benefits for triclosan dentifrices.     

Identification and consequences of distinct Löe-Silness gingival index examiner styles for the clinical assessment of gingivitis

BACKGROUND: In clinical studies, gingivitis is most frequently assessed by the L?e-Silness gingival index (GI). The objective of this work was to develop an understanding of how clinicians experienced with GI differ with respect to how they apply GI and to assess the impact of different examination styles on statistical outcomes and magnitude of treatment differences. METHODS: A method was developed to mathematically relate the average GI score and degree of bleeding observed for a subject. Graphical analyses were used to profile examiner styles with respect to using the GI index. A prospective single-center, examiner-blind study comparing the effects of a staggered prophylaxis on gingivitis was then conducted, where a difference in gingivitis was created between two balanced groups by providing subjects a prophylaxis at two staggered time points. Subjects were assigned to one of two cohorts; within each cohort, group 1 subjects received a dental prophylaxis following the baseline examination and group 2 subjects received a dental prophylaxis 8 weeks later. Five to 7 days after the group 2 prophylaxis, all subjects were examined for GI. Twelve experienced clinicians participated. RESULTS: Retrospective analyses indicated the presence of distinct examiner styles which are based on the frequency that a given GI score (0, 1, 2, or 3) is measured by a clinician. In the prospective study, all 12 examiners observed statistically significant differences between the prophylaxis treatment groups at the final visit for both mean number of bleeding sites and mean GI; the magnitude ranged from 21.5% to 84.6% for mean number of bleeding sites and 9.4% to 39.2% for mean GI. There were 4 distinct styles employed by these experienced clinicians. CONCLUSIONS: Varying examiner styles impact the structure of resulting data. Importantly, the implementation of arbitrary thresholds (e.g., 20%) regarding percent treatment differences between groups as a guideline for judging the clinical significance is scientifically unsupported. A more scientific criterion in the field of gingivitis clinical testing would be the independent demonstration of statistical superiority compared to a negative control and/or a demonstration of similar or superior efficacy to clinically proven positive controls. In addition, interexaminer calibration is a mechanism that can be utilized to minimize the impact of different examiner styles in clinical settings involving more than one examiner.     

Urea peroxide solution in the treatment of gingivitis in orthodontics.

A 3-month study was conducted to determine the effect of a 10 per cent urea peroxide solution on gingivitis and oral debris accumulation in orthodontic patients. Sixty fullybanded children (thirty-two girls, twenty-eight boys) 10 to 17 years of age were randomly placed into two groups of thirty members. The treatment group was assigned the use of the test solution and given normal oral hygiene instructions. The control group was given only the normal oral hygiene instructions. The subjects' gingival status was evaluated by means of the gingival index (GI) of O'Leary. The accumulation of oral debris was monitored by means of the oral debris index (ODI) of Greene and Vermillion as modified by Womack. Subjects were scored at the start of the study and approximately 1 and 3 months thereafter. Analysis of variance of the GI and ODI scores revealed significant treatment effects (p = 0.0013 and p = 0.0051, respectively), which substantiated the clinical observations. Rinsing with the test solution in conjunction with toothbrushing appears useful as an oral hygiene measure for orthodontic patients. No adverse reactions were experienced by any of the patients using the test solutions.     

Inhibition of experimental gingivitis in beagle dogs with topical mercaptoalkylguanidines

BACKGROUND: Nitric oxide is a free radical produced in host tissues by constitutive and inducible forms of the enzyme nitric oxide synthase. Nitric oxide plays physiological roles, but it is also involved in the pathophysiology of several inflammatory conditions, including arthritis, ulcerative colitis, and circulatory shock. Local increases in inducible nitric oxide synthase (iNOS) and reactive nitrogen products have also been demonstrated in humans and animals with periodontal disease. This masked, randomized, placebo-controlled preclinical investigation examined the effect of two mercaptoalkylguanidines, mercaptoethylguanidine (MEG) and guanidinoethyldisulfide (GED), which are iNOS inhibitors and reactive nitrogen scavenging compounds, on the development of experimental gingivitis in beagle dogs. METHODS: Fifteen female, 1-year-old beagles first completed a 2-week dose-escalation experiment during which a maximum tolerated dose was determined for MEG and GED gels. Thereafter, all animals were brought to optimal gingival health by mechanical scaling, followed by rigorous daily toothbrushing over a 4-week washout period. Experimental gingivitis was then induced, with cessation of plaque control and institution of a soft diet over 8 weeks. Beagles randomly received 0.3% MEG, 0.3% GED, or placebo (vehicle) gels, topically applied twice daily to premolar teeth. Gingival inflammation, bleeding tendency, and supragingival plaque were clinically measured at baseline and at 2, 3, 4, 6, and 8 weeks. Comparisons among groups and between group pairs (active versus placebo) were made using Kruskal-Wallis tests. RESULTS: From baseline to day 7, all groups expressed similar indices. Thereafter, significant and time-dependent increases in the plaque index (PI), gingival index (GI), and percentage of bleeding on probing (%BOP) were observed in placebo-treated beagles. Mean GI scores for beagles treated with GED or MEG gels remained at or below baseline levels for the entire treatment period. At weeks 2, 3, 4, and 8, GI scores were significantly lower for MEG and GED groups compared to the placebo group (P<0.05). In addition, MEG and GED gels significantly reduced gingival bleeding responses by 8 weeks (P<0.05). Although placebo-treated beagles demonstrated %BOP scores of 43% at week 8, GED- and MEG-treated beagles exhibited %BOP scores of 21% and 26%, respectively. Since no statistical difference among PI scores was noted for any of the time points, neither mercaptoalkylguanidine appeared to affect supragingival plaque levels. CONCLUSION: The data from this preclinical study indicate that mercaptoalkylguanidines, topically administered, may significantly reduce experimental gingivitis in the beagle dog.     

固定矫正与牙龈炎的关系探讨

目的 探讨正畸治疗患者牙龈炎发生的原因。方法 选取114例病例,分为成人组和青少年组。成人和青少年组又各自分实验组和对照组。在初戴固定矫正器2个月后检查牙龈,进行牙龈指数（GI）测定,从而比较成人与青少年患牙龈炎的比率。结果 成人组牙龈炎患病率低于青少年组,两者有显著性差异,P＜0．01。青少年对照组与相比,实验组患病率高,两者有显著性差异,P＜0．05。成人对照组与实验组相比,两者无显著性差异,P＞0．05。结论 口腔卫生的保健好坏,对正畸治疗患者牙龈炎的发生有着重要作用。进行正畸治疗的患儿家长,应配合督促儿童保持口腔卫生。     

The relative efficiencies of some periodontal partial recording selections

One hundred 11–15 year old clinic patients were examined, and the presence or absence of unequivocal gingivitis and periodontal pocketing was recorded separately for each permanent tooth, From the full-mouth data, each subject was also scored using combinations of teeth recommended for partial recording with the PMA, GI, and PDI index systems. Spearman's Rank Correlation Coefficient (r_s) was selected, after inspection of the frequency distributions, to express the associations between the partial recording and full-mouth scores. From the values of r_s, the relative efficiency of each partial recording combination was computed, in terms of the number of subjects required to provide a statistical test of similar power to that provided by a full-mouth examination of 100 subjects. The GI combination proved to be the most efficient. Values for r_s of 0.899 for gingivitis and 0.846 for periodontitis were obtained between this combination and the full-mouth scores. It was estimated that 124 and 139 subjects, respectively, would be required for gingivitis and periodontitis assessments, using the GI selection, compared with 100 for a full-mouth examination. None of the combinations adequately identified all subjects with one or more affected units.     

Equivalence testing with dental clinical trials

Clinical trials whose purpose are to show equivalence of two or more treatments have traditionally utilized methods for demonstrating superiority, and, if no statistical differences are found, the treatments are assumed to be equivalent. Methods for directly demonstrating equivalence have been developed by the pharmaceutical industry to establish the bioequivalence between drug formulations. This approach should have significant future implications for dental research. It is presently well-characterized in the statistical literature, but is virtually unknown within the dental literature and has had limited documented application with dental clinical trials. The purpose of this paper is to consider equivalence testing with dental clinical trials. Equivalence and superiority testing are contrasted, and comparisons between parallel and crossover designs with equivalence testing are discussed. To exemplify equivalency trial methodology for dental research application, several examples are proposed, including, in detail, an implant overdenture clinical trial to test the equivalence of treatment outcome between a two- and a four-implant overdenture treatment. Sample size calculations for otherwise-identical crossover and parallel equivalence studies are demonstrated. Results show that for a power of 0.90, a sample size of 24 is required for the crossover trial and over 150 subjects for the parallel design. For this dental research application, the equivalence/crossover design methodology is shown to be an efficient and appropriate approach.     

Effect of delmopinol hydrochloride mouthrinse on plaque formation and gingivitis in "rapid" and "slow" plaque formers

Abstract The aim of the present study was to investigate differences in the plaque and gingivitis inhibiting effect of delmopinol rinsing between “rapid” and “slow” plaque formers. 23 subjects (12 “rapid” and 11 “slow” plaque formers) were selected from 71 healthy young adults. The selection was based on the plaque index on the buccal surfaces of all premolars and 1st molars after 3-days without plaque control. The 23 subjects were randomly assigned into 3 groups with different mouthrinses, i.e., 0.1% delmopinol, 0.2% delmopinol, and placebo. The study was double-blind with parallel design between the “rapid” and “slow” plaque formers and cross-over design between 2 active periods and a placebo period. Each rinsing period lasted for 5 days. During the 3 test periods, the subjects refrained from all oral hygiene and rinsed 2 × daily with either one of the 3 solutions. Gingival crevicular fluid (GCF) was collected from buccal surfaces of upper canines and premolars and bleeding on probing (BOP) recorded at 6 sites around each tooth before and after each test period. Plaque assessment, including plaque index (PI) and standardized color slides for planimetric analyses obtained from the canines and premolars, were only recorded after each test period. Results showed that the mean PI and planimetry values for both the “rapid” and “slow” plaque formers were lower than the placebo, for either the 0.1% or the 0.2% delmopinol mouthrinse. The differences between the “rapid” and “slow” plaque formers were not statistically significant. There was a small reduction in BOP in both groups for the delmopinol periods, as against a slight increase in the placebo period: the difference between the placebo group and the 2 groups of plaque formers was not statistically significant (p>0.6 for both 0.1% and 0.2% delmopinol). Results suggested that both 0.1% and 0.2% delmopinol reduce plaque formation and gingivitis to a similar extent in subjects with extreme rates of plaque formation.     

A 6-month home usage trial of a 1% chlorhexidine toothpaste

Abstract Research and development has been aimed towards the development of toothpastes for oral hygiene and gingival health benefits. The most effective antiplaque agent to date, chlorhexidine. is difficult to formulate into active toothpaste products. Despite some encouraging findings for experimental chlorhexidine toothpastes, there are to date no commercially available products. Based on positive findings from an experimental gingivitis study, this investigation evaluated 2 chlorhexidine toothpastes, one with fluoride, as adjuncts to oral hygiene. The study was a double–blind controlled, parallel, balanced group design, extending over 6 months. A total of 297 volunteers commenced the study after screening for a minimum acceptance level of gingivitis. At baseline, 6, 12 and 24 weeks, stain, gingival, bleeding and plaque indices were recorded, together with a calculus index at 6, 12 and 24 weeks. After a baseline prophylaxis, volunteers used the allocated product 2 × per day, with no other oral hygiene instructions given. Plaque, gingival and bleeding scores improved in all 3 groups, but to an overall significantly greater extent in the active groups. However, staining and calculus indices were significantly increased in the active compared to the control group. If the local side-effects of chlorhexidine are considered to be acceptable, these chlorhexidine toothpastes could be recommended for the same clinical applications as other chlorhexidine products. The apparent compatibility of fluoride with chlorhexidine in the one product may be pertinent to caries prevention.     

活性银离子抗菌液治疗青春期龈炎的临床效果观察

目的观察活性银离子抗菌液治疗青春期龈炎的临床效果。方法选择78例青春期龈炎患者,随机分成两组,试验组使用活性银离子抗菌液配合洁治术,对照组单纯使用洁治术,分别在治疗前后检测牙龈指数(GI)、菌斑指数(PLI)、龈沟出血指数(SBI),并作统计学处理。结果通过临床对两组患者进行比较发现,使用活性银离子抗菌液含漱后试验组和对照组的GI、PLI差异有统计学意义(P<0.05),使用活性银离子抗菌液含漱后试验组和对照组的SBI差异无统计学意义(P>0.05)。结论用活性银离子抗菌液配合洁治术是治疗青春期龈炎的有效方法。     

The clinical effects of a mouthrinse containing 0.1% octenidine

The purpose of this three-month clinical trial was to evaluate the effects of a 0.1% octenidine mouthrinse on plaque, gingivitis, extrinsic dental stain, and the oral soft tissues. A total of 451 adult volunteer subjects was initiated into the study and given baseline dental examinations. The subjects were stratified into two balanced groups according to gender, plaque, and gingivitis scores. The subjects then received a dental prophylaxis and were provided with dentifrice, toothbrushes, and either a mouthrinse containing 0.1% octenidine dihydrochloride as the active ingredient or a similar placebo mouthrinse. Subjects were instructed to rinse with their assigned product for 30 s twice each day. Examinations were repeated at six weeks (soft-tissue assessment, gingivitis) and three months (soft tissues, plaque, gingivitis, dental stain). The results showed that the group rinsing with 0.1% octenidine had significantly less plaque (39%), gingivitis (50%), and bleeding sites (60%) than the group using the control product, but had significantly higher stain formation and experienced longer prophylaxis times to remove the stain. The oral soft-tissue examinations revealed no differences in the groups in either the numbers or types of lesions noted.