Library

Notes: Background: Plaque inhibition by chlorhexidine (CHX) rinses is dose related with a relatively flat dose–response curve above 5–6 mg twice daily. Low dose regimens could therefore reduce local side effects but maintain reasonable efficacy.Aims:  To compare the plaque inhibitory properties of two low-dose CHX rinse products with more conventional levels delivered from proprietary rinses. A secondary outcome was a comparison with a stannous fluoride/amine fluoride (SFAF) rinse product.Methods:  The study was a five-treatments, negative controlled, randomised, single blind crossover design balanced for residual effects, involving 20 healthy subjects in a 24-h plaque re-growth model. On day 1 of each study period, subjects were rendered plaque free, suspended tooth cleaning and followed the appropriate rinse regimen. On day 2, subjects were scored for plaque by index and area. The rinse codes and rinsing regimens were: (A) 15 mg CHX 2 × daily for 30 s (0.1% CHX), (B) 9 mg CHX 2 × daily for 60 s (0.06% CHX), (C) 10 ml SFAF rinse 1 × daily for 30 s, (D) 15 ml placebo 2 × daily for 60 s, and (E) 6 mg CHX 2 × daily for 30 s (0.06% CHX).Results:  Average mouth plaque indices and areas were highly significantly different between rinsing regimens. All test rinses were significantly more effective than the placebo rinse. There was a mean dose–response pattern for the CHX rinses, but there were no statistically significant differences between any of the test rinses.Conclusions:  Lower doses of chlorhexidine in rinses can be used to exert plaque inhibition comparable with products used at higher doses and equivalent to benchmark products such as the SFAF rinse. However, the availability of chlorhexidine from formulations has to be considered as in part explaining the results.

Notes: Aim: The aim of this study was to establish the prevalence of dentine hypersensitivity in a cross-sectional study of patients visiting general dental practitioners in the United Kingdom over a period of one calendar month.Methods: Nineteen dental practioners examined 4841 patients over a period of one calendar month and patients that had dentine hypersensitivity diagnosed were questioned further about their occupation and smoking habits. The amount of buccal gingival recession associated with the sensitive teeth was also recorded using a study form.Results: 201 patients were diagnosed as having dentine hypersensitivity, giving a prevalence figure of 4.1%. The commonest teeth affected were the upper premolar teeth and the commonest initiating factor was cold drinks. A tendency for a greater number of sensitive teeth was also found for patients with periodontal disease who also smoked. There was also a tendency for the patients with sensitive teeth to come from higher social groups.

Notes: Abstract. Many treatments for dentine hypersensitivity are formulated to directly or indirectly occlude the open dentinal tubules associated with the condition. Combining solutions of calcium chloride and potassium phosphate can result in the precipitation of amorphous calcium phosphate. Such a system applied to exposed dentine could occlude dentinal tubules and reduce sensitivity. The aims of this study using a placebo control were to assess the therapeutic value of amorphous calcium phosphate in dentine hypersensitivity and provide further information on the apparently natural improvement in the condition frequently observed in clinical trials. 38 subjects with dentine hypersensitivity affecting 1 tooth in each left and right sides of the jaws were recruited into this split mouth, randomised, double-blind study. At baseline, sensitivity was scored by the subjects on a 0–10 visual apologue scale after tactile, cool and cold water and evaporative stimulation of the test teeth. Active and control, water, solutions were then applied by a 2nd clinician. After 24 h, subjects returned for rescoring. On days 7 and 14, subjects were again rescored and the treatments reapplied. Further follow-up appointments for rescoring were on days 21, 28, 56 and 84. Plaque scores also were recorded from test teeth at each visit. Overall sensitivity decreased considerably and to a similar degree in test and control teeth with no consistent significant treatment difference. Plaque scores also decreased through the study period. It is concluded that either the amorphous calcium phosphate was without therapeutic effect or the activity was masked by the placebo response in the control teeth.

Notes: Abstract. Dentifrices have typically been formulated as pastes. Recently however, a number of liquid products have become available. The chemical plaque inhibitory activity of such products has so far received little attention. The aim of this study was to determine the plaque inhibitory effect of a proprietary liquid dentifrice by comparison to a negative control (water) and a conventional fluoride toothpaste. The study design was a randomised single centre, single blind 3-way crossover trial with the objective of validating claims of plaque inhibition for the liquid dentifrice. Volunteers were rendered plaque free then asked to brush for one minute with one of the three test products, following which they abstained from oral hygiene for the subsequent 24 h. The plaque area was recorded and then measured planimetrically. The results showed that more plaque accumulated with water and the liquid dentifrice compared with the fluoride toothpaste. Thus, there was a statistically significant difference between the fluoride toothpaste and water and between the fluoride toothpaste and the liquid dentifrice. There was no significant difference between the liquid dentifrice and water. It is concluded that in this particular model system, the liquid dentifrice provided little chemical plaque inhibitory action.

Notes: Abstract Acidified sodium chlorite (ASCI is recognised as a highly potent, broad spectrum antimicrobial system that has been successfully developed for uses in veterinary, food processing and medical device fields. The current studies aimed to investigate the persistence of antimicrobial action and plaque inhibitory properties of 3 ASC mouthrinses by comparison with positive control, chlorhexidine 0.12%, and placebo control, water, rinses. Both studies were randomised, double-blind, cross-over 5-cell designs balanced for carryover. The 1st study involved 15 healthy subjects who immediately before and at 30, 60, 180, 300 and 420 min after rinsing provided 2 ml saliva samples. The samples were immediately processed for total anaerobic bacterial counts recorded after 96 h incubation. Washout periods were a minimum of 3 days. The second study involved 20 healthy subjects who on day 1 of each study were rendered plaque free, suspended normal oral hygiene methods and commenced rinsing twice daily with the allocated rinse. On day 5, plaque was scored by index and area after disclosing with erythrosin. Washout periods were 2 1/2 days. The 3 ASC and chlorhexidine rinses produced similar reductions in salivary bacterial counts which remained significantly below the placebo control to 7 h. There were no significant differences between ASC and chlorhexidine rinses except at 30 and 60 min when significantly greater reductions were produced by 2 ASC rinses compared to the chlorhexidine rinse. Plaque indices and areas were considerably and significantly lower with the ASC and chlorhexidine rinses compared to the placebo rinse. There were no significant differences between plaque scores for the 3 ASC rinses and the chlorhexidine rinse, although for 2 ASC rinses plaque scores were lower than for the chlorhexidine rinse. The results indicate that the 3 ASC rinses have equivalent plaque inhibitory action to chlorhexidine as a rinse. Similar to chlorhexidine. the plaque inhibitory action of the rinses appears to be derived from a persistence of antimicrobial action in the mouth.

Notes: Abstract. Home-use studies on dentine hypersensitivity have most commonly involved toothpastes and rarely have mouthrinses been employed. Potassium and/or fluoride toothpastes have been shown effective in the treatment of dentine hypersensitivity The aim of this study was to evaluate the effectiveness of a total formulation, containing potassium citrate, sodium fluoride, cetylpyridinium chloride mouthrinse compared to the base rinse minus actives in the reduction of dentine hypersensitivity. The study was a randomised placebo controlled, double blind parallel design. At a screening visit, 90 adult subjects were recruited who were suffering from dentine hypersensitivity from at least 1 tooth responding to tactile stimulation (45gm pressure) and had at least 2 teeth responding to evaporative stimulation (air blast). During a washout period of 28 days and throughout the 56-day study period, subjects used a soft filament toothbrush and standard fluoride toothpaste. At baseline (day 1), threshold sensitivities to incremental tactile (10 g to 70 g) and evaporative stimuli were determined. Gingival health was assessed by recording bleeding on probing at 25 g pressure at mesiobuccal and lingual sites. Plaque scores from buccal and lingual surfaces of disclosed teeth were also measured. Subjects then used the prescribed rinse. 10 ml for at least 30 s after brushing 2× per day returning on days 28 and 56 for rescoring of sensitivity, gingivitis and plaque. Data from 88 subjects were used with the intent to treat analyses and 83 in the completely evaluable analyses. Groups were well balanced for demographic data and product returns suggested good compliance. Both groups showed highly significant improvements in tooth sensitivity. The pattern was for greater improvement in the test compared to the control group (statistically significant for the plaque score), whereas bleeding scores, already low, showed no change in either group. By definition, the placebo rinse could not have exerted any therapeutic action; the study therefore provides clear direct evidence as to the magnitude (30%-40%) of the little studied, but assumed, placebo response in dentine hypersensitivity trials.

Notes: The relationship between malocclusion and the health of the masticatory apparatus is reviewed. While there is evidence that certain features such as traumatic deep overbite, unprotected incisors and impacted teeth may adversely affect the longevity of the dentition, the relationship of dental irregularity to periodontal disease, caries and mandibular dysfunction is less certain. Studies in the Held of social psychology indicate that an unattractive physical appearance may evoke an unfavourable social response in many facets of social interaction but the place of dentofacial anomalies in this context has not been satisfactorily assessed. The individual's adjustment to his own imperfections in dental alignment is variable and there is no evidence that children with visible irregularities will in general be emotionally handicapped. Effectiveness studies have yet to be undertaken but the factors which will have to be taken into account in assessing the benefits of orthodontic treatment are the definition of treatment need, treatment standards, the disadvantages of treatment and the influence of other determinants of dental health. The need for further research is underlined.

Notes: Abstract Clinical trials on dentine hypersensitivity have been numerous and protocols varied. To date there is little consensus as to the conduct of studies on this poorly-understood yet common and painful dental condition. A committee of interested persons from academia and industry was convened to discuss the subject of clinical trials on dentine hypersensitivity and a consensus report is presented. A double-blind randomized parallel groups design is recommended, although cross-over designs may be used for the preliminary screening of agents. Subjects may have multiple sites scored. Sample size will be determined by estimating the variability in the study population, the effect to be detected and the power of the statistical test to be used. Subject selection is based on a clinical diagnosis of dentine hypersensitivity, excluding those with conflicting characteristics such as currently-active medical or dental therapy. The vestibular surfaces of incisors, cuspids and bicuspids are preferred as sites to be tested. A range of sensitivity levels should be included. Tactile, cold and evaporative air stimuli should be applied. Negative and benchmark controls should be incorporated. Most trials should last 8 weeks. Sensitivity may be assessed either in terms of the stimulus intensity required to evoke pain or the subjective evaluation of pain produced by a stimulus using a visual analog or other appropriate scale. The subject's overall assessment may be determined by questionnaire. Outcomes should be expressed in terms of clinically significant changes in symptoms. Follow-up evaluation is required to determine the persistence of changes. At least 2 independent trials should be conducted before a product receives approval.

Notes: abstract Dental health education employing five different teaching methods was given to classes of 9- to 10-year-old schoolchildren. A control class received no teaching. The dental health knowledge of the classes was assessed before teaching, and immediately, 1 week and 3 months after teaching by the use of a questionnaire. All methods resulted in a variable increase in marks immediately after teaching. This was followed by a fall in marks for each class over the 3-month period. The poster and pack methods of presenting information, overall, had little or no effect on the recall of information. The talk, visual aids and project methods all significantly increased dental health knowledge for the 3-month period.