Mechanical Oral Hygiene Procedures Research Articles

Manual vs Mechanical Oral Hygiene Procedures: Has the Role of the Dental Hygienist in Phase 2 Post-lockdown Really Changed?

Purpose: Some authors have highlighted the danger of intraoral use of rotating instruments which can produce droplets and aerosols. During the Covid lockdown phase, dental operators were limited to providing emergency treatment that could not be postponed. Therefore, it is necessary for the dental team to restart safely to treat neglected oral diseases that may also affect systemic health. The role of the dental hygienist has apparently changed for procedures performed close to the patient's oral cavity, particularly in terms of the droplets and aerosols produced during oral hygiene practices. Through an analysis of the most recent literature on the use of dedicated PPE and changed post-Covid 19 work processes, and a review of the differences between manual causal therapy and mechanical therapy in terms of outcome after oral hygiene treatment, we define how the role of the dental hygienist can change positively. Materials and Methods: Narrative reviews of the literature in terms of PPE adopted and oral hygiene procedures performed were carried out in Pubmed. Results: 188 articles from February 2020 to May 2020 using the search terms 'dentistry' and 'covid-19' were examined. 10 reviews of the literature were performed using the search terms 'mechanical procedures' and 'manual hygiene'. Conclusion: Only continuous update of evidence-based literature on the new standards in oral hygiene procedures and the different results yielded by different procedures can ensure a safe working environment for the dental hygienist while supporting the dentist in this phase of the pandemic.

Nickel ion release from dental alloys in two different mouthwashes.

Background. Mouthwashes are widely used as adjuncts to mechanical oral hygiene procedures. Nonetheless, there is little information regarding the effect of various mouthwashes on the amount of ions released from the nickel-chromium (Ni‒Cr) alloys used in the fabrication of fixed prostheses. Therefore, the present study was conducted to evaluate the effect of two types of mouthwash on the release of Ni ions from dental alloys. Methods. Forty-two disk-shaped specimens were prepared with a diameter of 10 mm and a height of 2 mm. Two mouthwashes were examined in this study: Oral B and Listerine. A control group was also considered using distilled water. Each Ni‒Cr disk was immersed in the mouthwashes and distilled water in polypropylene test tubes, and then incubated at 37°C to simulate the oral temperature. After 45 days of incubation, the samples were tested for Ni ions using inductively coupled plasma mass spectroscopy. Data were analyzed using ANOVA. Results. In the Halita group subjects exhibited 2.04±0.65 reduction in OLS. OLS reduction in the chlorhexidine group was 1.95±0.74. Statistical analysis showed no significant difference between the two groups (P>0.05). Conclusion. As the results indicated, the amount of ion release was within the safe limits in the two experimental groups. However, it is recommended that prescribe Listerine mouthwash should not be prescribed for the patients with a history of Ni allergy.

Chlorhexidine mouthwash plaque levels and gingival health.

Data sourcesCochrane Oral Health's Trials Register; Cochrane Central Register of Controlled Trials (CENTRAL) Medline; clinicaltrials.gov and the World Health Organization International Clinical Trials Registry Platform. There were no language or date restrictions on searches.Study selectionRandomised controlled trials (RCTs) assessing the effects of chlorhexidine mouthrinse used as an adjunct to mechanical oral hygiene procedures for at least four weeks on gingivitis in children and adults.Data extraction and synthesisTwo reviewers independently abstracted data and assessed risk of bias. Mean and standardised mean differences were used for continuous outcomes and risk ratios for dichotomous outcomes. Meta-analysis was carried out where studies of similar comparisons reported the same outcomes at the same time interval.ResultsFifty-one RCTs involving a total of 5,345 patients were included. Only one study was at low risk of bias, the other 50 were at high risk. For patients with mild gingivitis (gingival index [GI] 0 to 3 scale) four to six weeks' use of chlorhexidine mouthrinse reduced gingivitis by 0.21 (95% CI; 0.11 to 0.31) with a similar effect at six months. There were insufficient data to assess the effect on patients with moderate or severe gingival inflammation. For plaque there was a larger effect in favour of chlorhexidine mouthrinse at four to six weeks, SMD (standardised mean difference) = -1.45 (95% CI; -1.90 to -1.00), with a similarly large reduction at six months. A large increase in extrinsic tooth staining was seen with chlorhexidine use at four to six weeks, SMD = 1.07 (95%CI; 0.80 to 1.34) and seven to twelve weeks and six months. A range of other adverse effects were reported including taste disturbance/alteration, oral mucosa symptoms including soreness, irritation, mild desquamation and mucosal ulceration/erosions, and a general burning sensation or a burning tongue or both.ConclusionsThere is high quality evidence from studies that reported the Löe and Silness Gingival Index of a reduction in gingivitis in individuals with mild gingival inflammation on average (mean score of 1 on the 0 to 3 GI scale) that was not considered to be clinically relevant. There is high quality evidence of a large reduction in dental plaque with chlorhexidine mouthrinse used as an adjunct to mechanical oral hygiene procedures for four to six weeks and six months. There is no evidence that one concentration of chlorhexidine rinse is more effective than another. There is insufficient evidence to determine the reduction in gingivitis associated with chlorhexidine mouthrinse use in individuals with mean GI scores of 1.1 to 3 indicating moderate or severe levels of gingival inflammation. Rinsing with chlorhexidine mouthrinse for four weeks or longer causes extrinsic tooth staining. In addition, other adverse effects such as calculus build up, transient taste disturbance and effects on the oral mucosa were reported in the included studies.

Chlorhexidine mouthrinse as an adjunctive treatment for gingival health.

Chlorhexidine mouthrinse as an adjunctive treatment for gingival health.

Comparative effects of aqueous single-phase and oil-water two-phase mouthrinses containing bamboo salt, magnolia bark andCentella asiaticaextracts on reducing gingivitis: a randomized clinical trial

Objectives: The aim of this study was to assess the antiplaque and antigingivitis effectiveness of aque ous single-phase and oil-water two-phase mouthrinses, containing bamboo salt, magnolia bark, and Centella asiatica extracts, in Korean adults. Methods: In this double-blinded clinical trial, a total of thirty-four participants aged over 19 years were randomly allocated to three experimental groups: 1) control group; 2) aqueous single-phase mouthrinse (ASM) group, and; 3) oil-water two-phase mouthrinse (OTM) group. The experimental mouthrinses all contained sodium fluoride, and the ASM and OTM contained additional ingredients of bamboo salt, magnolia bark, and Centella asiatica extracts. For the OTM, 50% essential oil was added to create an oil-water two-phase mouthrinse. A two-week randomized crossover design with a two-week washout period was applied. Following a complete dental prophylaxis, participants were instructed to use the prescribed mouthrinse twice daily for two weeks as an adjunct to their usual mechanical oral hygiene procedures. Pre- and post-experiment clinical examinations were performed to measure the plaque index (PI) and bleeding on probing (BOP) for the full mouth. Paired t-test was applied to compare the intergroup differences for all clinical variables. Results: Compared to the control group, ASM showed a significantly reduced BOP (P<0.05). However, there was no statistically significant difference in the effects of the three mouthrinses on reducing the PI. Conclusions: The results of this study indicate that the use of an aqueous, single-phase mouthrinse containing bamboo salt, magnolia bark and Centella asiatica extracts could help alleviate gingivitis.

The Plaque Inhibitory Effect of Aloe Vera Mouthrinse in A Four Day De Novo Plaque Formation Model- A Randomized, Double Blind Crossover Study

Mechanical oral hygiene procedures are most widely accepted procedures for controlling bacterial plaque, but these methods have certain limitations. Based on several clinical trials, chlorhexidine mouthrinse have been accepted as a benchmark to be used as an adjunct to mechanical oral hygiene aids, however it is associated with side effects in its long term use. The present study was undertaken to evaluate the antiplaque efficacy of a herbal Aloe vera mouthrinse and compare it to gold standard Chlorhexidine. A randomized, double blind, placebo-controlled, three group crossover, four day de novo plaque accumulation model was used. Study involved three experimental phases with a ten day washout period in between each phase. Twelve student volunteers were refrained from all oral hygiene measures for four days, but rinsed twice daily with 10 ml of one of the randomly assigned mouthrinse (chlorhexidine, Aloe vera, and placebo mouthrinse) in each test phase. Plaque index and plaque area was measured on day four. The Aloe vera mouthrinse showed a significant inhibition of plaque re-growth compared to placebo (P<0.0001), but the lowest values of plaque index and plaque area were obtained with chlorhexidine. The study concluded that Aloe vera has a promising plaque inhibitory potential but is not as efficacious as chlorhexidine in preventing plaque re-growth.

Comparison of Manual and Electric Toothbrush in Dental Plaque Removal: A Clinical Trial

Background: Mechanical oral hygiene procedures are the most effective means of plaque removal and toothbrush is the most commonly used tool for mechanical plaque removal worldwide. There is an array of available manual and electric toothbrushes in the market. Thus, choosing the best one for dental plaque removal can be of great help for patients. Objectives: This study aimed at compare the efficacy of dental plaque removal using a manual and an electric toothbrush. Materials and Methods: This experimental, single-blinded sequential clinical trial was conducted on 12 patients (ten females and two males) who aged 21 to 30 years old. The tested manual toothbrush was 35-mm soft Oral-B Pulsar and the electric one was Oral-B Professional Care 8500 DLX chargeable D18. Patients’ dental plaque score was set as zero through scaling, root planning, and polishing. Subjects were avoided tooth cleaning for three days and on day four, plaque accumulation was assessed using Tureskey's modification of Quigley and Hein plaque index. Results: The mean of plaque index was 2.13 ± 0.83 and 2.11 ± 1.01 in the manual and electric toothbrush groups, respectively. No significant difference was detected between the study toothbrushes in terms of plaque removal (P = 0.374); however, with the manual tooth brushing, plaque removal was significantly greater in the buccal than in lingual surface and in the maxilla than in the mandible (P = 0.03 and P = 0.015, respectively). Conclusions: Similar to previous studies, this study could not show the superiority of electric toothbrush over manual in plaque removal. After 72 hours, the mean of plaque index was greater in buccal than in lingual surface, which may be attributed to the natural cleansing action of the tongue.

The Effect Of Listerine Mouthwash On Dental Plaque, Gingival Inflammation And C - Reactive Protein (CRP)

Aims and Objectives: The objectives of this study were to assess the antiplaque and antigingivitis properties of Listerine ® mouth rinse and to investigate its effect on serum level of C-reactive protein. Materials and Methods: patients received Listerine or placebo (water) in a single-blind 4-week trial. Thirty qualifying subjects aged 20-50 years completed a 2-week preparatory period during which scaling and polishing were done twice. Subjects were then randomly grouped into: Listerine ® or water (control) group. Clinical periodontal parameters including visible plaque index (VPI), sulcus bleeding index (SBI), calculus index (CI), extrinsic tooth stain index (SI) and percentage of sites with bleeding on probing (BOP) were obtained from test group as well as matched controls. The measurements were performed at baseline and 4 weeks thereafter. Moreover, serum C-reactive protein levels (CRP) were assayed. Subjects then started rinsing twice daily with 20 ml of their respective mouthwash as adjunct to their usual mechanical oral hygiene procedures. Subjects were re-examined after 4 weeks, and intergroup differences for all clinical variables and CRP level were tested using appropriate statistical procedures. Results: All thirty subjects were evaluated after 4 weeks. Rinsing compliance was high for both groups. There were no statistically significant differences between the two groups at baseline for all clinical variables with the exception of the percentage of sites with BOP which was slightly significantly higher for the Listerine ® group compared with the water group (p=0.047). At the end of the experimental period, Listerine® group showed statistically significant reductions in the VPI (-24.1), SBI (-0.9) and percentage of sites with BOP (-28.7) compared with the water group (p<0.05). However, there were no statistical significant differences in CI and SI between the two groups. Moreover, Listerine ® mouth rinse did not show statistical significant reduction in the serum levels of CRP compared with the water group (-0.4 and -0.7 respectively, p=0.743). Conclusion: This 4-week controlled clinical trial demonstrated that Listerine ® mouth rinse possesses antiplaque and antigingivitis activities. Insofar, Listerine ® did not result in any side effects such as calculus formation and teeth staining. Furthermore, Listerine ® couldn’t show any effect on the serum levels of CRP relative to baseline measures.

How to deal with morning bad breath: A randomized, crossover clinical trial

Context:The absence of a protocol for the treatment of halitosis has led us to compare mouthrinses with mechanical oral hygiene procedures for treating morning breath by employing a hand-held sulfide monitor.Aims:To compare the efficacy of five modalities of treatment for controlling morning halitosis in subjects with no dental or periodontal disease.Settings and Design:This is a five-period, randomized, crossover clinical trial.Materials and Methods:Twenty volunteers were randomly assigned to the trial. Testing involved the use of a conventional tongue scraper, a tongue scraper joined to the back of a toothbrush's head, two mouthrinses (0.05% cetylpyridinium chloride and 0.12% chlorhexidine digluconate) and a soft-bristled toothbrush and fluoride toothpaste for practicing oral hygiene.Statistical Analysis Used:Data analysis was performed using SPSS version 17 for Windows and NCSS 2007 software (P < 0.05). The products and the periods were compared with each other using the Friedman's test. When significant differences (P < 0.05) were determined, the products and periods were compared in pairs by using the Wilcoxon's test and by adjusting the original significance level (0.05) for multiple comparisons by using the Bonferroni's method.Results:The toothbrush's tongue scraper was able to significantly reduce bad breath for up to 2 h. Chlorhexidine reduced bad breath only at the end of the second hour, an effect that lasted for 3 h.Conclusions:Mechanical tongue cleaning was able to immediately reduce bad breath for a short period, whereas chlorhexidine and mechanical oral hygiene reduced bad breath for longer periods, achieving the best results against morning breath.

Comparative efficacy of two daily use mouthrinses: randomized clinical trial using an experimental gingivitis model

Two antimicrobial agents, a fixed combination of essential oils (EOs) and 0.07% cetylpyridinium chloride (CPC) are found in commercially available mouthrinses, Listerine® Antiseptic and Crest® Pro HealthTM, respectively. Both mouthrinses have been shown to control dental plaque and gingivitis in short and longer term studies. The aim of this study was to determine the comparative effectiveness of these two mouthrinses using a 2-week experimental gingivitis model. Qualified subjects were randomly assigned to one of three mouthrinse groups: a fixed combination of EOs, 0.07% CPC, or negative control (C) rinse. Following baseline clinical assessments and a dental prophylaxis, subjects began a two-week period in which they rinsed twice daily with their assigned rinse and abstained from any mechanical oral hygiene procedures or other oral care products. Subjects were reassessed at the end of the two-week period. One hundred and forty-seven subjects were randomized and 142 completed this study. After two weeks use, the EOs rinse was superior (p < 0.011) to the CPC rinse in inhibiting the development of gingivitis, plaque, and bleeding, with 9.4% and 6.6% reductions compared to CPC for gingivitis and plaque, respectively. Both rinses were superior to the negative control rinse (p < 0.001). This study demonstrates that the essential oil-containing mouthrinse has superior antiplaque/antigingivitis effectiveness compared to the 0.07% CPC-containing mouthrinse without mechanical oral hygiene influence.

Three different rinsing times and inhibition of plaque accumulation with chlorhexidine

This study assessed the plaque inhibiting effect of a 0.2% chlorhexidine (CHX) solution (Corsodyl) with three different rinsing times following a 72 h non-brushing period. The clinical investigation was a single-blind, randomised study involving 90 volunteer students (40 male and 50 female, mean age 23.2 years). Subjects were randomly allocated to one of three groups for which the protocol only differed with respect to the duration of rinsing. At the start of the trial, all participants received a dental prophylaxis to remove all plaque deposits. Subjects refrained from all mechanical oral hygiene procedures, but rinsed two times per day for the allocated duration with CHX mouth rinse over a period of 72 h. The chlorhexidine preparation was of 0.2% concentration used at a dose of 10 ml for either 15, 30 or 60 s. After 72 h, the Quigley & Hein plaque index (PI) from all volunteers was recorded at six sites per tooth. All participants received a questionnaire to evaluate their perception of rinsing duration. After 72 h, the mean whole-mouth PI was 1.33, 1.18 and 1.24, respectively, for the 15, 30 and 60 s rinsing group. The difference in plaque scores between the three groups was not statistically significant. Results from the questionnaire showed a significant difference between the groups for their perception of rinsing duration. No significant difference was observed in the level of plaque after 72 h of non-brushing whether the subjects rinsed for 15, 30 or 60 s with 0.2% chlorhexidine.

Periodontal therapeutics – a viable option?

Research in recent years in periodontology has seen a shift from surgery towards medicine. While surgery, particularly regenerative, and including implants, continues to form an important element of periodontal treatment, the volume of treatment required and the results of recent and ongoing non-surgical studies clearly show that most future periodontics will be based on a physician-type approach. Improved diagnostics based on more precise periodontal disease classification, simplification of mechanical oral hygiene equipment and procedures, and the development of conventional and non-conventional chemical and physical adjuncts may be expected to reduce the rate of common periodontal disease advance, resulting in less complex treatments, and more of the latter coming to lie within the competence of the generalist and the hygienist working together. The rationale for non-surgical adjunctive therapy is extensive, far beyond the usual antimicrobial logic. It will also be important to control the oral microflora for systemic reasons, since increasingly strong links are being established between focal infection of oral origin, much of it periodontal, and a range of systemic diseases, including coronary heart disease, stroke, gastrointestinal disorders, and low birth weight, apart from severe, overt systemic infections. All these developments derive from a greatly improved understanding of the fundamentally ecological nature of the natural microbial biofilm that is dental plaque, and of its interactions with its human host.

The use of 0.2% chlorhexidine in the absence of a structured mechanical regimen of oral hygiene following the non-surgical treatment of periodontitis.

The aim of the present study was to evaluate a 0.2% chlorhexidine mouthrinse following the non-surgical treatment of advanced human periodontitis in the absence of a structured mechanical oral hygiene regimen. 10 patients and a total of 1483 sites were used. Recordings for plaque, bleeding, pocket depth and attachment levels were made at baseline and at 3, 6, 9, and 12 months. Debridement was performed under local anaesthesia. No instruction or reinforcement in mechanical oral hygiene procedures was given at any time. However, at each visit the patients were instructed in the 2x daily use of 0.2% chlorhexidine mouthwash. The plaque indices, scored as % of sites with removable deposits, showed negligible improvement from baseline scores of 80%-100% for all categories of initial probing depth. Mean bleeding score was reduced to 10-20% irrespective of initial probing pocket depth, site location or tooth surface location. Sites > or = 7 mm at baseline demonstrated a reduction in mean probing pocket depth of 3.9 mm and a gain in mean probing attachment level of 2.5 mm. Moderately deep sites (4-6.5 mm) demonstrated a reduction in mean probing pocket depth of 2 mm and a gain in mean probing attachment level of 0.8 mm. Shallow sites (< or = 3.5 mm) demonstrated a reduction in mean probing pocket depth of 0.5 mm and a loss in mean probing attachment level of 0.2 mm. Site-specific attachment level analysis demonstrated that over 80% of losing sites were shallow with low bleeding frequency, indicating that the loss of attachment may have occurred for reasons other than inflammatory periodontal disease. The results indicate that chlorhexidine can be used as an adjunct to inadequate mechanical oral hygiene over an observation period of 1 year.

Delivery of Antiplaque Agents from Dentifrices, Gels, and Mouthwashes

Antiplaque agents delivered from toothpastes, gels, or mouthrinses can augment mechanical oral hygiene procedures to control the formation of supragingival plaque and the development of early periodontal disease. Clinically effective antiplaque agents are characterized by a combination of intrinsic antibacterial activity and good oral retention properties. The overall oral retention of an antiplaque agent is determined by the strength and rate of association of the agent with its receptor sites and the accessibility of these sites. The substantivity of an antiplaque agent and its clearance from the oral cavity are determined by the rate of dissociation of the agent from the receptor sites and the salivary composition and flow rate. Positively charged and non-charged organic molecules, metal ions, enzymes, and surface-active agents have all been considered as antiplaque agents. To exert clinical antiplaque activity, an antimicrobial agent must be formulated in a chemically compatible delivery vehicle to give optimal release and uptake to the sites of action in a biologically active form during its time of application. In principle, antiplaque activity may be enhanced by combining antimicrobial agents with broadly similar, but complementary, modes of action. Alternatively, the activity of a single agent may be increased by use of a retention aid to enhance oral substantivity. Substantial evidence exists to demonstrate the validity of the first approach. However, there are few data, as yet, to support the effectiveness of the second. The oral mucosa is the bulk retention site for all clinically proven antiplaque agents. Plaque, the pellicle-coated tooth surface, and saliva are probably all sites of biological action. A detailed understanding of the interactions between agents and the various receptor sites, and of the importance of these receptor sites to biological activity, is generally lacking.

The effect of mechanical oral hygiene procedures on bleeding on probing

The effect of mechanical oral hygiene procedures on bleeding on probing

Routes to chemical plaque control

A logical approach to the prevention of periodontal disease is through excellent supragingival plaque control. Such control is not generally achieved by mechanical oral hygiene procedures alone. Thus, there is a clear rationale for the use of antiplaque agents to augment mechanical means. The principle routes to chemical plaque control are to prevent colonization of the tooth surface, to inhibit the growth of microorganisms, the prevent plaque maturation, to modify plaque biochemistry and to modify plaque ecology to a less pathogenic flora. The most successful approach to date has been to use broad spectrum antimicrobial agents to reduce plaque growth and, in consequence, plaque metabolism. Currently, only the chlorhexidine and Listerine mouthwashes and a toothpaste containing zinc citrate and Triclosan have proven efficacy in controlled clinical trials. Their effectiveness is a result of good oral substantivity as well as broad spectrum antimicrobial activity. All other routes to chemical plaque control ...

The effect of mechanical oral hygiene procedures on bleeding on probing

The purpose of the present study was to investigate the effect of mechanical oral hygiene procedures on bleeding on probing in relation to age and periodontal status. The study was carried out on 49 individuals divided into 7 experimental groups according to age and having been either treated for destructive periodontal disease or having an intact healthy periodontium. In order to eliminate any pre-existant gingival inflammation, all subjects received a carefully controlled oral hygiene program. At the start of the experiment, all subjects were instructed to abstain from oral hygiene procedures for 24 h. Thereafter, clinical baseline measurements were carried out, including bleeding on probing (BOP) using a standardized probing pressure. Next, all subjects cleaned their teeth according to their normal oral home care protocol using a multitufted toothbrush, toothpicks and interdental brushes. BOP scores were again assessed 30 min after completed tooth cleaning procedures. The results revealed a significant increase in BOP after the mechanical oral hygiene procedures in every individual in all experimental groups (p less than 0.05). Further analysis showed that the increase in BOP was independent of the periodontal status of the subjects. However the BOP scores after mechanical oral hygiene procedures were higher in the young age groups. It was concluded that the diagnostic predictability of BOP in the treatment of periodontal diseases might be affected by temporarily elevated BOP scores shortly after mechanical oral hygiene procedures.

Spiramycin as a selective dental plaque control agent

Spiramycin was tested as a chemotherapeutic plaque control agent. Sixty‐ three volunteers (29 experimental and 34 control) abstained from mechanical oral hygiene procedures for 11 weeks. The participants were divided randomly into exeperimental and control groupa and received, on a double blind basis, either 20–500 mg capsules of spiramycin or 20 capsules of placebo with directions to take 1 capsule 4 times a day for 5 days. At each examination visit intra‐oral photographs were taken, gingival and plaque indices recored, and plaque samples collected for laboratory study. In the experimental group there was a statistically significant decrease in plaque as measured by wet weight, turbidity, nitrogen, and carbogydrat parameters for at least 3 weeks. There was a significant decrease in the number of Streptococcus mutasn and S. sanguis in the plaque samples at weeks 1 and 3, but there was no detectable influence on the number of Gram‐negative organisms.

Traumatization of teeth and gingiva related to habitual tooth cleaning procedures.

Traumatization of oral hard and soft tissues connected with mechanical oral hygiene procedures has been reported in the dental literature. Definitions, classifications and localization of such lesions are listed, and in vivo and in vitro experiments within the field are reviewed. Existing literature suggests that hard tissue lesions are mainly due to abrasives in dentifrices, whereas gingival lesions may be caused by toothbrushing per se. Factual knowledge about the prevalence, severity and clinical significance, as well as relevant and reliable experiments, is scarce and further research on these topics seems to be indicated.

Prevalence of oral soft and hard tissue lesions related to mechanical toothcleansing procedures.

The prevalence of oral soft and hard tissue lesions related to mechanical oral hygiene procedures was recorded and correlated to toothbrushing habits and oral hygiene status in two selected samples. Fifty-one percent of 533 persons examined exhibited gingival retractions and 45% had wedge-shaped defects in the cervical area of one or several teeth. Both types of lesions were often seen in the same area, indicating a common etiologic factor. The subjects with a good oral hygiene status, as well as those who brushed more than twice daily, showed a high frequency of lesions. The various toothbrushing techniques did not, however, seem to influence the development of such lesions in the present material. Subjective symptoms were reported in a few cases only.