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— The purpose of the study was to examine the justification of the common assumption that early periodontal disease can be diagnosed on the basis of qualitative radiographic changes in the alveolar bone margin. The material comprised 100 bite wing radiographs of quantitatively intact interdental septa between the mandibular first and second premolars of 65 males aged 19–22 years. The width of the periodontal space, the continuity of the crestal cortical bone layer, and the pattern of trabeculation of each septum were used as criteria for classifying the septa as either healthy or probably or positively diseased. The study revealed that no relationship exists between the Gingival Index score and the presently studied qualitative radiographic findings. It was concluded that the constant interplay between physiologic constructive and destructive phases within the alveolar bone efficiently masks the minute qualitative radiographic changes pertaining to early periodontal disease.

The aim of this 12-month parallel design controlled clinical trial was to assess the effect of the Braun Oral-B Plak Control electric toothbrush on supragingival plaque and gingival health, and to compare it with a conventional soft manual toothbrush (Jordan). A total of 111 patients aged between 20 and 63 years, from a general population, with bleeding on probing at 30% or more of all sites examined were entered into the study. At baseline, immediately after periodontal examination, all volunteers received a thorough scaling of their teeth. Volunteers in both groups were told to brush their teeth for 2 min 2 x a day. Oral hygiene instruction was given at the start of the study and was not repeated. At 3, 6 and 12 months, assessments were carried out by a single clinician who was not aware which group the volunteers belonged to. Analysis of results demonstrated that over the 12 months of the study, the Braun Oral-B Plak Control was significantly more effective in improving gingival health than the manual toothbrush. There was, however, no difference between the 2 groups in terms of plaque removal, with the number of sites with visible plaque decreasing by a similar amount in both groups. In conclusion, results indicate that the Braun Oral-B Plak Control toothbrush is safe and more effective than a manual toothbrush in improving gingival health.

Short-term success of the use of self-assessment for motivating adults to improve their oral health status has been reported. The purpose of this trial was to evaluate the long-term effectiveness of two self-assessment strategies, one focused on gingival bleeding (group I) and another focused on plaque (group II). At baseline, 493 14- and 15-year-olds were assigned randomly to a group. Each subject was given a manual describing one of the self-assessment processes. Dental hygienists provided standardized classroom based instruction and two weeks later, individualized counselling. Examinations were conducted at baseline 6, 12, 18 and 24 months for gingival bleeding on probing, plaque, calculus, and probing depth; and at baseline and 24 months for recession and decayed, missing and filled surfaces (DMFS). Following the 12-month examination, subjects received an oral prophylaxis and individual counselling. The results revealed no statistically significant differences between groups for any clinical parameter at the final examination. However, the mean number of sites with gingival bleeding decreased steadily from baseline to 24 months with a 59% decrease and 55% decrease for groups I and II, respectively. This study suggests that self-assessment approaches can be effective in improving the long-term periodontal health status of teenagers.

In the present site-by-site follow-up study, the change in amount of approximal alveolar bone was assessed after 1 year from the baseline examination in 38 and after 2 years in 22 dentate subjects all with insulin-dependent diabetes mellitus. The diabetics, aged 35 to 56 years at baseline, had a history of a mean duration of 18 years of insulin-dependent diabetes mellitus and were under medical treatment at the outpatient clinic of the III Department of Medicine, University Central Hospital of Helsinki as well as at 2 diabetic clinics of the Helsinki Health Centre. Based upon their long-term medical records, 26 subjects were after 1 year, and 16 subjects after 2 years from the baseline, identified as having poorly controlled insulin-dependent diabetes (PIDD). At the 1-year examination, 12 subjects were classified as having controlled insulin-dependent diabetes (CIDD) as compared to 6 subjects at the 2-year examination. After 1 and 2 years, from baseline, site-by-site measurements were recorded for plaque index scores, bleeding after probing, loss of attachment, and radiographic loss of alveolar bone. After 1 and 2 years from baseline, the PIDD subjects exhibited higher mean %s of sites with improved bleeding scores (P < 0.01, chi 2-test) than the CIDD subjects. At the 2-year examination, the mean % of sites with loss of approximal alveolar bone was greater in the PIDD than in the CIDD group (P < 0.05, chi 2-test). The greatest differences between PIDD and CIDD subjects were found when recordings for only canines were analyzed at the 1- and 2-year examinations (P < 0.05, chi 2-test). The results of our current 2-year longitudinal site-by-site examinations confirm earlier results that poorly controlled insulin-dependent diabetes mellitus is strongly related to the amount of alveolar bone loss.

In a previous study, 800 mg pieces of sorbitol-flavored gum, each piece containing 5 mg chlorhexidine (CHX) acetate, when chewed 2 at the time 5 x daily, were found to have an excellent plaque growth inhibiting effect. The aim of Trial 1 of the present study was to assess whether chewing only 2 x daily, 2 pieces of the same concentration CHX gum for about 10 min would be as effective. 6 dental students participated in the 3 x randomly crossed over double-blind clinical trial. During the 5-day chewing periods, no other oral hygiene measures were allowed. The Hibitane Dental (HD) rinse was used as a positive and the gum base containing neither CHX nor the sweetening agent as a negative control. At the end of each test period, recordings were made for the plaque index (PII), the plaque wet weight (PWW) and the relative area of plaque covered tooth surface (plaque area %). Chewing of CHX gum twice daily inhibited plaque growth as effectively as the HD rinse. The aim of Trial 2 was to assess the antiplaque effect of lower concentration CHX gums with, hopefully, a less unpleasant taste. For this trial, 8 dental students were recruited to chew 2 x daily during 6-day periods two 800 mg pieces of sorbitol-flavored gum, each piece now containing either 5 mg, 4 mg or 3 mg CHX acetate. The effect of these dosages did not differ from the effect of the HD rinse.(ABSTRACT TRUNCATED AT 250 WORDS)

Ankkuriniemi O, Ainamo J. Dental health and dental treatment needs among recruits of the Finnish Defence Forces, 1919-91.The first two surveys of the dental health of young Finnish men were conducted in 1919 and 1965. The objective of four subsequent surveys (1976, 1981, 1986, and 1991) was to collect both interview and clinical examination data for the monitoring or changes in the oral health status of the recruits. A significant reduction in self-reported toothache, gingival bleeding, and number of decayed teeth was observed from 1976 to 1991. At examination, the numbers of decayed teeth, teeth indicated for extraction, teeth in need of fillings, and missing teeth decreased substantially, as did the teeth with visible plaque, subgingival calculus, and teeth with 4-mm or deeper periodontal pockets. This comprehensive series of successive cross-sectional oral health surveys clearly shows that since 1976 a significant decrease in oral disease and treatment needs has taken place among the Finnish population...

The subgingival microflora was assessed by means of dark field microscopy in 106 pockets of 47 subjects with long-term insulin-dependent diabetes mellitus (IDD). The microbiota of 55 healthy sulci (probing depth4 mm) and 51 periodontally diseased (probing depthor = 4 and 6 mm) pockets were analyzed. The mean duration of the IDD of the diabetic subjects was 23.7 years (range from 10 to 41 years). The diabetic patients, aged 30-65 years, were under medical treatment at the III Department of Medicine, University of Helsinki Central Hospital, and at 2 clinics of the Helsinki Health Centre. Based upon their long-term medical records, 26 subjects were assessed to have poorly controlled insulin-dependent diabetes mellitus (PIDD) and 21 had controlled insulin-dependent diabetes (CIDD). The PIDD subjects exhibited higher mean blood glucose levels (12.9 +/- 4.6 mmol/l, mean +/- S.D.) than the CIDD subjects (7.9 +/- 3.6 mmol/l) (p0.001, t-test). The mean glycosylated hemoglobin HBA1 (HBA1c) levels were 11.2 +/- 4.6% (10.3 +/- 1.2%) and 8.8 +/- 1.8% (7.7 +/- 1.4%) for PIDD and CIDD subjects, respectively. These differences were statistically significant (p0.01 and p0.001, t-test). For each individual, site-specific recordings were made for plaque index and bleeding index scores, probing depth, loss of attachment and radiographic loss of alveolar bone. Dark field microscopy analysis of the presence of spirochetes, motile rods, cocci, non-motile rods, filaments and fusiforms was performed in the total of 106 pockets. According to the results of the dark field microscopy, the % of spirochetes and motile rods in the periodontally diseased pockets was significantly higher in the PIDD than in the CIDD subjects (9.2 +/- 13.4% and 10.8 +/- 14.3% versus 4.0 +/- 5.2% and 3.1 +/- 3.2%, p0.01 and p0.001, chi 2-test, respectively). Moreover, the PIDD subjects had lower mean %s of coccoid cells in periodontally diseased sites than the CIDD subjects (52.1 +/- 20.8% versus 60.7 +/- 9.0%, p0.001, chi 2-test).

A double-blind, randomised, 4-week clinical trial with parallel group design in 57 patients with gingivitis was conducted for studying the antibacterial efficacy and safety of a delmopinol HCl aqueous solution 2 mg/ml (0.2% w/v), which was used for unsupervised mouth-rinsing and compared with placebo and chlorhexidine digluconate 2 mg/ml (0.2% w/v, Hibitane Dental, ICI Pharmaceuticals, UK). The plaque index and plaque wet weight were used to measure plaque formation, and gingival fluid flow and bleeding on probing to measure gingivitis. According to the reduction from baseline, chlorhexidine showed a significantly better effect on plaque formation than the placebo after 4 weeks treatment for both plaque measurements. Delmopinol exhibited significantly lower plaque index scores than placebo. The difference between chlorhexidine and delmopinol was not statistically significant for any of the plaque measurements. For gingivitis, no statistically significant differences were obtained between the effects of delmopinol, chlorhexidine and placebo. A transient anaesthetic sensation in the oral mucosa was experienced more clearly by the patients in the delmopinol group than by those using chlorhexidine or placebo rinses. Rinsing with chlorhexidine resulted in more staining of the teeth and tongue than did delmopinol and placebo. The placebo solution tasted better than the 2 active solutions. The results showed that rinsing with either delmopinol HCl aqueous solution 2 mg/ml or chlorhexidine digluconate 2 mg/ml 2x daily for 60 as a supplement to normal oral hygiene, following an initial professional tooth cleaning, leads to a lower plaque formation than rinsing with placebo.(ABSTRACT TRUNCATED AT 250 WORDS)

Several authors have determined clinically the width of attached gingiva (AG) over the deciduous and early permanent dentitions in children. They have noticed that when comparing the width of AG over deciduous teeth to the width of AG over the succeeding newly erupted permanent teeth, a clear diminishing in AG can be seen. The aim of the present cross-sectional study was to assess the width of radiologically-defined AG (RAG) over the permanent teeth of 6-, 10- and 12-year-old children. Altogether 123 subjects were recruited. The mucogingival junction (MGJ) was revealed with Schiller's iodine solution and marked over each tooth with a piece of metal wire before taking a panoramic radiograph. The width of RAG over permanent teeth was measured from the radiographs as the midfacial distance from the cementoenamel junction to the mucogingival junction. When comparing the width of RAG over 1st molars and the 1st and 2nd incisors, statistically significant differences were found between 6- and 10-year-olds, between 6- and 12-year-olds and between 10- and 12-year-olds. For the 1st maxillary incisor, the difference in width was not statistically significant between ages 10 and 12 years. The findings seem to justify the conclusion that an inadequate width of AG will correct itself from 6 to 12 years of age without interference by means of periodontal surgery.

The purpose of this descriptive cross-sectional community based investigation was to analyze the relationship between professionally measured and perceived gingival health in a sample of 1217 adolescents (age 14.0 +/- 0.7 yr). The responses to two questionnaire items relating to self-reporting of "gingivitis" ("inflammation of gums" in Finnish) and "bleeding from gums" are reported along with Community Periodontal Index of Treatment Needs (CPITN), percentage of bleeding sites (BOP%) and modified Papillary Bleeding Index (PBI) scores. It was found that current or past "gingivitis" was less often reported than "bleeding from gums" by this sample and that responses to both items exhibited low levels of agreement with the clinical measures. The results suggest that the self-reporting of gingival health may be useful in monitoring the gingival health of populations but does not have sufficient validity for screening individuals for gingivitis as defined by dental professionals. Furthermore, it is suggested that the term "bleeding from gums" rather than "gingivitis" should be used during clinical or group oral health promotion.

This study was designed for analysis of the discriminating power of 4 different quantifications of supragingival plaque: (1) plaque wet weight (PWW); (2) the plaque index (PlI); (3) the PLQ index measuring the coronal extension of plaque; (4) the area % of stained plaque. Different quantities of plaque were produced by adding chlorhexidine acetate (CHX), hydrogen peroxide (H2O2), or sucrose to experimental chewing gums. Total mean scores of 12 subjects in each of 3 test groups revealed that chewing of CHX gum resulted in the lowest plaque scores with all 4 quantifications and that the highest scores were recorded for the PWW or PlI of the sucrose gum users. Chewing of the H2O2 gum produced as much plaque as the sucrose gum when evaluated according to the PLQ index and exceeded the sucrose gum scores when evaluated according to the area % index. The PWW discriminated best between low, medium and high plaque scores after chewing of both CHX, H2O2 and sucrose gums. PlI scores 1 and 3 remained stable whereas the frequency of PlI score 0 strongly decreased and that of score 2 strongly increased when going from gums producing low (CHX) and medium (H2O2) to large (sucrose) amounts of plaque. The PLQ index discriminated well between low and medium but poorly between medium and large amounts of plaque. The area % index functioned well when subjects with low (CHX) and medium (H2O2) plaque scores were subgrouped into those with30%, 30-70% or70% of their tooth surfaces covered with stained plaque.(ABSTRACT TRUNCATED AT 250 WORDS)

In the present two-year longitudinal investigation, the progression of periodontal disease was assessed after 1 year from the baseline examination in 38 dentate subjects and after 2 years in 22 dentate subjects with a mean duration of 18 years of insulin-dependent diabetes mellitus. The diabetics, aged 35 to 56 years at baseline, were under medical treatment at the outpatient clinic of the III Department of Medicine, University Central Hospital of Helsinki and at 2 diabetic clinics of the Helsinki Health Centre. Based upon their long-term medical records, 26 subjects were at baseline identified as having poorly controlled insulin-dependent diabetes (PIDD) with a mean blood glucose level of 12.5 mmol/l and a mean glycosylated hemoglobin (HBA1) level of 10.1%. 12 subjects were classified as having controlled insulin-dependent diabetes (CIDD) with a mean blood glucose level of 6.7 mmol/l and a mean HBA1 level of 9.2% at baseline. For each individual, recordings were made at baseline and after 1 and 2 years from the baseline for the plaque index, gingival index, pocket depth, loss of attachment, bleeding after probing, gingival recession, and radiographic loss of alveolar bone. At baseline and 2 years after the baseline examination, the PIDD subjects had similar plaque conditions as the CIDD subjects. At baseline and after 1 and 2 years from baseline the PIDD subjects had more gingivitis and bleeding after probing (P < 0.05, chi 2-test) than the CIDD subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

A newly developed metronidazole 25% dental gel was compared with subgingival scaling in the treatment of adult periodontitis. 206 patients in 9 centres participated in the study. Probing pocket depth (PPD) and bleeding on probing (BOP) were recorded before treatment and 2, 6, 12, 18, and 24 weeks after the treatment. All patients had at least I tooth in each quadrant with a PPD of 5 mm or more. The treatments consisted of 2 applications of dental gel (days 0 and 7) in 2 randomly selected quadrants (split mouth design) and 2 sessions of subgingival scaling (1 quadrant on day 0, and 1 quadrant on day 7). Instruction in oral hygiene was given 2 weeks after completed treatment. The average PPD and the average frequency of BOP were calculated over all sites with initial PPD of 5 mm or more. PPD and BOP were thus, at each examination, calculated from the same sites. The mean PPD was 5.9 mm before gel application and 5.8 mm before scaling (p= 0.31). BOP was 88% in both treatment groups. 24 weeks after the treatment. PPD and BOP were significantly reduced in both groups and for both parameters (p < 0.01). PPD was reduced by 1.3 mm after gel application and 1.5 mm after scaling; BOP was reduced by 32% and 39%, respectively. The difference between the treatments was statistically significant, but considered as clinically unimportant.

The apically repositioned flap procedure, by definition, implies that the mucogingival junction (MGJ) is shifted into an apical location. That this actually would be the case has never been shown in long-term studies. The 13 subjects in the present study had during the years 1964-1965 received treatment of moderately advanced periodontal disease (probing pocket depths less than or equal to 5 mm) in the lower jaw. An apically repositioned flap (ARF) procedure was applied in the left or right half of the mandible and a gingivectomy (GE) was performed in the contralateral side. Starting in December 1981, the patients were recalled for clinical and radiographic determination of long-term results. The width of the band of keratinized gingiva was measured clinically and the distance from the MGJ to the lower border of the mandible (LBM) was measured from orthopantomograms. Slightly less keratinized gingiva was observed on the sides where GE had been used. There was no statistically significant difference in the orthopantomographic distance from the MGJ to the LBM between ARF and GE operations. The results indicate that the apically repositioned flap procedure does not result in a permanent apical shift of the MGJ.

Out of a pool of 12 middle-aged or elderly diabetic patients demonstrating rapid periodontal break-down, the 2 oldest cases with follow-up periods of 19 and 16 years are described. The common feature of all 12 patients was that they were either unaware of or unable to control their diabetic condition at the time of the active, stage of their periodontal disease. The bone loss progressed in spite of specialist periodontal care and the patients again responded to treatment only after their elevated blood glucose levels had been brought back to normal. Thus, the rapid periodontal breakdown was not found to be associated with the diabetic condition per se, but rather with the hyperglycemia. This clinical follow-up study does not answer the question of whether rapid periodontal destruction occurs in all patients with poorly controlled diabetes. Neither do the observations imply that rapid bone loss would be pathognomic of high blood glucose levels. However, the observations seem to suggest that there may be an inter-relationship between rapid periodontal breakdown and elevated blood glucose levels. Therefore, any sudden change towards an increased progression rate of periodontal breakdown at adult age, as observed from periodic radigraphs with intervals of only a few years, should be followed up with a medical examination in order to outrule or verify the possibility of a high blood glucose level.

The study was performed on a material of 365 Finnish schoolchildren aged 13--15 years. One-third of the children were from Jyväskylä, with 0.2 parts/10(6) fluoride in the drinking water, one-third from Kuopio, with an artificially corrected 1.0 parts/10(6) fluoride content since 1959, and one-third from Hamina, where the natural fluoride content of the drinking water varies between 2.5 and 5.0 parts/10(6). All the children were scored for the Visible Plaque Index (VPI), the Gingival Bleeding Index (GBI) and for past caries experience (DFS). With increasing fluoride content of the drinking water the DFS scores were found to decrease significantly. No such difference was observed with regard to the VPI scores. The prevalence of gingival bleeding was found to be highest in Hamina (2.5 parts/10(6)). A highly significant positive correlation was found between individual VPI and GBI scores in all three towns. No corresponding correlations were found between the individual VPD and DFS scores. The latter finding is in desagreement with the generally accepted view that oral hygiene is an efficient caries-preventive measure.

In a previous paper a slight increase in gingival bleeding tendency was reported after the use of chlorhexidine rinses in dental students with clinically healthy gingivae. For further clarification of this finding the study was repeated using a split mouth approach. 30 dental students brushed the teeth in either the left or the right side of their mouth twice daily during a 7-day period. After each brushing, they rinsed for 1 min with 10 ml of a 0.2% chlorhexidine digluconate solution. Both the Plaque Index (P1I) scores and the bleeding tendency after massage of the gingival margin were low at the initial examination. The low P1I scores at baseline were further reduced on both sides of the jaws. On the side which was only rinsed the P1I scores were higher than on the side of combined mechanical and chemical cleaning. The gingival bleeding tendency was found to decrease on the brushed side and to increase on the side which was only rinsed. An increased bleeding tendency was most often observed in those individuals whose gingivae were the healthiest at baseline. A SEM analysis of the 2 sides of the dentition indicated that bleeding after chlorhexidine rinses may be associated with irritation from debris which, after the 7-day period of no mechanical oral hygiene measures, seemed to obliterate the gingival sulcus.

The bacteria forming pathogenic dental plaque on the tooth surfaces have long constituted a challenge for researchers with an interest in chemical degerming agents. As the plaque grows outside the vascularized tissues, most trials have been conducted with locally applied antibiotics and antiseptics. When these are introduced into the oral cavity, they will, if effective, reduce the amount of supragingival plaque. No means have so far been demonstrated for chemical control of the plaque growing underneath the gingival margin. The results obtained from trials with various antibiotics have not been very promising, especially when compared to the risks involved. Also many antiseptics with an excellent degerming effect in vitro have been tried. Most of them have proved inactive in the human mouth. Failure may be due to the protective properties of mucus and other constituents of the saliva and, apparently, (o the short retention time of the antimicrobial agent in the oral cavity. Good retentive properties have been observed with chlorhexidine (CHX). Two daily 1-min rinses with a 0.2 % aqueous solution of CHX digluconate totally prevents growth of supragingival plaque and even when CHX has been included in. gels and dentifrices, a both statistically and clinically significant reduction in the amount of plaque has been demonstrated. At present CHX seems to be agent of choice in chemical control of supragingival dental plaque. However, due to some secondary side effects, it is mostly used only for short period treatments.

In earlier studies it was shown that the distance from the cemento-enamel junction to the mucogingival junction, i.e. the anatomical width of fibrously attached gingiva, increases significantly from 23 to 43 years of age. The aim of the present study was to examine whether alveolar growth continues to result in an increase in this dimension after the age of 43. In a total of 21 males aged 65.7 ± 9.1 years and 21 females aged 64.5 ± 6.1 years, with an average of 23 occluding teeth, the mucogingival junction was marked with short pieces of metal wire. Orthopantomograms were then taken and the distances measured from the mucogingival junction to the cemento-enamel junction and to the orthopantomographic projection of the bottom of the nasal cavity in the maxilla and from the mucogingival junction to the cementoenamel junction and to the lower border of the jaw in the mandible. The measurements were taken along the long axis of each occluding tooth. The bilaterally pooled results indicated that alveolar growth continues to increase the distance between the cemento-enamel junction and the mucogingival junction in both males and females from age 43 to 65 years. However, the growth was slower during this period than from age 23 to 43 years. The distance from the mandibular border to the mucogingival junction of the same jaw did not change from 23 to 65 years of age. In the maxilla, an increase in the distance from the floor of the nasal cavity to the mucogingival junction was indicative of a continuous growth through adult age of the basal bone in the male but not in the female cranium.

The conceptions of Finns regarding their own periodontal status were surveyed in 1972. The interviewed sample, drawn to cover the total Finnish population aged 15 years and over, comprised 965 persons. After exclusion of 233 edentulous subjects, a total of 732 dentulous persons were accepted for the present interview study. 10 percent of the interviewees were aware of their having gingivitis at that time. 57 percent were of the opinion that they had never had gingivitis. On the other hand, 20 percent of the interviewed persons had recently observed gum bleeding while 54 percent stated that they had never observed it. 21 percent of the interviewees were aware of their having dental calculus and 46 percent had the impression that they had never had calculus. 24 oercent of those interviewees who presently had calculus or had had calculus stated that they had never had it removed. Generally Finns failed to realize that gingival bleeding is a symptom of gingival inflammation. This point should be made clear in the dental health education of the future. The knowledge could help individuals to evaluate the state of their own periodontal tissues in order to obtain the best possible benefit from efficient home care.

Conceptions among the general public in Finland regarding the etiology and prevention of dental caries and periodontal disorders were surveyed in two interviews in 1971 and 1972. Both population samples interviewed comprised about 1,000 persons aged 15 years and over. Inadequate oral hygiene was the most common (65%) possible cause chosen by I he subjects among the causes of dental caries. Only 44% of the interviewees considered sugar to be a cause of caries. Thorough cleaning of the teeth (83%) and dentist's check-ups twice a year (67%) were the factors most frequently chosen in caries prevention. Avoidance of sugar (56%) ranked as the third in frequency. As regards symptoms of periodontal disorders, tender gingiva, gingival bleeding, and loosening of the teeth were correctly suggested as symptoms by 62, 61 and 45%, respectively. Poor oral hygiene (77%) was the cause of gingivitis most commonly chosen by the interviewees, while simultaneous systemic disease (37%) was considered more important than, for example, dental calculus (31%). As regards treatment of periodontal disorders, careful toothcleaning (73%) received most support. However, this factor was closely followed by misconceptions regarding the supposed advantageous value of drugs and rinses (50%), chewing of fibrous foods (45%), and vitamin therapy (38%).

Needs for tooth extractions, conservative dental treatment--including periodontal and caries treatment--and occlusal rehabilitation--including stomatognathic and prosthetic treatment or a combination of these--in a Finnish adult population were summarized and time estimates for the treatment calculated. The study population consisted of 1,275 adults in four age cohorts--25, 35, 50, and 65 years. A decrease was observed from five hours of total dental treatment time needed at ages 25 and 35 years to four hours at age 50 years and three hours at 65 years. At the age of 25 years, 86 percent of the treatment time (255 min) was needed for conservative therapy, the corresponding figures at 65 years being 35 percent (66 min). On the other hand, a fivefold increase (from 13% to 62%) in the proportion of time needed for occlusal rehabilitation was observed between age 25 and 65. A combination of stomatognathic and prosthetic treatment was most frequently needed. The percent of time needed for tooth extractions varied from 1 to 3 percent among the four age cohorts.

An experimental study was designed for assessment of whether two recently marketed flavored chlorhexidine mouthrinses, Hibitane Dental® (ICI) and Plak-Out® (Hawe), have as good plaqueinhibiting effect as the 0.2 % aqueous solution of chlorhexidine gluconate. Thirteen dental students used in different sequences each one of the three rinses for i week by rinsing twice daily for 1 min. During the rinsing periods no other oral hygiene measures were allowed. Between two rinsing periods the subjects cleaned their teeth mechanically for 1 week. At the start of each test and control period, the teeth were professionally cleaned with rubber cups and an abrasive paste. At the end of the five I-week periods the mesial, lingual and facial aspects of the teeth in the right halves of the jaws of each participant were scored for the Plaque Index by the same investigator. After the mechanical cleaning, higher PU scores were recorded than after the chlorhexidine rinses. No difference could be observed among the PII scores after rinsing with the aqueous or the two flavored chlorhexidine solutions. Zusammenfassung Die plaqueinhibierende Wirkung zweier Chlorhexidtin Mundspullosungen mit Geschmackszusdtzen ZTJT Beurteilung, ob zwei kurzlich auf dem Markt erschienene Chlorhexidin-Mundspulloisungen mit Geschmackskorrigentien, Hibitane Dental® (ICI) und Plak-Out® (Hawe) gleiche plaqueinhibierende Eigenschaften besitzen wie eine 0,2 %-ige wasserige Chlor-hexidin-GIukonatlosung, wurde eine experimentelle Studie durchgefuhrt. Dreizehn Studenten der Zahnmedizin spulten ihren Mund in den versehiedenen Versuchsabschnitten der Studie wahrend einer Woche 2 mal taglich eine Minute lang. Wahrend der Mundspulperioden wurden keinerlei anderen mundhygienischen Massnahmen zugeiassen. Zwischen zwei Spiilperioden reinigten die Probanden eine Woche lang ihre Zahne mit mechanischen Hilfsmitteln. Vor dem Testbeginn und dem Beginn der Kontrollperiode wurden die Zahne der Probanden mit Gumminapfchen und einer abrasiven Polierpaste professioneli gereinigt. Am Ende der funf "Einwochenperioden" wurde der Plaque-Index der mesialen, linguaien und fazialen Zahnoberflachen der rechten Kieferhalfte vom gleichen Untersucher registriert. Nach der mechanischen Reinigung wurden hohere Pl.l Bewertungseinheiten (scores) registriert als nach den Chlorhexidinsplilungen, Zwischen den PI, 1-Bewertungseinheiten nach der Spiilung mit der wasseringen und den beiden Chlorhexidiniosungen mit GeschmackszusStzen, wurden keinerlei Untersehiede wahrgenommen. Resume Inhibition de la plaque: action de deux bains de Bouche aromatise s a base de chlorhexidine Une etude experimentale a ete coneue pour determiner si deux produits aromatises a base de chlorhexidine pour rinc ages de bouche recemment introduits sur le marehe, Hibitane Dental® (ICI) et Plak-Out® (Hawe), sont aussi efficaces pour inhiber la plaque que la solution aqueuse a 0,2 % de digluconate de chlorhexidine. Treize etudiants en dentisterie ont utilise dans un ordre different chacun de ces trois produits pendant une semaine a raison de deux rincages par jour pendant une minute. Pendant les periodes de rincage, aucun autre soin dhygiene bucco-dentaire netait autorise. Entre deux periodes de rincage, les sujets se nettoyaient les dents par rocedes mecaniques pendant une semaine. Au debut de chaque pe riode, experimentale ou temoin, les dents subissaient un nettoyage professionnel a J'aide de cupules de caoutchouc et d'une pate abrasive. A la fin des cinq periodes d'une semaine, les scores de l'indice dc Plaque PlI ont eteevalues par un meme examinateur chez chaque participant, au niveau des faces mesiales, linguales et faciales des dents de la moitie droite des mâchoires. Apres le nettoyage par procedes mecaniques, les scores de PII enregistres etaient plus eleves quapres les rincages a la chlorhexidine. Aucune difference ne pouvait etre observee entre les scores de PII apres les rincages au moyen de la solution aqueuse ou des deux solutions aromatisees.

Tooth position has been suggested to be an important factor in gingival recession. Due to conflicting reports in the literature, this study was undertaken to examine the effects of labial tooth movement on changes in the marginal periodontium. Orthodontic tooth movement was performed in five monkeys (Macaca nemistrina). Oral health was established and exploratory surgery was performed to assess the level of the connective tissue attachment and marginal bone. Measurements of the gingival margin and mucogingival junction were taken and orthodontic forces were applied. The central incisors were moved labially a mean distance of 3.05 mm. Posttherapy measurements were performed to assess the change which occurred as a result of tooth movement. Significant recession of the gingival margin, connective tissue level and marginal bone was found.

In a recent study, sorbitol flavored chewing gum was found neither to increase nor decrease the normal rate of plaque formation, whereas high plaque scores were obtained with sucrose gum during 4 days of no mechanical tooth cleaning. The aim of the present study was to see if chewing sorbitol or xylitol flavored gum together with sucrose gum would affect the growth rate of plaque and whether chewing of xylitol flavored gum could reduce the amount of already formed plaque. Twenty-seven dental students refrained from mechanical oral hygiene measures from Monday to Friday morning for 3 weeks. The students were randomly divided into three groups. A three time crossed-over double-blind approach was used. During each test period one group chewed a combination of one piece sorbitol and one piece sucrose flavored gum five times per day, the second group correspondingly chewed xylitol and sucrose flavored gum, while the third group served as a no hygiene control group. After each test period the students in the control group chewed one piece of xylitol gum every 15 minutes for 2.5 hours. The participants started out each week with clean teeth and were at the end of each test period scored for visible plaque on the facial, mesial and lingual surfaces of their teeth. There was somewhat more plaque after 4 days of chewing sucrose-sorbitol and sucrose-xylitol gum combinations than after no oral hygiene alone. There was no difference between the two test treatments. The 2.5-hour chewing of xylitol flavored gum after the no oral hygiene period did not result in a reduction, of the 4–day-old plaque.

– In order to assess the long term effect of dental health education, the gingival state and dental conditions of 68 dentists' children aged 11.4 ± 3.4 years were compared with those of their age- and sex-matched classmates from (a) parents with anoUier academic education of corresponding length, and (b) parents with no academic or high school education. A tendency for bleeding of the gingival margins at pressure was observed most often in children with non-academic parents and was least frequent in dentists' children. The reported frequency of toothbrushing being the same in all three groups, it was suggested that the efficacy of the brushing among the dentists' children must be superior to that of the others. Also the DMF scores were found to be lowest in the group of dentists' children. The non-academic children correspondingly presented the lowest frequency of intact first molars. The study confirmed the already accepted view that the educational level of the parents correlates positively with the dental health of their children. The finding that dentists' children are even better off than children of other academic parents was concluded to justify an intensification of dental health education in future dental care.

The present study was undertaken in response to a growing concern among clinicians about an increase in gingival recession among children and adolescents. Groups of 50 boys and 50 girls aged respectively 7, 12, and 17 yr were examined at Espoo Health Centre in 1983. Gingival recession was measured on the facial and lingual aspects of all permanent teeth. Whenever the gingival margin was located on root cementum, the distance from the gingival margin to the enamel border was measured to the nearest 0.5 mm. Recession was categorized as “slight” (0.5 or 1 mm) or “extensive” (1.5–3.5 mm). The prevalence of gingival recession was 5% at 7 yr, 39% at 12 yr, and 74% at 17 yr of age. More girls than boys had recession in the two youngest age groups. At 17 yr recession was equally common in both sexes and both “slight” and “extensive” recession was most often recorded on facial surfaces of first molars, premolars and canines. The alarmingly high prevalence of gingival recession at young age warrants further study of both the reasons and the consequences of early cementum exposure.

Since hormonal changes during the menstrual cycle may alter the vulnerability of the female gingiva, the present study was undertaken to investigate whether there are any differences in the number of toothbrushing lesions occurring during different phases of the menstrual cycle. 45 women of 20-35 years of age and with healthy gingiva were examined for overt signs of gingival laceration or ulceration. Such signs were recorded as a brushing injury. Dental plaque was assessed using the visible plaque index (VPI) and gingival inflammation using the gingival bleeding index (GBI). The examinations were made on the 1st day of menstruation (MD), on the estimated ovulation day (OD), and on the day with the predominance of progesterone secretion (PD). The examinations were made during 1-3 menstrual cycles for each individual; the study includes 78 cycles. No statistically significant differences were found between the numbers of brushing injuries on the 3 days of examination (MD, OD, & PD). During PD, a significantly positive correlation (p less than 0.01) was observed between VPI and GBI scores, but on OD and MD, the correlations were highly significant (p less than 0.001). A weak significant positive correlation (p less than 0.05) was found between GBI scores and the number of brushing injuries on the 1st day of menstruation, while during other phases of the menstrual cycle, no such correlation was found. The present study gave little evidence that the hormonal status of women could be of clinical significance in the development of soft tissue trauma from habitual toothbrushing.

In clinical practice the authors have found the 2-mm wide Periopaper slightly too large for insertion into the gingival crevice. This study investigated the reliability of Periotron readings for quantitation of gingival fluid when using filter paper strips which are narrower than the Periopaper. The round-ended strips were cut to a standard size 1 mm wide and 15 mm long using a conchotome. A microsyringe was used to deposit 0.1 microliter of four different fluids (distilled water, undiluted horse serum, diluted horse (1:2) and human (1:2) sera) onto Periopaper and the narrow S-690 strips. The moistened end of each strip was placed between the jaws of both the Periotron 600 and the Periotron 6000, and the maximum digital reading was recorded in two series of 20 measurements for each of the four fluids and two strips, giving a total of 640 assessments. A comparison between the two series confirmed the excellent reproducibility of Periotron readings. The comparison between strips revealed from 10% (Periotron 600) to 20% (Periotron 6000) lower readings for the S-690 than for the Periopaper strips for all fluids. The SD of the readings for both the S-690 and the Periopaper strip was low enough to make the difference between strips statistically significant. The slightly lower readings obtained with the narrow S-690 strip were found as reliable as those recorded when using Periopaper.

The study was carried out in order to categorize visual signs of trauma caused to gingival tissues by standardized toothbrushing. The teeth of 12 dental hygienist students were professionally brushed after 2 days of no oral hygiene measures. A modified Bass technique was used in brushing. After visual classification the brushing lesions were replicated in order to assess the corresponding changes as seen in SEM examination. The visual evaluation comprised three types of soft tissue appearance: a positive lesion, an uncertain lesion and a non-traumatized gingival unit Ninety out of the 101 lesions which were clinically classified as positively traumatic were found traumatized also in the SEM analysis. Of the 26 gingival lesions which were classified as clinically uncertain, 13 were determined traumatic in the SEM analysis. Clinical evaluation was thus found to correlate significantly to the SEM findings although discrepancies between the two classification systems were also observed.

The effect of citric acid conditioning of the root surfaces during periodontal surgery was studied in 12 patients with residual pockets ≥ 5 mm two months following oral hygiene instruction and initial root planing. Full thickness, replaced flap procedure (“modified Widman”) was performed with or without topical citric acid application using a split mouth approach. Six months post-operatively, improvement of the periodontal conditions was observed as evidenced from reduction of probing pocket depth, gain of probing attachment level and gingival recession. A mean probing attachment level gain for pooled acid treated surfaces of 2.1 mm was obtained as compared to 1.5 mm for the non-acid treated control surfaces. Our previous dog and human studies have demonstrated new connective attachment after acid conditioning of root surfaces as contrasted to readaplation of a junctional epithelium in the non-acid treated controls. However, the results of the present study indicate that from a clinical standpoint, the use of citric acid application might only provide a small improvement in probing attachment levels.

Three teeth from each of 14 adult patients with advanced periodontitis were included in this study. The Test Tooth was an incisor or canine with increased mobility associated with an occlusal interference and a ≥ 5 mm deep pathologic pocket. The Infected Control Tooth was a non-mobile incisor or canine with a ≥ 5 mm pocket. A non-mobile incisor or canine with pockets ≤3 mm served as the Healthy Control Tooth. At least 7 d prior to Day 0 the patients were taught an effective oral hygiene regimen and received a supragingival prophylaxis. At Day 0, sulcular fluid for assay of protein content and Collagenase activity was collected from each chosen pocket. Immediately thereafter the Test Teeth of 7 subjects were scaled and root planed and the Test Teeth of 7 subjects occlusally adjusted. At Day 14, the treatments were reversed for the two groups. Sulcular fluid for the assays was again collected at Days 14 and 28. The protein content and collagenase activity in deep pockets was elevated during periodontitis in both mobile and immobile teeth. After establishment of a supragingivally clean oral environment, a rapid decrease of the collagenase activity took place following scaling and root planing of the root surfaces within the periodontal pockets (p≤0.05). Also, occlusal adjustment of the hypermobile teeth with deep pathological pockets reduced the protein content and collagenase activity in sulcular fluid (p ≤ 0.02). There was a further reduction of collagenase activity when occlu-sally adjusted teeth were scaled and root planed (p≤0.02). No change in the protein content or collagenase activity was observed in the deep pockets of the untreated Control Teeth in the same patients.

Toothbrushing is generally recommended as one of the main means of preventing dental caries and periodontal problems. The present study was an attempt to evaluate the validity of such a claim. In three Finnish towns with low (0.2 part/106), optimal (1.0 part/106) and high (2.5 parts/106) fluoride content in their drinking water, about 40 schoolchildren were examined in each age group of 13, 14 and 15 years. A total of 365 children were first interviewed about their oral health habits, including frequency of toothbrushing. Their teeth were then scored for visible plaque (VPI), gingival bleeding (GBI) and past caries experience (DFS). The total mean scores for the children were VPI = 43 %, GBI = 40 %, and DFS = 14.5. Girls were found to brush more often than boys. About 50 % of the girls and only 10 % of the boys reported brushing their teeth more often than once daily. Among the girls the frequency of toothbrushing significantly increased from age 13 to 15. In all groups high frequencies of toothbrushing were associated with low VPI and GBI scores. No correlation was found between the frequency of toothbrushing and the DFS scores of the children. This lack of correlation persisted also after the total material was grouped according to sex, age, and fluoride content of drinking water. The results indicate that uncontrolled toothbrushing helps to prevent periodontal disorders but has no measureable effect on dental caries.

The objective of the study was to evaluate the benefit left from free dental care at public school after an average time interval of 7 years (mean: 7.03 years). The school dental service given to 66 Army recruits was extracted from their respective school dental care records, and then compared with the caries situation at the time of their military service. The results showed that the average number of 10.42 filled and extracted tooth surfaces at the end of school dental care had increased to a score of 36.72 DMFS 7 years later. The increase was significantly higher than expected on the basis of the average caries development between ages 7 and 15 years. Of the teeth filled during school dental care, only 26% were in no need of additional treatment, 15% had been properly retreated afterwards and the rest were either decayed (35%), retreated and redecayed (13%) or extracted (11%). Of the teeth that had been given root canal treatment at school, 27% had been extracted within the following 7 years. The caries situation was worst in the group of recruits who had had free dental care for the longest period of time. It was concluded that constant free repair of the teeth does not seem to give long term relief from the caries problem.

The aim of the present study was to determine whether the type of toothbrush grip affects gingival injury during brushing. The cleanness of the teeth achieved by use of 2 different brush grips was also evaluated. The teeth of 13 dental nurse students were brushed by a dental hygienist. Using the split mouth technique, one side of the mouth was brushed for 2 min holding the toothbrush with a pen grip and the other side for another 2 min using the palm grip. The procedure was repeated 11 days later with reversed brush grips on the 2 sides of the jaws. More gingival injuries were found when the toothbrush was held with the palm grip than with the pen grip. This difference was statistically significant (P less than 0.01). No statistically significant difference were observed between corresponding plaque scores as measured according to the PLQ-index, irrespective of whether the plaque scores were presented as plaque remaining after experimental brushing or as the difference between the PLQ scores before and after brushing.

Two degerming mouthrinses, a 1% povidone-iodine and a 0.2% aqueous solution of chlorhexidine gluconate, were tested with regard to their degerming effect on the saliva. The study comprised two parts. In the first part 19 dental students with good oral hygiene rinsed their mouths at weekly intervals with 10 ml of the povidone-iodine and 10 ml of the chlorhexidine solution. A control group of 12 students and nurses with healthy teeth and gums rinsed their mouths with 10 ml of plain water. In the second part 11 adult patients with periodontal disease used the two test rinses at weekly intervals both before and after periodontal prophylaxis including scaling of the teeth. Non-stimulated saliva was simpled immediately before and 5, 30, 60, and 120 min after each rinse. Part of the saliva was cultured on blood agar plates to show the growth of aerobic microbes. The remainder of the saliva was poured over a Dentocult dip-slide for determination of the number of acidophilic bacteria. The results showed that in the water control group the bacterial count increased in spite of the rinse. When compared with the prerinse values, both test rinses clearly reduced the amounts of bacteria. Chlorhexidine reduced the bacterial count 5 min after the rinse about one logarithm more than povidone-iodine, did, and the degerming effect of chlorhexidine was also of longer duration than that of the povidone-iodine solution. The periodontal prophylaxis in the adult group did not seem to lower the pre-rinse bacterial counts but did slightly improve the duration of the effect of both test solutions. The dip-slide tests showed that 28% of the subjects had no growth of acidophilic bacteria. This absence was not dependent on the other bacterial flora of the saliva. In the cases with a positive dip-slide test, the number of acidophilic bacteria decreased with both test solutions according to the pattern revealed by the blood agar plate cultures.

The aim of this radiographic investigation was to compare the approximal bone height adjacent to class II amalgam restorations with and without overhangs to the bone height adjacent to homologue intact tooth surfaces, and to determine the possible effect of age and sex on the relative amount of such bone resorption. The x-rays of 43 persons aged 27--45 years and 42 persons aged 46--64 years were examined. In the total material the average amount of bone loss increased with age and was 0.34 mm greater in men than in women. About 50% of all posterior tooth restorations had an overhang. A comparison between the mean heights of approximal bone adjacent to sufaces with an overhang and homologue intact surfaces showed a statistically significant difference. When equal comparisons were made separately in the younger and the older age groups, only the older group showed a similar difference at a statistically almost significant level. The effect of overhanging restorations thus seemed to be accentuated with age. When men and women were studied separately, only men showed statistically significant differences between the age groups. The investigation confirms earlier results that overhanging posterior restorations are associated with excessive marginal approximal bone loss.

The aim of this 4 times cross-over double-blind clinical trial was to test the plaque-inhibiting effect of 2 fluoride-containing toothpastes. One toothpaste contained 0.8% chlorhexidine together with amine fluoride (0.1% F degrees) and a suitable abrasive agent. The other contained 1.7 U/g glucose oxidase and 8.0 U/g amyloglucosidase, added to an amine fluoride (0.1% F degrees) toothpaste. 1% Hibitane dental gel was used as a positive and a conventional fluoride toothpaste (Vademecum MFP Fluor) as a negative control. 9 dental students, in a randomized sequence, applied the 4 dentifrices twice daily from Monday afternoon to Friday morning with cap splints, designed to cover the teeth and about 2 mm of gingiva. No other oral hygiene measures were allowed during the 4 test periods. On Fridays, the teeth were cleaned professionally and good oral hygiene was maintained during the week-ends. At the beginning and at the end of each test period, per student plaque thickness was recorded using the plaque index, the visible plaque index, and plaque fresh weight as parameters, and the area of plaque as related to the area of the tooth surface was recorded planimetrically and according to the PLQ index. The best plaque growth-inhibiting effect was recorded for the positive control (CHX) with the test chlorhexidine toothpaste (TX) as next best. The enzyme-containing toothpaste (TE) did not differ significantly from the negative control (C). All the significant differences in anti-plaque effect between the 4 toothpastes were obtained by recordings of plaque thickness and none on the basis of area of plaque.

In our previous report we found that the dental health of Finnish 13-15-yr-old children had significantly improved from 1973 to 1982. The aim of this study was to assess whether the improved dental health was associated with frequency of toothbrushing and associated use of fluoride dentifrice. In both 1973 and 1982 some 360 children were scored for the DFS index. In each of three towns with 0.2 ppm, 1.0 ppm, and 2.5 ppm fluoride in the drinking water, samples of about 40 children were randomly picked from each age cohort of 13, 14, and 15 yr. The children were grouped into "infrequent", "daily", or "frequent" brushers. Overall, from 1973 to 1982 the proportion of "daily" and "frequent" brushers had increased from 56% to 75% (P less than 0.001). The overall DFST (T = total) and DFSA (A = approximal) scores had declined significantly in all brushing frequency groups. Looking at separate fluoride areas, the actual decline was found to have occurred in the low fluoride area where in 1982 the DFS scores were 50% or less of the 1973 scores (P less than 0.05). In the low fluoride area in 1973, no association was found between brushing frequency and DFS scores whereas in 1982, high brushing frequency was found to be associated with low DFS scores (P less than 0.05). The decrease in DFS scores was suggested at least partly to be associated with the increased frequency of brushing the teeth with fluoride dentifrice.

The purpose of this investigation was to assess the value of sulcular fluid flow (SFF) measurements in evaluation of the healing of deep periodontal pockets after scaling and root planing. Fourteen adult patients with advanced periodontal disease received supragingival prophylaxis and instructions in oral hygiene. Immediately after baseline examination, meticulous scaling and root planing were performed. One to five selected pockets per patient were monitored on Days 0, 30, 120 and 210. Subgingival microbial proportions, sulcular fluid flow, probing depth, Gingival Index and bleeding after probing were assessed and recorded. The subgingival microbial proportions were determined with darkfield microscopy. The periodontal conditions were markedly improved by Day 210 as depicted by the microbial proportions. The proportion of motile micro-organisms was reduced from 51% at baseline to 9% on Day 30. This result was sustained until Day 210. Healing was also evident from the changes in Gingival Index scores and bleeding after probing. Probing depth was reduced from a mean of 8.3 to 4.5 mm. Correlations between the individual means recorded for the clinical parameters and bacterial proportions were calculated for the pooled data of all four examinations. Sulcular fluid flow did not correlate with the clinical parameters. Gingival Index, bleeding after probing or probing depth. The latter three parameters correlated significantly with the microbial proportions and each other. When the pooled tooth surface recordings of Days 30, 120 and 210 were divided into two groups according to the proportion of motile bacteria (the groups with less than 18% of spirochetes and motile rods and the groups with greater than 18% of spirochetes and motile rods), a significant difference in the mean amount of sulcular fluid flow (P less than 0.01) and mean probing depth (P less than 0.001) could be demonstrated between the two groups.

In 1970 an interview study was conducted which revealed that 23% of the adult population of Finland was edentulous. The sample comprised 1000 Finns aged 15 year's and over and was rendered representative of the entire population by means of stratified random sampling. All interviews were performed by the commercial poll Organization Suomen Gallup. In 1980 the same questions were presented to a new representative sample of of equal size. A comparison of the results revealed that the frequency of edentulousness in the total population was exactly the same as in 1970. A decrease had occurred in age groups up to 49 years whereas in the oldest age group of over 64 years the frequency of edentulousness had further increased from 54 % in 1970 to 67 % in 1980. Insufficient periodontal treatment was suggested as one of the main reasons for frequency loss of teeth at advanced age. The comparison further revealed that edentulous subjects more often used removable dentures in 1980 than in 1970. It would seem that having neither natural nor artificial teeth has become socially less acceptable. The frequency of removable partial dentures had decreased.

During a clinical trial for evaluating the antiplaque effect of two flavoured chlorhexidine rinses, the observation was made that bleeding after gentle massage of the gingival margin occurred more often after chemical than after mechanical oral hygiene measures. In order to ascertain the validity of this unexpected observation, the same dental students participated in a repetition of the trial 18 months later. The results of the two trials indicate that gingival bleeding after gentle massage of the margin with the side of a periodontal probe actually occurs more frequently after rinsing twice daily with a 0.2% aqueous chlorhexidine solution for 1 week than after meticulous mechanical oral hygiene measures during an equally long time period. The average frequency of bleeding, in per cent of all examined gingival units, ranged from 1.3% after mechanical cleaning of the teeth to 5.4% after rinsing with chlorhexidine for 1 week. Neither the frequency of bleeding nor the difference between mechanical and chemical plaque control were considered to be of clinical significance. Further microbiological and histological studies are being conducted in an attempt to clarify the reason for the observed bleeding tendency.

A clinical trial was designed to test the relative numbers of gingival lesions caused during standardized brushing of the teeth of 22 volunteer dental nurse students with a manual soft multitufted, a manual soft V-shaped, and an electric toothbrush. First, the left or the right side of the jaws of each subject was brushed by a dental hygienist using the manual V-shaped or the electric brush, and the other side using the manual multitufted brush. At the 2nd brushing 1 week later, the same hygienist used the multitufted brush for brushing the side contralateral to the one in which it was used the 1st week and the V-shaped manual brush instead of the electric and vice versa. After each brushing, the number of new gingival lesions was recorded and the cleansing effect evaluated by assessment of the amount of remaining plaque. This examiner was unaware of the type of brush used. The V-shaped manual toothbrush was found to have caused more gingival abrasion than the electric toothbrush (P less than 0.005) and a similar difference was found between the multitufted manual and the electric toothbrush (P less than 0.05). There was no clinically significant difference between the plaque removing effects of the 3 brushes tested.

The purpose of the study was to assess the anti-plaque effect of chlorhexidine (CHX) in chewing gum. The 0.80 g pieces of test gum contained 5 mg chlorhexidine acetate with or without a hydrogen peroxide releasing agent. The gum base with flavouring agents but containing neither CHX nor H2O2 was used as a control. 12 dental hygiene students volunteered to participate in the 3x crossed-over double blind clinical trial. During the 4-day test periods, no other oral hygiene measures were allowed than chewing 2 pieces of gum at the time for approximately 10 min. 5 times daily. Between test periods, meticulous mechanical oral hygiene measures were practised for 3 days. At the beginning and at the end of each test period, the quantity of plaque was assessed using the plaque index, plaque wet weight, and the area of plaque on the tooth surface as criteria. The results indicated that both CHX gums completely inhibited the increase in plaque index and plaque weight. With regard to area of plaque, the difference between the 2 test gums and the control gum was less marked but still present. The test persons subjectively assessed the gum base to have a poor cleansing effect hut also the least unpleasant taste. It was concluded that use of both the chlorhexidine gum and the gum-containing chlorhexidine in addition to the hydrogen peroxide releasing agent had an excellent plaque growth inhibiting, effect during the 4-day lest periods.