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Relative effectiveness of powered and manual toothbrushes in elderly patients with implant-supported mandibular overdentures.

AIM: The aim of this study was to compare the clinical effectiveness of a powered toothbrush (Braun Oral-B Plaque Remover 3-D) and a manual soft toothbrush (Oral-B Squish-grip brush) for the control of supragingival plaque and soft tissue inflammation around implants supporting mandibular overdentures. MATERIAL AND METHODS: The study sample involved 40 edentulous subjects, aged 55-80 years, having 2 unsplinted mandibular implants supporting a complete removable overdenture opposed by a maxillary complete denture. In this single-blinded, randomised, cross-over clinical trial, two 6-week experimental phases were separated by a 2-week wash-out period. 2 weeks prior to each experimental phase (pre-entry visits), implant abutments were polished to remove all plaque and a standardised instruction in the use of the toothbrush was given. Modified plaque and bleeding indices were recorded at the start and end of each experimental period. Mean index scores at each phase were analysed using paired t-test, and the mean number of sites showing a change in plaque or mucositis were compared using the Mann-Whitney U-test. Combined data from 2 different implant systems were considered after controlling for implant type. RESULTS: Only minor changes in plaque and bleeding scores were observed following the two test periods. There were no statistically significant differences between the manual and powered toothbrushes. CONCLUSION: Manual and powered brushes were found to be of comparable efficacy with regard to improvement in peri-implant bleeding and plaque indices.

Aged↗

Longitudinal association between plaque and gingival bleeding in smokers and non-smokers.

BACKGROUND/AIMS: Whereas accumulation of dentogingival plaque inevitably leads to inflammatory reactions in the adjacent gingival tissue, there is limited information with regard to factors influencing naturally occurring fluctuation between gingival health and disease. The major aims of the present study were to investigate site-specific associations between plaque and gingivitis as well as transition dynamics of naturally occurring gingivitis in smoking and non-smoking young adults. METHODS: 65 systemically healthy young adults, 19 to 30 years old, participated. 33 volunteers smoked at least 20 cigarettes per day, whereas 32 subjects were non-smokers. Clinical periodontal conditions were assessed four times within a time period of 6 months. An ecological approach in data analysis as well as site-specific analyses considering the correlated structure of data were performed. RESULTS: At the outset and after 6 months, smokers had significantly more supragingival plaque than non-smokers. At the final examination, bleeding upon probing as well as calculus were more prevalent in smokers. A site-by-site analysis revealed that smokers tended to have a weaker association between supragingival plaque and bleeding on probing than non-smokers (median Mantel-Haenszel's common odds ratio 1.91 vs. 2.89, p=0.07). Multiple logistic regression analyses adjusted for periodontal probing depth, plaque and calculus identified smoking status to significantly increase the risk for the first transition of non-bleeding to bleeding upon probing by 86% (p<0.01). In contrast, recovery of bleeding sites was positively influenced by female gender, but not smoking. CONCLUSIONS: In multivariate analyses adjusted for probing depth, plaque and calculus, smokers appeared to be at higher risk for the transition from non-bleeding to bleeding on probing. Weaker associations between plaque and naturally occurring gingivitis in smokers may have important consequences for preventive strategies for gingivitis.

Adult↗

Effect of an amine-fluoride-triclosan mouthrinse on plaque regrowth and biofilm vitality.

BACKGROUND: The purpose of this double-blind, prospective, latin-square crossover randomised study was to examine the efficacy of a mouthrinse solution containing a combination of triclosan, amine fluoride and sodium fluoride on supragingival plaque regrowth compared to a placebo and a chlorhexidine solution. METHODS: 12 volunteers refrained after professional oral prophylaxis from all mechanical hygiene measures for the following 96 h and rinsed instead cross-over in a randomised order with either chlorhexidine digluconate (0.2%, positive control), a verum solution (0.5% amine fluoride, 0.028% sodium fluoride, 0.03% triclosan) or a placebo solution. The plaque index was assessed after 24 and 96 h (PI 1, PI 2) and the plaque area (PA) photographed and calculated after 96 h of undisturbed plaque regrowth. Moreover plaque samples were taken after 24 and 96 h and examined with the vital fluorescence technique to assess the vitality of the biofilm microbiota (VF 1, VF 2). RESULTS: The amine-fluoride-triclosan solution reduced the clinical parameters (PI and PA) as well as the vitality of the plaque flora (VF) significantly when compared to the placebo solution. The verum reached a 36.5% (p<0.05) and a 39.8% reduction (p<0.0001) in PI 1 and PI 2, respectively, concomittant with a reduction of 23.8% and 32.2% (p<0.001) in VF 1 and VF 2 and of 46.9% (p<0.0001) in PA at day 4. This was less than the reductions found with the positive control, i.e., the 0.2% chlorhexidine solution (54.2% and 71.1% reduction in PI 1 and PI 2, 40.0% and 53.4% in VF 1 and VF 2 and 71.5% in PA). However, significant differences between both active solutions were only established for PI 2 and PA. CONCLUSION: During 4-day plaque regrowth the amine-fluoride-triclosan product displayed a significant antibacterial and plaque-reducing action in comparison to the control.

Adolescent↗

Salivary microbiota levels in relation to periodontal status, experience of caries and miswak use in Sudanese adults.

OBJECTIVES: The purpose of the present investigation was to assess the salivary levels of 25 oral bacteria in relation to periodontal status and experience of caries, and to compare the levels of these bacteria between habitual miswak and toothbrush users in adult Sudanese subjects. MATERIAL AND METHODS: The study subjects consisted of 56 individuals with age range 19-53 years (mean 35.2 years) and included 30 miswak and 26 toothbrush users. The periodontal status and presence of dental caries were assessed clinically. Whole saliva was collected from all subjects, and the levels of 25 selected bacterial species in saliva were assessed by the checkerboard DNA-DNA hybridization method using whole genomic DNA probes. RESULTS: A high percentage of the subjects had detectable levels (> or = 105 bacterial cells) of several bacterial species in saliva. Between 12% and 16% of the subjects showed high (> or = 106 cells) salivary levels of the periodontitis-associated bacteria A. actinomycetemcomitans, P. melaninogenica, P. intermedia, C. rectus and E. corrodens, whereas only two (3.6%) and four (7.1%) subjects had high levels of P. gingivalis and F. nucleatum, respectively. There were no significant differences in the levels of all or most bacterial species by age group, gender or periodontal status. Presence of > or = 105 L. acidophilus bacterial cells in saliva was associated with high caries scores (p = 0.02). There were significantly higher levels of A. actinomycetemcomitans, P. melaninogenica, C. rectus, P. micros, V. parvula, S. mutans, S. anginosus, A. israelii, C. sputigena, and C. gingivalis, and significantly lower levels of P. intermedia, F. nucleatum, S. sputigena, E. corrodens, L. acidophilus, S. sanguis, S. salivarius, S. oralis, and S. mitis in the miswak than in the toothbrush group. CONCLUSIONS: : The findings suggest that miswak may have a selective inhibitory effect on the level of certain bacteria in saliva, particularly several oral streptococci species. This is the first report that the checkerboard DNA-DNA hybridization method can be useful for assessing the levels of a wide range of bacterial taxa in saliva.

Adult↗

Clinical efficacy of a new sonic/ultrasonic toothbrush.

OBJECTIVES: The purpose of this clinical study was to evaluate the efficacy of the Ultra Sonex Ultima(R) in comparison with a conventional manual toothbrush. MATERIAL AND METHODS: In all, 64 healthy volunteers (32 females, 32 males) took part in the parallel-design treatment-blind study. After a screening examination and stratification by age, sex and papillary bleeding index (PBI), the participants were randomly assigned to two groups with 32 subjects each. Four weeks later, the Turesky modification of the Quigley-Hein plaque index (PI), the approximal plaque index (API), and the PBI were recorded at baseline. Four and 8 weeks after baseline, the indices were recorded again. RESULTS: During the study period of 8 weeks, the API showed no difference between the manual and the electric toothbrush. For the median PI, a statistically significant difference (p < 0.001) was found after 4 (manual: 2.16 vs. electric: 1.34) and 8 weeks (1.96 vs. 0.92). After 4 weeks, the median PBI was 0.75 for the manual and 0.43 for the electric brush (p < 0.01). The values after 8 weeks were 0.63 (manual) and 0.29 (electric, p < 0.001). CONCLUSION: The Ultra Sonex Ultima may be more efficacious than manual toothbrushes in removing plaque and preventing gingivitis in patients without severe periodontal disease.

Adolescent↗

Relationship of changes in interleukin-8 levels and granulocyte elastase activity in gingival crevicular fluid to subgingival periodontopathogens following non-surgical periodontal therapy in subjects with chronic periodontitis.

OBJECTIVES: To determine the effect of scaling and root planing (SRP) on the interrelations of subgingival periodontopathogens and both interleukin-8 (IL-8) and granulocyte elastase activity in gingival crevicular fluid (GCF), and to assess their relations to the short-term treatment response in management of chronic periodontitis. MATERIAL AND METHODS: GCF and subgingival plaque were collected from 16 subjects with untreated chronic periodontitis at baseline and 4 weeks after SRP. IL-8 levels were determined by ELISA. Granulocyte elastase activity was analyzed with a specific substrate, pGluProVal-pNA, and the maximal rate of elastase activity (MR-EA) was calculated. 5 DNA-probes were used to detect the presence of A. actinomycetemcomitans (A. a.), B. forsythus (B.f.), P. gingivalis (P.g.), P. intermedia (P.i.), and T. denticola (T.d.), with a sensitivity = 103 cells/paper point. RESULTS: IL-8 and MR-EA levels in GCF decreased significantly after SRP (p < 0.001) with a corresponding reduction of total count of the species. Of the sites with probing depth (PD) >/= 5.0 mm and co-infection by B.f., P.g., P.i. & T.d. at baseline, the sites without persistent co-infection of these species after SRP exhibited a significant reduction of IL-8 levels (p < 0.02), MR-EA levels (p < 0.02) and PD (p < 0.01). No such change was found in the sites where such a co-infection persisted. Moreover, reduction of IL-8 levels in those pocket sites was accompanied by a concomitant reduction of MR-EA (p < 0.02) and PD (p < 0.01), while no significant change in MR-EA levels and PD was noted in those pocket sites that exhibited an increase of IL-8 levels after SRP. At baseline, the former group of sites showed significantly higher IL-8 levels than the latter group of sites (p < 0.02). CONCLUSIONS: IL-8-related granulocyte elastase activity was related to the change in infection patterns of the target periodontopathogens following scaling and root planing. Varying initial IL-8 levels in GCF and a corresponding shifting change of granulocyte elastase activity in GCF may characterize the different short-term treatment responses.

Adult↗

Substantivity of toothpaste slurries and their effect on reestablishment of the dental biofilm.

OBJECTIVES: Toothpastes are good vehicles for antibacterial substances to exert a prolonged effect. This effect depends on the substantivity and ability to interfere with plaque metabolism and/or vitality. It was the purpose of this clinical, randomized 2 x 4 cell crossover study to evaluate and to compare the antibacterial effects of two toothpastes (Colgate Total(R), COL and Parodontax(R), PAR) applied as slurries on established plaque over 24 h (Part I) and their effect on 4-day plaque regrowth (Part II). Chlorhexamed(R) (0.1%; CHX) and water served as positive and negative controls. MATERIAL AND METHODS: After professional toothcleaning eight students were asked to refrain from all mechanical hygiene measures for the next 72 h. After 48 h plaque was sampled and vitality of the plaque flora examined (baseline, VF0%). The subjects then rinsed for 1 min with 15 mL of one of the test or control solutions. Every second hour up to 14 h and 24 h after rinsing, plaque sampling and staining was performed to assess plaque vitality (VF2-24, Part I). In Part II, the classical 4-day plaque regrowth design was used with two rinses (1 min) a day as the only oral hygiene measure. Vitality values were assessed on day 1 and day 4 (VF1, VF2). At day 4, teeth were stained to assess the whole mouth plaque index (PlI) and to evaluate the percentage of plaque area (PA) of the anterior teeth. RESULTS: Compared to placebo, all active rinses reduced plaque vitality significantly over a period of 24 h (Part I). PAR, COL and CHX revealed reductions of 18-31%, 28-50% and 19-50%, respectively. In Part II, similar reductions of all parameters were found for all active rinses (PAR 12-30%, COL 34-51%, CHX 40-64%). CONCLUSIONS: Colgate Total has shown a significant action on plaque regrowth and a high substantivity during 24 h, while Parodontax revealed a more moderate but still significant effect.

Adult↗

Porphyromonas gingivalis, Bacteroides forsythus and other putative periodontal pathogens in subjects with and without periodontal destruction.

BACKGROUND AND AIMS: Bacteria play an essential role in the pathogenesis of destructive periodontal disease. It has been suggested that not all bacteria associated with periodontitis may be normal inhabitants of a periodontally healthy dentition. In particular, Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans have been isolated infrequently from subjects without periodontitis. The aim of the present study was to compare prevalence and proportions of a number of periodontal bacteria in periodontitis patients and control subjects. MATERIAL AND METHODS: In all, 116 consecutive subjects diagnosed with moderate to severe periodontitis (mean age 42.4) and 94 subjects without radiographic evidence of alveolar bone loss (mean age 40.4) were recruited for the study. The gingival condition in the control group varied between gingival health and various degrees of gingivitis. In patients, the deepest pocket in each quadrant was selected for microbiological sampling. In control subjects all mesial and distal sites of all first molars were selected for sampling. All paper points from a patient were pooled and processed for anaerobic cultivation within 6 h after sampling. Clinical variables of sampled sites included bleeding index, probing pocket depth and clinical attachment level. RESULTS: A. actinomycetemcomitans, P. gingivalis, Prevotella intermedia, Bacteroides forsythus, Fusobacterium nucleatum and Peptostreptococcus micros were significantly more often prevalent in patients than in controls. The highest odds ratios were found for P. gingivalis and B. forsythus (12.3 and 10.4 resp.). Other odds ratios varied from 3.1 to 7.7 for A. actinomycetemcomitans and P. micros, respectively. Absolute numbers of target bacteria were all higher in patients, but only the mean percentage of B. forsythus was significantly higher in patients in comparison to controls (P < 0.001). CONCLUSIONS: A. actinomycetemcomitans, P. gingivalis, P. intermedia, B. forsythus, F. nucleatum and P. micros are all significant markers for destructive periodontal disease in adult subjects. Based on calculated odds ratios, B. forsythus and P. gingivalis are the strongest bacterial markers for this disease and are infrequently cultured from subjects without periodontal bone loss.

Adult↗

A clinical comparison of three powered toothbrushes.

AIM: The purpose of the present study was to compare the ability of the Braun Oral-B 3D Excel power toothbrush (BPT), the Sonicare power toothbrush (SPT) and the Philips Sensiflex 2000 (HX 2550) power toothbrush (PPT) to control plaque and reduce experimentally induced gingivitis. MATERIALS AND METHODS: Two experiments were carried out in two different groups of subjects using a split-mouth design whereby the two halves of the mandible which had been allowed to develop gingivitis were brushed over a 4-week period with the test toothbrushes. Experiment 1 compared the BPT with the SPT (n = 35) and experiment 2 compared the BPT with the PPT (n = 32). The study used a run-in period of 2 weeks, which, together with the 3-week experimental gingivitis phase, represented the pretrial phase of the experiment. The purpose of this phase was two-fold: first, to enable the subjects to become acquainted with the two power brushes and for them to receive proper oral hygiene instruction, and, second, to develop a reasonable level of gingivitis on the mandible. Those subjects with at least 40% of sites exhibiting bleeding in each quadrant in the mandible at day 21 of the experimental gingivitis phase were allowed to continue with the trial. During the next 4 weeks (treatment phase) of each experiment, subjects were told to brush according to a split-mouth design, the right and left sides of the mouth being randomly allocated to a toothbrush. During this period, no rinsing with an antiseptic mouthwash or flossing was allowed and a standard toothpaste (Zendium(R)) was used. After 1, 2 and 4 weeks, the plaque index (Quigley & Hein) and the bleeding tendency on marginal probing were assessed in the mandible. RESULTS: Experiment 1 showed that the bleeding score was reduced from 1.63 to 1.12 at 4 weeks by the BPT and from 1.65 to 1.26 by the SPT. This reduction was more rapid and greater with the BPT (P < 0.05). The plaque index was reduced from 2.19 at day 21-1.03 at 4 weeks by the BPT, and from 2.18 to 1.20 by the SPT. The difference between the two toothbrushes was not significant. Experiment 2 showed that the bleeding score was reduced from 1.77 at day 21 to 1.07 at 4 weeks by the BPT and from 1.75 to 1.24 by the PPT. This reduction was more rapid and greater with the BPT (P < 0.05). There was no significant difference in plaque index at 4 weeks (BPT, 1.09; PPT, 0.95). Data from the questionnaire at the end of the study revealed that, in both experiments, most subjects preferred the BPT. CONCLUSIONS: The data from this study show that the design and action of the Braun Oral-B 3D Excel power toothbrush are more effective in resolving gingivitis than the Sonicare & the Philips Sensiflex 2000 power toothbrushes.

Attitude to Health↗

Contribution of changing diagnostic criteria toward reduction of caries between 1971 and 1997 in children attending the same school in Florianopolis, Brazil.

AIM: To assess the relative impact of changing diagnostic criteria on changes in the prevalence and severity of caries between 1971 and 1997. MATERIAL AND METHODS: All 12- and 13-year-old children attending the same school, "Padre Anchieta Primary School", in Brazil in 1971 (n=202) and 1997 (n=175) were examined by a single dentist. The criteria for the diagnosis of caries proposed by Radike in 1968 were used in both 1971 and 1997. In 1997, a second clinical examination was conducted and the WHO criteria proposed in 1987 were used. RESULTS: Comparison of caries experience expressed as changes in the mean DMFT scores indicated a 67.7% reduction between 1971 and 1997 from 9.2 to 3.0 when Radike's criteria were used in 1971 and the WHO criteria were used in 1997. The reduction in caries was independent of the diagnostic criteria adopted in the 1997 dental examination, but the reduction of caries was smaller, from 9.2 to 6.2 (31.8%), when caries experience in 1971 and 1997 was measured using Radike's criteria. CONCLUSION: The observed reduction of caries is not a statistical artifact. However, while 47.2% of this reduction is real, 52.8% of it is a statistical artifact due to changes in the criteria for measuring caries used by epidemiologists.

Adolescent↗

Relationship between oral hygiene practices and oral status in dentate elderly people living in residential homes.

OBJECTIVES: To investigate the relationship between the oral hygiene practices of dentate elderly people living in residential homes, their requests for assistance and their oral health status. METHODS: 164 people (81.2+/-7.4 years) participated in an interview and oral examination, and provided a stimulated saliva sample. RESULTS: The mean number of coronal decayed surfaces (CDS) was 2.4+/-5.9, stimulated salivary levels (log(10)cfu/ml) of mutans streptococci, lactobacilli and yeasts were 1.6+/-2.1, 3.0+/-2.2, 2.1+/-1.7, respectively, and 53% had root decayed surfaces (RDS). Plaque (PI) and gingival (GI) Indices were 2.3+/-0.7 and 1.6+/-0.4 and denture debris scores (DDS) were high. 31% of the population cleaned their mouths twice daily without requesting help and they had significantly fewer yeasts, RDS, restorations on root surfaces, lower PI, GI (P<0.005) and DDS (P<0.0001) than the 69% who cleaned less often. 50% of those who cleaned less frequently requested assistance with oral hygiene but only 5% said that their carers supported them. Those residents who requested help had significantly higher levels of yeasts, lactobacilli (P<0.001), retained roots, DDS, RDS (P<0.005), PI and GI (P<0.0001). CONCLUSION: The elderly residents' perceived need for assistance with oral hygiene was related directly to oral hygiene status and to clinical indicators of mucosal and dental diseases.

Aged↗

Follow-up study of dental students' esthetic perceptions of mild dental fluorosis.

OBJECTIVES: Several studies have assessed people's esthetic perceptions of dental fluorosis, suggesting that concerns may be greater than believed previously. Few studies have assessed dental students' perceptions and none has done so over time. The purpose of this paper is to report on changes in dental students' esthetic perceptions of dental fluorosis and other conditions. METHODS: Fourth-year dental students (n=45) completed questionnaires about computer-generated photographs of fluorosis and other conditions, using the same protocol as when they were entering dental students. Results were compared for each of the eight images at the individual level using paired statistical tests. RESULTS: Although many patterns were generally consistent, there were a substantial number of differences in results over time, concerning both the mild fluorosis and non-fluorosis images. In general, students tended to score both fluorosis and non-fluorosis images more favorably as fourth-year students. When rating images from very pleased (1) to very embarrassed (10), fourth-year students rated the images significantly more favorably than they had done as first-year students for normal/control, incisal third only dental fluorosis, and a more generalized, mild fluorosis. Similarly, with a visual analog scale from satisfactory (0) to unsatisfactory (69), fourth-year students reported significantly lower (more favorable) scores than they had done as first-year students for the normal/control, diastema/no fluorosis, more involved mild fluorosis, and incisal third only mild fluorosis. There were no obvious changes in the relative levels of favorable evaluation of fluorosis vs. the other conditions. CONCLUSIONS: Fourth-year dental students generally had more favorable esthetic perceptions of mild dental fluorosis and other conditions than they had reported as entering students.

Adult↗

A blind caries and fluorosis prevalence study of school-children in naturally fluoridated and nonfluoridated townships of Morayshire, Scotland.

OBJECTIVES: To undertake a blind caries and fluorosis prevalence study of Grade 1 (aged 5/6 yr) and Grade 4-7 (aged 8-12 yr) children from naturally water-fluoridated (1 ppm, since 1985) Burghead, Findhorn & Kinloss (F), and nearby nonfluoridated Buckie & Portessie (N-F), in rural Morayshire, Scotland. METHODS: A blind clinical (+ 10% repeats) caries study of the above townships' 5/6-yr-old lifetime (15 F; 43 N-F), and 8-12-yr-old lifetime (55 F; 136 N-F)/school-lifetime (31 F; 37 N-F) residents was undertaken following bussing of these children to a common examination site in close-by Elgin Town Hall. Initially, each child was asked about their own perception of the aesthetics of their maxillary front teeth. Fluorosis was assessed clinically using the TF Index, as well as photographically - for later blind scoring (+ 10% repeats for lifetime 8-12-yr-olds) of slides by four dental and two lay 'jurors', alongside a now-established UK 'bench-mark' mildly mottled (TFI = 2), fluorosis comparator slide, judged in previous studies to be aesthetically lay-acceptable. In addition, by parental questionnaire, information was sought concerning their child's fluoride supplement and dentifrice usage histories. RESULTS: For 5/6-yr-olds, mean primary caries scores were 96.0% less in fluoridated than nonfluoridated subjects (P < 0.01). In 8-12-yr-olds, DMFT values favoured water-fluoridated subjects; their caries-free trend was significant (P < 0.001 overall). Clinically, 33% of all lifetime F subjects and 18% of all N-F pupils had fluorosed maxillary anterior teeth (P = 0.045), but no statistically significant difference was found between the 7% F and 3% N-F subjects with TFI scores > 2 (P = 0.25). Photographically, 'jury' mottling assessment (+ 10% repeats) of projected slides resulted in at least 1 : 6 positive scores in 43.6% of F and 30.9% of N-F pupils, albeit they unanimously scored only nine F and five N-F children as having fluorosed teeth (P < 0.01). In no case did all members score TFI > 2. Dental and lay scorers rated TFI = (1/2) in only a further 9.1% and 5.5% of F subjects, respectively, compared to 0.7% and 1.5% respectively of N-F pupils. Again, TFI > 2 was scored unanimously in no child. No differences were found regarding the children's own degree of anterior tooth aesthetic nonacceptability between F (11%) and N-F (12%) prevalence (P = 0.75). Finally, only one F child had taken F supplements and, while 26 N-F had used F drops, no significant relationship was found between their usage and TFI values in the latter group (P = 0.49). Additionally, no relationship was noted between clinical TFI scores and the age at which parents stated fluoridated dentifrice toothbrushing commenced, between 0 and 24 + months of age. CONCLUSIONS: Considerable caries benefit has accrued to those Morayshire rural children who have received naturally fluoridated water (at 1 ppm) throughout their lives, as compared to their socioeconomically similar, nonfluoridated rural counterparts. Furthermore, in spite of all but two subjects claiming to have brushed regularly with fluoridated dentifrice (and no evidence of the availability of nonfluoridated toothpaste being purchasable in the five townships), only borderline mild fluorosis disadvantages have been noted clinically, and none by the subjects' own aesthetic perceptions. Finally, no evidence was found to suggest any delay in permanent tooth eruption patterns of the F subjects. It would seem appropriate therefore, that adjustment of Scots' drinking waters' natural fluoride levels to 1 ppm should be pursued to extend similar dental advantages to the vast majority of that population (both young and old) which, it is well documented, has the worst dental health of mainland UK.

Age Factors↗

Assessment of a preclinical training system with indirect vision for dental education.

The aim of the present study is the evaluation of a pre-clinical training system using indirect vision for dental education purposes. The study population was undergraduate dental students between the ages of 18-20, at the beginning of their first dental course. From a total of 105 students, those presenting some condition that would have had influence on their manual skills and those who for some circumstance left the study after beginning it were excluded, resulting in 69 students (51 female and 18 male) taking part in the study. The study design involved two sessions separated by a 7-day interval in which the students used a reflection box to develop psychomotor skills in mirror use. In every session they performed an initial evaluation test, some training exercises and a final evaluation test. The evaluation tests and the training exercises consisted in following a curved, straight or convoluted shape in the reflection box. Four groups of students were used who trained in different ways using curved or straight lines. Evaluation of the tests was based on the number of errors made and the time to completion. All students showed an improvement in their performance of following curved and straight lines with indirect vision after this form of training. The results after the first training session were statistically significant, while the further improvement was not significant after the 2nd training session. Those students who trained first with curved lines and later with straight lines produced more errors than the other groups. Female students performed better than male students in this assessment.

Adolescent↗

Vascular endothelial growth factor (VEGF) expression in oral tissues: possible relevance to angiogenesis, tumour progression and field cancerisation.

The aim of this study was to assess whether vascular endothelial growth factor (VEGF) expression in oral tissues is associated with angiogenesis, disease progression or field cancerisation. Vascularity and VEGF immunoreactivity were quantified in 68 archival specimens including normal oral mucosa (NOM), dysplasia (DYS) and squamous cell carcinoma (SCC). Vascularity increased significantly with disease progression; it was also higher in NOM adjacent to SCC than in NOM from healthy tissue, suggesting an association with field cancerisation. VEGF expression in epithelial cells was evaluated using two antibodies and three indices. VEGF indices and vascularity were not directly correlated. The expression of VEGF was similar in all DYS and NOM specimens, whether or not adjacent to a concurrent lesion. A comparison of SCC with NOM or DYS led to opposite results, depending on the VEGF antibody and index used. We conclude that VEGF expression in the oral mucosa may play a physiological role, but does not appear to be associated with angiogenesis, field cancerisation or transition to dysplasia. Further studies concerned with tumour development require examining specific VEGF isoforms and standardisation of the methodology.

Antibodies↗

Oral lichen planus: immunohistology of mucosal lesions.

BACKGROUND: Current evidence suggests that immunological mechanisms are involved in oral lichen planus (OLP) pathogenesis. The events implicate activated epithelia that comprise antigen-presenting Langerhans cells, immunocompetent keratinocytes and subepithelial inflammatory infiltrate. Also, the presence of a high density of leucocyte cells may occur for the expression of a variety of adhesion molecules. The aim of this study was to analyse the immunoexpression of some adhesion molecules as well as lymphocytic markers in order to determine the disease pathogenesis in a Venezuelan population. METHODS: The 18 OLP and 10 normal oral mucosa biopsies were immunostained for CD4, CD8, CD1a, LFA-1, VCAM-1 and ICAM-1. RESULTS: The results showed an increased number of CD4+, CD8+, CD1a+ cells in OLP. Serial sections showed CD4+ and CD8+ cells also expressed LFA-1. The expression of ICAM-1 and VCAM-1 were significantly higher in OLP. CONCLUSIONS: The immunological reaction begins with Langerhans cells activation, which presents an antigen to CD4+ lymphocytes. Those cells through ICAM-1 and LFA-1 promote epithelial destruction. Afterwards, cytokine production, ICAM-1 and VCAM-1 expression can activate CD8+ lymphocytes leading to the chronic form of the disease.

Antigens, CD1↗

Expression of type 2 nitric oxide synthase and p53 in Warthin's tumour of the parotid.

Although the pathogenesis of Warthin's tumour is not fully understood, it is generally thought that the tumour arises from heterotopic salivary ducts within pre-existing lymphoid tissue. Prolonged nitric oxide (NO) production by the enzyme type 2 nitric oxide synthase (NOS2) has been implicated in the pathogenesis of many solid tumours, but not in Warthin's tumour. Since NO and NOS2 are known to be associated with p53, the immunohistochemical expression of both NOS2 and p53 was investigated in 23 cases of Warthin's tumour. Widespread diffuse cytoplasmic immunostaining for NOS2 was found in tumour epithelial cells of all 23 cases studied, and it was additionally expressed in normal salivary duct epithelium. p53 staining was localised to the nuclei of tumour epithelium in 16 cases, with a similar pattern of distribution to tumour NOS2 expression. A significant correlation was found between NOS2 and p53 staining in the tumours (P < 0.001). In contrast to NOS2, p53 was not expressed by normal salivary ductal cells in any of the cases studied. NOS2 is widely expressed by the tumour epithelium of Warthin's, and its association with p53 expression is discussed. The role of NO in the pathogenesis of Warthin's tumour remains to be established.

Adenolymphoma↗

Infrequent genetic alterations of the tumor suppressor gene PTEN/MMAC1 in squamous cell carcinoma of the oral cavity.

BACKGROUND: Fifty tumor specimens from primarily untreated patients were analyzed to elucidate the involvement of the tumor suppressor gene PTEN/MMAC1 in the development of oral squamous cell cancer. METHODS: Eight microsatellite markers, spanning 10 cM of genomic DNA located centromeric, telomeric or intragenic of PTEN/MMAC1 were used for loss of heterozygosity (LOH) and breakpoint analysis. The microsatellite panel within or in close proximity (1 cM) to the 10q23.3 locus showed a LOH rate of 12%. Complete sequence analysis of the genes coding region was performed in all 10 cases that exhibited LOH in one of the eight microsatellite markers within or around the PTEN/MMAC1 gene. Comparative multiplex PCR reactions served to screen for homozygous deletions. RESULTS: There was no association between allelic loss of the gene, overall patient survival and recurrence-free survival. Sequencing did not reveal any mutation in the coding region of PTEN/MMAC1. Differential PCR analysis failed to detect any homozygous deletion. CONCLUSIONS: We conclude that PTEN/MMAC1 gene alterations do not play a key role in tumorigenesis of oral squamous cell cancers.

Adult↗