Relationship between enamel bond fatigue durability and surface free‐energy characteristics with universal adhesives

The relationship between enamel bond fatigue durability and surface free‐energy characteristics with universal adhesives was investigated. The initial shear bond strengths and shear fatigue strengths of five universal adhesives to enamel were determined with and without phosphoric acid pre‐etching. The surface free‐energy characteristics of adhesive‐treated enamel with and without pre‐etching were also determined. The initial shear bond strength and shear fatigue strength of universal adhesive to pre‐etched enamel were higher than those to ground enamel. The initial shear bond strength and shear fatigue strength of universal adhesive to pre‐etched enamel were material dependent, unlike those to ground enamel. The surface free‐energy of the solid (γ_S) and the hydrogen‐bonding force () of universal adhesive‐treated enamel were different depending on the adhesive, regardless of the presence or absence of pre‐etching. The bond fatigue durability of universal adhesives was higher to pre‐etched enamel than to ground enamel. In addition, the bond fatigue durability to pre‐etched enamel was material dependent, unlike that to ground enamel. The surface free‐energy characteristics of universal adhesive‐treated enamel were influenced by the adhesive type, regardless of the presence or absence of pre‐etching. The surface free‐energy characteristics of universal adhesive‐treated enamel were related to the results of the bond fatigue durability.     

Chewing ability of subjects with shortened dental arches

Abstract – Objectives: The objective was to study chewing ability in subjects with shortened dental arches in Tanzania. Methods: A sample of 725 adults with shortened dental arches comprising intact anterior regions and 0–8 occluding pairs of posterior teeth and 125 adults with complete dental arches were recruited. Subjects were classified into nine categories according to arch length and symmetry. Chewing ability was investigated by interview on chewing complaints and on perceived difficulty of chewing 20 common Tanzanian foods, 12 soft, and 8 hard. Results: Categories with extreme shortened arches (0–2 pairs of occluding premolars) reported most frequent (95–98%) and most severe complaints (‘cannot chew all foods’ or ‘have to use special or specially prepared food’). Categories with intact premolar regions and at least one occluding pair of molars had nearly no complaints (95–97%). The other arch categories had an intermediate volume of complaints (33–54%). Perceived difficulty of chewing deteriorated with a decrease of occluding pairs of teeth. Subjects with 0–2 pairs of occluding premolars had major difficulties with chewing. Subjects with 3–4 pairs of occluding premolars or asymmetric arches comprising a short side with none or one pair of premolars and a long side including at least one occluding pair of molars had more difficulties with chewing compared to subjects with more complete dental arches. As a whole, they perceived for hard foods, ‘minor problems, not adapted’. Conclusions: Shortened dental arches with intact premolar regions and at least one occluding pair of molars provide sufficient chewing ability. Shortened arches with 3–4 pairs of occluding premolars and asymmetric arches with a long side result in impairment of chewing ability, especially for hard foods. In extremely shortened arches comprising 0–2 occluding premolars, chewing ability is severely impaired.     

Reproducibility and overlapping of bitewing radiographs: comparison of Eggen-bite with Kwik-bite

In the present study the reproducibility of horizontal dimensions and of overlappings of two filmholder techniques with aiming devices (Eggen-bite and Kwik-bite) and additionally the number of overlappings on the resulting bitewing radiographs were compared. The overlapping reproducibility was significantly higher with Kwik-bite. The microdensitometric reproducibility demonstrated the same tendency, but the result was not significant. Bitewings carried out by an oral radiologist demonstrated fewer overlappings with Eggen-bite than with Kwik-bite, while bitewings carried out by inexperienced students revealed no difference between the methods. Both reproducibility and number of overlappings should be taken into consideration when bitewing filmholder techniques are used in epidemiological and longitudinal studies.     

Pulpal responses to "composite" dental materials lined with Tubulitec® or Dropsin®

abstract — Previous studies have shown that neither Tubulitec® nor Dropsin® produced serious changes in the dental pulp when used as liners under amalgam restorations. In the present investigation, based on 136 monkey teeth, the composite materials Addent Concise® and Adaptic® were shown to induce harmful inflammatory reactions in about one third of the teeth. Tubulitec reduced this irritative response significantly but not totally. The protective effect demonstrated from a Dropsin lining was inferior to that provided by Tubulitec.     

Effects of dental health education for mothers with young children in London

Dental health education for mothers with young children is thought to be capable of achieving a high standard of dental health for these children. This study considers the dental health of a sample of 5-yr-old children whose mothers were given dental health education at an early stage in their child's life. The dental health education was given to one group during home visits and to a second through leaflets sent by post. Comparisons were made with a third group of children whose mothers had been randomly selected to form a control group. Sixty-nine percent of children whose mothers were given advice at home were caries free, compared to 58% of children in the control group. Scores for gingivitis were also significantly lower in the first group. No significant differences in disease levels were seen between children whose mothers had been sent leaflets through the post and those in the control group. In relation to the use of fluoride supplements, 25% of the children whose mothers had been given personal advice received fluoride supplements regularly throughout the period of the study. Children of these highly motivated mothers showed less caries (83% were caries free) and lower levels of gingivitis than children who had never received supplements.     

Dental treatment need and dental general anesthetics among preschool‐age children with cleft lip and palate in northern Finland

Cleft lip and palate incidence is high in northern Finland. This study aimed to investigate the proportion of children in need of restorative dental treatment among cleft lip and palate patients in northern Finland, as well as their need for dental treatment under general anesthesia. The records of 183 cleft lip and palate patients, treated in Oulu University Hospital from 1997 to 2013, were reviewed. Data on dental caries were analyzed in association with cleft type, considering also the presence of syndromes. The frequency of dental general anesthetic (DGA) use, and of treatments, were also analyzed. Dental treatment need was most frequently observed, in this rather limited study population, in patients with the most severe deformities, namely bilateral cleft lip and palate, of whom 60% had caries. Among the study population, 11.5% (n = 21) had a syndrome. Of those, 57.1% had dental caries at the age of 3 or 6 yr, and only four could be treated without a DGA. Dental treatment under general anesthesia was performed in 14.8% of cleft patients without a syndrome, but in 38.1% of those with a syndrome. General anaesthesia is required for the provision of dental care more often in cleft (17.5%) than in non‐cleft (0.2%) patients, and especially for those with a syndrome.     

Sulfated glycoproteins in the acquired pellicle and in plaque from Macaca fascicularis demonstrated with labeled sulfate

abstract – A sulfated glycoprotein was demonstrated in 2-h pellicle material collected from monkeys. Furthermore, a sulfated macromolecule present in plaque extracts was identified as a sulfate glycoprotein by electrophoresis on cellulose acetate strips. The present data indicate that acidic proteins are selectively adsorbed to tooth surfaces in. vivo .     

Demand for and utilization of dental services among Hong Kong employees with and without dental benefit coverage

Abstract The objectives of the present study were to investigate the effects of employer-provided dental benefits on the pattern of demand for and utilization of denial services among Hong Kong employees and to analyse whether employees' awareness about an existing denial benefit programme influenced their denial service demand and utilization. Staff from 11 selected companies with and without dental benefits responded to questionnaires concerning their personal factors, demand for dental services, and utilization of denial services and about their awareness of their dental benefit coverage. Overall response rate was 67%. The socio-demographic characteristics of those respondents who were covered and those who were not were similar. Forty per cent of the covered respondents were not aware of their dental benefit coverage, so analysis was performed with three groups of respondents, covered and aware, covered and unaware, and uncovered. A larger proportion of employees in the “aware” group had visited a dentist in the previous 12 months and had visited a dentist for asymptomatic reasons. The “aware” group reported more “low expenditure” items and less “high expenditure” items. Those who were aware of their dental benefit coverage irrespective of the type of scheme reported a significantly higher demand than those who were not aware of their coverage. Demand and utilization of the covered, but unaware, group was more similar to the uncovered group than lo the “aware” group. Coverage per se had no apparent effect on the demand for dental services. Further studies will be necessary lo establish that higher dental care demand and utilization induced by third party schemes also leads to improved oral health.     

Oral health in children and adolescents with myotonic dystrophy

Myotonic dystrophy or dystrophia myotonica (DM) is a hereditary neuromuscular multisystem disease with a varying clinical expressivity and severity. The objective of this study was to assess the oral health in children with myotonic dystrophy and to compare it with a control group. Fifty-six DM patients, aged 2.7-18.0 yr, were compared with age- and gender-matched control patients with respect to caries, plaque, and gingivitis. Oral function and signs of temporomandibular dysfunction (TMD) were assessed, and the ability to co-operate in dental treatment was estimated. Questionnaires concerning eating habits, dental care, traumatic injuries to teeth, and orofacial function were also used. The DM patients had significantly more caries, plaque, and gingivitis than did control patients. They had more TMD problems and lower co-operation ability than the healthy control persons. General sedation was frequently needed to carry through dental treatment. DM patients are at risk of caries, gingivitis and TMD problems, and need intensified prophylactic care. Behavior management problems are common.     

Effect of oral hygiene education on children with and without subsequent orthodontic treatment

Abstract – The aim of the present investigation was to study whether an intense period of individual oral hygiene education would result in proper dental health behavior and to compare the effects of such education on 30 individuals undergoing subsequent orthodontic treatment and 30 controls without such treatment. The investigation consisted of two experimental periods: one period of oral hygiene education during which information on proper plaque control was given fortnightly for 6 weeks and one follow-up period of 30 months corresponding to the orthodontic treatment phase. The results suggest that it is possible to achieve and maintain a high standard of dental health behavior following an intense period of individual oral hygiene education. A certain deterioration of the gingival status was observed after 3 months in the orthodontically treated children. This was interpreted as being due to the influence of subgingivally located orthodontic bands. After 30 months a high level of oral hygiene and gingival status as well as a low caries activity were still apparent with only minor and insignificant differences between the children subject to orthodontic treatment and the controls.     

Protective effect of Copalite surface coating on mercury release from dental amalgam following treatment with carbamide peroxide

Abstract – The effect of Copalite coating on mercury release from dental amalgam following treatment with 10%, 20%, 30% and 40% carbamide peroxide was assessed in vitro, using a cold‐vapour atomic absorption Mercury Analyzer System. Eighty samples of dental amalgam were automatically mixed in a dental amalgamator and condensed into silicon embedding molds. Forty amalgam samples were coated with three uniform layers of Copalite intermediary varnish and the other 40 samples were left uncoated. The coated and non‐coated amalgam samples were exposed for 24 h to 10%, 20%, 30% or 40% carbamide peroxide preparations and compared with samples exposed to phosphate buffer. In the non‐coated samples a significant increase of mercury concentration in solution was found following exposure to all carbamide peroxide preparations tested. Mercury concentration was directly related to carbamide peroxide concentration. In the Copalite‐coated samples, significantly lower concentrations of mercury in solution were found as compared to the non‐coated samples (P<0.01). In conclusion, exposure of amalgam restorations to 10%–40% carbamide peroxide‐based bleaching agents increased the mercury release. Pre‐coating of the external amalgam surfaces with Copalite significantly reduced the release of mercury.     

Strength of bond with Comspan Opaque to three silicoated alloys and titanium

Abstract – In Sweden high-gold alloys or cobalt-chromium alloys are used for resin-bonded prostheses. The bond strength between a resin cement and different sandblasted or silicoated metals were measured before and after thermocycling; in connection with this some rapid thermocycling methods were studied. The effect of different storage times and different protection coatings on bond strength were tested. Finally, the influence of rubbing and contamination with saliva on bond strength were investigated. Silicoating increased the bond strength significantly. The highest bond strengths were these of silicoated Wirobond and titanium, unsusceptible to thermal stress; the bond strengths of the sandblasted metals were the weakest, and sensitive to thermocycling as well. The influence on bond strength for silicoated gold alloys, protected with an unpolymerized composite resin coating, stored in sealed plastic bags up lo 7 days, was negligible. Rubbing and contamination with saliva did not influence bond strength. Preferably, silicoated Wirobond and titanium should be used for resin-bonded prostheses, but gold alloys may still be adequate for clinical use. The experimental method described for storing, sealing, and cleaning the silicoated metal surfaces in this article can be recommended for laboratory and clinical use.     

Oral health-related quality of life in patients with dental anxiety

OBJECTIVES: To investigate the frequency of impaired oral health-related quality of life (OHRQoL) in patients with dental anxiety. METHODS: OHRQoL was measured with the German version of the 14-item Oral Health Impact Profile (OHIP) developed by Slade and Spencer (1994) in 173 adult patients with dental anxiety [Dental Anxiety Scale (DAS) score 15 or above and Dental Fear Survey (DFS) score 60 or above]. The OHIP summary scores were characterized with an empirical cumulative distribution function and compared with the level of impaired OHRQoL in the general population (n = 2026, age: 16-79 years). In addition, OHIP item prevalences (responses 'fairly often'/'very often') were compared between patients and population subjects. The correlation between DAS, DFS and OHIP scores was calculated using the Pearson correlation coefficient. RESULTS: A median value of 1 and a 90th percentile value of 13 were observed for general population subjects. In contrast, patients with phobic dental anxiety had a median OHIP-14 of 21 and the 90th percentile of 40. All problems mentioned in the OHIP-14 were more prevalent in patients than in population subjects. The most frequently occurring items in patients were 'self-conscious', 'life in general was less satisfying', and 'feeling tense' with prevalences of 50% or greater. In contrast, these items had prevalences of only 1-3% in the general population. A low to moderate relationship between OHRQoL and both dental anxiety measures (DAS and DFS) was observed (r = 0.25/0.26, P < 0.01). CONCLUSIONS: Patients with dental anxiety/fear suffer considerably from impaired OHRQoL and the degree of this impairment is related to the extent of dental anxiety/fear.     

Dental fear, regularity of dental attendance and subjective evaluation of dental erosion in women with eating disorders

This questionnaire study, with a response rate of 53%, examined self-induced vomiting, erosions and dental attendance in women with eating disorders (EDs) as well as dental fear and its effect on attendance and communication with the dentist. A survey of 371 responding women with EDs, who were recruited from a self-help organization, revealed that dental fear was higher in women with EDs compared to the general population. Dental fear was present in 32.1% of women with EDs, and very high dental fear was present in 16.5% of women with EDs. Of those with very high dental fear, 32.3% had not visited a dental clinic at all in the preceding 2 yr, and 43.5% only initiated contact when they had symptoms. Self-induced vomiting was especially frequent in women with bulimia nervosa (87.9%) and in those with more than one ED (the 'mixed group') (80.6%). Among those with self-induced vomiting, 45.3% thought that they had erosions, although only 28.4% had erosions diagnosed by a dentist. Of women with EDs, 61.4% failed to disclose their condition. High dental fear did not affect willingness to disclose the ED. We conclude that dentists should examine ED patients carefully for dental erosions. Moreover, they should realize that most ED patients avoid disclosing their disorder and that dental fear further complicates dental treatment in these patients.     

Diagnosing dental caries in populations with different levels of dental fluorosis

The aim of this study was to assess the reliability of the Nyvad visual–tactile caries-diagnostic criteria when used among children who have been lifelong residents in areas with 'optimal' or low concentrations of fluoride in the drinking water. In each of two areas with drinking water fluoride concentrations of 0.3 and 1.1 ppm (0.3 and 1.1 mg/l) fluoride, respectively, 150 children were clinically examined twice, 2 wk apart, for dental fluorosis, using the Thylstrup-Fejerskov index (TF index), and for dental caries using the Nyvad visual–tactile caries criteria. The prevalence of dental fluorosis was 45% in the 1.1 ppm fluoride area and 21% in the 0.3 ppm fluoride area. When the results of the duplicate caries recordings were compared at the surface level, only minute differences were observed in the percentage agreement (91.7 and 90.7%, respectively) and in the kappa values (0.73 and 0.72, respectively). When individual DFS counts were compared across examinations using Bland–Altman plots and estimation of prediction intervals for the differences, we observed a greater variability of the differences between recordings among children from the low-fluoride area. Contrary to our expectations, a pronounced dental fluorosis background did not reduce the reliability of the caries recordings, which appeared to be slightly less reliable at very low levels of dental fluorosis.