Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 37
Filter
1.
Arch Oral Biol ; 163: 105981, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38669743

ABSTRACT

OBJECTIVES: An ex-vivo study was aimed at (i) programming clinically validated robot three-year random toothbrushing, (ii) evaluating cervical macro- and microwear patterns on all tooth groups of different functional age, (iii) documenting and codificating wear related morphological features at the cemento-enamel junction in young teeth and on roots in older teeth. DESIGN: Following ethical approval random toothbrushing (44 strokes per tooth horizontally, rotating, vertically; 2x/d) with manual toothbrushes and low-abrasive dentifrice was performed in an artificial oral cavity with brushing-force 3.5 N on 14 extracted human teeth. Morphological features were examined by SEM at baseline and after simulated 3 years using the replication technique. 3D-SEM analyses were carried out with a four-quadrant back scattered electron detector. Wilcoxon-Mann-Whitney-test was used for statistical analyses. RESULTS: 3-year random toothbrushing with horizontal, rotating and vertical brushing movements revealed morphological features classified as four enamel patterns, one dentin pattern and three cervical patterns. Negative impacts were enamel, cementum and dentin loss. Positive impact on oral health was removing dental calculus and straightening cervical traumatic and iatrogenic damages. The volume loss varied from x̅=34.25nl to x̅=87.75nl. Wear extended apically from 100 to 1500 micrometres. CONCLUSION: Robot simulated toothbrushing in an artificial oral cavity, with subsequent SEM and 3D-SEM assessment, elucidated both negative and oral health-contributing micromorphology patterns of cervical wear after simulated 3-year random toothbrushing. Cervical macro- and microwear of cementum revealed, for the first time, what we describe as overhanging enamel peninsulas and enamel islands on roots in young teeth, but no enamel islands on roots from older teeth after root cementum loss. In contrast, many older teeth exhibited enamel peninsulas.


Subject(s)
Microscopy, Electron, Scanning , Robotics , Tooth Cervix , Tooth Wear , Toothbrushing , Humans , Tooth Wear/etiology , Tooth Cervix/pathology , Dental Enamel , Dental Cementum/pathology , Dentin , Dentifrices , In Vitro Techniques
2.
J Dent Res ; 97(13): 1431-1437, 2018 12.
Article in English | MEDLINE | ID: mdl-30067429

ABSTRACT

Prospective clinical studies of composite restorations revealed their safety and longevity; however, studies did not elucidate the dynamic mechanisms of deterioration caused by fractures and secondary caries. Therefore, the aims of this 29-y controlled study were 1) to follow up on the clinical behavior of posterior composite restorations annually and 2) to compare clinical outcomes with micromorphologic scanning electron microscopy features. After ethical approval, the single-arm study commenced in 1987 with 194 class I or II primary posterior composite restorations with glass ionomer cement providing pulp protection. Each restoration was evaluated annually for 15 y and then again at 29 y per the US Public Health Service-compatible Clinical, Photographic and Micromorphologic coding index, with clinical and photographic criteria for anatomic form, color matching, surface quality, wear, marginal integrity, secondary caries, and clinical acceptability. Parallel micromorphologic criteria were applied at baseline and after 1, 3, 5, 7, 10, 15, and 29 y to assess surface roughness, texture, marginal integrity, fractures, ledges, and marginal gaps with semiquantitative coding and with quantitative 3-dimensional scanning electron microscopy profilometric measurements of marginal grooves next to the enamel, grooves within the bonding zone, and ledges. Statistical analysis included the calculation of the annual failure rate and the use of Kaplan-Meier methodology and nonparametric tests. The cumulative survival rates were 91.7% (6 y), 81.6% (12 y), and 71.4% (29 y). The mean annual failure rate was 1.92%. Significant changes in the restoration-tooth interface from baseline to 5 y resulted in functional masticatory equilibrium. Clinical deterioration year by year, including micromorphologic microfractures and wear, reflected unique dynamic changes in long-term surviving restorations with very low secondary caries and fracture risks (German Network for Health Care Research VfD 29 99 003924).


Subject(s)
Composite Resins , Dental Caries/therapy , Dental Restoration Failure , Dental Restoration, Permanent/methods , Berlin , Bicuspid , Dental Marginal Adaptation , Female , Glass Ionomer Cements , Humans , Longitudinal Studies , Male , Microscopy, Electron, Scanning , Molar , Photography , Surface Properties , Treatment Outcome
3.
J Dent Res ; 93(10): 943-9, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25048250

ABSTRACT

The aim of this meta-analysis, based on individual participant data from several studies, was to investigate the influence of patient-, materials-, and tooth-related variables on the survival of posterior resin composite restorations. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a search resulting in 12 longitudinal studies of direct posterior resin composite restorations with at least 5 years' follow-up. Original datasets were still available, including placement/failure/censoring of restorations, restored surfaces, materials used, reasons for clinical failure, and caries-risk status. A database including all restorations was constructed, and a multivariate Cox regression method was used to analyze variables of interest [patient (age; gender; caries-risk status), jaw (upper; lower), number of restored surfaces, resin composite and adhesive materials, and use of glass-ionomer cement as base/liner (present or absent)]. The hazard ratios with respective 95% confidence intervals were determined, and annual failure rates were calculated for subgroups. Of all restorations, 2,816 (2,585 Class II and 231 Class I) were included in the analysis, of which 569 failed during the observation period. Main reasons for failure were caries and fracture. The regression analyses showed a significantly higher risk of failure for restorations in high-caries-risk individuals and those with a higher number of restored surfaces.


Subject(s)
Composite Resins/chemistry , Dental Materials/chemistry , Dental Restoration, Permanent/standards , Dental Caries Susceptibility , Dental Restoration Failure , Humans , Risk Factors , Survival Analysis , Time Factors
4.
Arch Oral Biol ; 57(7): 870-6, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22341566

ABSTRACT

UNLABELLED: The assessment of the fluoride kinetics in whole saliva as well as in the different salivary phases (supernatant saliva and sediment) is essential for the understanding of fluoride bioavailability. OBJECTIVES: To assess the fluoride content, provided by sodium fluoride and amine fluoride, in the supernatant saliva and in salivary sediment. METHODS: Seven trained volunteers were randomly attributed to 2 groups in a cross-over design and brushed their teeth in the morning for 3 min with a product containing either sodium fluoride or amine fluoride. Saliva was collected before, immediately after tooth brushing and 30, 120, and 360 min later and measured. The samples were centrifuged 10 min at 3024 × g. Fluoride content of the supernatant saliva and of the sediment was analysed using a fluoride sensitive electrode. All subjects repeated the study cycles 2 times, and statistical analyses were made using the nonparametric sign test for related samples, the Wilcoxon-Mann-Whitney-test for independent samples. RESULTS: There was a significant increase in fluoride immediately after tooth brushing in both groups in saliva and sediment. The distribution of fluoride between salivary sediment and supernatant saliva (ratio) varied considerably at the different collection times: decreased from 17.87 in baseline samples of saliva to 0.07 immediately and to 0.86 half an hour after tooth brushing in the sodium fluoride group and from 14.33 to 2.85 and to 3.09 in the amine fluoride group. Furthermore after 120 min and after 360 min after tooth brushing the ratio increased from 17.6 to 31.6 in the sodium fluoride group and from 20.5 to 25.76 in the amine fluoride group. No difference was found in the sediment-supernatant saliva ratio between the sodium fluoride and the amine fluoride groups 360 min after tooth brushing. CONCLUSION: For the assessment of fluoride kinetics in whole saliva it is necessary to pay attention to at least four factors: fluoride formulation, time after fluoride application, fluoride concentration in supernatant saliva and fluoride concentration in salivary sediment. This study was approved by the Ethical Committee of the University of Witten/Herdecke permission 21/2008.


Subject(s)
Cariostatic Agents/analysis , Dental Plaque/microbiology , Fluorides/analysis , Saliva/chemistry , Biological Availability , Cross-Over Studies , Dental Plaque/chemistry , Dental Plaque/ultrastructure , Fluorides/administration & dosage , Fluorides/pharmacokinetics , Humans , Ion-Selective Electrodes , Microscopy, Electron, Scanning , Saliva/drug effects , Saliva/microbiology , Statistics, Nonparametric
5.
J Microsc ; 245(1): 26-33, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21919904

ABSTRACT

It was the purpose of this pilot study to investigate resin infiltration into various types of initial subsurface caries lesions using a combined microscopic technique with polarized light microscopy and fluorescence microscopy and subsequent scanning microscopy with EDX-element analysis. Six extracted premolars with initial caries lesions were used. Five were infiltrated with resin after imbibition of the subsurface carious pore volume of enamel with sodium fluorescein solution. After light curing the unbound dye was removed by washing out in water. Serial sections were cut through the lesions and investigated with polarized light microscopy, fluorescence microscopy and simultaneously with both microscopic techniques. The same sections were then studied with scanning electron microscopy and EDX-element analysis to prove the infiltration of the resin into the lesions. The results showed, that the combination technique adds further morphologic information to infiltration behaviour of the resin. The individual volume of early acute lesions versus chronic lesions involving dentin, and the fluorescein bound by resin was well documented in serial sections. The EDX calcium and phosphorus signals correlate negatively with the lesion extension, and the carbon signal correlates positively, thus labelling the resin infiltration. It could be demonstrated that resin infiltration is dependent from the pore volume of the lesion. It can be concluded that the combined polarized light microscopy with fluorescence microscopy is an advantageous tool for studying infiltration of resin into hard tissues.


Subject(s)
Dental Caries/therapy , Microscopy/methods , Resins, Synthetic/pharmacokinetics , Humans , Pilot Projects
6.
Eur J Dent Educ ; 15(4): 236-43, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21985208

ABSTRACT

INTRODUCTION: In this study, we investigated the value of an individual selection procedure to choose dental students for the Faculty of Dental Medicine at the University of Witten/Herdecke, Germany. The selection procedure was divided into the following four steps: step one consisted of a formal application; step two consisted of a practical test; step three consisted of a personal interview; and step four consisted of a final selection by an independent committee. MATERIAL AND METHODS: Data from 196 students were collected from the university files. The following data were compared: the grades of the final secondary school certificate (Abiturnoten) were compared with the grades of the Natural Science Examination (naturwissenschaftliche Vorprüfung), first Dental Examination (zahnärztliche Vorprüfung) and State Board Examination (Staatsexamen); specialisation or non-specialisation at secondary school in natural sciences was compared with the grades of the Natural Science Examination and the first Dental Examination; the results of the practical test of the selection procedure were compared with the grades of the practical examination in the first Dental Examination; the interview recommendations to the committee were compared with the grades of the first Dental Examination and the State Board Examination. RESULTS: The results showed a positive correlation (R = 0.34; P < 0.001) between the secondary school grades and the Natural Science Examination grades. The correlation was weaker between the grades of the first Dental Examination and State Board Examination. No correlation was found between the specialisation during secondary school in biology, chemistry and physics or non-specialisation, and the results of the Natural Science Examination and first Dental Examination. A weak correlation was found between the grades the candidates obtained in the practical test of the selection procedure and the first Dental Examination.


Subject(s)
School Admission Criteria , Schools, Dental , Students, Dental , Curriculum , Educational Measurement , Female , Germany , Humans , Interviews as Topic , Male , Predictive Value of Tests
7.
Open Dent J ; 5: 84-9, 2011.
Article in English | MEDLINE | ID: mdl-21687564

ABSTRACT

Aim of this in-vitro-study was to assess the remineralization potential of a tooth cleaning tablet with different fluoride content quantitatively using EDX analysis.Twenty three caries free impacted third molars were examined; enamel surfaces were wax coated leaving two 3x4mm windows for exposure to demineralization/remineralization cycles. The teeth were randomly assigned to 4 groups of 5 control and 6 experimental teeth each. Demineralization by standardized HEC-gel, pH 4.7 at 37°C for 72h, was alternated by rinsing in remineralization solution, pH 7.0 at 37°C for 72h, total challenge time 432h. The negative control group N was treated during remineralization cycles with saline; positive control group P was treated with remineralization solution; experimental group D1 was exposed to remineralization solution containing Denttabs(®)-tablets with 1450 ppm F; experimental group D2 was exposed to remineralization solution and Denttabs(®)-tablets with 4350 ppm F. Each tooth was cut into serial sections and analyzed by scanning electron microscopy with EDX element analysis for assessment of the different zones of the lesions in 3 representative sections. Statistical analysis was based on the AVOVA test for repeated measurements and post hoc Bonferroni adjustment. The results showed a significantly higher Ca and P content in the body of the lesion in both fluoride treated groups compared to the controls. It can be concluded that higher concentrations of NaF may be more effective in remineralization of early advanced caries lesions.

8.
Int J Dent Hyg ; 9(1): 53-9, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21226851

ABSTRACT

OBJECTIVE: To document oral hygiene and periodontal conditions in the rural population of The Gambia. BASIC RESEARCH DESIGN: Cross-sectional study according to the recommendations of the WHO for oral health surveys. CLINICAL SETTING: Examination by two calibrated investigators in the health centres of rural communities after a public radio call. Patients were randomly allocated to the investigators. PARTICIPANTS: 162 patients (20-54 years old; 52.5% female, 47.5% male). INTERVENTIONS: Patients were interviewed for personal information and examined in a full-mouth recording. MAIN OUTCOME MEASURES: Oral Hygiene Index (OHI), Gingival Index (GI), Community Periodontal Index (CPI), and the Gingivitis-Periodontitis-Missing/Teeth Index (GPM/T). Statistical analysis was performed using the Wilcoxon-rank-sum test and Kruskal-Wallis test with statistical significance at P < 0.05. RESULTS: OHI increased by age from 6.9 to 9.2 (P < 0.05) and showed in tendency higher levels in men (P = 0.07), while the GI remained stable at 1.2. Community Periodontal Index codes increased by age (P < 0.05) and showed a fourfold higher prevalence for severe periodontitis in males (P < 0.05). Likewise, an age-related increase in GPM/T was evident (20.5 versus 25.4), significantly in the number of moderate periodontitis and missing teeth (P < 0.05). In GPM/T, males again demonstrated significantly more teeth affected by periodontitis than women. No statistical associations were found between ethnic groups or for different oral hygiene methods concerning CPI or GPM/T. CONCLUSIONS: Prevalence of predominantly mild to moderate periodontal disease indicates treatment needs that should be considered when developing a national oral health care plan in The Gambia (West Africa).


Subject(s)
Dental Health Surveys , Health Status , Oral Hygiene/statistics & numerical data , Periodontal Diseases/epidemiology , Rural Population/statistics & numerical data , Adult , Cross-Sectional Studies , Female , Gambia/epidemiology , Humans , Male , Middle Aged , Pilot Projects , Prevalence , Severity of Illness Index , Sex Factors , Statistics, Nonparametric , Young Adult
9.
Open Dent J ; 4: 185-90, 2010 Aug 27.
Article in English | MEDLINE | ID: mdl-21221176

ABSTRACT

UNLABELLED: The aim of this preliminary investigation was to compare the individual saliva secretion rate with the fluoride bioavailability in saliva after using sodium fluoride and amine fluoride. METHODS: To assess oral fluoride kinetics 10 highly trained volunteers brushed their teeth with one of the formulations and saliva was collected. The amount of saliva was measured, and the fluoride content was determined. Data underwent statistical analysis using the Mann-Whitney-U test and Pearson correlation. The ex vivo experiment I included individual saliva collection of the same volunteers. Then the oral hygiene products were solved in equal amounts of whole saliva (ex-vivo experiment II), and the fluoride content was measured. Finally, both products were dispersed in distilled water (ex-vivo experiment III) to calculate the dissociation of both products in water. RESULTS: In vivo results of fluoride content after 3 min. tooth brushing demonstrated a negative correlation with saliva secretion: for NaF r = -0.695 (p<0.01) and for amine fluoride r = -0.446 (p<0.01). The in-vitro experiment I resulted for NaF in 251.7±22.4 µg/g fluoride and for amine fluoride in 171.7±14.4 µg/g. CONCLUSIONS: Fluoride bioavailability of saliva after exposure to NaF was higher compared to amine fluoride. The individual secretion rate changes the fluoride content and normal secretors keep the fluoride availability longer.

11.
Eur J Dent Educ ; 12 Suppl 1: 40-7, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18289267

ABSTRACT

Dental education, like any other educational programme in a research-intensive university environment, must be research led or at least research informed. In this context, as the research and knowledge base of dentistry lies in the biological and physical sciences, dental education must be led by advances in research in both these areas. There is no doubt that biotechnology and nanotechnology have, over the past 25 years, led research in both these areas. It is therefore logical to assume that this has also impacted on dental education. The aim of this paper is twofold; on one hand to examine the effects of biotechnology and nanotechnology and their implications for dental education and on the other to make recommendations for future developments in dental education led by research in biotechnology and nanotechnology. It is now generally accepted that dental education should be socially and culturally relevant and directed to the community it serves. In other words, there can be no universal approach and each dental school or indeed curriculum must apply the outcomes in their own social, cultural and community settings.


Subject(s)
Biotechnology/education , Education, Dental , Molecular Biology/education , Biocompatible Materials , Biomedical Technology , Dental Research , Education, Dental/trends , Forecasting , Genomics , Humans , Nanotechnology , Proteomics
12.
Ann Anat ; 189(2): 183-90, 2007.
Article in English | MEDLINE | ID: mdl-17419551

ABSTRACT

It was the aim of this study to investigate the distribution of Ca, P and C in predentin, dentin and enamel in human tooth buds and permanent teeth by EDX element analysis. The mandible of a 16-week-old human fetus containing eight mineralizing tooth buds and three human permanent molars were fixed in formaldehyde and embedded in Technovit 9100. Serial sections of 80 microm thickness of the mandible were cut in the frontal-dorsal direction, and polarized light micrographs were taken of these sections. The permanent teeth were cut in mesio-distal direction. The sections were investigated with scanning electron microscopy and EDX element analysis with a Philips XL 30 FEG scanning microscope and an EDAX energy-dispersive X-ray system using spot measurements, EDX line-scans and element mapping. Quantitative measurements were made in predentin, mineralizing dentin adjacent to predentin, mature dentin, mineralizing enamel and young enamel of developing teeth and mature enamel of permanent teeth. In developing teeth the Ca and P content increased rapidly from outer predentin towards mineralizing dentin. In enamel prisms of developing teeth the Ca and P content increased linearly from the surface towards the enamel-dentin junction. In permanent teeth only a small layer of predentin was found. The Ca and P content in enamel and circumpulpal dentin of permanent teeth was higher than in developing teeth. The Ca/P ratio differed between predentin and dentin areas reflecting different calcium phosphate compositions, but it was the same in mineralizing and young enamel. The differences in the distribution of Ca and P reflect different mineralizing patterns of the enamel and dentin matrices.


Subject(s)
Calcium/analysis , Molar/chemistry , Phosphorus/analysis , Tooth, Deciduous/chemistry , Tooth/chemistry , Tooth/embryology , Abortion, Spontaneous , Female , Fetus , Humans , Microscopy, Electron, Scanning , Tooth/ultrastructure , Tooth, Deciduous/ultrastructure
13.
J Oral Rehabil ; 31(10): 991-1000, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15387840

ABSTRACT

The summarized scanning electron microscopic-supported micromorphologic data of a 10-year longitudinal clinical study of GIC/Hybrid composite posterior restorations is reported. The aim of this study was to compare the results to USPHS-compatible clinical criteria of the CPM index and to analyse the deterioration pattern and the success rate. Out of a total of 194 Class I and Class II fillings 46 restorations were at baseline, after 1, 3, 5, 7 and 10 years. The restorations were micromorphologically examined using gold-sputtered replicas and coded according to the M-criteria of the CPM index. The features for surface roughness, surface texture, marginal integrity, excess of material, marginal fracture, loss of material, marginal leakage and other filling imperfections were assessed. Eighteen fillings showed perfect margins, rapidly deteriorating after the first year of service. Despite poor micromorphologic marginal conditions all restorations retained optimal functional characteristics. Parallel longitudinal micromorphologic and clinical assessment of posterior GIC/Composite restorations revealed fine structure and deterioration patterns of the tooth-biomaterial interface. The layer-technique using GIC as dentine replacement and resin-based composite as enamel replacement results, according to previous biocompatibility testing, and clinical data, in optimal pulp protection and correct anatomic form over a 10-year period. The myth of the need for perfect marginal integrity requires further discussion.


Subject(s)
Composite Resins , Dental Caries/therapy , Dental Restoration, Permanent/methods , Adolescent , Adult , Bicuspid/ultrastructure , Dental Caries/pathology , Dental Marginal Adaptation , Dental Restoration Wear , Female , Follow-Up Studies , Humans , Male , Microscopy, Electron, Scanning , Middle Aged , Molar/ultrastructure
14.
Ann Anat ; 185(5): 419-24, 2003 Oct.
Article in English | MEDLINE | ID: mdl-14575268

ABSTRACT

Dentin is one of the earliest bio-mineralization products to appear in the evolution of vertebrates. Dentin reactions to infection mimic earlier phylogenetic patterns, and carious lesions are divided into different zones which reflect the natural patho-morphological reaction of dentin to the carious attack. It was the aim of this study to investigate deep dentin carious lesions of human molars with combined polarization light microscopy, scanning electron microscopy and energy dispersive X-ray element analysis (EDX) for the determination of different zones of the carious lesions, their extent and the chemical content. Sixteen extracted teeth with deep dentin carious lesions were embedded in Technovit 9100 (Kulzer) and serial sections of 80 microm thickness were made. These sections were then examined with polarized light microscopy to identify the different zones of the lesions. The outlines of the zones were traced consecutively and 3D-reconstructions were made for the determination of the extent and calculation of the volumes of the different zones. From the volumes of the demineralizing dentin and the translucent zone a Dentin Demineralization Index (DDI) was calculated. Three sections of each lesion were then coated with carbon and studied with a scanning electron microscope. 3D-reconstruction of the teeth showed the rather stable translucent zone, interrupted by remnants of dead tracts, and very different volumes of demineralizing dentin. Therefore, with increasing size of the demineralizing dentin, the DDI increased. The chemical content was measured using energy dispersive X-ray analysis (EDX) in areas of intertubular dentin. The content of Ca, P, and C was significantly different in all zones. The Ca/P ratio was significantly different between sound dentin and demineralizing dentin. From the results we conclude that the mineral content of intertubular dentin of the translucent zone and demineralizing dentin is different from that of sound dentin, and the unique mineralization pattern of the translucent zone is a biological reaction to the carious attack. Because active dentin lesions exhibit many non-occluded open dentin tubules, further bacterial invasion or, in case of dentin treatment, the penetration of bonding agents towards the pulp is morphologically not prevented and therefore of clinical importance.


Subject(s)
Dental Caries/pathology , Dentin/chemistry , Dentin/ultrastructure , Dentin/pathology , Durapatite/analysis , Humans , Image Processing, Computer-Assisted , Microscopy, Electron, Scanning , Molar/cytology , Molar/pathology
15.
Arch Oral Biol ; 48(6): 467-73, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12749919

ABSTRACT

OBJECTIVES: It was the purpose of this study to investigate the effect of milk and fluoridated milk on experimentally induced caries-like-lesions. MATERIALS AND METHODS: Twelve extracted impacted human molars were covered with wax leaving two 3 mm x 3 mm windows on the buccal and lingual surfaces and incubated alternating in demineralizing solution at pH 4.85 and in milk, F-milk, saline, and remineralizing solution, respectively. Afterwards serial ground sections were cut and investigated by polarization-light-microscopy (PLM) and SEM using EDX element analysis. RESULTS: The results showed increased thickness of the superficial layer in the F-milk samples. Quantitative element analysis revealed a significant increase in the fluoride content of the superficial layer and of the body of the lesion of the F-milk group. The body of the lesion of the F-milk group was less demineralized than in the other groups. CONCLUSION: From the results we conclude, that the parallel investigation by PLM, SEM combined with EDX quantitative element analysis is a powerful method to assess caries-like-lesion formation and that fluoridated milk has protective properties in inhibiting demineralization.


Subject(s)
Dental Caries/prevention & control , Dental Enamel/drug effects , Fluoridation , Milk , Molar , Animals , Dental Caries/metabolism , Dental Caries/pathology , Dental Enamel/chemistry , Dental Enamel/ultrastructure , Fluorides/analysis , Humans , In Vitro Techniques , Microscopy, Electron, Scanning , Microscopy, Polarization , X-Ray Diffraction
16.
J Oral Rehabil ; 29(12): 1131-8, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12472848

ABSTRACT

The aim of this study was to assess retrospectively the caries susceptibility of posterior teeth with composite restorations after 18 and 20 years. The sample was selected out of the recall of a dental office. Sixteen restorations were reassessed after 18 and 20 years. All findings have been rated according to the C criteria of the CPM index. For the micromorphological evaluation with SEM, replicas were made using a two-step impression technique. All restorations demonstrated marginal imperfections and a predominant rough surface. At the 18 year-evaluation two restorations exhibited secondary caries. Despite of extended marginal gap formations none of the 12 restorations reexamined at 20 years showed secondary caries. Direct composite restorations can serve over a long period of time despite of poor qualitative parameters. Micromorphological marginal deterioration and clinical gap formation do not necessarily result in a higher risk for secondary caries.


Subject(s)
Composite Resins , Dental Caries Susceptibility , Inlays , Dental Restoration Wear , Humans , Microscopy, Electron, Scanning , Retrospective Studies , Time Factors
17.
Int Dent J ; 52(3): 144-50, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12090264

ABSTRACT

AIM: To describe the oral health status and the dental service use pattern of a Turkish population in Witten, Germany, and to assess the factors affecting this use pattern. DESIGN: Cross-sectional. PARTICIPANTS: 532 Turkish people older than 12 years. METHODS: The data were obtained through a structured questionnaire and oral examination. The World Health Organisation methodology was followed in assessing the oral health status. RESULTS: Comparison of the study population with German studies showed a similar caries experience in younger groups, but in older groups a lower treatment level. The proportion of regular dental attendees indicated no difference according to age. A person was more likely to use dental services regularly if he had a better level of German language and preferred German services. Perceived oral condition, educational level and sex were also important for care pattern. Regular use of services was negatively associated with the mean number of decayed, missing and periodontally involved teeth, but positively related to the number of filled teeth. CONCLUSIONS: Since factors reflecting the level of adaptation to Germany were also important determinants of the dental utilisation pattern, efforts to improve the utilisation of services should be based on the socio-educational development of Turkish people in Germany.


Subject(s)
Dental Health Services/statistics & numerical data , Ethnicity , Adolescent , Adult , Age Factors , Cross-Sectional Studies , DMF Index , Dental Restoration, Permanent , Educational Status , Female , Germany , Health Status , Humans , Language , Logistic Models , Male , Middle Aged , Odds Ratio , Oral Health , Periodontal Index , Periodontal Pocket/classification , Sex Factors , Social Environment , Tooth Loss/classification , Turkey/ethnology
19.
J Oral Rehabil ; 28(8): 748-54, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11556956

ABSTRACT

The aim of this study was to examine an in vitro dental plaque model for volumetric assessment and 3D reconstruction of experimentally bacterial induced caries-like lesions. Twenty-three extracted, impacted human molars were coated with a varnish leaving a 3 x 3 mm window on the smooth surface. The teeth were coated with human saliva and Streptococcus sobrinus 6715 adhered onto the enamel via a sucrose dependent mechanism. The coated teeth were incubated for 1, 7, 14 and 28 days. At the end of each incubation period microhardness was measured on three sectioned teeth of each incubation period at the enamel surface and at 450 and 750 microm depth perpendicular to the enamel surface. The enamel surface was investigated by scanning electron microscopy (SEM) prior to embedding and serial sectioning of 12 other teeth. The serial sections were studied with polarization light microscopy to investigate subsurface demineralization. The outlines of the caries-like lesions were then traced consecutively on transparencies, digitized and three-dimensionally reconstructed to demonstrate the expansion of the lesion into enamel for volumetric assessment. Microhardness was significantly reduced on the enamel surface after 7, 14 and 28 days incubation. The SEM investigation showed a surface demineralization with dissolution of the prism cores after 28 days incubation. Polarization light microscopy demonstrated caries-like lesions with an irregular expansion into enamel. The results demonstrate that the described method produces caries-like lesions which can be used for further experimental studies regarding demineralization and remineralization processes.


Subject(s)
Biofilms , Dental Caries/microbiology , Dental Plaque/microbiology , Humans , Models, Biological
20.
J Adhes Dent ; 3(2): 185-94, 2001.
Article in English | MEDLINE | ID: mdl-11570687

ABSTRACT

PURPOSE: To summarize all clinically relevant data of a 10-year prospective evaluation of posterior glass-ionomer cement/composite restorations (Ketac Bond/Visio-Molar radiopaque). MATERIAL AND METHODS: For this study 194 hybrid composite fillings (115 Class I, 79 Class II) were applied in 73 adult patients. The exposed dentin was covered with glass-ionomer cement. The clinical evaluation was carried out at baseline, after 6 months and at 1-year intervals up to 10 years. The USPHS-compatible CPM Index was used with the C and P criteria presented here for anatomic form, color match, surface quality, wear, marginal integrity, marginal ledge, marginal discoloration, secondary caries, and clinical acceptability. Thermal and electrical sensitivity testing were recorded annually. RESULTS: At baseline, 194 restorations were rated. The drop-out of patients comprised 108 fillings after 10 years. During this time, 24 restorations could not be followed up because of new carious lesions at different sites and/or prosthodontic treatment (drop-out of teeth). Forty-six composite restorations were longitudinally controlled over 10 years, and 16 more fillings failed before the end of the study (3 filling fractures, 7 partial filling losses, 1 total filling loss, 5 cases of secondary caries). Only Class II composite restorations exhibited secondary caries (4 fillings after 7 years and 1 filling after 9 years). After 10 years, the correct anatomic form was preserved in 44 fillings, but all restorations showed rough surface and wear. The majority of restorations (26 fillings) was free of marginal discoloration, and the color match showed only 3 fillings being too dark. The marginal integrity was optimal at baseline and during the first year. During the second year a continuing degradation started and lasted until the end of the study. Thirteen restorations showed optimal marginal integrity after 10 years. CONCLUSION: The USPHS-compatible CPM Index represents a sensitive rating system for long-term observation of posterior composite restorations. The early risk of failure is attributed to bulk fractures and partial loss of filling material. The longevity over 10 years is a maximum of 74.2%, and the very low secondary caries rate and the high percentage of correct anatomical form confirm the clinical safety of posterior composite restorations.


Subject(s)
Composite Resins/chemistry , Dental Restoration, Permanent , Glass Ionomer Cements/chemistry , Adolescent , Adult , Color , Composite Resins/standards , Dental Caries/etiology , Dental Marginal Adaptation , Dental Pulp/physiology , Dental Restoration Failure , Dental Restoration Wear , Dental Restoration, Permanent/classification , Dental Restoration, Permanent/methods , Dental Restoration, Permanent/standards , Dentin/ultrastructure , Dentin Sensitivity/etiology , Follow-Up Studies , Glass Ionomer Cements/standards , Humans , Longitudinal Studies , Middle Aged , Prospective Studies , Quartz/chemistry , Quartz/standards , Surface Properties , Survival Analysis
SELECTION OF CITATIONS
SEARCH DETAIL
...