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Biomedical subjects

K H Kunzelmann

Publications and source records attributed to K H Kunzelmann.

At least 37 records · Page 2Linked to original sources
PubMed1999

Two-year clinical evaluation of direct and indirect composite restorations in posterior teeth.

STATEMENT OF PROBLEM: Few long-term clinical studies have reported data of modern posterior composites as direct and indirect restorations. PURPOSE: This prospective, long-term clinical trial (1) evaluated direct and indirect composite restorations for clinical acceptability as posterior restoratives in single or multisurface carious teeth and (2) provided a survey on the 2-year results. MATERIAL AND METHODS: Nine dental students placed 88 composite restorations (Tetric, blend-a-lux, Pertac-Hybrid Unifil), 43 direct composite restorations and 45 indirect inlays, under the supervision of an experienced dentist. The first clinical evaluation was performed 11 to 13 months after placement by 2 other experienced dentists, using modified USPHS criteria. A second follow-up of 60 restorations took place within 20 to 26 months after placement. RESULTS: A total of 93% of indirect and 90% of direct composite restorations were assessed to be clinically excellent or acceptable. Two restorations (1 indirect composite inlay and 1 margin of a direct composite restoration) failed during the second year because of fracture. Indirect inlays demonstrated a significantly better "anatomic form of the surface" than direct composite restorations. Premolars revealed a significantly better margin integrity and postoperative symptoms than molars. CONCLUSION: Posterior composite restorations provided a satisfactory clinical performance over a 2-year period when placed by relatively inexperienced but supervised students.

Bicuspid↗
PubMed1999

Effects of surface finish and fatigue testing on the fracture strength of CAD-CAM and pressed-ceramic crowns.

STATEMENT OF PROBLEM: All-ceramic molar crowns can be fabricated with CAD-CAM or laboratory methods with different materials, and a polished or oven-glazed surface. PURPOSE: This in vitro study determined the fracture strength of various all-ceramic crowns, with and without prior cyclic loading. MATERIAL AND METHODS: Standardized molar crowns were fabricated with a CAD-CAM machine (Cerec 2), software with machinable ceramic materials (Vita Mark II and ProCAD), and also conventional heat-pressed IPS Empress crowns fabricated at 2 dental laboratories. Groups of 40 crowns of each material were manufactured with either a polished or an oven-glazed surface finish. Cyclic loading that simulated oral conditions were performed on half of each group. Afterward, all crowns were loaded until catastrophic failure.Results. Fracture loads of the polished ProCAD crowns without prior cyclic loading was 2120 +/- 231 N, significantly higher than that of the polished Vita Mark II crowns (1905 +/- 235 N), but was not significantly different from the strength of 2 laboratory-fabricated Empress crowns. Oven-glazing of ProCAD crowns improved the fracture strength significantly, up to 2254 +/- 186 N. Prior cyclic loading decreased the strength of all tested crowns significantly, but the reduction was less for the Cerec crowns than the Empress crowns. CONCLUSION: Cerec ProCAD crowns demonstrated significantly greater strength than the Vita Mark II crowns, better resistance to cyclic loading and lower failure probability than the laboratory-fabricated IPS Empress crowns. Prior cyclic loading significantly reduced the strength of all-ceramic crowns, but had less effect on Cerec crowns than on the IPS Empress crowns. Oven-glazing of ProCAD crowns resulted in significantly higher strength and higher resistance to cyclic loading than surface polishing.

Analysis of Variance↗
PubMed1998

One-year clinical evaluation of composite and ceramic inlays in posterior teeth.

STATEMENT OF PROBLEM: There are only a few studies available that deal with the clinical behavior of composite and ceramic inlay systems as potential substitutes for amalgam restorations. PURPOSE: This prospective clinical trial evaluated composite and ceramic inlay systems for clinical acceptability as restorative materials in single or multisurface cavities of posterior teeth and provided 1-year results. MATERIAL AND METHODS: Forty-seven composite inlays (Tetric, Blend-a-lux, Pertac) and 24 heat-pressed ceramic inlays (IPS Empress) were placed in 45 patients by 7 student operators under the supervision of an experienced dentist. The first clinical evaluation was performed 11 to 13 months after placement of the restorations and used modified United States Public Health Services criteria. RESULTS: Satisfactory results over this period were found, as 100% of ceramic inlays and 94% of composite inlays were assessed to be clinically excellent and acceptable. Only 3 composite inlay restorations were scored delta (unacceptable). Two inlays exhibited secondary caries and 1 demonstrated loss of pulp vitality. For the criteria "anatomic form of the surface" and "marginal integrity," ceramic inlays were significantly better than composite inlays. CONCLUSION: Posterior tooth-colored inlays provided acceptable and excellent clinical service, even if they are placed by relatively inexperienced student operators.

Adult↗
PubMed1997

One-year clinical evaluation of composite fillings and inlays in posterior teeth.

In the course of a prospectively designed long-term clinical trial, composite fillings and inlays were evaluated for clinical acceptability as restorative materials in one, two or more surface cavities of posterior teeth over a 1-year period. In 45 patients, 88 restorations were placed by nine student operators, under the supervision of an experienced dentist, to compare the two half sides using the composite resins Tetric (Vivadent), blend-a-lux (Blend-a-med), and Pertac-Hybrid Unifil (Espe). The first clinical follow-up check took place within a time period of 11-13 months after placement of the restorations using modified USPHS criteria. The interpretation of the clinical criteria showed satisfactory results over this time period: more than 85% of the inlays and direct fillings were rated "alpha" or "bravo", using the parameters of assessment defined in this study. Only three restorations (two fillings, one inlay), all in molars, were rated "delta", i.e., unacceptable. The reasons for their replacement were marginal opening, secondary caries, and loss of sensitivity. For the criteria "surface texture", "anatomical form of the surface", and "occlusion", composite inlays were significantly better than composite fillings. These results indicate that posterior composite restorations provide acceptable and excellent clinical service, even if they are placed by relatively inexperienced student operators.

Adult↗
PubMed1997

Chronic ulcerative stomatitis.

Chronic ulcerative stomatitis (CUS) has recently been described as a new disease entity characterized by chronic ulceration of oral mucosa which responds to treatment with hydroxychloroquine. It has a particular type of stratified epithelium-specific, antinuclear autoantibody as an immunological marker. Twelve cases have been reported in the literature. We present a 40-year-old woman with an 11-year history of chronic oral ulcerations. Other dermatological diseases, including oral lichen planus, pemphigus vulgaris and cicatricial pemphigoid, as well as bullous lupus erythematosus, were excluded. The clinical diagnosis of CUS was confirmed on the grounds of the immunological and ultrastructural findings. The lesions initially responded to high doses of systemic corticosteroids but relapsed promptly after dose reduction. Dapsone was ineffective. Hydroxychloroquine, given at a dosage of 200-400 mg/day, led to a complete and long-lasting remission.

Adult↗
PubMed1997

A new optical 3-D device for the detection of wear.

For the clinical performance of new dental restorative materials to be accurately assessed, the three-dimensional anatomical changes of the functional surfaces of the restoration must be elucidated over time. To this end, a highly accurate 3-D optical scanner has been developed that utilizes the principles of triangulation and a reference-free automated 3-D superimposition software. The aim of this study was to assess the accuracy and the precision of the new system with and without referenced positioning. Additionally, the ability of the system to determine wear of posterior fillings three-dimensionally has been shown. Gypsum replicas of restored teeth were evaluated. The tooth surfaces were scanned with a resolution of 250,000 surface points within a measuring time of 20 to 40 sec. The results show that the precision and accuracy of 3-D data acquisition depend on the surface inclination. Up to an angle of 60 degrees, the precision is better than 3 microns, and the accuracy is better than 6 microns. If exact repositioning of the object before and after occlusal loading is possible, e.g., with in vitro studies, differences on the surface can be determined with a precision of 2.2 microns. In reference-free measurements, which are a necessity in clinical studies, the 3-D data acquisition in combination with the automatic matching program can detect wear with an accuracy of 10 microns. The application of this measuring device for the detection of wear of a composite filling functioning in the mouth has been shown. Since this measuring technique is automated, and measurements of high accuracy can be attained in a short period of time, this system offers the possibility for complex analyses of three-dimensional wear to be conducted on a large number of samples in clinical studies.

Algorithms↗
PubMed1991

[Individually controlled sedation using Midazolam].

Midazolam might be an alternative to general anesthesia for noncooperative children. 40 children were treated during 94 midazolam sedations to evaluate the potential dental therapy. An average of 2 fillings and 1 endodontic treatment was possible per sedation. The initial Midazolam dosage was 0.6 mg/kg. Every 15 min another 0.3 mg Midazolam/kg were administered to maintain the treatability of the children. 30 min after the initial Midazolam dosage dental treatment could be started. The average duration of a sedation was 76 min. Our results suggest that sedations complement under dental treatment general anesthesia.

Anesthesia, Dental↗
PubMed1991

[Treatment of deciduous teeth under rectal Midazolam sedation].

Individual controlled sedation using Midazolam proves to be a valuable addition to the range of therapeutic options for non-cooperative children. In a clinical study the oral and rectal routes of administration were compared with each other. Rectal application allowed considerably better dose adjustment. While the quality of sedation and the therapeutic range were equal with both routes, rectal application had the advantage that treatment can be commenced sooner. The sedation was of shorter duration and left the patient with less unpleasant memories. Rectal application was easier and required a smaller amount of Midazolam than oral administration.

Administration, Oral↗
PubMed1990

Dental fear and pain: effect on patient's perception of the dentist.

A questionnaire was developed including the Dental Anxiety Scale (DAS) and the Dental Beliefs Survey (DBS) as subscales to examine the epidemiology of dental fear and dental beliefs in Germany. The survey was administered before treatment to a sample of 474 dental patients. Of the respondents 56% were female. The mean age was 34.3 yr (SD 12.4 yr). The mean DAS score was 8.6 (SD 3.7). Mean DBS score ranged from 1.73 to 2.75 for single items. The correlation between DAS and DBS scores was highly significant (rs = 0.39, P less than 0.001). Absence or presence of dental pain revealed significant differences for DAS and DBS scores (P less than 0.001). Both tests are valid screening forms for the German linguistic context and easy to implement in daily dental routine.

Adolescent↗
PubMed1990

[Interaction of dental treatment anxiety and oral health].

Measurements of oral health (PBI, DMFS), dental treatment anxiety (DAS) and frequency of dental utilization were taken in a sample of 474 dental patients. Regression analysis shows that DAS scores are significantly correlated with DS, but not with MS and FS. Dental anxiety has a negative impact on the frequency of dental utilization, which is a predictor variable of oral health status. These results permit the conclusion that our attention should be focussed on reducing dental treatment anxiety to improve oral health.

Adolescent↗
PubMed1990

[The influence of cavity preparation on the width of marginal gaps in Cerec inlays].

In a study of the influence of the proximal box shape on the marginal fit of Cerec inlays, MOD cavities were prepared in 10 extracted teeth. One box was prepared with sharp edges as recommended by Mörmann (1989), the other was conventionally U-shaped. The width of the marginal gap was measured with a microscope at five different points. The results showed with high significance that the marginal gap of the U-shaped box preparation is smaller. It is recommended to use conventional U-shaped proximal box preparations for Cerec-inlays, too.

Dental Cavity Preparation↗
PubMed1990

[Fine polishing of Cerec inlays using diamond polishing systems].

The surface roughness of Cerec-inlays after polishing with diamond polishing pastes or Diafinish-disks was compared to polishing with aluminium oxide disks (AOD). SEM evaluation of the occlusal surface of extracted teeth revealed that diamond polishing pastes or Diafinish-disks produced smoother surfaces than AOD. The pastes, however, damaged the bonding resin. It is recommended to use AOD and diamond polishing systems for the approximal surfaces of the inlays extraorally. Intraorally AOD or Diafinish-disks are recommended.

Dental Polishing↗
PubMed1990

[Stress profile during curing contraction of composite resin adhesives].

The wall-to-wall curing contraction of thin composite resin layers was recorded with a tensometer. The composite resin was applied to cylindrically shaped ceramic sample holders with diameters of 3 mm, 4 mm and 8 mm. The distances of the sample holders was set at 50 microns, 100 microns, 150 microns, 200 microns and 300 microns. The shrinkage stress recordings clearly show that the shrinkage forces are governed by the distance of the sample holders and not by the volume or the configuration factor of the composite resin layers.

Adhesives↗
PubMed1990

[Middle course between group and individual preventive programs].

A pilot study was initiated to prove the effectivity of a prophylaxis programme for small groups of preschool children. A total number of 190 children was examined twice a year at the Dental School of Erlangen. The dental examination included df-s index and plaque index according to Quigley-Hein. Tooth cleaning was performed in small groups under professional supervision. Professional plaque removal and local fluoridation concluded each session. Twice a year the parents were offered oral hygiene instructions and informed about the relationship between sugar and caries. After two years the dfs-values were significantly lower in the test group than in the control group. Mean dfs scores ranged from 1.9 for the experimental to 3.8 for the control group. These comparatively low recordings--as against other investigations--may be due to the relatively high social standing of the children.

Child↗
PubMed1990

[Precision of the Cerec-System: the milling unit].

The Cerec-System is a computer-assisted method for fabrication of customized ceramic inlays. Until now there are no data available to judge the precision of this system, which is a function of several variables. This study investigated the tolerance of the milling unit by using computer-constructed data sets for test purposes. REM pictures show how the diamond bur is affected by several milling cycles. Overall precision along the x- or z-axis is largely independent of the inherent properties of the milling instrument used, such as wear. Precision along the y-coordinate, however, is dependent on the number of milling cycles and the feed along the horizontal axis. Best results can be obtained by using a new bur and slow feed.

Dental Polishing↗
PubMed1989

[The patient--his anxiety and his assessment of the dentist as variables in the compliance model].

The publication concerns the relationship between the two variables "patient anxiety" and "assessment of the dentist by the patient". Two instruments were used: the German versions of the "Dental Anxiety Scale" and the "Dental Belief Survey". The answers of 383 patients, age 18 to 80 years, demonstrated that both tests are highly age dependent. There is no difference between males and females in either test in the overall population nor in the individual age categories. Patient anxiety and assessment of the dentist by the patient show a highly significant correlation.

Adult↗