PubMed Health⌕ Search

Biomedical subjects

A F Käyser

Publications and source records attributed to A F Käyser.

At least 19 recordsLinked to original sources
PubMed1999

The shortened dental arch concept and its implications for oral health care.

The minimum number of teeth needed to satisfy functional demands has been the subject of several studies. However, since functional demands--and consequently the number of teeth needed--can vary from individual to individual, this minimum number cannot be defined exactly. In general, occlusion of a complete dental arch is preferable. However, this goal might be neither attainable, for general, dental or financial reasons, nor necessary. Many studies demonstrate that shortened dental arches comprising the anterior and premolar regions can meet the requirements of a functional dentition. Consequently, when priorities have to be set, restorative therapy should be aimed at preserving the most strategic parts of the dental arch: the anterior and premolar regions. This also implies that in cases of a shortened dental arch, the prompt replacement of absent posterior molars by free-end removable partial dentures leads to overtreatment and discomfort. The shortened dental arch concept is based on circumstantial evidence: it does not contradict current theories of occlusion and fits well with a problem-solving approach. The concept offers some important advantages and may be considered a strategy to reduce the need for complex restorative treatment in the posterior regions of the mouth.

Adult↗
PubMed1997

Dentists' attitudes to the shortened dental arch concept.

The aim of restorative dentistry in high-risk groups tends to shift over time from the preservation of complete dental arches towards the preservation of functional dental arches, using a functionally oriented approach. An example of this approach, aimed at limited treatment goals, is the shortened dental arch (SDA) concept. The objective of this study was to investigate dentists' attitudes to the SDA concept in general practice. A questionnaire seeking information pertaining to the attitudes and application of the SDA concept in clinical practice was sent to all dentally qualified members of staff in the field of restorative dentistry in the Nijmegen School of Dentistry (n = 64). From a 64% response, it was found that all but one of the respondents view the SDA concept as having a useful place in clinical practice. Although the respondents indicated only regular or occasional use of SDA in < 10% of patients, the outcome of SDA management was generally satisfactory or at least sufficient, notably in the care of special category patients. The findings support the view that the SDA concept has a role in contemporary clinical practice.

Attitude of Health Personnel↗
PubMed1997

Fit of direct retainers in removable partial dentures after 8 years of use.

In a cross-sectional study the fit of direct retainers was assessed after 8 years of use. A total of 101 metal frame removable partial dentures (RPD) were investigated, including 54 extension base prostheses without any tooth supported replacement and 47 tooth supported prostheses that replaced only premolars and molars. Of the frameworks studied, about 60% of the clasps showed a space between retainers and abutments. Logistic regression analyses demonstrated that the age of the RPD and the type of opposing dentition significantly influenced the fit of the clasps. The relative risks and a backward regression analysis revealed that the variable non-rigid extension base RPD had the greatest influence on clasp fit. It was concluded that in extension base RPDs a rigid design should be preferred.

Adult↗
PubMed1997

[Occlusion repair or occlusion loss? Results of preliminary treatment as the starting point].

Epidemiological data confirm that the number of elderly with an impaired dentition is increasing. The treatment of patients with an impaired dentition should be focused on maintaining oral function during life-time. However this goal is hardly achievable because of the complicating factors in an impaired dentition. This article describes the Nijmegen Dental School approach in the treatment of impaired dentition and stresses the importance of the preliminary treatment in order to answer the question whether restoring or extracting teeth is the most appropriate treatment modality.

Aged↗
PubMed1996

[Partial models in fixed prosthodontics].

In general there is consensus regarding the required criteria for crown- and bridge restorations. However, the variety in methods used for their fabrication is large. Textbooks and courses tend to advocate the use of full arch impressions without supplying objective data indicating better clinical behaviour of these restorations compared with the use of quadrant impressions. This article presents advantages, disadvantages, indication and essential steps when using quadrant models.

Dental Casting Technique↗
PubMed1995

The survival rate of bridges. A study of 1674 bridges in 40 Dutch general practices.

The survival rate of 1674 bridges and the influence of several factors on the lifetime of bridges were analysed, based on data from patient records that belonged to a random sample of 40 Dutch general practices. It appears that the 12 year survival rate of the bridges is 87%. There is a significant difference in the survival rate between the bridges that meet and do not meet Ante's law, and only a weak significant difference between the bridges with vital vs. non-vital abutment teeth. Gender and age of the patient, length of the bridge, presence of a post and core build-up, or the construction of the bridge (conventional fixed vs. cantilever pontic) appear to have no influence on the survival rate of the bridges in this sample.

Adult↗
PubMed1995

Satisfaction with reduced dentitions in elderly people.

Natural dentitions of elderly people are often reduced and the remaining teeth are heavily restored. It is unknown whether they are satisfied or dissatisfied with this situation. To get more insight into this phenomenon 320 dentate non-institutionalized elderly subjects were clinically examined and interviewed by means of a questionnaire. Analysis of the data showed that only 13% of the subjects had at least a complete dentition from the right first molar to the left first molar; 50% had less than four occlusal units, 39% of the subjects were wearing a removable partial denture. Ninety per cent of the subjects was satisfied with the dental state and nearly all subjects mentioned they could chew well (97%), despite the fact that 91% of the subjects mentioned they had to deal with one or more dental discomforts. Satisfaction decreased significantly when the number of the occlusal units was reduced or a removable partial denture was present. The conclusion is drawn that although the dentitions of the elderly are often reduced they are, in general, satisfied with their dental state.

Aged↗
PubMed1995

Porosity in resin composite core restorations: the effect of manipulative techniques.

Forty acrylic resin duplicates of an endodontically treated and extracted human molar were restored with two resin composite materials for core restorations. Two different manipulation techniques, bulk insertion and syringe application, were used. In a simulated clinical setup, the core buildups produced by the different manipulation techniques were investigated for voids. In 20 duplicates, a post was placed to simulate a metal post and resin composite core buildup. The syringe technique produced significantly fewer incorporated voids for both resin composite core materials than did the bulk insertion technique. It was not possible to demonstrate a relationship between the presence of voids and the presence of a metal post.

Analysis of Variance↗
PubMed1994

A 6-year follow-up study of oral function in shortened dental arches. Part I: Occlusal stability.

In this clinical 6-year follow-up study subjects with shortened dental arches (SDA, n = 55), characterized by the absence of molar support, are compared with subjects with complete dental arches (CDA, n = 52) with respect to occlusal stability. In addition, a small group of subjects with SDA and removable partial dentures in the lower jaw (SDA+RPD, n = 19) is included in this study. The aim of this study was to describe effects regarding occlusal stability in subjects with SDA during a 6-year period. The applied parameters for occlusal stability are: number of occlusal contacts in the anterior region, overbite, interdental spacing and alveolar bone support. The results of this study show that: (i) SDA do provide durable occlusal stability; (ii) free-end RPD do not contribute to occlusal stability in SDA; and (iii) SDA with periodontally involved teeth show continuing periodontal breakdown.

Adult↗
PubMed1994

A 6-year follow-up study of oral function in shortened dental arches. Part II: Craniomandibular dysfunction and oral comfort.

In this clinical 6-year follow-up study subjects with shortened dental arches (SDA, n = 55), characterized by the absence of molar support, are compared with subjects with complete dental arches (CDA, n = 52) with respect to items concerning craniomandibular dysfunction and oral comfort. In addition, a small group of subjects with SDA and removable partial dentures in the lower jaw (SDA + RPD, n = 19) is included in this study. Oral comfort is defined using the following criteria: (i) absence of pain and distress, meaning the absence of signs and symptoms of craniomandibular dysfunction: (ii) chewing ability; and (iii) appreciation of the appearance of the dentition in relation to absent posterior teeth. Additionally, complaints about the free-end RPD are described. It is concluded that: (i) a SDA (consisting of 3-5 occlusal units, OU) is not a risk factor for CMD and is able to provide long-term sufficient oral comfort; and (ii) free-end RPD (in the lower jaw) in SDA do not prevent CMD and do not improve oral function in terms of oral comfort.

Adult↗
PubMed1994

A meta-analysis of durability data on conventional fixed bridges.

A meta-analysis was performed on the dental literature since 1970, presenting clinical data of conventional bridges. 42 publications were found that contained durability data of conventional fixed bridges. These publications dealt with 33 different samples. According to the exclusion criteria 26 studies were excluded for the meta-analysis. The data of 4118 conventional bridges were analyzed. The calculated overall survival rate was 74.0 +/- 2.1% after 15 yr.

Adult↗
PubMed1993

An analysis of durability data on post and core restorations.

An attempt was made to review the dental literature since 1970, presenting clinical data of posts and core restorations, by the use of a meta-analytic procedure. Fourteen publications were found that contained durability data on post and core systems. According to the exclusion criteria 11 studies were excluded for further analysis of the data. The survivals of these studies varied from 98.6% survival after a follow-up period of more than 10 years (F.S. Weine et al. 1991, J. Endodont. 17, 293-297) to 77.6% survival after a mean follow-up period of 5.2 years (D.H. Roberts, 1970, Br. Dent. J. 128, 117-124). The data of the three selected studies were reconstructed according to the method of Kaplan-Meier but could not be combined for an overall survival assessment because the study characteristics were too heterogeneous. Therefore the survivals were presented separately. The reconstructed survivals of the studies after 6 years were 81% survival (standard error 6%) for resin composite build-ups in combination with screw posts and 91% survival for two studies including cast posts and cores (standard errors respectively 3% and 2%). Although it was not meaningful to combine the data for an overall survival, the meta-analytic method of this study revealed homogenic survival data and as such the followed procedure is considered to be an appropriate method to obtain insights in clinical durability data.

Clinical Trials as Topic↗
PubMed1993

Survival rate and failure characteristics of the all metal post and core restoration.

In this retrospective study 516 teeth restored with a cast post and core build-up were followed from 1970 till 1990. The data was derived from the dental records of 283 dental clinic patients treated by senior students. The survival rate was found to be 82% after 10 years for post and cores in the anterior region. The most frequent failure characteristic was recementation (46%), followed by rerestoration (32%). The solitary provisions in posterior teeth showed a relative high survival rate, compared with other tooth-types and locations.

Equipment Failure↗
PubMed1993

Clinical performance of different post and core systems--results of a pilot study.

During the period 1974-1986, 112 post and core build-ups were inserted in 74 patients. The build-ups consisted of a metal prefabricated post (Dentatus, Unimetric or Radix) in combination with a composite core. After an average follow-up period of 7.9 years, 14 failures (12.5%) were noticed. Eight teeth could be rerestored and six teeth had to be extracted. However, when correction was made for teeth with a bad initial prognosis and for extractions not related to the build-up restoration, eight failures remained caused by failure of the build-up (7.5%). The Dentatus posts seemed to increase the risk for failure.

Dental Restoration Failure↗
PubMed1993

Oral function in dentate elderly with reduced dentitions.

This study covers the characteristics of reduced dentitions in a population of elderly people. The sample consisted of 329 independently living individuals between 55 and 75 years of age. They all had one or more natural teeth and were all interviewed and investigated clinically. The findings showed that 13% of the subjects had a natural dentition with at least the first molars; 4-7 natural occlusal units (defined as 'pairs of opposing teeth that support the occlusion') occurred in 37% of the subjects; 1-4 natural occlusal units in 41% and 0 units in 9% (only anterior contacts). A removable partial denture was worn by 39% of the subjects; most of them were acrylic based dentures (61%). The percentages of restored teeth per subject were high. The need for further restorations, however, was low. Periodontal problems were uncommon; 25% of the subjects had one pocket above 5 mm; 8% had severe problems. Poor oral hygiene was present in a quarter of the cases. Most of the subjects (70%) had no pain or noises in the temporomandibular joint. Only 10% of subjects had more than one sign of craniomandibular dysfunction. Most of the subjects (85%) visit their dentist regularly and 65% had their last tooth extraction more than three years ago. A majority mentioned that they have never had problems with their dentition in the past; 50% had had no real toothache for the last five years. However, problems with food-packing were often mentioned. It can be concluded that, although the dentitions of the elderly in this population are often reduced, their dentitions are in general in good condition and few give TMJ problems.

Aged↗
PubMed1993

Prevalence in the Dutch adult population and a meta-analysis of signs and symptoms of temporomandibular disorder.

A nationwide survey of oral conditions, treatment needs, and attitudes toward dental health care in Dutch adults was carried out in 1986. One of the aims of the study was to assess the prevalence of signs and symptoms of temporomandibular disorder (TMD). A sample of 6577 persons (from 15 to 74 yr of age), stratified for gender, age, region, and socio-economic status, was contacted. Of this sample, 4496 persons participated in the behavioral part of the study, of whom 3526 were examined clinically. The TMD prevalence was based on (1) perceived signs and symptoms of TMD and (2) clinical examination of joint sounds, deviation, and pain on mandibular movements. A total of 21.5% of the Dutch adult population perceived some dysfunction, and 44.4% showed clinically assessed signs and symptoms of TMD. In nearly all age groups, the signs and symptoms of TMD appeared more in women than in men. Agreement between the results of the clinical examination and the anamnestic dysfunction index was significant (p < 0.0001); however, the Pearson's correlation coefficient was low (r = 0.29). The odds-value (risk-ratio) that subjects who perceived signs and symptoms of TMD would present with clinically assessed signs and symptoms of TMD was 2.3. The results of the survey were compared with results of a meta-analysis performed on 51 TMD prevalence studies. The analysis revealed (1) a perceived dysfunction rate of 30% and (2) a clinically assessed dysfunction of 44%, both based on compound samples of, respectively, over 15,000 (23 studies) and over 16,000 (22 studies) randomly selected subjects.

Adolescent↗