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Biomedical subjects

W Kalk

Publications and source records attributed to W Kalk.

At least 37 records · Page 2Linked to original sources
PubMed1997

Patients' perception of sensory disturbances of the mental nerve before and after implant surgery: a prospective study of 110 patients.

In a randomized controlled clinical trial 110 edentulous patients with severe mandibular bone loss have been treated with ITI-dental implants using three different treatment strategies: (1) a mandibular overdenture supported by two implants with ball attachments, (2) two implants with an interconnecting bar or (3) by four interconnected implants. As implant surgery involves elevation of the mucoperiosteum, bone remodelling at the implant site and insertion of implants close to the mental foramen, altered sensations of the mental nerve caused by the surgery are to be expected. An altered sensation of the lower lip can also be caused by pressure of an ill-fitting lower denture on the mental foramen, or in the case of severe bone loss of the alveolar ridge, on the alveolar nerve itself. This article presents the results of the patients' perception of the sensation of their lower lip before, 10 days after and 16 months after implant surgery in the mandible. It shows that 25% of the patients describe a sensory disturbance before treatment. This 25% also showed high scores on the Hopkins Symptoms Check List indicating a tendency to somatize complaints. Eleven percent of the patients report a sensory disturbance in the lower lip 10 days after surgery. Ten percent report a sensory disturbance 16 months after surgery of which one third also reported a disturbance before the treatment. This implies the risk of a sensory disturbance of the lower lip to be a possible complication after implant surgery. Therefore patients must be informed about this phenomenon before treatment.

Adult↗
PubMed1997

An analysis of satisfaction with complete immediate (over)dentures.

OBJECTIVES: The purpose of the study was to investigate denture satisfaction related to treatment modality, age, gender, denture quality, chewing ability, denture experience and patients' attitude towards denture wearing. METHODS: In a randomized controlled clinical trial 74 patients who required immediate denture therapy were treated either with complete immediate dentures, or with complete immediate overdentures on the lower canines with and without Dyna Direct magnetic attachments. All patients were evaluated clinically and by questionnaires over a one year period after denture insertion. RESULTS: Regression analysis showed that the quality of the denture, chewing ability, attitude towards dentures in general and the expectation of the new dentures can explain the variance in denture satisfaction for 23-27%. CONCLUSIONS: It can be concluded that with respect to satisfaction the technical quality of the dentures, as well as patients' previous attitude towards wearing dentures are the most important factors in immediate denture treatment. The treatment modality, having received an overdenture or not, appeared to be unimportant in this respect in the first year after denture insertion.

Attitude to Health↗
PubMed1997

Patient satisfaction with implant-supported mandibular overdentures. A comparison of three treatment strategies with ITI-dental implants.

In a randomized, controlled clinical trial, 110 edentulous patients with atrophic mandibles were treated with International Team for Oral Implantology-dental implants using three different treatment strategies: a mandibular overdenture supported by two implants with ball attachments, two implants with an interconnecting bar, or four interconnected implants. The patients' opinions and their social functioning were evaluated by means of a questionnaire directly before and 16 months after treatment. Before treatment most patients had complaints about the retention of their mandibular denture. Sixteen months after treatment almost all patients were generally satisfied with their dentures. Since no significant difference was found between the three treatment strategies, it was concluded that simple implant treatment such as an overdenture retained by two ball attachments is sufficient.

Analysis of Variance↗
PubMed1997

[Serious periodontal destruction in the elderly. Intensive treatment or an overdenture prosthesis?].

A minority of dentate elderly people have advanced periodontal disease. Is both non-surgical and surgical periodontal treatment or overdenture treatment the therapy of choice? Research data comparing these treatments, from patients' or professionals' point of view, are as yet not available. Concerning efficacy and cost-effectiveness, overdenture treatment appears to be superior to periodontal treatment.

Aged↗
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

Evaluation of plasma-spray and magnetron-sputter Ca-P-coated implants: an in vivo experiment using rabbits.

The bone response to different plasma-spray and magnetron-sputter calcium phosphate (Ca-P)-coated implants was evaluated in a rabbit animal model. Four types of Ca-P coatings have been investigated: a plasma-spray Ca-P coating (HA-PS), a heat-treated plasma-spray Ca-P coating (HA-PS/ht), an amorphous magnetron-sputter coating (Ca-P-a), and a crystalline magnetron-sputter coating (CA-P-c). Seventy-two specially designed cylindrical implants were inserted in the lateral and medial femoral condyles of 18 New Zealand White rabbits. The four differently coated implants were positioned in one animal according to a split-plot design. After implantation periods of 3, 6, and 9 weeks, the bone-implant interface was evaluated histologically. Besides descriptive light microscopical evaluation, quantitative histomorphometrical measurements were done to determine bone contact and the amount of bone surrounding the implant-bone interface. Light microscopical examination revealed that all types of coatings followed the same process of bone healing. Measurements of bone contact at 6 and 9 weeks did not reveal significant differences between the various coatings. For the amount of bone, in a circular region at a certain distance from the implant, the Ca-P-c-coated implants showed a significantly greater amount of bone after 6 weeks of implantation than did the other three Ca-P coatings. At 9 weeks this difference could no longer be measured. On the basis of these findings we concluded that magnetron-sputtered Ca-P coatings show the same process of bone healing as the plasma-sprayed Ca-P coatings when inserted into the trabecular femoral bone of rabbits.

Animals↗
PubMed1996

Treatment results with immediate overdentures: an evaluation of 4.5 years.

In a controlled clinical trial, 74 patients who required complete immediate dentures were randomly treated with immediate mandibular overdentures on two mandibular canines with or without magnetic attachments or with complete immediate dentures. All were borderline situations for overdenture therapy. The patients were evaluated for 4.5 years after denture insertion. The results demonstrated that 50% of the dentures had been renewed or had required replacement; in this respect, no differences were found among the three groups. In the overdenture groups, 15% of the abutments were extracted; most abutment restorations were replaced or had to be replaced. Two thirds of the magnets were lost or in bad condition. No significant differences were found in relation to patient satisfaction; most patients were satisfied with their dentures. It is the authors' opinion that even though the abutment conditions were disappointing after 4.5 years, mandibular overdenture therapy is indicated in borderline situations because of the 50% reduction in mandibular bone loss found.

Alveolar Bone Loss↗
PubMed1996

Two-center clinical trial of implant-retained mandibular overdentures versus complete dentures-chewing ability.

This study is a two-center clinical trial with the aim to assess the treatment effects of implant-retained mandibular overdentures versus conventional complete dentures. Treatment had been assigned according to a balanced allocation method. The following criteria were used to enhance the comparability of the treatment groups: age, gender, the edentulous period of the mandible, the number of previously made mandibular dentures, the number of years having worn the present mandibular denture and the symphyseal bone height. 151 patients with severely resorbed mandibles participated in the study, they were treated at two centers. Ninety-one patients received an implant-retained mandibular overdenture (IRO) and 60 patients a conventional complete denture (CD). Since some patients refused the allocated treatment the "Intention To Treat" principle was applied. This implies that patients are evaluated in the originally allocated treatment group regardless of the actual treatment they received. Patient's experiences were evaluated before treatment and 1 yr after insertion of the new dentures. Results before treatment showed that both treatment groups were comparable: they were dissatisfied with their mandibular denture and they could hardly chew tough or hard foods. One year after insertion of the new dentures the IRO-group was satisfied with their mandibular denture, whereas only one third of the CD-group was satisfied. With respect to the chewing ability the IRO-group scored significantly better than the CD-group(P<0.0001).

Adult↗
PubMed1996

[Adjustment of complete dentures. Have oral stereognosis and denture quality a predictable value?].

The denture complaints of 397 complete denture wearing participants were assessed. The quality of the dentures and denture bearing surfaces were professionally scored as well. Combination of these scores gave a specific denture quality, the so-called 'prosthetic condition'. The oral stereognostic capability was recorded with an Oral Stereognosis Test. There was no correlation between denture complaints and the results of the Oral Stereognosis Test, nor between denture complaints and prosthetic condition.

Adult↗
PubMed1995

Effect of calcium phosphate (Ca-P) coatings on trabecular bone response: a histological study.

The trabecular bone response to noncoated and fluorapatite (FA), hydroxyapatite (HA), and hydroxyapatite heat-treated (HAHT) plasma-sprayed coated implants was investigated in a goat animal model. Forty-eight cylindrical implants were inserted into the trabecular bone of the lateral and medial femoral condyles of twelve goats according to a split plot design. After an implantation period of twelve weeks, the bone-implant interface was evaluated histologically. Quantitative histomorphometrical measurements demonstrated a significant difference in bone contact between implants inserted in the lateral and medial condyles. In addition, a significant difference in bone apposition was observed between the coated and the uncoated implants. Finally, all Ca-P coatings showed reduction in coating thickness. Measurements revealed that FA and HAHT showed less reduction in coating thickness than HA coating. Despite the coating reduction, the bone remained in close contact with the implant surface.

Analysis of Variance↗
PubMed1995

Patient satisfaction with implant-retained mandibular overdentures. A comparison with new complete dentures not retained by implants--a multicentre randomized clinical trial.

OBJECTIVES: The aim of this study was to establish the treatment outcome of full denture treatment with or without implant support, in which the outcome assessment focuses on the patient's subjective evaluation ('denture-satisfaction'). DESIGN: A multicenter randomized clinical trial. SUBJECTS: Thirty-two men and 118 women (mean age 56 +/- 9, range 35-84 years) participated in the study. The mean height of the mandible was 13 +/- 2 mm, measured on a lateral cephalometric radiograph. The patients were randomly assigned to either a group treated with implant-retained mandibular overdentures and a new maxillary denture, or to a control group treated with a new set of complete dentures. MAIN OUTCOME MEASURES: Denture satisfaction was assessed using questionnaires focusing on denture-related complaints and 'a general satisfaction rate'. RESULTS: Based on the baseline data, from the 'denture complaints' questionnaire six interpretable factors could be extracted. One factor did not vary following treatment and was excluded from the outcome analysis. At the 1-year evaluation three out of five factors showed significantly better scores for the group treated with implants than for the control-group. The same was found for the general satisfaction rate. CONCLUSION: For patients with a severely resorbed mandible, overdentures retained by dental implants appear to provide a more satisfactory solution to their denture-related problems.

Adult↗
PubMed1995

Elderly people's adaptability to complete denture therapy: usability of a geriatric behaviour-rating scale as a predictor.

Accurately predicting prognosis of complete denture therapy requires a reasonable estimation of the ability of a patient to adapt. The aim of the current study was to test the usability of a geriatric behaviour-rating scale (BOP) as a predictor of elderly people's ability to adapt after complete denture therapy. Ninety-five complete denture-wearing residents of four nursing homes for somatically handicapped patients were randomly divided into two groups, 48 test subjects for whom replacement dentures were prepared and 47 test subjects whose current dentures were improved on. The results of these treatments were evaluated by comparing the scores on the so-called 'scale of appreciation' (complaints of and (dis)satisfaction with complete dentures) prior to and at 2 and 6 months post-treatment. Univariate correlations were computed between the scores on the 'scale of appreciation' or the differences in scores at the three evaluation-moments and the foremost BOP-subscale (BOP1, infirmity) and some factors that were considered to be of influence on the process of adaptation. The BOP1 was the only factor showing a significant correlation with the 'scale of appreciation' at 2 months posttreatment; this suggests that little infirmity was connected with a low value of complaints of and dissatisfaction with complete dentures or a positive alteration of this value. It is concluded that the BOP1 can be a useful predictor of complete denture therapy in this group of elderly people. A relationship between elderly people's adaptability to complete denture therapy and the BOP or any other geriatric behaviour-rating scale could be possible.

Adaptation, Psychological↗
PubMed1995

Factors to consider in selecting an occlusal concept for patients with implants in the edentulous mandible.

This article discusses the occlusal concepts when making implant-supported and implant-retained mandibular overdentures. The dentate or edentulous condition of the maxilla plays a significant role in this respect. If the maxilla is edentulous, balanced occlusion is indicated. In a maxillary Kennedy class I or II situation, either group function or balanced occlusion is advocated depending on the characteristics of the opposing dentition. When a complete dentition is present in the maxilla or in the case of a Kennedy class III or IV situation, mutually protected occlusion or group function is recommended depending on the length, position, and number of implants. It is stressed that detailed preimplant placement diagnosis and treatment planning are essential to obtain a high standard of treatment with overdentures supported and retained by implants.

Contraindications↗
PubMed1995

Satisfaction with complete immediate dentures and complete immediate overdentures. A 1 year survey.

The aim of this study was to evaluate denture satisfaction over a 1 year period after extraction of the last teeth. Seventy-four patients who required immediate denture therapy in the mandible were randomly treated, (1) with complete immediate dentures (22); (2) with immediate overdentures on two lower canines without attachments (26); or (3) with immediate overdentures on two lower canines provided with Dyna direct magnetic attachments, inserted on the abutments 9 months after treatment (26). Denture satisfaction was estimated by means of questionnaires, filled out by each patient at certain periods, starting before treatment and ending 1 year after denture insertion. After 1 year approximately 85% of the patients in the three groups were satisfied with their dentures, had got used to them and could eat well. This phenomenon was constant over the whole first year period. No differences in denture satisfaction were found between the three groups. It can be concluded that although patients who receive immediate complete dentures might experience a lot of discomfort during the first year of edentulousness, they are satisfied, in general, with their dentures independent of the treatment procedure.

Adaptation, Psychological↗
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

["Prosthetic condition" and satisfaction with dentures].

This study introduces the concept of 'prosthetic condition', combining the professionally assessed complete denture quality and quality of the residual alveolar ridge. In a group of 397 complete maxillary and mandibular denture wearers the prosthetic condition was assessed and the denture satisfaction recorded. The total prosthetic condition (maxillary and mandibular combined) was good in 225 (57%), moderate in 81 (20%), and poor in 91 (23%) subjects; the mandibular prosthetic condition was good in 155 (39%), moderate in 148 (38%), and poor in 94 (23%) subjects; 297 (75%) subjects were satisfied with their dentures. None of the criteria used for the prosthetic condition could explain the denture satisfaction. Furthermore, there was no significant correlation between prosthetic condition and denture satisfaction.

Adult↗
PubMed1994

Relationship between wearing a removable partial denture and satisfaction in the elderly.

Natural dentitions of elderly people are often reduced, remaining teeth heavily restored and removable partial dentures (RPD's) frequently used to replace absent teeth. Lack of knowledge exists on how the elderly experience the comfort of these replacements. To get more insight 320 dentate noninstitutionalized subjects between 55 and 75 yr of age were clinically examined and interviewed by means of a questionnaire. Data showed that only 13% of the subjects had a complete dentition from the right to the left first molar; 50% had less than four occlusal units. 39% of the subjects was wearing a RPD. Analysis showed that subjects with a RPD were in general less satisfied with their dental state than subjects without a partial denture. However, when the RPD added occlusal units to the dentition, satisfaction increased significantly. No differences in satisfaction were found between subjects with a metal frame prosthesis and an acrylic denture, nor between tooth-bounded and distal extension prostheses. The conclusion can be drawn that the indication for a RPD should be limited in elderly people, unless the RPD increased the number of the occlusal units.

Aged↗