Biomedical subjects

R P van Oort

Publications and source records attributed to R P van Oort.

At least 19 recordsLinked to original sources

PubMed2005

[Oligodontia: treatment plan and therapy].

The aim of this retrospective study was to gain insight in treatment planning and therapy for patients with oligodontia. Records of 58 treated patients with oligodontia were screened using several parameters: gender, year and age of registration, symptoms, case history, treatment plan and therapy. Treatment plans were sorted into the following categories: tooth-supported overdentures, fixed or removable partial dentures and implant-supported restorations. Dependent on the complexity of oligodontia, it is advocated to make a treatment plan before the age of 12 years old and to follow the provided treatment conscientiously until the final prosthetic treatment. After analyzing the 58 treatment plans, the following conclusions could be made: the treatment plan was not in all cases made before the age of 12 years, it was not clear in all cases who was the coordinator of the treatment and dental implants are becoming more and more important in treating patients with oligodontia.

Adolescent↗

PubMed2003

[Dental treatment anxiety. A review of useful anxiety-measuring instruments].

Dental anxiety is a common problem. Different tests have been developed to measure the nature and the severity of dental anxiety or phobia. These tests can help to identify highly anxious patients who need special dental care. In this article, the dental anxiety tests useful in The Netherlands are reviewed.

Dental Anxiety↗

PubMed2001

Treatment outcome of bone-anchored craniofacial prostheses after tumor surgery.

BACKGROUND: Percutaneous endosseous implants have acquired an important place in the prosthetic rehabilitation of patients with craniofacial defects. The objective of this study was to evaluate the clinical outcome of the use of endosseous implants in the orbital and auricular region as well as to assess the satisfaction of patients with implant-retained craniofacial prostheses after tumor surgery. METHODS: The clinical outcome and patient satisfaction of implant-retained prostheses in the auricular and orbital region were evaluated in a group of 26 patients with facial defects after tumor surgery by using standardized questionnaires and a clinical assessment. Twelve patients (n = 31 implants) received the implants during ablative tumor surgery, from which 7 patients (n = 20 implants) were treated with radiation therapy after surgery (mean, 65 grays [Gy]). Fourteen patients (n = 44 implants) received the implants after the tumor surgery, from which 5 patients (n = 21 implants) were irradiated after ablative surgery (mean, 54.4 Gy), but before implant placement. RESULTS: No implants were lost in patients who had not undergone irradiation (100%), whereas 5 implants were lost in the irradiated group (87.8%). The overall implant survival rate was 93.3%. The peri-implant tissues had a healthy appearance, and no cases of osteoradionecrosis occurred. When compared with patients treated with conventional adhesive retained facial prostheses, satisfaction was higher in patients treated with implant-retained facial prostheses. CONCLUSIONS: From this study, it is concluded that implant-retained facial prostheses are better tolerated than adhesive retained prostheses and offer an improvement in the quality of life. Radiotherapy is not a contraindication for the use of osseointegrated implants in the maxillofacial region, but the loss of implants is higher than in nonirradiated sites.

Adult↗

PubMed2000

Effectiveness of three treatment modalities for the edentulous mandible. A five-year randomized clinical trial.

Currently, 3 treatment options are available for patients with denture complaints and an edentulous mandible with a height of at least 15 mm: meticulous construction of a new set of dentures (CD), construction of a new set of dentures following preprosthetic surgery to enlarge the denture-bearing area (PPS), and construction of an implant-retained mandibular overdenture (IRO). The aim of this study was to evaluate patient satisfaction and subjective chewing ability of edentulous patients treated with one of these treatment modalities. Ninety edentulous patients (Cawood class IV and V, mean mandibular height 20.7 mm) were randomly assigned to receive 1 of these 3 groups. Denture satisfaction and chewing ability were assessed using questionnaires focusing on denture-related complaints and problems chewing different types of food were assessed before treatment, and 1- and 5-years after treatment. At the 1-year evaluation, significantly better scores were observed in the 2 surgical groups (IRO, PPS) than in the CD group. At 5-year evaluation the "complaints of the lower denture" showed a significantly better score in the IRO group when compared to the PPS and CD groups. No significant differences were observed between the PPS and CD group. From this study it is concluded that both in the short and long term denture satisfaction appears most favourable in the IRO group when compared to the PPS and CD groups. Implant-retained overdentures are therefore a satisfactory treatment modality for edentulous patients with problems with their lower denture, even in cases of not severely resorbed mandibles.

Analysis of Variance↗

PubMed1999

Bone grafting of cleft lip and palate patients for placement of endosseous implants.

OBJECTIVE: Fixation of a prosthesis or single tooth replacement using osseointegrated implants has the potential to overcome functional and psychological inconveniences that many patients experience from such appliances. However, the dimensions of the recipient site are relatively often inadequate for implant placement. This study assessed grafting of this site with autogenous bone as a solution for the latter problem. METHODS: Ten cleft lip and palate patients had bone grafts; six had iliac crest grafts to the maxillary sinus floor (31 implants), and four had chin bone grafts to the local defect in the anterior maxilla (six implants). Implants were inserted during the grafting procedure (one patient) or after 3 months (nine patients). RESULTS: No inflammation of the bone grafts or the maxillary sinus occurred. One implant was lost during the healing phase. Four single tooth restorations, one fixed bridge, and five implant-supported overdentures were made. During the follow-up, which was 47 months (range, 28 to 65 months) in the anterior maxilla group and 56 months (range, 28 to 68 months) in the posterior maxilla group, no loss of implants was observed, and all prosthetic appliances functioned well. CONCLUSIONS: It is concluded that bone grafting followed by placement of dental implants can serve as a reliable alternative for conventional prosthetic rehabilitation of cleft patients.

Adolescent↗

PubMed1998

[Fixation of facial and auricular prosthesis with osseous implants in cranial bone].

OBJECTIVE: To evaluate the use of osseointegrated implants to fix facial and auricular prostheses. DESIGN: Retrospective. SETTING: University Hospital Groningen, the Netherlands. METHODS: Thirty patients were treated with Brånemark implants for fixation of auricular (21 patients) and orbital (9 patients) prostheses during May 1988-December 1995. The complications during the procedure, the success rate of the implants, skin reactions around the implants and patient satisfaction were recorded. RESULTS: A total of 97 implants were placed. One implant had to be removed after the healing period because it was loose. No other implants were lost during the follow-up period (mean 36 months; range: 12-91). The skin around the implants sometimes showed a mild reaction which could be adequately treated. In most of the cases no inflammation of the skin was observed. Retention, ease of handling and wearing comfort of the facial prostheses were excellent. CONCLUSION: Fixation of facial and auricular prostheses can be improved by osseointegrated implants resulting in high patient satisfaction.

Adolescent↗

PubMed1998

[Comparison of dental implant systems for mandibular overdentures].

OBJECTIVE: To compare three implant systems in patients with severely resorbed mandibles 1 year after insertion of the mandibular denture. DESIGN: A prospective multicenter randomized clinical trial. SETTING: Centers at University of Nijmegen and Groningen. METHODS: Three different implant systems were used: the transmandibular implant, the IMZ and the Brånemark system. Treatment was assigned to 88 patients according to a balanced allocation method. Evaluation included clinical and radiographic parameters. A Clinical Implant Performance scale (CIP) was constructed based on all conceivable complications of the different implant systems. RESULTS: During the healing period 1 IMZ- and 1 BRA-implant were lost. One TMI was removed after functional loading. The results of the clinical and radiographic parameters and the CIP-scale showed no significant differences between the three implant systems. CONCLUSION: Taking the one year evaluation into account the three systems used did not differ in clinical and radiographic performance.

Dental Implantation, Endosseous↗

PubMed1998

[Overdenture prostheses on implants versus complete dentures].

OBJECTIVE: To establish the treatment outcome of implant retained overdentures (IRD) versus complete dentures (CD) in which the outcome assessment focuses on the patient's subjective evaluation ('denture-satisfaction and chewing ability'). DESIGN: A multicenter randomized clinical trial (prospective). SETTING: The department of Oral Function and Prosthetic Dentistry of the University of Nijmegen, the department of Oral and Maxillofacial Surgery of the University Hospital Nijmegen and the department of Oral and Maxillofacial Surgery and Maxillofacial Prosthodontics of the University Hospital Groningen. METHODS: In this study 151 patients with severely resorbed mandibles participated, treatment had been assigned according to a balanced allocation method. Denture satisfaction and chewing ability were assessed using questionnaires before and 1 year after treatment. RESULTS: Before treatment all patients were dissatisfied with their mandibular denture and they could hardly chew tough or had food. One year after treatment the IRD-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 < or = 0.0001). 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.

Alveolar Bone Loss↗

PubMed1998

Overdentures stabilised by two IMZ implants in the lower jaw--a 5-8 year retrospective study.

Clinical and radiographical parameters were assessed in forty patients with overdentures stabilised by two IMZ implants connected by a bar in the lower jaw in a 5-8 years retrospective study. Results indicated that most patients had healthy peri-implant tissues, the mean pocket probing depth was 3.1 mm and the median periotest value was -4. Three implants were removed after the healing period and replaced by three new implants. One implant was lost after six years. One implant was mobile on palpation. None of the patients showed objective signs of dysaesthesia in the lower lip or chin. The peri-implant bone level of most implants had remained stable after one year of service. The overall success rate was 94% (Albrektsson et al.) and it is therefore concluded that two IMZ implants, connected with a bar in the lower jaw, provide a stable base for long-term support of a mandibular overdenture.

Adult↗

PubMed1997

[A prosthodontic concept using implants in the resorbed edentulous maxilla].

For the treatment of the atrophic edentulous maxilla implant supported overdentures provide the opportunity to obtain proper lip support, speech and cleanliness. A superstructure with high rigidity is needed for an optimal distribution of occlusal loading, to ensure good prognosis for implant survival. A prosthodontic concept using a hybrid construction meets these criteria. It consists of a cast and precision-milled mesostructure fixed to the implants, over which that a removable cast prosthodontic device is placed to which the teeth are attached. It is essential to follow a strict treatment protocol to obtain a good and predictable result.

Alveolar Bone Loss↗

PubMed1997

A controlled clinical trial of implant-retained mandibular overdentures: clinical aspects.

In a controlled clinical trial, treatment effects of mandibular overdentures on two different implant-systems in edentulous patients were compared one year after insertion of the new dentures. The implant-systems used were the Brånemark system (Brå) and the IMZ-system. Treatment was randomly assigned to 60 patients according to a balanced allocation method. Evaluation included peri-implant and radiographical parameters. According to the Delphi method a clinical implant performance scale (CIP) was constructed based on all conceivable complications of the different implant systems. During the osseointegration period, five Brå- and one IMZ-implants were lost. The results of one of the peri-implant parameters and the radiographical score showed significant differences considering the (pseudo) pocket probing depth (Brå better than IMZ, P < 0.001) and the radiographic-score (IMZ better than Brå, P < 0.003). The results for the CIP-scale were less favourable for the Brå-group than for the IMZ-group; however, these differences were not significant.

Adult↗

PubMed1996

Clinical aspects of a multicenter clinical trial of implant-retained mandibular overdentures in patients with severely resorbed mandibles.

In a multicenter clinical trial treatment, the effects of overdentures on different implant systems in patients with severely resorbed mandibles were compared 1 year after the insertion of new dentures. The implant systems used were the transmandibular implant (TMI), the IMZ (IMZ), and the Brånemark system (BRA). Treatment was randomly assigned to 88 patients according to a balanced allocation method. Evaluation included peri-implant and radiographic parameters. According to the Delphi method a Clinical Implant Performance scale (CIP) was constructed based on all conceivable complications of the different implant systems. During the healing period, one IMZ and one BRA implant were lost, and one TMI implant was removed after functional loading. The results of the peri-implant and radiographic parameters and the CIP scale revealed no significant differences between the three implant systems.

Adult↗

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

[Prosthetic reconstruction after oncological surgery in the head and neck region].

The aim of maxillofacial prosthetics is the treatment of patients with head and neck disease in a multidisciplinary way. Intraoral and facial defects are preferably reconstructed by surgical transplantation methods. Patient factors and oncologic factors determine the indication of prosthetic reconstructions. The treatment of patients with an intraoral or facial defect should be based on a close cooperation between maxillofacial prosthetist and MFP technician. The rehabilitation process and the specific role of each are described.

Dental Technicians↗

PubMed1996

[Cost-effectiveness analysis of dental implants].

In this article the cost-effectiveness of dental implants (rootform and transmandibular) is compared with making complete dentures combined with vestibuloplasty and just a set of new dentures. The cost components of labour and technique are analysed at the individual patient level. Effectiveness was measured using a ratio scale. Several assumptions for the long run effectiveness of the treatment options are necessary due to lack of information about this in the literature. Assumptions were made regarding: survival rate, life span of dental implants and complete dentures, costs of aftercare and development of oral health in the long run. The main conclusion is that overdentures on rootform implants are superior to complete dentures combined with preprosthetic surgery or overdentures on a transmandibular implant. The choice between treatment with rootform implants or just a new set of dentures is a more difficult matter.

Cost-Benefit Analysis↗

PubMed1995

[Dental implants: cost-effectiveness analysis].

The efficacy and effectiveness of dental implants have been proven during the last years. An economic evaluation must be integrated within the clinical evaluations to determine economic (allocative) efficiency. According to the literature dental implants will show better results. The treatment is, however, more expensive. Assessment of costs and benefits can lead to more efficiency in dental care. The possibilities to evaluate the outcome of treatment are discussed and essential aspects of the economic evaluation are described.

Consumer Behavior↗

PubMed1994

Overdentures supported by two IMZ implants in the lower jaw. A retrospective study of peri-implant tissues.

Between 1987 and 1990, 57 edentulous patients were treated with overdentures supported by 2 endosseous IMZ implants connected by a bar in the lower jaw. The condition of the peri-implant tissue was evaluated for a loading period ranging from 12 to 57 months (mean 30 months and median 24 months). The evaluation parameters included Plaque Index, Bleeding Index, Gingiva Index, pocket depth, dysesthesia of chin or lip, peri-implant bone loss and loss of implants. During the healing phase prior to the construction of an overdenture, 3 implants were lost. After a healing period of 6 months, these implants were successfully replaced. During the follow-up period, a Plaque Index < or = 1 was observed in 45 patients and an abundance of plaque and calculus was observed in 1 patient. Heavy or profuse bleeding and severe gingival inflammation was observed in 3 patients. The mean pocket depth was 3.6 +/- 1.7 mm. None of the patients experienced lip or chin dysesthesia. Marginal bone loss was observed around 30 (26%) implants. From this study it is concluded that, once proper osseointegration is obtained, 2 IMZ implants connected with a bar in the lower jaw supply a proper base for the support of an overdenture; the condition of the peri-implant tissues is steady and independent of the follow-up time.

Adult↗

PubMed1993

Use of the final denture base for the intermaxillary registration in an implant-supported overdenture: technical note.

A method of implant-retained overdenture treatment based on the early use of the final denture base during registration of the maxillomandibular jaw relation is described. Using this stable denture base, an accurate recording of jaw relation and an adequate try-in procedure are facilitated without displacement of the base, especially in the situation of an unfavorable flat edentulous mandibular residual ridge.

Alveolar Bone Loss↗