[Developing a plan of treatment with a cast metal frame removable partial denture]. / Het opstellen van een behandelplan voor een frameprothese.

When considering prosthetic replacement of absent teeth, a treatment plan is necessary. In evaluating whether replacement of teeth is sensible, the causes and consequences of tooth loss must be considered. This concerns information about problems having to do with the patient, potential complications, purely prosthodontic problems, and specific problems. The patient-related problems require collecting data through patient history as well as a clinical and radiologic examination. Complications are risk-factors which negatively influence the prognosis of general health or of a treatment. Potential complications should be eliminated as much as possible through a preliminary treatment. Purely prosthodontic problems are conditions in the area of absence of several teeth or parts of them, and in the area of occlusal and mandibular stability and articulation. Specific problems may be related to inadequate interocclusal space and the quality of the abutment teeth. A cast metal frame removable partial denture may be a relatively inexpensive and minimally treatment alternative for an expensive and complicated treatment with 1 or more fixed partial dentures.

[Designing metal frame removable partial dentures]. / Het ontwerpen van conventionele frameprothesen.

Oral health care providers have the full responsibility for designing metal frame removable partial dentures and making all of the necessary preparations. Important principles of design are that the denture should hamper natural cleaning and daily oral hygiene as little as possible and that it should have good stability and retention. The designing process follows several phases without a strict chronological sequence. If it is necessary to return to a previous phase, the process follows a circular sequence. The usual phases are evaluating dental arch study casts, examining diagnostic set-ups, selecting abutment teeth, surveying dental arch study casts, selecting the major connector, selecting minor connector and clasp types, selecting artificial teeth, modifying the denture design from theoretically ideal towards practically optimal, and carrying out the intended tooth preparations in a dental arch study cast. Tooth preparations in the working cast together with a denture design prescription will provide the dental technician with the information needed for manufacturing the metal frame removable partial denture.

[Treatment of removable partial dentures. 2. Causes and consequences of a reduced occlusal system]. / Behandeling met een partiële gebitsprothese 2. Oorzaken en gevolgen van een gereduceerd occlusiesysteem.

The occlusal system is part of the orofacial system and consists of the maxillary and mandibular alveolar ridge and teeth which are occluding or not or the removable denture teeth. The most prevalent causes of loss of teeth are insufficient oral self care or inadequate professional oral healthcare service. A reduced dentition can be described in terms of diastemas in the anterior region and number of occluding pairs of (pre)molars, differentiated as interrupted or shortened dental arches. Characteristic of a healthy functional occlusal system are the absence of pathology and the possibility to practice all oral functions without inconvenience. The consequences of a reduced occlusal system may be overload and/or migration of teeth, mandibular instability, and impaired esthetics and chewing function. Morphological and functional alterations can be considered to be adaptations to changed situations or to be pathological. The distinction between adaptation and pathology cannot be sharply defined. If prosthetic replacement of teeth is needed, the trend is to avoid removable partial dentures.

[Routine oral examinations and specific after-care for removable partial dentures]. / Periodieke mondonderzoeken en specifieke nazorg bij partiële gebitsprothesen.

Following treatment with a removable partial denture, routine oral examinations are required to stabilize the existing condition in a sustainable way and to make possible the timely treatment of anomalies which have appeared. In cases of problems assessed during a routine oral examination in relation to the removable partial dentures, maintenance, restorative and prosthetic treatment may be indicated. Maintenance treatments are indicated for small and easily retrievable alterations. In removable partial denture treatment, adequate space between prepared tooth and denture is essential. Possible prosthetic treatments of a removable partial denture are relining, rebasing, improving or renewing the maxillomandibular relation, repairment, and extension.

[Conventional retaining of removable partial dentures]. / Conventionele verankering van frameprothesen.

Mechanical and biological criteria have to be met in retaining the metal frame of a removable partial denture. Additionally, a removable partial denture is part of the occlusal interface by the clasps and the denture teeth. With respect to mechanical aspects, all rigid parts of the removable partial denture are of importance. However, as clasp arms tend to loose retention during long-term function, it is primarily the minor connectors and rigid clasp arms that provide stability and retention by friction with the guiding planes of the abutment teeth. With respect to biological aspects, comfort and cleansing ability are most important. Their functioning is enhanced by a low number of components crossing the marginal gingiva, such as minor connectors and infrabulge clasps. In the occlusal interface, occlusal interferences both in occlusion and during articular excursions should not be introduced by retainers or denture teeth.

[Adhesive attachments for removable partial dentures]. / Adhesieve precisieankers bij frameprothesen.

Since twenty years adhesive dentistry plays a certain role in the design of removable partial dentures. With the use of adhesive attachments the esthetics and retention of a removable partial denture can be improved. To apply these attachments successfully the contour of a sound abutment has to be corrected by grinding to provide retention and resistance. The procedures for constructing removable partial dentures with adhesive attachments are described. It is recommended to apply adhesive attachments in the general dental practice.

[Restoration materials in overdenture abutment teeth]. / Restauratiematerialen in pijlerelementen onder een overkappingsprothese.

To assess the performance of amalgam, resin composite and resin-modified glass ionomer cement as filling material in overdenture abutment teeth, 155 restorations were made to seal the root canal orifices in 49 patients. The three restorative materials were randomly assigned to the abutment teeth using a number of balancing criteria. All patients were reviewed every six months and received the same preventive regimen. Survival was assessed at two levels: complete survival even without maintenance treatments (Scomp) and survival of the original restoration independent from eventual maintenance treatments (Sorig). The calculated overall survival of Sorig and Scomp were 63 +/- 6% and 57 +/- 6% respectively (mean +/- SE). At both levels no statistically significant differences were observed between the survival of the investigated materials. The results of this study did not point out a superior restorative material for the seal of root canal orifices of overdenture abutment teeth. The distribution of failures over the patients indicated a certain patient dependency.

A 4-year clinical study on amalgam, resin composite and resin-modified glass ionomer cement restorations in overdenture abutments.

OBJECTIVE: To assess the performance of three different filling materials in overdenture abutment teeth. METHODS: In 49 patients amalgam, resin composite and resin-modified glass ionomer cement were used to seal the root canal orifices of 155 overdenture abutment teeth. After initial preparation of the cavities, the three restorative materials were randomly assigned to the abutment teeth using a number of balancing criteria. All patients were reviewed every six months and received the same preventive regimen. Survival was assessed at two levels: Sorig (survival of the restoration independent from eventual maintenance treatments) and Scomp (restorations survived even without maintenance treatments). RESULTS: The calculated overall survival percentage of the original restorations (Sorig) after four years was 63 +/- 6% (mean +/- SE). Calculation for the overall complete survival (Scomp) revealed a percentage survival of 57 +/- 6%. At both levels, the differences between the survivals of the investigated materials were not statistically significant (p-values > 0.05). Two abutments were lost, severe caries was the reason for one extraction and another abutment tooth was extracted for periodontal reasons. CONCLUSIONS: The results of this study did not point out a superior restorative material for the seal of root canal orifices of overdenture abutments. The distribution of failures over the patients indicates a certain patient dependency.

[Single tooth replacement with a removable partial denture]. / De solitaire tandvervanging met een uitneembare prothetische voorziening.

The indication of removable partial dentures in cases of single tooth replacement is limited. This is due to a number of disadvantages closely connected to the use of removable partial denture. An often applied use is that of a mucosa-borne transitional acrylic denture to improve patients aesthetics until the definitive denture can be made. Acrylic dentures may be indicated as a definitive denture when limited financial resources are available. A metal frame removable partial denture can be applied to lengthen a shortened dental arch or in specific cases in which fixed partial dentures are not the preferable treatment option. The success of the treatment with a removable partial denture is highly dependent on the follow-up service and the oral hygiene awareness.

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.

Ten-year evaluation of removable partial dentures: survival rates based on retreatment, not wearing and replacement.

From a group of 1480 patients, 1036 were treated with metal frame removable partial dentures (RPDs) at least 5 years before this analysis. Of those, 748 patients who wore 886 RPDs were followed up between 5 and 10 years; 288 patients dropped out. The 748 patients in the study groups were wearing 703 conventionally designed metal frame RPDs and 183 RPDs with attachments. When dropout patients and patients who remained in the study were compared, no differences were shown in the variables analyzed, which indicated that the dropouts did not bias the results. Survival rates of the RPDs were calculated by different failure criteria. Taking abutment retreatment as failure criterion, 40% of the conventional RPDs survived 5 years and more than 20% survived 10 years. In RPDs with attachments crowning abutments seemed to retard abutment retreatment. Fracture of the metal frame was found in 10% to 20% of the RPDs after 5 years and in 27% to 44% after 10 years. Extension base RPDs needed more adjustments of the denture base than did tooth-supported base RPDs. Taking replacement or not wearing the RPD as failure criteria, the survival rate was 75% after 5 years and 50% after 10 years (half-life time). The treatment approach in this study was characterized by a simple design of the RPD and regular surveillance of the patient in a recall system.

Survival and retreatment need of abutment teeth in patients with overdentures: a retrospective study.

The retreatment need was assessed in 148 patients wearing 125 overdentures in the mandible and 56 in the maxilla. The total number of abutment teeth was 512. During the evaluation period 44 abutments were extracted. The endpoints of the survival analysis after 6 yr were 89%, taking the loss of all abutments as the failure criterion for overdentures. During the clinical examination it was found that 31% of the abutments needed treatment while the retrospective part showed a mean yearly restoration need of 17.5%. Caries was the most important reason for retreatment. These data demonstrated that patients with overdentures should be regarded as high risk patients for retreatment of abutments. Therefore a stringent maintenance program, including regular recall appointments and the application of a preventive regimen, is desirable.

[Fit of anchors in frame prostheses]. / Pasvorm van ankers bij frameprothesen.

The fit of clasps was assessed in 101 removable partial dentures (RPD), including 54 free-end prostheses without any tooth bound replacements and 47 tooth bound prostheses replacing only premolars and molars. The age and the design of the RPD had a significant influence on the fit: in older and in stress broken free-end RPD's the clasps had a worse fit in terms of standing away from the abutment tooth.

Distal extension removable partial dentures supported by implants and residual teeth: considerations and case reports.

The traditional treatment for an edentulous maxilla opposed by a partially edentulous mandible with a complete denture and a distal extension removable partial denture is fundamentally inadequate. Continuing resorption of alveolar bone under the denture base of the removable partial denture causes changes in the occlusal plane. Consequently, overloading of the anterior maxillary region occurs, usually leading to increased bone resorption in the anterior maxillary ridge. Placement of implants beneath the distal extension denture base of the removable partial denture can result in a stable and durable occlusion. Two patients in whom the use of implants combined with a cast metal removable partial denture provided occlusal stability and improved functional comfort are presented.

Effects of chlorhexidine-containing gel and varnish on abutment teeth in patients with overdentures.

Previous experiments have shown that daily use of 1% chlorhexidine gel strongly reduced caries development in the abutment teeth under overdentures. The present experiment was designed to determine whether intermittent application of chlorhexidine, either in a varnish or in a gel, might be used as an alternative preventive method, less demanding for the patient. To this end, 31 patients were distributed among four treatment groups, with the number of mutans streptococci in plaque and saliva used as a balancing criterion. The treatments consisted of a single application of 40% chlorhexidine varnish, daily application of 1% chlorhexidine gel for one week, or the corresponding placebo treatments with varnish or gel without chlorhexidine. Patients were re-called for bacteriological and clinical examination at various intervals during an eight-week period following treatment. Chlorhexidine varnish and chlorhexidine gel applications significantly suppressed mutans streptococci on the abutment teeth for four and eight weeks, respectively. In agreement with earlier findings, the numbers of Actinomyces viscosus/naeslundii in plaque were significantly increased after chlorhexidine varnish treatment. The chlorhexidine gel reduced plaque accumulation and gingival bleeding for one week but had no long-lasting effect. The results seem to justify a long-term clinical test of intermittent chlorhexidine applications as an alternative for daily use in patients with overdentures.

[Etiology and prevention of root caries ]. / Etiologie en preventie van tandwortelcariës.

The prevalence of root caries is increasing. An optimal prevention is important because of the difficulties encountered in restoring these lesions. The pathogenesis of root and enamel caries have strong similarities. Consequently, for both the same preventive means should be applied. It is important to adjust the intensity of the preventive measures to the risk level of the individual patient. For high risk patients the use of chlorhexidine is advised.

Cingulum bar as a major connector for mandibular removable partial dentures.

In the international literature and textbooks, the cingulum bar as a mandibular major connector is often neglected. It is a viable alternative to a lingual bar where the distance between the marginal gingivae and the mucolingual fold is restricted. It also provides indirect retention and thereby eliminates the need for a conventional indirect retainer. Patient comfort with an RPD with a cingulum bar seems acceptable because the connector forms one unit with the anterior teeth. The replacement of a lost natural anterior tooth with a denture tooth is not difficult. The metal bulk of the bar may be a disadvantage and esthetics may be compromised if spacing is present. Marked lingual inclination of the anterior teeth prevents the use of a cingulum bar. Different laboratory requirements are discussed.

Effects of chlorhexidine gel on periodontal health of abutment teeth in patients with overdentures.

The aim of this study was to test the effect of chlorhexidine gel application on periodontal health of abutment teeth in patients with overdentures. 19 patients with immediate overdentures were distributed at random among 2 experimental groups. In these groups, a placebo and chlohexidine gel were daily applied. Patients were recalled at 6-month intervals over a period of 2 years. In both groups, pocket depth, tooth mobility and bleeding index were initially found to decrease after insertion of the overdenture. In the chlorhexidine group, the bleeding index remained very low over the 2-year period. Whereas in the placebo group, the bleeding index gradually returned to the baseline values. The pocket depth in the chlorhexidine group remained below the baseline value, in contrast to values in the control group. The width of the attached gingiva decreased in both the groups, but less in the chlorhexidine group.

Effects of fluoride and chlorhexidine on the microflora of dental root surfaces and progression of root-surface caries.

The effects of fluoride and chlorhexidine varnishes on the microflora of dental root surfaces and on the progression of root-surface caries were studied. Forty-four patients, surgically treated for advanced periodontal disease, were distributed at random among three groups. All patients received a standardized preventive treatment. Furthermore, the dentition of the patients in the two experimental groups was treated, at three-month intervals, with chlorhexidine and fluoride varnish, respectively. Patients in the control group received no additional treatment. In the experimental groups, plaque samples were collected from selected sound and carious root surfaces at baseline and at three, six, and nine months after the onset of the study. The presence of root-surface caries was scored at baseline and after one year. In addition, the texture, depth, and color of the root-surface lesions were monitored. Mutans streptococci on root surfaces were suppressed significantly (p less than 0.05) during the whole experimental period in the chlorhexidine varnish group, but not in the fluoride varnish group. A non-significant increase in the number of Actinomyces viscosus/naeslundii was noted after treatment with chlorhexidine and fluoride varnish. The increase in the number of decayed and filled root surfaces after one year was significantly lower in the experimental groups than in the control group. After treatment with chlorhexidine varnish, significantly more initial root-surface lesions had hardened than in the other groups.