[Prosthetic dilemmas. Prosthetic decisions and planning for partially edentulous patients]. / Prothetische dilemma's. Prothetische beslissingen en planning bij partieel betande patiënten.

The treatment with implants of partially edentulous patients involves several prosthodontic and implantological dilemmas. The treatment plan is based on a thorough dental diagnosis and a prognosis for the remaining dentition. In addition, various aesthetic and functional parameters are important, such as smile line, gingival contour, presence of interdental papilla, visible amount of gum when laughing, support of the soft tissues, bone heights and occlusal relationships. The planning may include dental, surgical and orthodontic treatments, in order to create a favourable starting point for treatment with implants.

[Alveolar ridge augmentation with hydroxylapatite. A clinical evaluation]. / Hydroxylapatiet-augmentatie. Een klinische evaluatie.

In a retrospective study on the effects of an absolute augmentation of the atrophic alveolar ridge with hydroxylapatite, the patient satisfaction rate with the present denture and the loss in height of the augmentation were assessed. Most patients indicated an improved functioning with their dentures after the operation; nevertheless, the patient satisfaction rate was lower than expected. Additionally a concerned loss in height of the augmentation was demonstrated over the evaluation period of 3.5 years. In selected cases, however, the hydroxylapatite augmentation of the atrophic alveolar ridge may still have its value in preprosthetic surgery.

The incomprehensible success of the implant stabilised overdenture in the edentulous mandible: a literature review on transfer of chewing forces to bone surrounding implants.

The approach of implant stabilised overdentures has become one of the routine treatment modalities for compromised edentulous ridges. The purpose of this literature review is to analyze survival rates of loaded implants, occlusal forces and stress distributions of implant stabilised overdentures in edentulous mandibles and of fixed loaded implants at least over a medium-term period. which is comparable with fixed prostheses. Patients with implant stabilised overdentures and with fixed bridges on implants generate similar occlusal forces. The number of implants under a prosthetic construction seems to have less influence on stress distribution than design of the superstructure and related direction of forces.

Clinical evaluation of mandibular overdentures supported by multiple-bar fabrication: a follow-up study of two implant systems.

A retrospective follow-up study was undertaken to assess the clinical condition, complications, and prosthodontic aftercare of two different implant systems over a long period. Thirty-six patients treated with a total of 135 ITI type F endosseous implants, and 37 patients treated with the transmandibular implants and a total of 146 transmandibular posts, were studied during a mean follow-up period of 70 months and 44 months, respectively. The choice of implant type was mainly influenced by a change in financial support by the National Health Insurance Company in The Netherlands in 1987. Cumulative success rates were calculated using the Kaplan-Meier product limit method. In the analysis, the risk for failure of the implants was adjusted for differences in mandibular bone height. There were no differences between the two treatment groups with regard to age, gender, period of edentulousness, and mandibular bone height. During the follow-up period, plaque, bleeding, and hyperplasia scores demonstrated no significant differences between the two groups. The ITI type F group showed significantly more recession, and the transmandibular implant group demonstrated significantly increased Periotest values. After adjusting for differences in bone height, patients treated with ITI type F implants had a lower risk of failure (relative risk, 0.55; 95% confidence interval 0.32 to 0.95). However, neither of the implant systems fulfilled Albrektsson's criteria of success.

[The single, hollow titanium cylinder implant (I.T.I.)]. / Het holle cilinder titanium implantaat type F (I.T.I.).

In cases of extreme bone loss of the edentulous jaw, nowadays, implants are suitable to create retention and stabilisation for the dentures, next to the wellknown preprosthetic surgical techniques. It is also possible to use this implant as replacement of a single tooth or as abutment for a bridge. The single hollow titanium cylinder implant type F is described. Also the surgical technique for application of this implant is explained. In the period October 1983 till December 1987, 126 implants (39 patients) were placed; eight of them are removed (6%).