One year clinical performance and post-operative sensitivity of a bioactive dental luting cement--a prospective clinical study.

A one-year clinical study was performed on the efficacy of a bioactive dental cement (Ceramir C&B) with calcium aluminate and glass ionomer components. The study was performed on 38 crown and bridge abutments in 17 patients. Preparation parameters were recorded, as well as working-times, setting-times, and other handling characteristics. Baseline data were also recorded for gingival inflammation (GI) and pre-cementation sensitivity. Post-cementation parameters included sensitivity, gingival tissue reactions, marginal integrity and discolorations. All patients were seen for recall examinations at 30 days, and 6 months. For sixteen patients one-year recall data were collected on retention and subjective sensitivity. Fifteen subjects were available for one year clinical examinations. Three independent examiners found the working and setting time of the cement to be well within expected limits and that cement removal was easy. Four patients reported low-grades of immediate post-cementation sensitivity, however, this disappeared after an occlusal adjustment or without intervention within one month. At 12 months no retentive failures were recorded and no subjective sensitivity reported. All crowns were rated in the "Excellent" quality category for marginal integrity. Both GI-scores and scores for tooth sensitivity decreased during the course of the study. One year recall data yielded no incidence of secondary caries and no visible marginal discoloration. The new cement was thus found to perform favorably as a luting agent for permanent cementation.

Characterisation of structures in salivary secretion film formation. An experimental study with atomic force microscopy.

The purpose of the present study was to characterise the structure dynamics of pure salivary secretions retained on controlled surfaces with different surface energies in the early stage of salivary film formation. Germanium prisms prepared to have either low surface energy or medium surface energy were incubated in fresh secretions of either human parotid saliva (HPS) or human submandibular/sublingual saliva (HSMSLS) for 15, 90, and 180 min. After controlled rinsing with distilled water, the surfaces were air dried and thereafter imaged with atomic force microscopy (AFM). The amount of adsorbed material and the size of the structures detected increased with increased saliva exposure time. The film thicknesses varied from 10 to 150 nm, and both HPS and HSMSLS films contained structures with diameters varying from 40 nm to 2 microm. Some of these were clustered into special formations. The HPS films exhibited a more granular morphology than the HSMSLS films. Furthermore, branched lines were detected on the low surface energy germanium prisms incubated in saliva. The results indicate that exposure time, surface energy, and type of salivary secretion all are factors affecting the adsorption characteristics of salivary films.

Characterization of the binding of delmopinol to salivary precipitates.

The aim of this study was to quantify the amount of delmopinol recovered in different molecular weight ranges of salivary proteins in the supernatant and pellet of delmopinol-saliva mixes. Unstimulated whole saliva was collected from 5 subjects and mixed with radiolabeled delmopinol to obtain a final drug concentration of 9.7 mM. The salivary-delmopinol solutions were incubated and then centrifuged. The resulting pellets and supernatants were studied in an electrophoresis assay. Each individual sample was run in three different electrophoretic gel lanes. The first lane was stained with silver dyes; the second lane was used for electrophoretic blotting and autoradiography; the third lane was cut in standard slices that were dissolved and analyzed with scintillation counting. The scintillation results demonstrated that higher radioactivity levels were detected at high molecular weight ranges (700-600 kDa). Furthermore, pellet samples were found to contain the highest amounts of delmopinol. The autoradiography results confirmed that delmopinol was bound to proteins of high molecular weight (700-600 kDa).

Tooth preparation.

This final article in the series describes the modification of teeth to improve their shape for the support and retention of RPDs.

Initial prosthetic treatment.

This article describes measures designed to provide short-term solutions to existing RPD problems and to establish an optimum oral environment for the provision of definitive prostheses.

Indirect retention.

This article explains the mechanism of indirect retention for RPDs and discusses the factors which determine its effectiveness. Examples are given of designs which incorporate indirect retention.

Connectors.

This article describes the types and functions of connectors for RPDS. It also considers the relative merits and limitations of these connectors.

Communication between the dentist and the dental technician.

Factors contributing to good RPD design are described, including the respective inputs of the dentist and dental technician. Poor communication in current practice is reported and an appropriate format for a work authorization presented.

The removable partial denture equation.

This article describes the benefits and risks of providing RPDs. It emphasises the importance of co-operation between the dental team and patient to ensure that the balance of this 'equation' is in the patient's favour.

Removable partial dentures. 1. Need and demand for treatment.

This article considers first, factors influencing the need and demand for removable partial dentures (RPDs) and second, the particular requirements and problems of elderly patients related to such treatment.

Retention.

This article describes the mechanisms for retaining RPDs and considers the different types of direct retainer. The factors influencing the effectiveness of retentive clasps and governing the choice of clasp are discussed.

A system of design.

This article describes a method of building RPD components into an effective design and indicates how the details of the design can be communicated clearly to the dental technician.

Bioadhesion--a phenomenon with multiple dimensions.

This paper reviews some relevant citations regarding the non-specific forces that must be considered in oral bioadhesive events. These range from forces related to restorative dentistry to those related to prevention and molecular biology. Types of interactions discussed are: 1. Van der Waal's forces; 2. electrostatic double-layer forces; 3. solvent-dependent interactions; 4. hydrogen bonding; 5. hydrophobic interactions; 6. hydration forces; 7. steric forces; and 8. covalent bonds. Examples are given of the various types of interaction that occur at different surface separation (< or =400 A) between adsorbed films of a pure salivary protein fraction (PRP1).

Immediate functional loading of Brånemark dental implants. An 18-month clinical follow-up study.

A clinical and radiographical study was performed to compare the outcome of oral rehabilitation in the edentulous mandible by fixed supraconstructions connected to implants installed according to either i) a 1-stage surgical procedure and immediate loading (Experimental Group-EG), or ii) the original 2-stage concept (Reference Group-RG). The EG comprised 16 subjects with edentulous mandibles. Beyond the non-smoking criteria the following specific inclusion criteria were adopted: i) all patients had to consider themselves to be in good general health, ii) the amount of bone had to enable the installation of 5-6, at least 10 mm long fixtures to be bicortically anchored (Mk II fixtures; Nobel Biocare AB, Göteborg, Sweden) between the mental foramina, and iii) the patients had to be available for the follow-up and maintenance programme. A total of 88 implants were placed in the EG (16 patients) compared to 30 in the RG (11 patients). In the EG, fixed appliances were connected to the implants within 20 days following implant installation while the fixed appliances in the RG were connected about 4 months following fixture installation. At the time for delivery of the supraconstructions all 27 patients were radiographically examined, an examination that was repeated at the 18-month follow-up. The analysis of the radiographs from the EG disclosed that during the 18-month observation period the mean loss of bone support amounted to 0.4 mm. The corresponding value observed in the RG was 0.8 mm. During the 18-month observation period no fixture was lost in any of the 2 groups examined. The implants under study as well as those in the reference material were at all observation intervals found to be clinically stable. The present clinical study demonstrated that it is, at least based on an 18-month observation period, possible to successfully load titanium dental implants immediately following installation via a permanent fixed rigid cross-arch supraconstruction. However, such a treatment approach has so far to be strictly limited to the inter-foramina area of the edentulous mandible.

A long-term follow-up of allergy to nickel among fixed prostheses wearers.

Skin allergic hypersensitivity to nickel is well known and well documented in the professional literature. Sixteen partially dentate patients with long-standing histories of recurrent hypersensitive skin reaction to nickel were entered into a clinical trial in 1979. All the patients received crowns or bridges made of an alloy containing 66% of nickel with porcelain fused to the metal framework. During the first three years, annual clinical dental and dermatological investigations were performed on all the subjects, including repeated patch tests. Follow-up examinations took place in 1988 and 1994. None of the subjects had any mucosal or systemic reaction following oral exposure to the nickel containing alloy, nor the exacerbations of skin lesions.