Search

A total of 509 consecutive Branemark TM implants (Nobelpharma AB, Gothenburg, Sweden) were inserted in 146 patients between December 1982 and May 1989, on which 217 fixed partial dentures were planned. The cumulative failure rates after abutment connection were 3.9% and 4.1% for the maxillae and mandible, respectively. The lack of continuous prosthesis stability was limited to 4.1% for the maxillae and 5.4% for the mandible. The average annual marginal bone loss was 0.77 mm (SD = 1.0) and 0.96 mm (SD = 0.9) for the maxillae and mandible, respectively, during the first year and averaged 0.1 mm for the following years. The mode of connection between teeth and implants or the use of porcelain instead of composite resin as occlusal material did not influence the marginal bone height around the implants. Technical complications were most often related to the materials used. The results of a medium-term follow-up encourage the use of the Branemark osseointegration system in the treatment of partial edentulism.

Thermodynamic approaches to bacterial adhesion emphasizing macroscopic properties of interacting bacterial cell and solid substratum surfaces are often criticized for not sufficiently accounting for microscopic, stereochemically complementary molecular interactions between the surfaces. Yet, as is demonstrated in this paper for a set of oral streptococci, three completely different overall macroscopic bacterial cell surface properties (elemental composition by XPS, surface free energy by contact angles and isoelectric point) are related in a comprehensible way, even though bacteria are analyzed at different states of hydration. Moreover, streptococcal adhesion from a moderate flow (σ=21 s−1) to inert solid substrata was related to both the interfacial free energy of adhesion and a strain-dependent microbial factor. This empirical factor measures the effect of cell surface appendages or excretion of (anti-) adhesives which assist or impede adhesion in excess of strictly thermodynamic considerations. Although bacterial adhesion strongly decreased after precoating substrata with bovine serum albumin or salivary proteins, negative slopes between the number of adhering streptococci and the interfacial free energy of adhesion (calculated on basis of the bare solid substratum surface free energies) suggest that surface free energy effects are transferred through adsorbed protein films. Much stronger evidence for such modification of adsorbed protein films by substratum surface free energies is obtained from in vivo experiments in the human oral cavity which demonstrated that the amount of plaque collected on various materials after nine days exposure to oral fluids was approximately five times smaller on a low surface free energy material as PTFE-teflon than on a high surface free energy material such as enamel.

The efficacy and safety of ciramadol (Cir) as an analgesic in relieving moderate to severe pain after oral surgery has been studied in 79 patients randomly assigned to receive single oral doses of Cir 15, 30 or 60 mg, codeine 60 mg or placebo. During the 6-hour observation period, the three ciramadol-treated groups indicated greater pain relief than the codeine 60 mg or placebo groups. In general, Cir 60 mg was significantly more effective than codeine 60 mg, and all doses of Cir were superior to placebo. The proportion of patients in each Cir group reporting adverse experiences was significantly higher than in either the placebo or codeine groups. The experimental system proved very effective in demonstrating analgesic potency of Cir. The very high incidence of side-effects in the three ciramadol-treated groups makes it unfit for further clinical use in ambulant patients.

The utility of a planimetric method for measuring in vivo plaque growth on teeth within 24 hours was tested. A reproducible photographic technique was developed. With this technique color slides were made after plaque disclosure with neutral red 0.5% and enlarged up to 25 times natural size for tracing on paper. The percentage of tooth surface covered by plaque was calculated with a planimeter. To obtain a stable and interpretable staining of the plaque three dye applications were applied. The interpretation of the slides was only reproducible when the slides were examined the same day and with the use of a tooth outline. Under these conditions an intra-examiner correlation coefficient of 0.999 was found. Furthermore, it was possible to detect significant differences in rate of plaque growth between two subjects within a time interval of four hours.

The plaque-removing effect of a convex-shaped multitufted brush was compared with that of a conventional flat multitufted brush. Two group (five and seven dental students, respectively), well instructed in the modified Bass technique, participated in a blind, splitmouth, crossover study during two consecutive experimental periods of 96 hours of undisturbed plaque growth. After each of these periods, a supervised brushing session was performed, followed by toothpick utilization. Plaque removal was evaluated using the modified Navy Plaque Index (MNPI) and planimetry. A 4% erythrosin solution was used as a disclosing agent. Planimetrically, the flat Oral B brush appeared significantly more effective than the convex shaped Ph brush (P less than 0.001). This superiority was even enhanced after the use of toothpicks (P less than 0.0005). The differences between the brushes, however, were too small to be detected by the less discriminating MNPI. Although it has been claimed that the convex brush could assure approximal plaque control, the results indicate that for the convex-shaped, as well as for the flat brush, an approximal aid is essential for good plaque control. The hypothesis that the design of the convex-shaped brush could facilitate the modified Bass technique for the average patient could not be proven in this study.

Early plaque growth and plaque topography were studied in 15 young adults with a healthy periodontium during a 4-day period of no oral hygiene. After perfect tooth-cleaning, the recolonisation of the buccal surfaces of 48 teeth (front teeth and premolars) was recorded at the start and after 6, 12, 24, 30. 36, 48, 54, 60, 72, 84 and 96 h. At each visit, reproducible colour slides of the buccal tooth surfaces were taken after plaque disclosure. Plaque extension was calculated planimetrically as a % of the total surface area of the tooth. At the end of the experimental period, an average of 27.7% of the surface area was covered by plaque. The early plaque growth followed an exponential curve with a slight tendency for saturation at 96 h. During the night, the plaque growth rate decreased by up to 50%. Clear differences in plaque growth rate were observed between types of teeth, and the plaque growth pattern seemed to be closely correlated to irregularities of the tooth surface. The discontinuity in plaque growth and the influence from the tooth surface roughness have important implications for oral hygiene planning.

The purpose of this study was to examine the change in plaque area over nine days in vivo on four materials with different surface free-energies (s.f.e.). Twelve healthy dental students participated in a crossover, split-mouth, double-blind study. Supragingival plaque formation was recorded over a nine-day period, on four different materials: fluorethylenepropylene (Teflon) (FEP), parafilm (PAR), cellulose acetate (CA), and enamel (E) with s.fe. of 20, 26, 57, and 88 erg/cm2, respectively. Strips made from the first three materials were stuck to the buccal surface of an upper incisor. The remaining incisor was carefully polished and served as an enamel surface. The increase in plaque was evaluated after three, six, and nine days. A planimetrical analysis was used so that the plaque area could be expressed as a percentage of the total buccal tooth surface. This procedure was repeated on each subject, so that at the end, each pair of central or lateral incisors received the four tested materials. The results indicated that the adherence of micro-organisms on pellicle-coated substrata was influenced by the material's s.f.e.; there was an association between the s.f.e. of the substrata and the supragingival plaque extension in vivo. High surface free-energy substrata in the oral cavity attracted more micro-organisms than did low energetic materials. Additionally, the bacterial adhesion seemed very weak on surfaces with a low s.f.e.

Strips of teflon and cellulose acetate were glued to the upper lateral incisors of human volunteers in a split mouth, double blind study on the influence of the substratum surface free energy (s.f.e.) on supragingival dental plaque accumulation during a three day period of no oral hygiene. Plaque accumulation, microbial composition of the plaque and s.f.e. of the microorganisms were determined and compared to plaque developed on natural enamel surfaces. Significantly less microorganisms colonised the polymer surfaces (p < 0.002). Streptococcus sanguis I was the predominant microorganism found in enamel samples, comprising about one-third of the total microflora, whereas it was recovered infrequently and in lower numbers from the polymeric surfaces, which predominantly contained Streptococcus sanguis II. Only on cellulose acetate sometimes high numbers of Streptococcus mitis and Streptococcus morbillorum were detected. The mean s.f.e. of the total plaque flora was lowest on teflon (84.5 mJ m-2) followed by cellulose acetate (86.0 mJm-2), whereas enamel harboured a microflora with a significantly higher mean s.f.e. (930 mJ m-2; p < 0.05). Also within the same bacterial species lower s.f.e. strains were isolated from the polymer surfaces compared to enamel. The results conform to a previously postulated model in which the interfacial free energy is the driving force for adhesion of microorganisms to solid surfaces. ©1989 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted. ispartof: Microbial Ecology in Health and Disease vol:2 issue:1 pages:11-18 status: published