Non-surgical approach to advanced chronic periodontitis: a 17.5-year case report.

This 17.5-year longitudinal case report details the treatment of advanced chronic periodontitis in a female patient commencing at 34 years of age. The woman was provided with periodontal care comprising of temporary fixation, scaling and root planing, intra-pocket irrigation using a root canal syringe and regular supervised maintenance. The patient presented with a 10-year history of bleeding gums. Therapy conducted in general practice had included simple curettage and irrigation. However, these treatments proved unsuccessful and the patient often changed dentists seeking better treatment. She presented to the University Dental Hospital, for diagnosis and treatment of her periodontal conditions after her mandibular lateral incisor had exfoliated. On presentation a purulent exudate could be expressed from all of the pockets. All anterior teeth, excluding the maxillary canines, demonstrated +2 to +3 mobility. The patient did not want any surgical treatment or her teeth extracted. It was decided to treat the patient conservatively without surgery. By postponing extraction, the authors were in a better position to determine the prognosis of the remaining teeth after the infection was under control. Although six teeth were extracted during the 17.5 years, this case report suggests that a non-surgical approach is a viable option while maintaining regular visits for periodontal care.

Impact of components of denture acrylic resin on gingival cell growth and sensitivity to Candida albicans adhesion.

The effects of four liquid components of denture acrylic resin on host cell activity and fungal adhesion were investigated in this study. The low concentration (1 micromol l(-1)) of the liquid components caused no change in the activities and morphologies of the gingival fibroblast cells, compared with control and dimethylsulphoxide-exposed cells. However, when the cells were exposed to high concentrations (1 mmol l(-1)) of benzqyl peroxide, morphological change was observed, implying that the exposure of the cells to high concentrations of the liquid components of denture acrylic causes the loss of adhesion proteins from the cells. Thus the amount of Candida adhesion to human gingival cells was analysed, and the adherence of fungi to the cell was significantly reduced when the cells were pre-exposed to methyl methacrylate, hydroquinone and benzoyl peroxide at a concentration of 1 micromol l(-1) (P < 0.01), which did not affect either the cell viability or the cell morphology. These results, taken together, suggested that the renewal of dentures could be a possible therapeutic and/or preventive aid for oral candidosis in denture-wearing patients.

Effect of serum concentration on Candida biofilm formation on acrylic surfaces.

The biofilm formation of the oral fungal pathogen Candida on denture acrylic strips coated with saliva, serum and, saliva-serum pellicle were examined in vitro using Candida albicans (four isolates), Candida glabrata (three isolates) and Candida tropicalis (three isolates). The degree of biofilm activity varied depending upon both the isolate and the pellicle. Significantly increased biofilm activity on the pellicle (particularly serum)-coated strips was observed with three isolates of C. albicans and another of C. glabrata on protein-coated acrylics, with increasing concentration of serum in the pellicle. Similar trends were observed with one isolate of C. albicans and C. glabrata, although the effects of pellicles were not significant. In contrast, with all three isolates of C. tropicalis and a single isolate of C. glabrata, although the biofilm activity on the protein-free control strips was significantly higher than that of saliva-coated strips, the increase in activity of pellicle-admixed biofilm depended upon the serum concentration. Candidal biofilm formation on acrylic surfaces is essentially promoted with increasing concentration of serum in the pellicle. This suggests that inflammation in the oral environment would facilitate fungal colonization on denture acrylic.

Influence of thickness on the linear dimensional change, warpage, and water uptake of a denture base resin.

This study examined the influence of thickness on changes (linear dimensions, warpage, and water uptake) in a denture base resin following two processing methods (heat polymerization and microwave activation). Changes were influenced by both processing method and thickness. These findings suggested that the processing method and denture base resin thickness are important factors in the dimensional change of acrylic resin dentures, and that the overall dimensional denture base changes are the result of localized changes.

Quantification of thigmotropism (contact sensing) of Candida albicans and Candida tropicalis.

To quantify the thigmotropism, we adapted the our previous method using a chemotaxifilter system in combination with a bioluminescent adenosine triphosphate (ATP) assay based on firefly luciferase-luciferin system and analyzed the relationship between the ability of germ tube formation and thigmotropism of C. albicans and C. tropicalis. Both the ability to form germ tube and the amount of hyphae exhibiting thigmotropism varied depending upon both the species and strains of Candida. C. albicans formed more germ tubes than C. tropicalis. A good correlation was observed between the ability to form a germ tube and the capacity for thigmotropism, and the results gave a level of significance (p < 0.05). Further, SEM observation revealed that relatively long hyphae of C. tropicalis with penetrated through the pores of filter membrane. This phenomenon may be of importance in the development of pathogenesis of C. tropicalis as well as C. albicans.

Cyclical deformation behaviour of denture soft lining materials.

OBJECTIVES: The purpose of the study was to examine and describe the deformation behaviour of five denture soft lining materials under dynamic cyclic loading over a range of applied forces using apparatus designed to simulate masticatory performance. METHODS: Five lining materials were tested over 5-min periods using an Instron tensile testing machine that was modified to measure load and strain semi-continuously during cyclic loading. RESULTS: Strain energy and strain energy densities and moduli values for each material were calculated. The strain energy absorbed at separate times during the cycling period demonstrated the elastic behaviour of the materials over the 5-min simulated chewing cycle. CONCLUSIONS: All materials demonstrated elastic but not perfectly linearly elastic behaviour over the chosen loading and cycling frequency. Molloplast B absorbed most energy at the lower testing loads and Novus absorbed most energy at the higher loads.

Cleansing efficacy of commercial denture cleansers: ability to reduce Candida albicans biofilm activity.

A simple method to measure Candidal biofilm activity using pH change of Stomastat was developed and used to evaluate the efficacy of 11 commercial denture cleansers on Candida albicans biofilm. The initial number of yeasts inoculated correlated with the pH value of Stomastat after both 24- and 30-hour incubation periods (r=0.992; r=0.988, respectively; P<.01), which supported the method's validity. The ability of the cleansing agents to decrease fungal biofilm activity varied depending upon the components of the agents. In general, peroxide denture cleansers, a disinfectant, and one enzyme cleanser were more efficacious than the other types tested in this study.

Dimensional changes of relined denture bases with heat-cured, microwave-activated, autopolymerizing, and visible light-cured resins. A laboratory study.

The dimensional changes of relined denture bases were evaluated in a laboratory study. Heat-cured resin, two autopolymerizing resins, microwave-activated resin and a new visible light-cured resin were used as relining materials in this study. The gaps between the metal die and the relined denture bases were measured immediately after the relining procedure and subsequently on the first day, first week, fourth week, and eight week. The relined denture bases were stored in distilled water at 37 degrees C between measurements. It was shown that dimensional changes in relined denture bases were influenced by the relining materials and procedures, and that heat-cured resin proved to have the smallest dimensional change as well as the greatest dimensional stability in comparison with the other relining materials and procedures.

Influence of thickness and location on the residual monomer content of denture base cured by three processing methods.

The influence of thickness and location on the residual monomer content of acrylic resin plates was examined when they were processed by three methods: a conventional method, fluid resin technique, and a microwave curing method. The residual monomer contents were measured by gas liquid chromatography. The levels of residual monomer were influenced by the processing methods and thicknesses of acrylic resin specimens, but not by location within the specimens. These results suggest that dimensional accuracy and stability of acrylic resin dentures could be influenced by the processing method, the thickness of the bases, and the shape and size of the dentures.

Shrinkage of tissue conditioners with time--effect of the particle size in powder and the EtOH content in liquid.

The dimensional change of tissue conditioners with time was measured until 4 weeks after mixing. Shrinkage of the materials was evaluated in relation to particle size in powder and the EtOH content in liquid. The dissolution of EtOH and plasticizer were also measured to investigate the relation to dimensional change. Shrinkage with time was recorded. The smaller the particle size in powder and the more EtOH in liquid, the greater the shrinkage rate. The smaller the particle size in the powder and the more EtOH contained in the liquid, the greater the dissolution of EtOH. The dissolution of BPBG was below 1/100 comparing that of EtOH and no difference was recognized by particle size and EtOH content. On the basis of these results it is suggested that the dissolution of EtOH is related to shrinkage of tissue conditioners with time and that the component particle size in the powder and EtOH content in the liquid have a significant influence on dissolution of EtOH associated with shrinkage.

The usage period of dentures and their residual monomer contents.

The quantity of residual monomer content in 24 maxillary dentures was detected by gas liquid chromatography. The residual monomer contents tended to be lower in dentures used for long periods than in those used for short periods. Decreases in the quantities of residual monomer in acrylic resin dentures as a result of aging can be expressed in a hyperbola. The fitted curve also suggests that most of the loss could be accomplished in 5 years; however, complete loss of the residual monomer content takes many years.

Factors involved in the adherence of Candida albicans and Candida tropicalis to protein-adsorbed surfaces. An in vitro study using immobilized protein.

The adherence of Candida albicans and C. tropicalis to protein-adsorbed surfaces was investigated with surface-modified glass slides to which serum or salivary proteins were covalently bound. A specific adherence like a ligand-receptor interaction was observed between C. albicans and mucin- or salivary protein-immobilized glass slides. This interaction was eliminated by deglycosylation of the slides, suggesting that the receptor may be an oligosaccharide(s) contained mucin or saliva. A similar specific interaction was also observed between C. tropicalis and fibrinogen-immobilized glass surfaces. When the numbers of adherent cells to deglycosylated protein-immobilized glass glides were plotted against zeta potentials and contact angles of these protein-immobilized glass slides, a significant correlation was observed between the numbers of adherent cells and zeta potentials in the case of C. albicans (r = -0.87), whereas a significant correlation was observed between cell numbers and contact angles (r = 0.82) in the case of C. tropicalis. These results suggest that the forces governing the adherence of fungi to pellicle in dentures may vary depending upon the surface properties of fungi and substrate.

The dimensional accuracy of rectangular acrylic resin specimens cured by three denture base processing methods.

The dimensional accuracy of rectangular acrylic resin specimens was examined when they were processed by three methods: a conventional method, the SR-Ivocap system, and a microwave curing method. The dimensional accuracy was evaluated by the change of the distance vector V, which is calculated by means of measurements of the distances between fixed points on specimens. The specimen cured by the SR-Ivocap system exhibited less dimensional change (p less than 0.05) than those cured by the conventional and the microwave curing methods. The SR-Ivocap system might produce a more accurate denture base than the conventional and the microwave curing methods.

Clinical evaluation of castable apatite ceramic crowns.

Thirty-three castable apatite ceramic crowns were constructed for 26 patients. The crowns were clinically evaluated for anatomic form, marginal adaptation, cavosurface marginal discoloration, surface roughness, and color match for a period of 2 years at regular intervals. Results showed that all restoration had satisfactory anatomic form; all but one exhibited good marginal adaptation. Slight abrasion was noticed at the functioning cusps and all but three of the restorations demonstrated excellent color matching.

Denture stomatitis and ABO blood types.

To determine the interrelation between ABO blood types of denture wearers, denture plaque accumulation, and denture stomatitis, 442 denture wearers were studied using a simplified culture method, which is convenient to use in the dental office. The degree of plaque accumulation and the occurrence of denture stomatitis varied depending on the blood type of the patients. Especially in blood group O compared with other types, both denture plaque accumulation and denture stomatitis were found to be higher or more severe. These results suggest that the ABO blood group is one of the etiologic factors of denture stomatitis and that denture wearers of blood group O are more susceptible to denture stomatitis.

A method of determining residual monomer in acrylic resin using methyl ethyl ketone.

An improved method of extraction of residual monomer from acrylic resin has been described for determination of the concentration of residual monomer by gas chromatography. Four kinds of organic solvent selected according to their physicochemical properties (methanol, N,N-dimethylformamide, ethyl acetate and methyl ethyl ketone) were tested for their capacity to extract residual monomer at varying temperatures and time periods. Extraction with methyl ethyl ketone at 4 degrees C was found to be the most effective. The method is simpler and more effective than others reported so far, and therefore seems to be suitable for clinical laboratory use.

Effects of crude drugs and berberine hydrochloride on the activities of fungi.

The effects of crude drugs on fungi have been used for a thousand years in China and Japan. These drugs include: Saussureae radix, Magnoliae cortex, Cinnamomi cortex, Hydrangeae dulcis folium, and Artemisiae capillarius flos. The activity of Coptidis rhizoma and Phellodendri cortex was stronger than other crude drugs against the three fungi. Berberine hydrochloride, which is a component of the two crude drugs, was investigated. Minimal inhibitory concentration values of berberine hydrochloride were 1, 0.125, and 0.5 mg/ml against Candida albicans, C. tropicalis, and C. glabrata, respectively. In C. glabrata, compared with C. albicans and C. tropicalis, berberine hydrochloride greatly inhibited the growth of fungi.

[Clinical survey on denture stomatitis. 2. The relation between the maintenance of denture and denture stomatitis].

A previous study suggested that denture plaque played an etiologic role in denture stomatitis. In daily practice, it is important to instruct denture wearers about denture plaque control. In this study, the major areas of investigation were the degree of denture stomatitis and denture plaque, denture hygiene habits, wearing habits and age of present denture. 643 patients wearing dentures (1981-1988) were selected, from 47 to 91 years old. The following results were obtained. 1. About 50 percent of the 643 patients used brush for cleaning their dentures. The number of people wearing dentures during sleep was fewer than those who preferred removal of dentures during sleep. 2. Soaking dentures in denture cleanser reduced the degree of denture stomatitis and denture plaque. 3. The patients wearing dentures during sleep showed much more occurrence of denture stomatitis than those who had not that habit. 4. Denture stomatitis occurred frequently with increasing the age of the present denture. The present results indicate that the occurrence of denture stomatitis is closely related to the quality of the maintenance of denture.

[Clinical survey on denture stomatitis. 1. Relation between denture plaque and denture stomatitis].

Denture stomatitis is a very frequent complication of the denture wearers. In this study, the relation between denture plaque and denture stomatitis was evaluated by a simplified culture (STOMASTAT). 583 patients wearing dentures (1981-1987) were selected, from 47 to 91 years old. The following results were obtained. 1. Degree of denture plaque in 583 patients was severe, moderate, and no detection: 30, 35 and 35%, respectively. 2. Grade of denture stomatitis in 583 patients was severe, moderate, and no symptom: 24, 36 and 40%, respectively. In this survey, the occurrence of denture stomatitis was about 60%. 3. The good correlation between degree of denture plaque and grade of denture stomatitis was recognized in this study. The present results suggest that denture plaque plays an etiologic role in denture stomatitis and, in daily practice, it is important to instruct denture plaque control for denture wearers.

Non-specific adherence of Candida species to surface-modified glass.

The nature of the physicochemical forces involved in the adherence of Candida species to a solid surface was investigated using modified glass slides. It was found that hydrophobic yeasts adhered to hydrophobic surfaces mainly by hydrophobic interactions, whereas in less hydrophobic yeasts electrostatic interactions seemed to play a more important role in adherence to the solid phase.