The predominant microflora of the palatal mucosa in an elderly island population

Are the counts of Streptococcus mutans and Staphylococcus aureus changed in complete denture wearers carrying denture stomatitis? A systematic review with meta-analyses

STATEMENT OF PROBLEM

Despite the importance of Candida spp. on the etiology of denture stomatitis (DS), information on the role of the bacterial component is still scarce.

PURPOSE

The purpose of this systematic review was to evaluate whether the counts of Staphylococcus aureus and Streptococcus mutans were changed in complete denture wearers diagnosed with Candida-associated DS.

MATERIAL AND METHODS

The literature search was performed in 8 databases and by hand searching. The risk of bias was assessed according to the Newcastle-Ottawa qualifier. Meta-analyses were performed considering the microorganism evaluated (S. aureus or S. mutans) and the collection area (mucosa or dentures). The certainty of evidence was assessed according to the grading of recommendations assessment, development and evaluations (GRADE) criteria.

RESULTS

Participants with DS presented higher counts of S. aureus in the mucosa compared with those from the control group (OR, 3.16 [1.62, 6.15]; P<.001). No significant difference between the groups was observed for samples collected from dentures (OR, 0.73 [0.50, 1.07]; P=.110). Conversely, participants without DS presented higher counts of S. mutans both in the mucosa (OR, 0.19 [0.06, 0.63]; P=.006) and dentures (OR, 0.64 [0.41, 1.0]; P=.050).

CONCLUSIONS

Microbial counts in participants with DS changed as a function of the type of microorganism and collection site. The certainty of evidence ranged from very low to low. The findings reinforce the fact that bacteria also play a relevant role in DS and should be more extensively studied. Such information may be useful to guide further therapies to prevent or control DS.

Denture polymers with antimicrobial properties: a review of the development and current status of anionic poly(methyl methacrylate) polymers

The denture base polymer poly(methyl methacrylate) (PMMA) is highly susceptible for microbial colonization resulting in denture-associated infections. Over the years research has focused on ways to modify the PMMA properties via surface and chemical modification. These studies led to the development of new denture polymers that include anionic PMMA polymers. The new anionic polymers presented the possibility of compromising the physical and mechanical properties required for denture fabrication. These obstacles were overcome by generating anionic PMMA polymers with physical and mechanical properties suitable for denture fabrication. A large body of literature is available on the anionic PMMA polymers, their antimicrobial properties and their potential for the commercial and clinical application as dental biomaterials. This article describes a review and evaluation of the anionic PMMA polymers for their suitability to serve as denture base polymers, their antimicrobial properties, their efficacy to prevent denture-induced infection and their safety in the oral environment.

Transient oral microflora in Greeks attending day centres for the elderly and residents in homes for the elderly

OBJECTIVE

To examine the isolation frequency and the carriage of yeasts, Enterobacteriaceae, Staphylococcus and Enterococcus species in oral samples from elderly Greeks living alone or in institutions.

BACKGROUND

Ageing may promote changes in the oral ecosystem, which lead to colonisation of the mouth by microbes found less commonly or only transiently in younger subjects. Previous studies indicate a geographical variation in the isolation frequency of such bacteria in elderly populations.

MATERIALS AND METHODS

Medical and dental records were obtained from 66 attenders at elderly people's day centres (EPDC), and 82 residents of elderly people's homes (EPH), 66-95 years old. Mucosa smear samples were cultured on appropriate media for enumeration of the above species. Microbial identification was performed by conventional microbiological tests. The results were analysed using the Multiple Correspondence Analysis (MCA), ANOVA and other traditional statistical tests.

RESULTS

No statistically significant association was found between the place of residence and the wearing of dentures. The isolation frequencies of Staphylococcus aureus, Enterococcus and Enterobacteriaceae species were 21.6, 20.3 and 7.4% respectively. MCA, and further statistical analysis, revealed that the place of residence affected the isolation frequency of years (54.9% in EPH vs. 37.9% in EPDC). Moreover, ANOVA showed that living in EPH increased the carriage of yeasts.

CONCLUSIONS

Elderly Greeks exhibit a moderate to high oral carriage of transient bacteria compared with other elderly populations. Living in EPH seems to increase both the isolation frequency and carriage of yeasts.

Malodour in denture wearers: an ill-defined problem

Denture plaque has not been studied to the same extent as dental plaque, and although there are many similarities in microbial composition, there are some significant differences. Denture-induced stomatitis is associated with poor denture hygiene, a more acidogenic plaque and the presence of Candida albicans. Obligate Gram-negative anaerobic micro-organisms, although present in denture plaque, have rarely been specifically investigated. Opportunist pathogens including coliforms and staphylococci have been isolated from dentures. Teeth adjacent to partial dentures are more susceptible to caries and periodontal diseases, perhaps due to an increased plaque buildup at the prosthesis/tooth interface. Little work has been published on malodour associated with dentures. The inert material provides a substratum for the plaque biofilm, which encompasses a range of odour-producing species. The microbiology of the tongue in denture wearers has not been specifically studied. Thus the nature, origin and extent of malodour in denture wearers is ill-defined, but many species capable of producing malodorous compounds are present. The wide age and health range presented by denture wearers further confounds investigation. There is a need for further work in the area, both for cosmetic- and health-associated reasons in the increasing elderly population.

In vitro new dialysis protocol to assay the antiseptic properties of a quaternary ammonium compound polymerized with denture acrylic resin

AIMS

To develop an in vitro protocol in order to assess the antiseptic properties of a quaternary ammonium compound polymerized with acrylic denture resin base, using experimental resin discs and dialysis membranes.

METHODS AND RESULTS

Experimental acrylic resin discs were polymerized with Poly 202063A, an ammonium compound (2-50%). Antiseptic properties were assayed against two reference strains (Escherichia coli, Staphylococcus aureus) and a laboratory strain (Candida albicans), using three different conditions (test A, B and C). In test A, according to classical protocols the resin discs were first soaked in large volumes of microbial inoculum (45 ml). An original dialysis protocol was then designed to recreate the small biofilm volume on the prosthetic surface. In test B, discs and bacterial inoculum (600 microl) were introduced in a dialysis bag and dialysed against a sterile buffer. A bactericidal effect was observed against E. coli and Staph. aureus (<0.1% viable cells in initial bacterial suspension). A dose-dependent fungistatic effect was observed against C. albicans. Finally, in test C discs and sterile buffer (600 microl) were introduced in a dialysis bag and dialysed against microbial inoculum. Reduced activity was found outside the dialysis bag, demonstrating that free ammonium was able to diffuse through the dialysis membrane, displaying antiseptic properties.

CONCLUSIONS

The present protocol demonstrated that a quaternary ammonium compound remains efficient after heat polymerization with an acrylic denture base resin, both in immediate and distant microbial environments.

SIGNIFICANCE AND IMPACT OF THE STUDY

Such removable prosthetic devices with intrinsic antiseptic properties would contribute to improve the long-term management of denture stomatitis.

The association of yeasts and denture stomatitis with behavioral and biologic factors

OBJECTIVES

This study describes the association of yeasts and denture stomatitis with behavioral and biologic factors.

STUDY DESIGN

Seven hundred eighty 55-year-old citizens of Oulu, Finland, were examined clinically; 452 of them had complete dentures. Salivary yeasts and lactobacillus counts were detected through the use of Oricult-N and Dentocult-LB dip-slide techniques. Lifestyle factors were measured by means of questions concerning physical activity, tobacco smoking, alcohol consumption, and dietary habits. Other background variables used in cross-tabulations and logistic regression analysis were unstimulated salivary secretion rate, retention of denture, oral hygiene, gender, and socioeconomic status.

RESULTS

The prevalence of denture stomatitis was greater among subjects with an unhealthy lifestyle, subjects with higher lactobacillus counts, and subjects with poor oral hygiene. Salivary secretion rate and smoking were associated with the presence of yeasts, but general lifestyle measures were not.

CONCLUSION

The presence of yeasts tended to be associated with biologic factors, but behavioral factors reflecting lifestyle may be more important in the development of denture stomatitis.

Eradication of the long-term carriage of methicillin-resistant Staphylococcus aureus in patients wearing dentures: a follow-up of 10 patients

To cure the long-term carriage of methicillin-resistant Staphylococcus aureus (MRSA), eradication treatment was given to 10 patients wearing complete dentures. In addition to multiple body sites, MRSA was cultured from the dentures of six patients. The contaminated dentures were rebased and sterilized with heat in order to prevent recolonization. The patients did not use their dentures during the decolonization therapy. Subsequently, MRSA was eradicated from three of these patients but three others remained MRSA-positive despite at least two courses of combined systemic and topical eradication treatment. These particular patients had persistent stomatitis and their dentures were a poor fit, in poor condition and repeatedly grew MRSA. Eradication treatment was successful in the remaining four patients whose dentures were MRSA-negative. These results confirm that dentures may function as foreign bodies and sustain persistent nasopharyngeal. MRSA colonization. Therefore, we suggest that whenever eradication of MRSA is deemed necessary in cases of nasal, oral or pharyngeal carriage, heat treatment of the dentures should be included. Further comparative studies with larger patient populations are needed to evaluate the contribution of dentures to the long-term carriage of MRSA, as well as to assess the value of denture sterilization during the eradication course.

Effect of treatment of palatal inflammatory papillary hyperplasia with local and systemic antifungal agents accompanied by renewal of complete dentures

The aim of this study was to estimate the effect of local and systemic antifungal treatment, accompanied by renewal of complete dentures, on palatal inflammatory papillary hyperplasia (PIPH). The treatment groups consisted of 26 subjects treated with a local antifungal agent (miconazole, 2% gel) for 4 weeks and 13 subjects treated with a systemic antifungal agent (fluconazole, 50 mg) for 2 weeks (test groups). Ten subjects fitted with new complete dentures served as a control group. Variables examined before antifungal and prosthetic treatment included estimation of the size and color of the affected palatal area, measurements of the lengths of the papillae, and salivary variables. Six months after the completion of prosthetic treatment healing was determined as disappearance or marked reduction of the redness of the PIPH. Healing was more often observed in test groups (64%) than in the control group (20%) (p = 0.012). Fifty-eight per cent of the subjects treated with a local (miconazole, 2%) and 77% of those treated with a systemic (fluconazole, 50 mg) antifungal agent were healed. Even though papillary hyperplastic tissue did not disappear, the treatment of PIPH with an antifungal agent without surgery before renewal of dentures might be an alternative treatment in mild cases.