Intraoral Localization of Micro-organisms

Abstract

A method which could detect oral micro organisms in the exact location of their occurrence would reveal much concerning their role in dental caries. Most of the caries activity tests determine the presence of micro organisms in the saliva and not in situ. The detection and identification of oral micro-organisms in the carious lesion itself could help diagnosis and treat caries.Irreversible hydrocolloid full-mouth impressions were taken of dental clinic patients. The imprcssion material was carefully placed in the mouth and removed, so that a minimum of streaking of the dental plaque would occur. The impressions were boxed in wax and immediately poured with fortified selective agar medium. The medium was kept at 47' C., so that it would solidify on contact with the hydrocolloid. The poured impressions were chilled, and the agar medium model (Fig. 1) was carefully removed from the impression material. FIG. 1 (left).-Agar medium model. FIG. 2 (right).-Lactobacilli in the areas of open various lesions.Two selective media were used. The medium used for the isolation of oral lactobacilli was a modification of the formula of Rogosa, Mitchell, and Wiseman (J. Bact., 62:132, 1951). It consisted of lactobacillus selective broth containing brom-cresol green, 0.02 gm/liter, and 3 per cent fortified agart and adjusted to pH 5.5. Agar models were incubated anaerobically at 370 C. for 48 hours.The selective medium used for the isolation of oral yeasts was Sabouraud's dextrose broth containing penicillin, 20 units/ml; cyclohexamide, 0.5 mg/ml; streptomycin, 40 mg/ml; and 3 per cent fortified agar. Agar models from this were incubated at 300 C. for at least 72 hours. The modified LS medium showed lactobacilli in the areas of open carious lesions (Fig. 2). The yeast selective medium models had a growth of oral yeasts in the vicinity of carious lesions and in areas of chronic oral irritation. This technique, which transferred the micro-organisms from the oral tissue to the impression material and then to the agar model, localized the oral micro-organisms so that they could be related to the lesions in which they resided.

The Prevalence of Candida albicans in Denture Wearers in an Israeli Geriatric Hospital1

“…The method after Bahn, Quillman, &Kendrick [1962] was used to isolate the Candida from the palate. Alginate impressions of the maxilla were made.…”

Candida‐associated denture stoma titis. Aetiology and management: A review. Part 2. Oral diseases caused by candida species

“…20 The study was based on previous findings which showed t h at C. albicans was isolated more frequently from the denture fitting surface than from the corresponding mucosa. [21][22][23] The agar replica system was employed with an amino acid selective synthetic gr ow t h medium for C. albicans, supplemented with arginine, zinc sulphate and Bacto-agar. The results showed that the severity of palatal inflammation correlated with the number of C. albicans colonies on the agar replica, with the greatest number of colonies being observed in patients with Newton type III lesions.…”

Efficacy of sodium hypochlorite and coconut soap used as disinfecting agents in the reduction of denture stomatitis, Streptococcus mutans and Candida albicans

“…Apparently, the mechanical cleaning of the dentures is an effective mean to keep the mucosa healthy, however patients usually present difficulty in keeping them clean as it is necessary to use chemical cleansing agents to reduce the number of active micro‐organisms (20). Furthermore, studies (21, 22) have concluded that denture stomatitis is associated with the growth of Candida on denture biofilm, and not on the mucosa of the palate, suggesting that treatment would be better directed towards the denture, and not towards the mucosa (1).…”