Oral Microflora in Subjects with Reduced Salivary Secretion

Abstract

It is generally assumed that a decreased salivary secretion rate will promote plaque accumulation and increase the risk for caries, gingival inflammation, and mucosal infections. In this study, the effect of hyposalivation on the oral microflora was examined. The following micro-organisms were analyzed in rinsing samples from 14 subjects with hyposalivation: the total number of anaerobically growing micro-organisms, alpha-hemolytic streptococci, mutans streptococci, lactobacilli, Fusobacterium nucleatum, Prevotella intermedia/Prevotella nigrescens, Staphylococcus aureus, Candida albicans, and enterics. The study group, age 53 +/- 7 years, had no history of radiation therapy and showed no signs of inflammation in their salivary glands on biopsy. All were dentate with a mean of 24 +/- 3 teeth. Their salivary secretion rates were 0.03 +/- 0.02 mL/min (unstimulated) and 0.84 +/- 0.65 mL/min (stimulated). The control group was matched to the hyposalivation group according to age, sex, and number of teeth. There was a significantly increased number of lactobacilli, and a tendency, not statistically significant and with large variations within the groups, toward a higher proportion of mutans streptococci and a lower proportion of alpha-hemolytic streptococci in the hyposalivation group. The presence of micro-organisms associated with gingival inflammation and mucosal infections was comparable with that in the healthy controls. The results indicated that a low salivary secretion rate mainly promotes a flora associated with the development of caries.

Digestive Tract Microbiota in Healthy Volunteers

“…28 The oral cavity presented very diverse microbiota due to the different anatomical sites and constant exposure to the external environment. The method of collecting saliva without using chewing gum or paraffin tablets gave better results than in previous studies, [34][35][36][37][38] suggesting that the technique used in this study is more sensitive and causes fewer alterations to indigenous flora. Results from the back of the tongue were similar to those of other studies.…”

“…Results from the back of the tongue were similar to those of other studies. [35][36][37][38] Periodontal Gracey curettes were preffered for sampling from the supra-and subgingival biofilm. Our results were From a microbiological point of view, the esophagus has always been considered to be a saliva secretion passageway with transitory microbiota similar to the mouth and of little interest in research.…”

Evaluation of salivary flow in patients during head and neck radiotherapy

“…With the reduction of salivary flow, which is observed at the beginning of treatment, other alterations may occur including an increase of salivary viscosity, pH, ions and immunoglobulins levels 13 . As a consequence, irradiated patients often present higher risk for the development of dental caries and difficulties to swallow, speak and eat 1,4,7,12,17 . Although compensatory salivary production by non-affected salivary glands may exist, permanent salivary flow reduction is frequently found even one year after the end of the radiotherapeutic treatment.…”

Effects of radiotherapy on parotid salivary sialochemistry in head and neck cancer patients

“…The obvious qualitative salivary changes are a reduced pH and buffering capacity, altered salivary electrolyte levels, and changed non-immune and immune antibacterial systems [2,3]. Their compromise is intrinsically related to changes in the oral fl ora of irradiated patients and predisposes to dental caries [4][5][6][7].…”