Microflora of normal maxillary sinuses: does it justify perioperative antibiotic treatment in sinus augmentation procedures.

OBJECTIVES: To investigate bacterial flora of normal maxillary sinuses in order to facilitate perioperative antibiotic management in sinus augmentation procedures. MATERIALS AND METHODS: Specimens of maxillary sinus mucosa were harvested during planned orthognatic surgery in 18 patients with no evidence of rhinosinusitis. The samples were processed according to hospital routine for aerobic and anaerobic cultures. RESULTS: Ten maxillary sinuses were found sterile. Twenty-six (72%) maxillary mucosa specimens were culture-positive. Aerobes were recovered in 21 sinus samples (58%), predominantly as polymicrobial flora (18 cultures, 50% of all specimens), S. aureus in 2 sinuses of the same patient (6% of the samples), and Bacillus sp. in 1 sinus (3%). Anaerobes were isolated in 20 of 26 culture-positive specimens (56% of all sinus samples). They were recovered alone in 5 samples. Fifteen anaerobic cultures were polymicrobial (42% of all samples). Propionibacterium acnes was isolated from another 5 sinuses (14%) of 3 patients. CONCLUSIONS: Our data support the policy of perioperative antibiotic prophylaxis in sinus augmentation procedures where Schneiderian membrane is perforated. CLINICAL RELEVANCE: Evaluating the need of a perioperative antibiotic therapy in sinus augmentation procedures.

The in vitro effect of fluoridated milk in a bacterial biofilm--enamel model.

OBJECTIVES: The purpose of this study was to investigate the effect of milk and fluoridated milk on bacterially induced caries-like lesions. SAMPLE AND METHODS: Extracted impacted human molars were cut in half and covered with a varnish leaving a 4*4 mm window. The samples were coated with biofilm of S. sobrinus and were further divided into three experimental groups of S. sobrinus, S. sobrinus and milk and S. sobrinus and fluoridated milk. As negative controls served teeth incubated in saline. Of twenty tooth halves serial ground sections were cut through the lesions and investigated with polarization light microscopy (PLM) and scanning electron microscopy (SEM) and EDX element analysis. The PLM photographs were used for 3D reconstruction, volumetric assessment and determination of the extension of the lesion zones. Of eight tooth halves the biofilm on the enamel surface was studied with SEM and EDX element analysis. RESULTS: Volumetric assessment showed a statistically significant difference in the volume of the body of the lesion and the translucent zone between the milk group and fluoridated milk group. Quantitative element analysis demonstrated significant differences between sound enamel and the superficial layer in the fluoridated milk group. The biofilm on the enamel surface showed an increased Ca content in the milk group and fluoridated milk group. CONCLUSIONS: Milk as a common nutrient seems to play a complex role in in-vitro biofilm--enamel interactions stimulating bacterial demineralization on one hand, and, as effective fluoride carrier, inhibits caries-like demineralization.