BACKGROUND:The aim of the present study was the evaluation of the effectiveness as sterilizer of a modified version of a microwave device, which was previously tested by the same authors and found unsatisfactory.MATERIALS AND METHODS:Dental mirrors were contaminated by 10(4)-10(9) microorganisms of Stapbylococcus aureus and spores of Bacillus subtilis and Bacillus stearothermophilus. The inocula used were both wet and dry. The duration of the treatment was 4 minutes. Three series of tests were made: 1) microwaves and "adjuvant" solution (as suggested by the producer of the device); 2) microwaves only (in place of the "adjuvant" solution, a Na Cl 0.9% was used); 3) "adjuvant" solution only (into an oven at 25 degrees C).RESULTS:In the 1st and 3rd series of tests all the microorganisms and the spores were killed. In the 2nd series of tests a bactericidal effect against some, not all, microorganisms of the S. aureus species and against spores of B. subtilis and B. stearothermophilus was found.CONCLUSIONS:The results of this study suggest that the device tested has a sterilizing activity, which, however, is not due to the activity of microwaves only; but to the combined activity of microwaves, "adjuvant" solution and temperature (since inside the device, at the end of the treatment the temperature on the mirrors was 94 degrees C).

The aim of the present paper was the study of prevalence of traumatic dental injuries to the anterior teeth of Italian schoolchildren. 519, 6- to 11-year-old children from two primary schools in Rome were examined, in order to evaluate dental injuries on canines and incisors. Traumatic injuries were classified according to Garcia-Godoy et al.; this classification is the most appropriate for retrospective studies. Dental injury prevalence was 21.0%, this value was higher than values shown by surveys made in the emergency services, but similar to those of other retrospective studies made in other countries. Male/female ratio was 1.69, statistically significant at 99% level. The age distribution showed that the higher prevalence was among the 9 year-old children (26.9%), the lower among the 8-year-old children (14.3%); the 9 year-old incidence value was the highest. 74.6% of the teeth involved were maxillary central incisors. Enamel fractures were the most frequent trauma type (67.0%), followed by enamel-dentine fractures (19.3%) and concussions (8.3%). No serious fracture was found. Play was the major dental trauma cause (64.2%), followed by sports (17.4%). 16.5% of traumatized children and their parents did not report the cause. Traffic accidents were not reported as causes. In conclusion, the high prevalence of dental traumas in schoolchildren, involving more than one fifth of subjects, is emphasized. Most of traumas were, however, slight, so that sometimes the cause was not reported. Serious dental injuries were more uncommon. Traffic accidents and violent impacts, which often cause these traumas, were also uncommon.

Dental handpieces are often difficult to disinfect. This is one of the main reasons for the considerable risk of cross-infections in dental offices. The aim of the present study was the evaluation of the disinfectant property of a recent, commercially available, automatic instrument, described as capable to clean, disinfect and lubricate dental handpieces. The following experimental evaluations were made: 1) antimicrobial activity of the disinfectant (glyoxalaldehyde) used. The method described by the European Committee for Standardization was followed. Test microorganisms were Pseudomonas aeruginosa and Staphylococcus aureus. 2) disinfection of dental handpieces (69 contra-angles and 97 turbines of different marks). They were naturally infected using them on patients for 30 minutes at least. 3) disinfection of dental handpieces infected with bacterial suspensions of Staphylococcus aureus, Streptococcus pyogenes (beta-haemolyticus, group A), Candida albicans and Pseudomonas aeruginosa. The results of the first experiment showed a strong bactericidal power of the disinfectant with both the tested strains, after a contact time of only 1 minute. A great proportion of the dental handpieces tested during the second experiment were found disinfected: from 84% through 89% out of the various models of turbine handpieces; from 89% through 100% out of the models of contra-angle handpieces. Even though bacterial contamination level was low (about 10(3) microorganisms per handpiece), a satisfactory disinfectant ability in natural conditions was found. The results of the third experiment were unclear. The tested instrument reduced 10(5)-10(8) times the original bacterial count when the gram positive microorganisms (Staphylococcus aureus, Streptococcus pyogenes) were used. On the other hand, when Pseudomonas aeruginosa and Candida albicans were used, the results were different: the bacterial count was reduced 10(6)-10(7) times in some cases, and only 10(2) times in other cases. This difference was found in the tests made using the same attachment and in those made using various attachments. In conclusion, the tested instrument showed, in most cases, a good disinfectant property, but the presence of unclear results suggests that some technical modifications are required.

Three different methods for detection and count of Streptococcus mutans in saliva have been compared with a microbiological method in order to estimate their efficacy and practicality. The study has been carried out on fifty children of six-eleven years old. The first method (stamp method) derives from that of Kohler and Bratthall, improved on the sampling, without saliva stimulation and, hence, more rapid. Furthermore, using a tongue depressor with a shovel-like extremity, we can either restrict the area where the grown colonies must be counted, avoiding any mistake, and stamp the spatula in the centre of the plate, not in the border, as the original method described, pressing it with the same force in every part, so that almost all the saliva collected can be plated on the Streptococcus mutans selective medium. As stated by this method, a tongue depressor is pressed first on the subject's tongue, then on a plate containing the medium. After incubation, the Streptococcus mutans colonies are counted on the plate's area limited by the stamp of the extremity of the spatula. According to Emilson we can also discriminate Streptococcus mutans and Streptococcus sobrinus colonies. The second method is a "strip mutans test" (Dentocult): saliva is stimulated making the subject chew a piece of paraffin and then it is collected passing a plastic spatula for ten times on the child's tongue. The spatula is introduced into a tube containing a liquid medium selective for Streptococcus mutans and then incubated.(ABSTRACT TRUNCATED AT 250 WORDS)

The aim of the present study has been the evaluation of the effectiveness of oral irrigation with or without toothbrushing and dental flossing, in individuals treated with fixed orthodontic appliances, on controlling the development of dental plaque and, hence, of gingivitis. Eight individuals with a good general and oral status have been chosen. Before the experimental period, they received instructions about oral hygiene with toothbrushing and dental flossing and then they have been monitored to verify they were doing well. At the time T0, the upper tooth have been banded, three Periodontal Indexes (Plaque Index according to Silness and Loe, Modified Gingival Index according to Lobene and Gingival Bleeding Index according to Ainamo and Bay) registered and subgingival plaque samples from the premolars' gingival sulcus collected in order to point out the total anaerobes bacterial counts, the rates of motile bacteria, spirochetes, Gram positive and Gram negative cocci and bacteria, by means of optical and dark field microscopy and of cultural methods. For their oral hygiene, the patients had to use, in the right side toothbrush and dental floss (Control 1), in the left side the oral irrigator alone (Test 1). One month later (time T1), the lower teeth have been banded, too. In the right side the patients had to use toothbrush and dental floss (Control 2), while in the left one they used the same devices as Control 2 plus the oral irrigator (Test 2). At the time T1 Periodontal Indexes and Microbiological analyses have been extended to all the four quadrants.(ABSTRACT TRUNCATED AT 250 WORDS)