Oral microbiology Establishment of oral anaerobes during the first year of life

Könönen E, Kanervo A et al. J Dent Res 1999; 78: 1634–1639

This longitudinal study indicates progressive and regular oral establishment of anaerobic species from 2 months of age.

Earlier investigators considered that anaerobes, which have significant potential for oral disease, did not colonize the mouth until tooth eruption, when gingival crevices provided a suitable habitat. Recent studies indicate that anaerobes colonize the oral cavity within the first 3 months of life. The present study of 44 healthy Caucasian infants born in Tampere, Finland, was a detailed microbiological analysis of salivary samples taken at ages 2, 6 and 12 months.

At 2 months, the commonest anaerobes cultured were Veillonella (2/3 subjects), with Actinomyces (1/3) and pigmented Prevotella (1/6). The presence of all three groups increased at 6 and 12 months (4/5; 9/10; 3/4 subjects respectively). At 2 months, Fusobacterium, non-pigmented Prevotella, and Porphyromonas were present in a few subjects, increasing at 6 and 12 months to affect most subjects. Along with Leptotrichia, which were found in few subjects, these organisms were termed 'early colonizers'. Late colonizing organisms, including Capnocytophaga, Prevotella intermedia and Lactobacilli, were found in a minority of subjects at 12 months, and rarely at 2 or 6 months.

The authors consider that the order of colonization is very significant, quoting factors such as the important role of Fusobacterium in plaque formation.

Oral surgery Treatment of lower second premolar agenesis by autotransplantation: four-year evaluation of eighty patients

Josefson E, Brattström V et al. Acta Odontol Scand 1999; 57: 111–115

This treatment is very effective in selected patients, and maintains alveolar ridge growth.

In Scandinavian populations, lower second premolar agenesis is estimated to affect 2.5–4% of the population. Treatment may be by orthodontics, prosthodontics, implants or surgical transplantation. Over a 2-year period, 110 transplants (66 premolar, mean age 13.5 yrs; 44 molar, 16.8 yrs) were performed for 80 patients in a Stockholm clinic.

Following extraction of the persistent primary molar (101 teeth), a recipient socket was prepared, checking size with a set of previously extracted sterilized teeth, matched radiographically to the donor. The donor tooth was very gently removed with an attached collar of cervical gingiva, placed in the new socket in infraocclusion, and retained 1 week with sutures over the occlusal surface. Where root formation was complete, RCT was performed subsequently.

All but 2 teeth were followed 4 years; these 2 were still satisfactory at 1 year. In 10 cases, failure occurred, 7 of these after 2–4 years. Most failure was by resorption or ankylosis. Orthodontic treatment was performed in 52 patients, but in only 11 was it required to increase space for the transplant.

Dental public health Sugar, drinks, deprivation and dental caries in 14-year-old children in the north west of England in 1995

Jones C, Woods K et al. Community Dent Health 1999; 16: 68–71

Drinking sugared and carbonated products related to higher caries, and drinking tea to lower caries.

In the 1994–5 academic year, a dental epidemiological survey of children aged 14 was undertaken in the former North Western Region of England. Following the examination of 6014 children (overall response rate 79%), subjects were asked questions about habits and frequencies of drink consumption.

Mean DMFT of the whole sample was 2.74, and the scores for the 20 individual districts involved showed a significant correlation with Jarman deprivation scores for these districts in the 1991 UK census (Spearman ρ = 0.61; P < 0.005). Males had a higher DT component score, and females a higher FT score.

Tea drinkers had a lower DMFT than coffee drinkers (2.56 v. 3.06; P < 0.001), and the reported number of cans of carbonated drinks consumed per week correlated with DMFT. Sugar-free drinks were not related to lower caries' experience.

Microbiology Guidelines for the use of antimicrobial agents to minimise development of resistance

Samaranayake L P, Johnson N W et al. Int Dent J 1999; 49: 189–195

Acquired resistance to antibiotics is a profound problem, which may lead to re-emergence of serious diseases if inappropriate usages persist.

Bacterial resistance may be acquired by genetic mutation, or the transfer of resistance-coding DNA on plasmids or transposons. Resistance can spread rapidly: in 1946, 90% of S. aureus isolates in hospitals were susceptible to penicillin, but this dropped to 75% by 1952. Huge amounts of antibiotics are used world-wide, and bodies such as the British House of Lords and WHO have urged a more careful practice of prescribing these drugs.

Different types and mechanisms of resistance are discussed, and the authors consider that antimicrobial abuse is a significant cause of the phenomenon. In the UK, about 7% of antimicrobial prescribing is by dentists. Overall, 20–50% of human prescriptions are questionable, and a higher proportion of the agricultural use of antibiotics.

The authors give simple guidelines for dental use of antimicrobials, including acute or spreading infections, persistent chronic infections after drainage, protection of medically compromised patients, and a few specific conditions such as osteomyelitis, ANUG and early-onset periodontitis. Where possible, sensitivity of organisms should first be determined; at the very least, prescription should be based on a rational diagnosis. They also recommend a programme of public education on the matter, to reduce the pressure which patients may bring to bear on clinicians.