Restoration margins in young adolescents: a clinical and radiographic study of Swiss Army recruits.

PURPOSE: The aim of the present study was to report the radiographical prevalence of overhanging fillings in a group of Swiss Army recruits in 2006 and to relate the dimensions of the overhangs to clinical parameters. MATERIALS AND METHODS: A total of 626 Swiss Army recruits were examined for their periodontal conditions, prevalence of caries, and stomatological and functional aspects of the masticatory system and halitosis. In particular, the present report deals with the presence or the absence of fillings, the presence or the absence of overhangs and their relation to clinical and radiographic parameters. RESULTS: A total of 16,198 interdental sites were evaluated on bitewing radiographs. Of these sites, 15,516 (95.8%) were sound and 682 (4.2%) were filled. Amalgam restorations were found in 94.1% and resin composite fillings in 5.9% of the sites. Of these 682 sites, 96 (14.1%) yielded overhanging margins of various sizes. This low prevalence of fillings represents not only a substantial reduction when compared with a similar Swiss Army study (Lang et al, 1988), but also an improvement in the quality of dental care delivery to young Swiss males. Plaque Index and Gingival Index increased statistically significantly with the presence of fillings, when compared with healthy non-filled sites. Clinical parameters that were significantly associated with the presence of overhangs included clinical attachment loss. Moreover, between 1985 and 2006 the prevalence of fillings was significantly reduced from 20.0% to 4.2% of all surfaces. Furthermore, the marginal fit of the fillings improved from 33.0% with overhangs to 14.1%. CONCLUSIONS: A significant improvement was observed in the periodontal and dental conditions of young Swiss males that was shown to have taken place within the previous two decades. From 1985 to 2006, the prevalence of fillings was reduced fourfold and that of overhanging margins twofold, documenting an improvement in the quality of restorative dentistry.

Highly entangled ground States in tripartite qubit systems.

We investigate the creation of highly entangled ground states in a system of three exchange-coupled qubits arranged in a ring geometry. Suitable magnetic field configurations yielding approximate Greenberger-Horne-Zeilinger and exact W ground states are identified. The entanglement in the system is studied at finite temperature in terms of the mixed-state tangle tau. By generalizing a conjugate gradient optimization algorithm originally developed to evaluate the entanglement of formation, we demonstrate that tau can be calculated efficiently and with high precision. We identify the parameter regime for which the equilibrium entanglement of the tripartite system reaches its maximum.

Periodontal conditions in Swiss army recruits: a comparative study between the years 1985, 1996 and 2006.

AIM: To compare the periodontal conditions of Swiss Army recruits in 2006 with those of previous surveys in 1996 and 1985. MATERIAL AND METHODS: A total of six hundred and twenty-six Swiss Army recruits were examined for their periodontal conditions, caries prevalence, stomatological and functional aspects of the masticatory system and halitosis. In particular, this report deals with demographic data, the assessment of plaque index (PlI), gingival index (GI) and pocket probing depth (PPD). RESULTS: Two per cent of all teeth were missing, resulting in a mean of 27.44 teeth per subject, and 77% of the missing teeth were the result of pre-molar extractions due to orthodontic indications. The mean PlI and GI were 1.33 and 1.23, respectively. On average, 27% of the gingival units bled on probing. The mean PPD was 2.16 mm (SD 0.64). Only 3.8% of the recruits showed at least one site of PPD > or = 5 mm, and 1.4% yielded more than one site with PPD > or = 5 mm. In comparison with previous, this survey yielded lower bleeding on probing (BOP) percentages than in 1985, but slightly higher scores than in 1996. This may be attributed to increased PlI scores in 2006. However, PPD remained essentially unaltered from 1996 to 2006 after having improved significantly from 1985. CONCLUSION: A significant improvement of the periodontal conditions of young Swiss males was demonstrated to have taken place between 1985 and 1996, but no further changes during the last decade were noticed.

[Reconstruction of a periodontally compromised dentition]. / Rekonstruktion eines parodontal geschädigten Gebisses.

The presented case report describes a systematic treatment concept, the treatment sequence and the maintenance care of a sixty-seven-year old female patient suffering from generalized chronic periodontitis with advanced attachment loss. Due to a pretherapeutic risk assessment, several teeth were classified as "irrational to treat" or "doubtful". Therefore, a comprehensive reconstructive rehabilitation after active periodontal therapy was necessary. The restoration of a periodontally compromised dentition represents various difficulties. The patient wished to have fixed reconstructions. Depending upon anatomical conditions several different reconstructions were used: conventional bridges, partly using a resected molar root, a solely implant-retained bridge and a combined implant-tooth-retained bridge.

[Frequency and nature of anterior tooth injuries and the use of mouth protectors in sports clubs in Bern]. / Häufigkeit und Art von Frontzahn-verletzungen und Gebrauch eines Zahnschutzes in Berner Sportclubs.

Tooth injuries are frequently associated with sports injuries. Most of them could be minimized or prevented by the use of a mouthguard. The present study investigated the occurrence of tooth injuries and the attitude of athletes of Bernese sports clubs towards mouthguards, by means of a questionnaire and clinical examination. A total of 172 out of 200 athletes from six sports clubs, who were contacted directly at the sports fields, returned the questionnaire. Fifty of them owned a mouthguard (= 29.1%) and 54 reported having suffered dental trauma. The majority of athletes did not wear a mouthguard, despite acknowledging its usefulness. Even after a dental injury, the rate of mouthguard-acceptance increased just marginally; only 38.9% of all injured athletes were wearing a mouthguard after dental trauma. Most of the athletes had not considered wearing a mouthguard at all. For many of them, impairment of speech and breathing and discomfort were reasons not to wear a mouthguard. Of the 54 reported athletes with dental trauma, 48 were examined clinically. The upper central incisors were by far the most frequently injured teeth. The clinical examination used an injury severity index (NIDR-Index, National Institute of Dental Research) ranging from grade 0 (no visible damage), to grade 6 (loss of tooth). The most common finding was grade 4 (injuries that were treated by reconstruction). In conclusion there is a need to optimize information for athletes concerning mouthguards and sports injuries. Providing such information is not only the responsibility of coaches and trainers, but also of dentists.