Oral health in German children, adolescents, adults and senior citizens in 2005.

OBJECTIVE: The aim of this field study (the "Fourth German Oral Health Study") was to obtain representative data on caries (DMFT index), periodontitis (CPI) and prosthetic status in the German population and to evaluate changes in the oral health of the German people as compared with the findings of the Third German Oral Health Study conducted eight years previously. BASIC RESEARCH DESIGN: The study took the form of a population-representative cross-sectional survey with random samples, and was complemented by a questionnaire to reveal sociological as well as behavioural data. PARTICIPANTS: The age cohorts in the present study were 12-year-olds (children), 15-year-olds (adolescents), 35- to 44-year-olds (adults) and 65- to 74-year-olds (senior citizens). RESULTS: All age groups showed considerable improvements in oral health with respect to caries. Of the children, 70.1% were free of dentine caries and the mean DMFT value was 0.7. In adults and senior citizens both the DMFT value and the number of missing teeth and edentulousness declined. With regard to periodontal conditions, increasing prevalence of moderate and severe findings was recorded in adults and senior citizens, owing probably to the larger number of natural teeth remaining in the oral cavity. CONCLUSION: The study documents a distinct improvement in oral health in the German population. Interrelated with the higher numbers of remaining natural teeth a higher prevalence of moderate and severe periodontal conditions in German adults and senior citizens was observed.

Prosthetic complications in fixed endosseous implant-borne reconstructions after an observations period of at least 40 months.

One hundred and seventy-two fixed reconstructions (317 prosthetic units), made on 283 ITI implants in 105 patients (age range 25-86 years) with a minimum follow-up period of 40 months, were taken into the study to analyse technical complication rate, complication type and costs for repair. The mean evaluation time was 62.5 +/- 25.3 months. Eighty were single crowns and 92 different types of fixed partial dentures (FPDs). In 45 cases the construction was screw retained and in 127 cases cemented with zinc phosphate cement or an acrylic-based cement. Complications occurred after a minimum period of 2 months and a maximum period of 100 months (mean: 35.9 +/- 21.4 months). Fifty-five prosthetic interventions were needed on 44 constructions (25%) of which 88% in the molar/premolar region. The lowest percentage of complications occurred in single crowns (25%), the highest in 3-4 unit FPDs (35%) and in FPDs with an extension (44%). Of the necessary clinical repair, 36% was recementing and 38% tightening the screws. Of all interventions, 14% were classified as minor (no treatment or <10 min chair time), 70% as moderate (>10 min but <60 min chair time) and 14% as major interventions (>60 min and additional costs for replacement of parts and/or laboratory). For seven patients the additional costs ranged from euro 28 to euro 840. Bruxing seemed to play a significant role in the frequency of complications. Longer constructions seemed to be more prone to complications. The relatively high occurrence of technical complications should be discussed with the patient before the start of the treatment.

A comparison of the visual and technical assessment of preparations made by dental students.

The preparation of acrylic teeth in a simulated clinical environment (phantom head) plays an essential role in pre-clinical dental education where evaluation is performed visually by instructors. The aim of this investigation was to verify the quality criteria of a tooth preparation for a metal-ceramic crown (tooth No. 21) with the help of digital measurement. Thirty-six acrylic teeth were prepared by students and one tooth was prepared ideally by a trained dentist: These were examined and compared. Five experienced instructors independently assessed the quality criteria with the use of a criterion list. Afterwards, the teeth were scanned with the 3D-laser scanner 'es1' (Etkon Company, Munich, Germany). The calculation of the correlation coefficient demonstrated a satisfactory correlation between visual and digital rating concerning convergence angle, shoulder width and occlusal reduction. Greater differences between experimental groups were observed with regards to other criteria on the applied criterion list. A directed calibration of the evaluators and a re-evaluation of some measurements would be necessary to gain more precise results.

Longevity of 2328 chairside Cerec inlays and onlays.

In a dental practice, 2328 ceramic inlays were placed in 794 patients. The restorations were manufactured chairside using Cerec technology and adhesively inserted at the same appointment. The clinical performance of the restorations was evaluated with the Kaplan-Meier analysis. The probability of survival was 95.5% after 9 years; 35 Cerec restorations were judged as failures. The prognosis for success was not significantly influenced by restoration size, tooth vitality, treatment of caries profunda (CP), type of tooth treated, or whether the restoration was located in the maxilla or mandible. The most common type of failure was the extraction of a tooth. In a clinical follow-up light-microscopic examination of 44 randomly selected restorations, an average composite joint width of 236.3 microns was found. 45.1% of the restorations exhibited a perfect margin, and 47.4% of the investigated joint sections showed underfilled margins.

Long-term survival of cast-gold inlays in a specialized dental practice.

At a dental office in Münster, Germany, the majority of gold inlays incorporated between July 1969 and August 1999 (n=2,071) in 531 patients were checked with reference to the dental records and assessed retrospectively to determine their longevity. One hundred seventy-five gold inlays were rated as failures (no longer in situ); 10 abutment teeth were extracted. The 20-year Kaplan-Meier survival rate for restoration-bearing teeth was 98.9%, and the 25-year rate for all gold inlays 73.4% (+/- 4.0%; 95% confidence interval respectively in brackets). Gold inlays inserted in maxillary teeth had significantly better probabilities of survival after this period than those inserted in lower teeth (P=0.0002). Based on the number of surfaces involved, 52.0% (+/- 45.3) of one-surface inlays, 64.3 (+/- 7.5) of two-surface inlays, 75.8% (+/- 7.6) of three-surface inlays, and 84.8% (+/- 5.4) of inlays with more than three surfaces were still in situ after 25 years.

[The preprosthetic preparation of the endodontically treated abutment tooth. Post and core technique: a questionnaire analysis]. / Die präprothetische Vorbereitung des wurzelbehandelten Pfeilerzahnes. Intraradikuläre Verankerung--Eine Fragebogenauswertung.

The goal of the questionnaire was to determine the materials and methods that general dentists in Switzerland at present use for the treatment of non-vital abutment teeth. Questionnaires were sent to 1000 dentists from a computer generated random sample of the list of members of the SSO (Swiss Dental Society). The return ratio was 36%. The responses provided information on the current philosophies and prevailing techniques used to restore endodontically treated abutment teeth. Most of the answering dentists believed it was necessary to stabilize a root treated tooth with a post. The preferred restoration in anterior teeth was the cast post and core, while composite resin build-up with a prefabricated post was predominantly made for posterior teeth. Conical or combined cylindrical-conical posts, which had a sand-blasted surface, were predominantly used. Most of the answering dentists strove to stabilize the remaining tooth structure by circular enclosure of the tooth structure by the later crown (ferrule effect). Zinc phosphate cement was still preferred for cementation of metal posts and ceramic posts were most often fixed with the help of the acid etching technique. The most frequently described failures were retention loss or root fractures.

Long-term clinical results of galvano-ceramic and glass-ceramic individual crowns.

STATEMENT OF PROBLEM: Alternatives to metal-ceramic restorations should possess clinical durability before being recommended to the dentist. Longitudinal clinical studies are required for evaluation so innovative types of restorations can meet the expectations of dentists and patients. PURPOSE: This study compared the performance of galvano-ceramic restorations (Auvo Galvano Crown [ACG]) and glass-ceramic individual crowns (Dicor) based on longitudinal clinical trials. MATERIAL AND METHODS: A total of 769 galvano-ceramic single crowns (AGC) in 322 patients and 173 glass-ceramic individual crowns (Dicor) in 88 patients were reviewed for 8 years and a maximum of 11 years, respectively, after cementation. Risk of fracture was determined with use of a survival analysis (Kaplan and Meier). RESULTS: Partial ceramic cracking was observed at the time of the last recording of data in 11 galvano-ceramic crowns, 8 of the units remained in place. Two crowns became dislodged and 1 tooth exhibited a fractured root, despite an intact crown. One restoration was removed because of hypersensitivity and 1 with partial ceramic fracture. Forty-two of the glass-ceramic crowns were completely fractured. After a comparable 7 years under risk, 96.5% (+/-3.4; 95% confidence interval) of the galvano-ceramic premolar and molar crowns and 92% (+/- 8.5) of crowns placed on incisors and canines crowns were intact. The corresponding data for the glass-ceramic restorations were only 70% (+/- 10.6) in posterior and 82.7% (+/- 8. 1) in anterior quadrants. CONCLUSION: Long-term results of electroformed individual crown restorations were superior to glass-ceramic restorations.

Risk of debonding in three-unit resin-bonded fixed partial dentures.

Resin-bonded fixed partial dentures are considered practical and conservative but have not always enjoyed longitudinal success. The long-term survival of 1637 three-unit resin-bonded fixed partial dentures was analyzed. A multistate analysis that included parameters such as debonding, rebonding, or renewal of the restoration was used. Five years after insertion 66.1% (+/- 3.7%) of the originally inserted prostheses remained in place. If additional rebonding was computed, the probability of survival was 82.0% (+/- 3.0%). Reconstruction of the metal frame after one or more dislodgements raised the success rate to 87.1% (+/- 2.6%). Rebonded resin-bonded fixed partial dentures developed a greater risk of debonding. The risk of failure for refabricated fixed partial dentures was similar to that of the originally inserted resin-bonded fixed partial dentures. There were no signs of greater caries incidence after multiple recementation procedures.

[The factors affecting the risk for the loss of resin-bonded bridges]. / Einflussfaktoren für das Verlustrisiko von Adhäsivbrücken.

1310 three-unit resin-bonded bridges were examined for their failure rates. After five years 86% (+/- 4%) were still in situ. 64% (+/- 5%) didn't need rebonding. Significant prognostic factors were: preparation of abutments, surface treatment (net retention, silicoating), type of luting agent (Bis GMA) and mobility of the abutments.

[Fracture rate of Dicor crowns under clinical conditions]. / Frakturrate von Dicor -Kronen unter klinischen Bedingungen.

Failure-time analysis of Dicor single crown restorations: Statistical methods of survival-analysis according to Kaplan-Meier were applied to investigate the effects of the fracture of 159 Dicor-restorations in 82 patients in a private dental office. After 33 months of service 77% (+/- 15%; 95% Conf. Int. for the mean) of the crowns were still under risk. Fractures were very high in molar crowns.

[Failure-time and risk analysis of fixed partial dentures]. / Verweilzeit- und risikofaktorenanalyse von festsitzendem Zahnersatz.

Statistical methods of survival-analysis were applied to investigate the effects of anatomical, constructional and individual factors, which determine the "life-time" of 4371 single crowns, 1669 bridges and 175 fixed splints of a total of 1841 patients of a private insurance company. After 15 years of service 64% of the bridges, 56% of the single crowns and 45% of the splints were still under risk. The number of abutments and units, location, date of insertion, jaw and extension/normal bridge were significant risk factors.

[Failure-time analysis of extensive amalgam restorations]. / Verweildauer von ausgedehnten Amalgamfullungen.

Statistical methods of survival-analysis were applied to investigate the "life-time" of three types of class II amalgam restorations: 1355 F3-, 355 F4-amalgam filling, 108 TMS-pin-retained extensive amalgam restorations and 222 single crowns of a total of 630 patients of a private dental office. After 8 years of service about 50% of the extensive amalgam fillings, but 12% of the single crowns were still under risk.

[Clinical long-term results with bonded bridges]. / Klinische Langzeitbefunde bei Adhasivbrückenpatienten.

788 patients with 3-unit resin-bonded bridges were followed up over a time period of up to 5 years after placement. In this multicenter study, the following clinical variables were analyzed: caries, periodontal disease, loss of pulp vitality and the behavior of the dental materials involved were assessed. Adverse findings were rare. More data are needed over a longer period of time to support the present results.

[Surface and circumference determination in resin-bonded retainer elements: a possibility for long-term prognosis?]. / Die Flächen- und Umfangbestimmung bei Adhäsivhalte-Elementen: eine Möglichkeit der Langzeitprognose?

An evaluation of about 300 abutment teeth of resin-bonded bridges (Rochette, electrochemically etched) and resin-bonded extracoronal attachments was performed to determine the surface area and the length of the circumference of the retainers. By using a combined indirect (preparation of the specimen) and direct (automatic image analysis) method for the determination of both parameters a mean value of 50 mm2 for the surface area and 30 mm for the circumference, respectively, was evaluated. In addition, two indices (loading-index (BI): sigma surface area/width of pontic tooth; moisture penetration-index (FPI): sigma surface area/sigma circumferences) as predictors for the longevity of resin-bonded reconstructions were calculated. The loading-index was a good predictor for successful reconstructions: the clinical success was the better, the bigger the retention area, and the smaller the circumference of the retainer and the smaller the pontic tooth.

Success rate experience after rebonding and renewal of resin-bonded fixed partial dentures.

In a study of 703 resin-bonded fixed partial dentures, the success rates of two groups were analyzed where rebonding or renewals were necessary. Results revealed that rebonding often leads to repeated failures whereas renewals showed a failure rate similar to the whole of the investigated material.

[Technology and progress in scientific information systems]. / Technologie und Fortschritt von Informationssystemen für die Wissenschaft.

The development of modern information technology has brought about dramatic changes in the field of auxiliary instruments for scientific research, and by the same token, for research in dentistry. In the context of data acquisition literature data bases play an important part; in the evaluation of data emphasis is being placed on data bases, improved online measuring techniques and statistical systems. Text and graphics programs may facilitate and improve the mediation of scientific results. The value of expert systems for establishing diagnoses seems highly questionable.

[Risk factors for three-unit bonded bridges]. / Risikofaktoren dreigliedriger Adhäsivbrücken.

Statistical methods of survival-analysis were applied to investigate the effects of anatomical factors and clinical procedures which determine the "life-time" of 3-unit adhesive bridges. Their influences were analyzed until the first loss of retention after insertion. Besides the therapist effect, increased mobility and macromechanical preparation of the abutments could be identified as significant variables. Bridges bonded to one non-mobile and one hypermobile abutment tooth were found to be especially threatened. Extensive macromechanical preparation of the hard tissues reduces the hazard of debonding remarkably; this effect may be replaced by improved retentive mechanism of retainers.