The aim of this retrospective data collection study was to determine the effect size of dry mouth on the survival of restorations and teeth. The data were collected from the electronic patient files of City of Oulu Public Dental Services (Finland). Study population consisted of 71 dry mouth patients and 142 control patients. The survival of 3208 restorations were analyzed using Kaplan-Meier survival curves and multivariate Cox regression analysis with shared frailty for patients. Separate analyses were performed for the survival of the teeth. The hazard ratio of restorations in dry mouth patients was 2.08 (95% CI: 1.65-2.63) compared to the control patients. For the dry mouth patients, the fixed prosthetic crowns outlasted composite fillings of all sizes, but the difference increased concomitantly with the filling size. The dry mouth patients had hazard ratio of 1.98 (95% CI: 1.02-3.82) for tooth extractions compared to the control patients. The teeth with fixed prosthetic crowns outlasted the teeth with direct restorative materials. The survival time of restorations and teeth are severely shortened in patients with dry mouth. Especially the survival time of the large composites is short in dry mouth patients whereas fixed prosthetic crowns have acceptable survival time also in dry mouth patients. When informing a dry mouth patient on the expected survival of a restoration or tooth, one should take into account that dry mouth patients´ restorations and teeth have severely shortened survival time.

The aim of this study was to investigate the prevalence and severity of erosive tooth wear (ETW) among Finnish adolescents and to evaluate how frequency as well as amount of the use of erosive products is associated with ETW. The study population consisted of 328 voluntary, >15-year-old secondary school students (males 49.1%, females 50.9%) in three municipalities in Finland. Clinical examination to measure ETW (BEWE index) was carried out by trained and calibrated dentists. Piloted questionnaires included questions on consumption of drinks, fruits and berries, as well as tooth brushing frequency. Means and medians of frequencies and amounts of consumed erosive products were calculated and associations with ETW severity were analysed by logistic regression models. One-third (36.9%) of the participants were in need of at least preventive measures for ETW (BEWE sum score ≥3), but severe ETW (BEWE sum score >9) was rare (2.1%). Boys had severe ETW significantly more frequently than girls (p < 0.001). Habitual consumption of erosive drinks was common especially among boys compared to girls (p = 0.001). ETW was significantly associated with the amount of consumed erosive drinks, fruits, or berries. The prevalence of ETW among adolescences in Finland seems to be at the same level as in other Nordic and European countries. Consumption of erosive products is common and thus, the risk for tooth erosion is high, especially in boys. In addition to erosive drinks, also berries and fruits are associated with ETW and should be included in individual dietary counselling when early signs of ETW are clinically detected.

Objectives. Statistical methods play an important role in medical and dental research. In earlier studies it has been observed that current use of methods and reporting of statistics are responsible for some of the errors in the interpretation of results. The aim of this study was to investigate the quality of statistical reporting in dental research articles. Methods. A total of 200 articles published in 2010 were analysed covering five dental journals: Journal of Dental Research, Caries Research, Community Dentistry and Oral Epidemiology, Journal of Dentistry and Acta Odontologica Scandinavica. Each paper underwent careful scrutiny for the use of statistical methods and reporting. A paper with at least one poor reporting item has been classified as ‘problems with reporting statistics’ and a paper without any poor reporting item as ‘acceptable’. Results. The investigation showed that 18 (9%) papers were acceptable and 182 (91%) papers contained at least one poor reporting item. Conclusions. The proportion of at least one poor reporting item in this survey was high (91%). The authors of dental journals should be encouraged to improve the statistical section of their research articles and to present the results in such a way that it is in line with the policy and presentation of the leading dental journals.

To investigate development of the use of statistical methods in dental journals in 1996, 2001, and 2006 hypothesizing that methods are becoming more sophisticated. All original research articles in four dental journals in 1996, 2001, and 2006 were reviewed: Journal of Dental Research (JDR), Caries Research (CR), Community Dentistry and Oral Epidemiology (CDOE) and Acta Odontologica Scandinavica (AOS). Evaluation covered 928 articles reporting original research findings based on systematic collection and statistical analysis of research data. Aspects measured were: research design, statistical methodology, description of procedures, and presentation of results. Percentage frequencies of reported statistical procedures were compared between journals and between years. The main findings of the study are: 1) that use of multivariate or specific methods did not increase from 1996 to 2006, 2) that traditional statistical significance testing is still widely used in dental journals and that use of confidence intervals increased in the period 1996 to 2006, 3) that statistical procedures are usually extensively described, and 4) that dental journals have different profiles in their statistical content. The authors of articles in dental journals might apply these results when designing their dental research, i.e. to use statistical methods and to present results in line with the policy and presentation of the leading dental journals.

Background: Reliable caries detection is a cornerstone in the modern caries treatment schema. This study aimed to evaluate adopting traditional and new caries detection methods by third-year dental students. Methods: Fifty-seven students were given lectures on caries detection, after which they evaluated 27 extracted carious teeth using traditional clinical assessment (CE), Nyvad’s, and ICDAS methods. On three teeth they also performed DIAGNOdent pen® (LF) scanning. Histological scores of the sectioned teeth (ICDAS, LF) and activity estimations of the lesions by the supervisors were used as golden standards (Nyvad, CE). For the ICDAS method , sensitivity and specificity were calculated using dentine caries (D3) as a cut-off point. Mean ICC and kappa values were calculated to evaluate interexaminer agreement for all lesions and methods. Spearman’s correlation coefficient evaluated LF scanning. Results: ICDAS method presented good sensitivity ( 0.78) and specificity (0.87). The inter-examiner agreement for different methods was fair or good (CE ICC = 0.69, κ = 0.53; Nyvad’s method ICC = 0.68, κ = 0.48, ICDAS ICC = 0.66, κ = 0.47). Variation in LF values was the greatest with lesions extending to middle third of dentin. In that case, the Spearman’s correlation coefficient was also the weakest. Conclusions: To follow the guidelines by the European Core Curriculum on Cariology, the third year dental students are introduced to methods for detecting lesion depth and assessing lesion activity as well as using new caries detection methods. Their performance in estimating lesion depth is good, and fair to good in estimating lesion activity even after basic training only.