HOW TO IDENTIFY SUBGROUPS IN LONGITUDINAL CLINICAL DATA: TREATMENT RESPONSE PATTERNS IN PATIENTS WITH A SHORTENED DENTAL ARCH.

BACKGROUND: When dental patients seek care, treatments are not always successful,that is patients' oral health problems are not always eliminated or substantially reduced. Identifying these patients (treatment non-responders) is essential for clinical decision-making. Group-based trajectory modeling (GBTM) is rarely used in dentistry, but a promising statistical technique to identify non-responders in particular and clinical distinct patient groups in general in longitudinal data sets. AIM: Using group-based trajectory modeling, this study aimed to demonstrate how to identify oral health-related quality of life (OHRQoL) treatment response patterns by the example of patients with a shortened dental arch (SDA). METHODS: This paper is a secondary data analysis of a randomized controlled clinical trial. In this trial SDA patients received partial removable dental prostheses replacing missing teeth up to the first molars (N = 79) either or the dental arch ended with the second premolar that was present or replaced by a cantilever fixed dental prosthesis (N = 71). Up to ten follow-up examinations (1-2, 6, 12, 24, 36, 48, 60, 96, 120, and 180 months post-treatment) continued for 15 years. The outcome OHRQoL was assessed with the 49-item Oral Health Impact Profile (OHIP). Exploratory GBTM was performed to identify treatment response patterns. RESULTS: Two response patterns could be identified - "responders" and "non-responders." Responders' OHRQoL improved substantially and stayed primarily stable over the 15 years. Non-responders' OHRQoL did not improve considerably over time or worsened. While the SDA treatments were not related to the 2 response patterns, higher levels of functional, pain-related, psychological impairment in particular, and severely impaired OHRQoL in general predicted a non-responding OHRQoL pattern after treatment. Supplementary, a 3 pattern approach has been evaluated. CONCLUSIONS: Clustering patients according to certain longitudinal characteristics after treatment is generally important, but specifically identifying treatment in non-responders is central. With the increasing availability of OHRQoL data in clinical research and regular patient care, GBTM has become a powerful tool to investigate which dental treatment works for which patients.

Tooth loss in periodontally treated patients: A registry- and observation-based analysis.

AIM: According to retrospective clinical studies, periodontal treatment retains teeth. However, evidence on the effectivity of periodontal treatment stemming from the general population is lacking. MATERIALS AND METHODS: We analysed data of periodontally treated patients from routine data of a major German national health insurance (BARMER-MV; sub-sample of the Federal State of Mecklenburg-Vorpommern) and from a clinical cohort (Greifswald Approach to Individualized Medicine, GANI_MED), as well as periodontally untreated and treated participants of the Study of Health in Pomerania (SHIP-TREND) with either ≥2 or ≥4 teeth with pocket depths ≥4 mm. Yearly tooth loss (YTL) estimates and incidence rates were evaluated. RESULTS: For moderately to severely affected groups, YTL and incidence rates were higher in BARMER-MV patients (0.35 and 0.18, respectively) than in untreated SHIP-TREND controls (0.19 and 0.08, respectively). In line, treated SHIP-TREND participants exhibited higher YTL rates than untreated SHIP-TREND controls (0.26 vs. 0.19). For severely affected groups, results with respect to tooth loss were inconclusive regarding the beneficial effects of periodontal treatment conducted either in the university (GANI_MED data) or in the general practice. CONCLUSION: Until 2021, periodontal treatment performed in German general dental practices within the national health insurance system was probably not efficient in retaining more teeth in the short- to mid-term. Since reimbursement schemes were changed in 2021 and now cover periodontal treatment to a much larger extent, the future will show whether these new reimbursement codes will improve the quality of periodontal treatment and whether they will lead to more long-term tooth retainment.

Anterior occlusion in shortened dental arches.

OBJECTIVES: The aim of this study was to examine the occlusion of anterior teeth in individuals with shortened dental arch (SDA). MATERIAL AND METHODS: In a case-control clinical study, 41 individuals with SDA and 41 individuals with complete dental arch (CDA) participated. The CDA control group was matched for age and gender. Testing for occlusal contacts of anterior maxillary teeth was conducted by biting on foil strips (8 µm) with subjectively normal bite force (NBF) and maximal bite force (MBF). The data was analyzed on individual and tooth levels. RESULTS: The median rates of anterior maxillary teeth with occlusal contacts were 0.67 (NBF) and 0.83 (MBF) in the SDA group and 0.50 (NBF) and 0.83 (MBF) in the CDA group. Within both groups, the contact rates were significantly higher in MBF. The group difference with NBF was significant. A generalized linear model showed that the odds of an anterior maxillary tooth to have an occlusal contact were greater in the SDA both for NBF with an odds ratio (OR) 2.277 and MBF with an OR 1.691. CONCLUSIONS: The findings suggest effective compensatory mechanisms relative to the occlusal function in individuals with SDA. CLINICAL RELEVANCE: The study delivers further evidence regarding the SDA concept as a viable option in the management of posterior tooth loss.

Three-year clinical performance of posterior monolithic zirconia single crowns.

STATEMENT OF PROBLEM: Monolithic zirconia has become widely used for single crowns, with the advantages of minimal tooth reduction and good esthetics. However, clinical studies evaluating the performance of and patient satisfaction with posterior monolithic zirconia crowns are sparse. PURPOSE: The purpose of this clinical study was to evaluate the clinical performance of and patient satisfaction with posterior monolithic zirconia crowns. MATERIAL AND METHODS: Within a prospective cohort study design, participants were recruited from a university dental clinic if they required 1 posterior monolithic zirconia crown. The clinical performance was evaluated at follow-up appointments 1, 2, and 3 years after insertion. Bleeding on probing and pocket probing depths for the crowned teeth were recorded. Overall patient satisfaction was measured by using a visual analog scale (VAS), and quality of life was measured by using the validated German version of the Oral Health Impact Profile 14 (OHIP-G14). Descriptive statistical methods were applied. Mean values were calculated and compared by using the paired t test (α=.05). RESULTS: Thirty participants received a monolithic zirconia crown (14 premolars, 16 molars). One biologic complication (vertical root fracture) was identified at the 1-year follow-up. Three years after insertion, 22 participants could be examined, and the crowns were still in function. The gingival and the periodontal status of the crowned teeth had not changed significantly over the 3 years. After insertion, a significant improvement in patient satisfaction was measured up to 3 years CONCLUSIONS: Posterior monolithic zirconia crowns led to enhanced patient satisfaction up to 3 years after insertion. They provided good middle-term success and offered a promising alternative to conventional metal-ceramic crowns.

Performance of fixed dental prostheses up to 6 years-A massive data analysis.

STATEMENT OF PROBLEM: Metal and metal-ceramic fixed dental prostheses (FDPs) have been clinically determined to provide long-term durable restorations. However, data on their performance under practice conditions are sparse. PURPOSE: The purpose of this clinical study was to evaluate the longevity of FDPs under practice conditions by analyzing a large insurance claims database. MATERIAL AND METHODS: Data were extracted from the data warehouse of a major German national health insurance company (BARMER). The analysis focused on the FDP types with the lowest deductibles in the insurance system. All metal-based FDPs replacing up to 3 adjacent teeth were included. Ceramic veneering was optional and only approved on the labial surfaces of maxillary teeth mesial to the first molar and mandibular teeth mesial to the second premolar. Fee codes allowed clinical courses to be traced on a day count basis. Three groups with FDPs replacing 1 tooth, 2 teeth, and 3 teeth were formed. Kaplan-Meier survival analyses were conducted for the target events removal or extraction, indicating FDP failure and extraction of an abutment tooth. RESULTS: The sample comprised 124 660 FDPs that replaced 1 tooth (76.5%), 2 teeth (19.8%), or 3 teeth (3.7%). The cumulative survival rates for removal or extraction at 6 years differed significantly, with 83.0% for 1-pontic FDPs, 78.1% for 2-pontic FDPs, and 74.0% for 3-pontic FDPs. Thus, approximately 1 of 6 one-pontic FDPs, 1 of 5 two-pontic FDPs, and 1 of 4 three-pontic FDPs failed. The cumulative survival rates for extraction of an abutment tooth at 6 years showed no significant difference, with 96.0% for 1-pontic FDPs, 95.6% for 2-pontic FDPs, and 95.1% for 3-pontic FDPs. CONCLUSIONS: The survival rates of FDPs according to insurance data were lower than those reported by clinical studies, indicating a gap between efficacy and effectiveness.

Routine Data Analyses for Estimating the Caries Treatment Experience of Children.

Oral health surveys are considered the gold standard for assessing the caries experience of children. Analyses of routine data offer additional opportunities not yet fully explored. This study aimed at estimating the caries treatment experience by mining an insurance claims database. Comprehensive claims data sets were extracted from the data warehouse of a major health insurance company (BARMER, Germany). A surrogate variable for caries experience was formed that reflected the proportion of children without any former potentially caries-related treatment (filling, root canal treatment, and extraction) at ages from 1 to 14 years. The statistical calculations were based on Kaplan-Meier survival analyses. The evaluation for the permanent dentition comprised N = 593,330 children at 6 years and N = 114,568 at 12 years. At 12 years of age, 66.8% had not yet experienced potentially caries-related treatments. This value hints at a significantly higher caries experience at 12 years compared to available epidemiological data. For the deciduous dentition, the respective rates were 74.0% at 6 years and 45.8% at 10 years. Although various sources of bias have to be taken into account, the potential of routine data mining is evident. The approach is supplemental to oral health surveys. It can be useful in coming closer to reality when estimating the caries experience of children. From our results, we conclude that the oral health of up to 14-year-olds in Germany remains in urgent need of improvement.

Massive data analyses show negative impact of type 1 and 2 diabetes on the outcome of periodontal treatment.

OBJECTIVES: The aim was to evaluate the impact of diabetes on the outcome of periodontal treatment based on massive data analyses. MATERIALS AND METHODS: Data originated from the database of a major German National Health Insurance. Patients who underwent periodontal treatment were allocated to four groups according to their medical condition: type 1 diabetes (D1), type 2 diabetes with the intake of oral anti-diabetics (D2M), type 2 diabetes without the intake of oral anti-diabetics (D2), and a control group without diabetes (ND). Four-year Kaplan-Meier survival analyses on the patient level and multivariate regression analyses were conducted for tooth extraction. RESULTS: Of 415,718 patients, 4139 matched the criteria for D1, 22,430 for D2M, and 23,576 for D2. At 4 years, the cumulative survival rate (no extraction) was 51.7% in the D1 group, 54.0% in the D2M group, and 57.7% in the D2 group. The ND control group had a significantly higher survival rate of 65.9% (P < 0.0001). In the multivariate analyses, both diabetes types were significantly associated with further tooth loss after periodontal treatment. CONCLUSIONS: The diagnosis of diabetes type 1 or 2 seems to be associated with a higher risk of tooth loss after periodontal treatment. CLINICAL RELEVANCE: The long-term prognosis of teeth in diabetes patients should be judged carefully.

[Utilization and expenses in dental care : An overview based on routine data from Germany]. / Inanspruchnahme und Ausgaben in der zahnmedizinischen Versorgung : Eine Übersicht auf Basis von Routinedaten aus Deutschland.

BACKGROUND: Utilization and expenses are among the most important parameters of healthcare systems. Moreover, they allow us to draw conclusions about the features and focus of currently practiced dentistry in Germany. OBJECTIVES: The aim was to describe the current status of the utilization of dental services and the related expenses in Germany based on routine data from the statutory health insurance system. MATERIALS AND METHODS: The underlying analyses were taken from the annual dental reports of the statutory health insurance company BARMER. They were based on Germany-wide claims data from 2010 to 2018. RESULTS: The utilization of dental services in Germany with annual rates around 70% is distinctly above average. In 2018, utilization rates for dental fillings in the age groups between 30 and 79 years were consistently around 30% and for new prosthetic restorations and dental crowns in the age groups between 55 and 84 years it was at least 10%. In the field of prevention, there has been a steady increase of screening exams for children (31.9% in 2010 and 35.2% in 2018). For individual prophylactic measures in 6­ to 17-year-olds, no clear trend was discernible (64.0% in 2010 and 65.4% in 2018). The expenses of the statutory health insurance increased moderately. CONCLUSIONS: With the high utilization rate, good prerequisites for prevention-oriented dentistry exist. Although there is a positive trend towards a slight increase in the utilization of preventive services, dental care is still mostly oriented towards invasive intervention. Further promotion of health literacy of the population and incentives promoting prevention can be seen as useful instruments to implement a substantial paradigm shift.

Discrimination of small sugar concentration differences helps the nectar-feeding bat Leptonycteris yerbabuenae cover energetic demands.

Every day nectar-feeding animals face an energetic challenge during foraging: they must locate and select flowers that provide nectar with adequate amounts of sugar to cover their very high energy needs. To understand this decision-making process, it is crucial to know how accurately sugar concentration differences can be discriminated. In a controlled laboratory setting, we offered the nectar-specialist bat Leptonycteris yerbabuenae the choice between different sugar solutions covering the entire concentration range of bat-pollinated plants (3-33%). When feeding on solutions below 10% sugar concentration, L. yerbabuenae were unable to cover their energetic demands because of physiological constraints. Their ability to discriminate sugar concentrations was better than that of any other nectar-feeding animal studied to date. At sugar concentrations below 15%, L. yerbabuenae can discriminate solutions differing by only 0.5%. The bats may utilize this fine-tuned ability to select nectar from flowers with reward qualities that provide them with the necessary amount of energy to survive.

Prospective study on metal ceramic crowns in private practice settings: 20-year results.

OBJECTIVES: Posterior metal ceramic crowns are still widely used as a standard treatment. The aim of this study was to obtain long-term data on their clinical performance. MATERIAL AND METHODS: Ten private practitioners participated in this prospective practice-based study. Patients were provided with two crowns each. Two groups were formed. The single crown group comprised 95 patients with 190 crowns. The retainer crown group comprised 138 patients with fixed dental prostheses and 276 retainer crowns. RESULTS: For the primary outcome "loss of tooth or crown," 20-year survival rates of 78.8% in the single crown group and 67.8% in the retainer crown group were found. Veneering ceramic defects occurred rather frequently, resulting in respective 20-year technical success rates of 74.2% for single crowns and 62.9% for retainer crowns. However, veneering ceramic defects causing crown losses were very rare events. CONCLUSIONS: The results contribute to our knowledge on long-term outcomes of treatments with metal ceramic crowns and show high survival and success rates over 20 years. CLINICAL RELEVANCE: Posterior metal ceramic crowns are a highly reliable option in private practice settings.

Predicting genome terminus sequences of Bacillus cereus-group bacteriophage using next generation sequencing data.

BACKGROUND: Most tailed bacteriophages (phages) feature linear dsDNA genomes. Characterizing novel phages requires an understanding of complete genome sequences, including the definition of genome physical ends. RESULT: We sequenced 48 Bacillus cereus phage isolates and analyzed Next-generation sequencing (NGS) data to resolve the genome configuration of these novel phages. Most assembled contigs featured reads that mapped to both contig ends and formed circularized contigs. Independent assemblies of 31 nearly identical I48-like Bacillus phage isolates allowed us to observe that the assembly programs tended to produce random cleavage on circularized contigs. However, currently available assemblers were not capable of reporting the underlying phage genome configuration from sequence data. To identify the genome configuration of sequenced phage in silico, a terminus prediction method was developed by means of 'neighboring coverage ratios' and 'read edge frequencies' from read alignment files. Termini were confirmed by primer walking and supported by phylogenetic inference of large DNA terminase protein sequences. CONCLUSIONS: The Terminus package using phage NGS data along with the contig circularity could efficiently identify the proximal positions of phage genome terminus. Complete phage genome sequences allow a proposed characterization of the potential packaging mechanisms and more precise genome annotation.

Four-year outcomes of restored posterior tooth surfaces-a massive data analysis.

OBJECTIVES: There is only sparse knowledge concerning the outcomes of treatments with posterior permanent restorations in general practice settings. This study aimed at evaluating outcomes based on a large dataset by using a novel approach on a tooth surface basis. MATERIALS AND METHODS: The study based on routine data from a major German national health insurance company. Respective treatment fee codes allowed for tracking the clinical courses on a tooth surface level. The study intervention was defined as the placement of a restoration on an interproximal or occlusal posterior tooth surface regardless of its actual extension and material on which no information was available. All surfaces restored between January 1st, 2010 and December 31st, 2013 were included. Kaplan-Meier survival analyses were conducted to estimate four-year survival. The primary outcome was a restorative re-intervention on the same tooth surface. Separate analyses were performed for the secondary outcomes "crowning" and "extraction". RESULTS: Over ten million interproximal surfaces and eight million occlusal surfaces in nine million posterior teeth had been restored. At 4 years, the cumulative survival rates concerning the primary outcome "re-intervention" for mesial surfaces (81.4%; CI 81.3-81.5%) and distal surfaces (81.2%; CI 81.1-81.2%) differed significantly from those for occlusal surfaces (77.0%; CI 76.9-77.0%). Restored surfaces in premolars showed significantly higher survival rates compared to molars. Four-year survival rates for the secondary outcome "crowning" were 91.9% (CI 91.8-91.9%) for mesial surfaces, 92.1% (CI 92.1-92.2%) for distal surfaces and 93.3% (CI 93.2-93.3%) for occlusal surfaces. The respective rates for the secondary outcome "extraction" were 94.5% (CI 94.5-94.5%) for mesial surfaces, 94.8% (CI 94.7-94.8%) for distal surfaces and 95.4% (CI 95.4-95.5%) for occlusal surfaces. CONCLUSIONS: Re-interventions after restorative treatment play a significant role in general practice settings. Surface-related survival rates of restorations reveal a need for improvement. CLINICAL RELEVANCE: This study allows the estimation of the probability of re-interventions after restoring posterior tooth surfaces. It is based on several million cases from general practises under the terms and conditions of a national health insurance system.

The randomized shortened dental arch study: influence of two different treatments on interdental spacing over 5 years.

OBJECTIVES: Being a secondary outcome in a multicenter randomized controlled trial, the present analysis focused on interdental spacing in the shortened dental arch (SDA). The aim was to evaluate changes in interdental spacing in dependence of two different treatments after an observation period of up to 5 years. MATERIAL AND METHODS: Patients were either treated with a partial removable dental prosthesis (PRDP) for molar replacement (PRDP group) or according to the SDA concept aiming at a premolar occlusion (SDA group) in a randomized manner. Interdental spacing in the anterior region was measured with gauges and categorized as "0" (<0.1 mm), "1" (<0.5 mm), "2" (0.5-1 mm), and "3" (>1 mm). The statistical analysis was performed with analysis of variance models followed by linear contrast. RESULTS: Ninety-one patients (SDA n = 41, PRDP n = 50) were included. Changes of interdental spacing were detected in 70.7 % of all cases. A significant difference between the mean score changes was found in the mandible comparing the PRDP group and the SDA group. The respective mean score changes from baseline to 5 years were 0.23 (SD 0.49) for the PRDP group and 0.02 (SD 0.30) for the SDA group (p = 0.023). CONCLUSIONS: Major interdental spacing could be observed in neither of the groups. The SDA concept resulted in a slightly better outcome. CLINICAL RELEVANCE: When deciding whether to replace missing molars, the present results give further support to the SDA concept.

Targeted 25-hydroxyvitamin D3 1α-hydroxylase adoptive gene therapy ameliorates dss-induced colitis without causing hypercalcemia in mice.

Systemic 1,25(OH)2D3 treatment ameliorating murine inflammatory bowel diseases (IBD) could not be applied to patients because of hypercalcemia. We tested the hypothesis that increasing 1,25(OH)2D3 synthesis locally by targeting delivery of the 1α-hydroxylase gene (CYP27B1) to the inflamed bowel would ameliorate IBD without causing hypercalcemia. Our targeting strategy is the use of CD11b(+)/Gr1(+) monocytes as the cell vehicle and a macrophage-specific promoter (Mac1) to control CYP27B1 expression. The CD11b(+)/Gr1(+) monocytes migrated initially to inflamed colon and some healthy tissues in dextran sulfate sodium (DSS) colitis mice; however, only the migration of monocytes to the inflamed colon was sustained. Adoptive transfer of Gr1(+) monocytes did not cause hepatic injury. Infusion of Mac1-CYP27B1-modified monocytes increased body weight gain, survival, and colon length, and expedited mucosal regeneration. Expression of pathogenic Th17 and Th1 cytokines (interleukin (IL)-17a and interferon (IFN)-α) was decreased, while expression of protective Th2 cytokines (IL-5 and IL-13) was increased, by the treatment. This therapy also enhanced tight junction gene expression in the colon. No hypercalcemia occurred following this therapy. In conclusion, we have for the first time obtained proof-of-principle evidence for a novel monocyte-based adoptive CYP27B1 gene therapy using a mouse IBD model. This strategy could be developed into a novel therapy for IBD and other autoimmune diseases.

Posterior alveolar ridge resorption in bar-retained mandibular overdentures: 10-year results of a prospective clinical trial.

OBJECTIVES: Data on posterior alveolar ridge resorption (PARR) in patients with two implant supported mandibular overdentures is very heterogeneous. The aim of this prospective study was to observe the PARR after ten years for a study population treated with a titanium bar retained overdenture on two IMZ-implants. MATERIAL AND METHODS: The data pool consisted of digital and digitized conventional panoramic radiographs taken prior to implant placement and at follow up appointments. Digital measurements were carried out following an established procedure ("Tuebingen method" by Gomez-Roman). For each patient a linear regression was calculated resulting in a relative area related PARR-value per year. A simplified geometrical scenario was used for the estimation of absolute bone height losses. RESULTS: Data of 23 patients was available. The mean observation period was 9.4 years (±2.4 years). An average area related PARR-rate of 1.02% per year was observed with high individual differences ranging from 0.15% and 2.63% per year. The estimated average ten year vertical bone loss in the chewing center was 1.5 mm. CONCLUSIONS: Posterior bone resorption was found to be in the range previously reported for different implant restorations and therefore does not represent a particular problem of two implant bar retained overdentures. The results strengthen the two implant concept.

The randomized shortened dental arch study: temporomandibular disorder pain.

OBJECTIVES: The aim of this multi-center, randomized controlled trial was to assess the impact of missing posterior support on the risk for temporomandibular disorder (TMD) pain by comparing patients with either shortened dental arches (SDA) or molar replacement by removable dental prostheses (RDP). METHODS: A sample of 215 patients with bilateral molar loss in at least one jaw was consecutively recruited in 14 prosthodontic departments of dental schools in Germany. Of the initial sample, 152 patients (mean age: 59.7 years; 53.9 % female) received randomly allocated interventions (SDA: n = 71; RDP: n = 81). Presence of TMD pain was assessed using patients' self-reports and was verified by physical examination and by pain intensity, as the mean of current pain, worst pain, and average pain in the last 6 months, with 10-point ordinal rating scales. Assessments were performed before treatment and at follow-ups until 60 months after treatment. Impact of interventions on TMD risk and pain intensity was computed by applying logistic and linear random-intercept models. RESULTS: Tooth replacement (RDP) did not significantly change the risk for self-reported (odds ratio [OR]: 1.1; confidence interval [CI]: 0.4 to 3.4) or clinically verified (OR: 0.7; CI: 0.1 to 4.3) TMD pain compared to no tooth replacement (SDA). Mean characteristic pain intensity was virtually identical in both groups (Coeff: 0.01; CI: -0.30 to 0.32). CONCLUSION: Retaining or preservation of an SDA is not a major risk factor for TMD pain over the course of 5 years when compared to molar replacement with RPDs. CLINICAL RELEVANCE: Seemingly, missing molars do not have to be replaced in order to prevent TMD pain.

Timing of antenatal corticosteroid administration in pregnancies with increased risk for premature birth: A retrospective cohort study.

OBJECTIVE: To investigate how often antenatal corticosteroids (ACS) were administered within the optimal time frame in women at risk of preterm birth (PTB) in relation to several diagnoses and risk factors. METHOD: The study was designed as a retrospective cohort trial, in which the data of all births taking place in 2016 in the German federal state of Rhineland-Palatinate were evaluated. Frequency analyses, subgroup analyses, and logistic regression were performed. RESULTS: Birth occurred within the ideal time frame (≥24 h, ≤7 days) in only 15.2% of all pregnant women who were treated with ACS because of an increased risk of PTB (N = 1544). The ideal time frame after ACS administration was reached in less than 25% of all cases in each subgroup, with little difference between the different diagnoses and risk factors for PTB (range 11.3%-22.2%). Patients with multiple pregnancy had a significantly higher chance for delivery within the ideal time frame. There was an odds ratio greater than 1 for a birth event within the ideal time frame in patients with preterm prelabor rupture of membranes, pre-eclampsia, oligohydramnios, amniotic infection syndrome, and in patients with multiple diagnoses. In most diagnoses, the average time between ACS administration and birth was significantly shorter compared with patients without the diagnosis or risk factor. CONCLUSION: In women at risk of PTB, the individual risk profile should first be identified before ACS management begins. The likelihood of achieving the ideal time frame additionally depends on the diagnosis.

Randomized controlled clinical trial on the three-dimensional accuracy of fast-set impression materials.

OBJECTIVES: The use of fast-setting impression materials with different viscosities for the one-stage impression technique demands precise working times when mixing. We examined the effect of varying working time on impression precision in a randomized clinical trial. MATERIALS AND METHODS: Focusing on tooth 46, three impressions were made from each of 96 volunteers, using either a polyether (PE: Impregum Penta H/L DuoSoft Quick, 3 M ESPE) or an addition-curing silicone (AS: Aquasil Ultra LV, Dentsply/DeTrey), one with the manufacturer's recommended working time (used as a reference) and two with altered working times. All stages of the impression-taking were subject to randomization. The three-dimensional precision of the non-standard working time impressions was digitally analyzed compared to the reference impression. Statistical analysis was performed using multivariate models. RESULTS: The mean difference in the position of the lower right first molar (vs. the reference impression) ranged from ±12 µm for PE to +19 and -14 µm for AS. Significantly higher mean values (+62 to -40 µm) were found for AS compared to PE (+21 to -26 µm) in the area of the distal adjacent tooth. CONCLUSIONS: Fast-set impression materials offer high precision when used for single tooth restorations as part of a one-stage impression technique, even when the working time (mixing plus application of the light- and heavy-body components) diverges significantly from the manufacturer's recommended protocol. CLINICAL RELEVANCE: Best accuracy was achieved with machine-mixed heavy-body/light-body polyether. Both materials examined met the clinical requirements regarding precision when the teeth were completely syringed with light material.

A prospective 10-year study of metal ceramic single crowns and fixed dental prosthesis retainers in private practice settings.

STATEMENT OF PROBLEM: Metal ceramic restorations are widely used in prosthodontics, but long-term data on their clinical performance in private practice settings based on prospective trials are sparse. PURPOSE: This clinical trial was designed to provide realistic long-term survival rates for different outcomes related to tooth loss, crown loss, and metal ceramic defect. MATERIAL AND METHODS: Ninety-five participants were provided with 190 noble metal ceramic single crowns and 138 participants with 276 fixed dental prosthesis retainer crowns on vital posterior teeth. Follow-up examinations were scheduled 2 weeks after insertion, annually up to 8 years, and after 10 years. Kaplan-Meier survival analyses, Mantel-Cox logrank tests, and Cox regression analyses were conducted. RESULTS: Because of variations in the time of the last examinations, the maximum observation period was 12.1 years. For the primary outcome 'loss of crown or tooth', the Kaplan-Meier survival rate was 94.3% ±1.8% (standard error) at 8.0 years (last outcome event) for single crowns and 94.4% ±1.5% at 11.0 years for fixed dental prosthesis retainer crowns. The difference between the survival functions was not significant (P>.05). For the secondary outcome 'metal ceramic defect', the survival rate was 88.8% ±3.2% at 11.0 years for single crowns and 81.7% ±3.5% at 11.0 years for fixed dental prosthesis retainer crowns. In Cox regression models, the only significant covariates for the outcome event 'metal ceramic defect' were bruxism in the medical history (single crowns) and signs and symptoms of bruxism (fixed dental prosthesis retainer crowns) with hazard ratios of 3.065 (95% CI 1.063 - 8.832) and 2.554 (95% CI 1.307 - 4.992). CONCLUSIONS: Metal ceramic crowns provided in private practice settings show good longevity. Bruxism appears to indicate a risk for metal ceramic defects.

SlCCD7 controls strigolactone biosynthesis, shoot branching and mycorrhiza-induced apocarotenoid formation in tomato.

The regulation of shoot branching is an essential determinant of plant architecture, integrating multiple external and internal signals. One of the signaling pathways regulating branching involves the MAX (more axillary branches) genes. Two of the genes within this pathway, MAX3/CCD7 and MAX4/CCD8, encode carotenoid cleavage enzymes involved in generating a branch-inhibiting hormone, recently identified as strigolactone. Here, we report the cloning of SlCCD7 from tomato. As in other species, SlCCD7 encodes an enzyme capable of cleaving cyclic and acyclic carotenoids. However, the SlCCD7 protein has 30 additional amino acids of unknown function at its C terminus. Tomato plants expressing a SlCCD7 antisense construct display greatly increased branching. To reveal the underlying changes of this strong physiological phenotype, a metabolomic screen was conducted. With the exception of a reduction of stem amino acid content in the transgenic lines, no major changes were observed. In contrast, targeted analysis of the same plants revealed significantly decreased levels of strigolactone. There were no significant changes in root carotenoids, indicating that relatively little substrate is required to produce the bioactive strigolactones. The germination rate of Orobanche ramosa seeds was reduced by up to 90% on application of extract from the SlCCD7 antisense lines, compared with the wild type. Additionally, upon mycorrhizal colonization, C(13) cyclohexenone and C(14) mycorradicin apocarotenoid levels were greatly reduced in the roots of the antisense lines, implicating SlCCD7 in their biosynthesis. This work demonstrates the diverse roles of MAX3/CCD7 in strigolactone production, shoot branching, source-sink interactions and production of arbuscular mycorrhiza-induced apocarotenoids.