Success and complication rates of non-precious alloy telescopic crowns in a general dental practice.

OBJECTIVES: This retrospective, single-center, practice-based cohort study aimed to analyze factors associated with the success of removable partial dentures retained by telescopic crowns (TRPD). MATERIALS AND METHODS: TRPD which were placed in a single practice of a practice-based research network were analyzed. Data from 139 patients (age (SD): 66 (11) years; 66 female) with 174 TRPD including 488 non-precious alloy telescopic crowns (TC) between 2004 and 2016 were included. TC without any technical complication were considered as successful, and as survived, if they were still in function at the last check-up. Multilevel Cox proportional hazard models were used to evaluate the association between clinical factors and time until failure. RESULTS: Within a mean follow-up period (SD) of 4.2 (3.3) years (min-max: 1 day-12 years), 372 (76%) TC (AFR5years,TC-level: 5.0%) as well as 136 (87%) TRPD (AFR5years,TRPD-level: 5.1%) ("worst-case scenario") and 150 (86%) TRPD (AFR5years,TRPD-level: 3.4%) ("best-case scenario") were considered as successful. The main failure types were recementation (n = 39), endodontic treatment (n = 36), and extraction (n = 35). TC in male patients showed 1.6 times higher risk for failure than in female patients (95%CI: 1.1-2.4; p = 0.023). TC on premolars showed 2.2 times higher risk for failure than on incisors (95%CI: 1.1-5.0; p = 0.023) and TC in dentures with ≤ 3TC showed 2.1 times higher risk for failure than TC in dentures with > 3TC (1.3-3.4; p = 0.042). Furthermore, TC on the most distal tooth in an arch showed 2.4 times higher risk for failure than TC on a more mesial tooth (1.5-3.8; p < 0.001). CONCLUSION: For removable partial dentures retained by telescopic crowns, high success rates could be found after up to 12 years. Patient-level and tooth-level factors were significantly associated with failure. CLINICAL RELEVANCE: For removable partial dentures retained by telescopic crowns, high success rates could be found after up to 12 years. Patient-level and tooth-level factors were significantly associated with failure.

A prospective, multi-center, practice-based cohort study on all-ceramic crowns.

OBJECTIVES: The aim of this prospective, multi-center, practice-based cohort study was to analyze factors associated with the success of all-ceramic crowns. METHODS: All-ceramic crowns placed in a practice-based research network ([Ceramic Success Analysis, AG Keramik) were analyzed. Data from 1254 patients with (mostly in-office CAD/CAM) all-ceramic crowns placed by 101 dentists being followed up for more than 5 years were evaluated. At the last follow-up visit crowns were considered as successful (not failed) if they were sufficient, whereas crowns were considered as survived (not lost) if they were still in function. Multi-level Cox proportional hazards models were used to evaluate the association between a range of predictors and time of success or survival. RESULTS: Within a mean follow-up period (SD) of 7.2(2)years [maximum:15years] 776 crowns were considered successful (annual failure rate[AFR]:8.4%) and 1041 crowns survived (AFR:4.9%). The presence of a post in endodontically treated teeth resulted in a risk for failure 2.7 times lower than that of restorations without a post (95%CI:1.4-5.0;p = 0.002). Regarding the restorative material and adhesive technique, hybrid composite ceramics and single-step adhesives showed a 3.4 and 2.2 times higher failure rate than feldspathic porcelain and multi-step adhesives, respectively (p < 0.001). Use of an oxygen-blocking gel as well as an EVA instrument resulted in a 1.5-1.8 times higher failure rate than their non-use (p ≤ 0.001). SIGNIFICANCE: After up to 15years AFR were rather high for all-ceramic crowns. Operative factors, but no patient- or tooth-level factors were significantly associated with failure. The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00020271).

Risk Factors for Failure of Direct Restorations in General Dental Practices.

The aim of this retrospective noninterventional multicenter practice-based study was to analyze factors influencing the survival of direct restorations. Records from patients who visited 5 private practices regularly were searched for the presence of direct restorations. Data were recorded from 7,858 patients with 27,407 direct restorations being detected at least 6 mo before the last recall visit. Multilevel Cox proportional hazard models were used to evaluate the association between clinical factors and time until failure. Within 228 mo, 5,493 failures could be observed. Median survival time was 207 mo. The annual failure rates were 3.8%, 4.0%, 4.6%, 4.9%, and 3.9% for class I, II, III, IV, and V restorations, respectively. Class II and IV restorations showed a 1.1-times (95% CI, 1.0 to 1.2) and 1.2-times (95% CI, 1.1 to 1.2) higher failure rate than class I restorations (P ≤ 0.029). Patients aged <20 y and >60 y showed up to a 1.4-times higher failure rate than patients aged 20 to 60 y (P ≤ 0.015). Restorations that underwent check-up twice a year or more showed a significantly higher failure rate than those that did so less than twice a year (P < 0.001). Furthermore, the dentists significantly influenced time until failure (P < 0.001). Regarding the restorative material, composites showed up to a 2.1-times longer time until failure than GIC (P ≤ 0.020). Moderate failure rates were observed for direct restorations in the private practice setting after up to 18.5 y. Within the limitations of the present study, several factors on the levels of practice (i.e., dentist), patient (i.e., age), and tooth (i.e., restorative material, restored surfaces according to the classification of Black) were significant predictors for the failure rate. Therefore, treatment decision should take into account most relevant factors (German Clinical Trials Register DRKS00015228).

Success and survival of post-restorations: six-year results of a prospective observational practice-based clinical study.

AIM: This prospective, noninterventional, multi-centre, practice-based study aimed to evaluate the longevity of endodontically treated teeth (ETT) restored with posts and to analyse factors influencing the success and survival of endodontic posts. METHODOLOGY: Eight general dental practitioners each placed up to 27 endodontic posts without any restriction to size and material. Teeth were restricted to incisors, canines and premolars. Multi-level Cox proportional hazards models were used to evaluate the association between clinical factors and time until failure. RESULTS: A total of 195 endodontic posts were followed-up for up to 6.5 years in 195 patients. Of these, 140 posts were judged as successful [mean success time: 59 (55-63) months]; the mean annual failure rate was 8.6%. This decreased to 4.4% when excluding recementations. 152 posts survived [mean survival time: 64 (60-67) months]. Recemented restorations had an eight times higher failure rate compared with new restorations. Furthermore, restorations with glass fibre post had a significantly lower success rate compared with titanium posts. CONCLUSION: Relatively low success and survival rates occurred for restorations with posts after root canal treatment in a private practice setting after a follow-up of up to 6.5 years. Recemented crowns had a high risk of failure.

Longevity of composite build-ups without posts-10-year results of a practice-based study.

AIM: The aim of this prospective, non-interventional, multi-center, practice-based study was, firstly, to evaluate the longevity of composite build-ups in endodontically treated teeth (ETT) without post placement and, secondly, to analyze factors influencing the success of these composite build-ups. METHODOLOGY: Each of seven general dental practitioners placed up to 50 composite build-ups without additional posts in ETT. Teeth were restricted to incisors, canines, and premolars. Several clinical data were recorded for 192 coronal restorations on ETT in 192 patients. Cox proportional hazard models were applied to analyze associations between clinical factors and time until failure. RESULTS: Within a follow-up period of 10 years, 167 restorations were judged as successful [mean success time, 110 (105-115) months] and 180 teeth survived [mean survival time, 114 (110-119) months]. The main failure type was fracture of the restoration (n = 15). The annual failure rate was 2.4%. In bivariate Cox regression, both factors such as number of restored tooth surfaces and adhesive were significantly associated with the failure rate. In multivariate Cox proportional hazards regression, none of the investigated factors were significantly associated with the failure rate. CONCLUSION: For composite build-ups in ETT without post placement, high success rates could be found after up to 10 years of observation time. Within the limitations of the present study, none of the analyzed factors such as "tooth type" or "number of restored tooth surfaces" was a significant predictor for the failure rate. CLINICAL RELEVANCE: Endodontically treated teeth can be successfully directly restored with composite build-ups even when no additional post is inserted. TRIAL REGISTRATION: The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00012882).

Risk factors for failure of class V restorations of carious cervical lesions in general dental practices.

OBJECTIVES: The aim of this retrospective, non-interventional, multi-center, practice-based study was to analyze factors influencing the survival of restorative treatments of one- and two-surface active cervical (root) caries lesions (CCLs). METHODS: Records from patients who visited five private practices regularly were searched for the presence of active one- and two-surface CCLs. Data from 1167 patients with 2070 CCLs being detected at least 6 months before the last recall visit were recorded. Kaplan-Meier-analyses were used to analyze time-to-failure. Cox proportional hazards models were used to evaluate the association between clinical factors and time until failure. RESULTS: Within 120 months [mean (SD) follow-up period:50 (40) months] 219 failures could be observed. Median survival time was 120 months. The AFR was 1.82% for one-surface restorations (CCL1) and 3.25% for two-surface restorations (CCL2). In multivariate Cox regression two-surface cervical restorations showed 1.75 times higher failure rates than one-surface cervical restoration. Furthermore, CCL being checked up more than twice a year showed significantly higher failure rates than restorations being checked up less than twice a year (p < 0.001). CONCLUSION: Low failure rates could be found for restorative treatment strategies of one- as well as for two-surface CCLs. CLINICAL SIGNIFICANCE: Restorative treatment of CCLs is a viable way to manage one-surface CCLs. However, the proximal extension of the CCL significantly shortens the longevity of the restoration. The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00012510).

Risk factors for failure in the management of cervical caries lesions.

OBJECTIVES: The aim of this retrospective, non-interventional clinical study was to analyze factors influencing the survival of restorative treatments of active cervical (root) caries lesions (aCCLs) and the success of non-invasive treatment options of inactive cervical (root) caries lesions (iCCLs). MATERIAL AND METHODS: Records from patients who visited a single private practice regularly were searched for the presence of solely buccal CCLs. Data from 345 aCCLs and 232 iCCLs being detected at least 6 months before the last recall visit in 295 patients were recorded. Kaplan-Meier analyses were used to analyze time to failure in both groups. Cox proportional hazards models were used to evaluate the association between clinical factors and time until failure. RESULTS: Within 120 months, 20 aCCLs had received a second restorative follow-up treatment. For iCCLs, 35 lesions had to be restored within 120 months. Median survival/success time was 111 months for aCCLs (annual failure rate 1.7%) and 120 months for iCCLs (annual "restoration" rate 4.3%). In multivariate Cox regression, active and inactive CCLs being checked up more than twice a year showed significantly higher failure/restoration rates than CCLs being checked up less than twice a year (p < 0.001). CONCLUSION: Low failure/restoration rates could be found for both treatment strategies for CCLs, and only the "number of check-ups per year" was significantly positively associated with failures. CLINICAL RELEVANCE: Caries monitoring is a viable way to manage CCLs. However, individual check-up interval should be defined carefully, since higher rate of check-ups seems to lead to increased intervention rates in the management of CCLs. The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00010003).

Determination of the electron escape depth for NEXAFS spectroscopy.

A novel method was developed to determine carbon atom density as a function of depth by analyzing the postedge signal in near-edge X-ray absorption fine structure (NEXAFS) spectra. We show that the common assumption in the analysis of NEXAFS data from polymer films, namely, that the carbon atom density is constant as a function of depth, is not valid. This analysis method is then used to calculate the electron escape depth (EED) for NEXAFS in a model bilayer system that contains a perfluorinated polyether (PFPE) on top of a highly oriented pyrolitic graphite (HOPG) sample. Because the carbon atom densitites of both layers are known, in addition to the PFPE surface layer thickness, the EED is determined to be 1.95 nm. This EED is then used to measure the thickness of the perfluorinated surface layer of poly(4-(1H,1H,2H,2H-perfluorodecyl)oxymethylstyrene) (PFPS).

Symmetry breaking of in-plane order in confined copolymer mesophases.

Packing of spherical-domain block copolymer mesophases confined to a thin film is investigated as a function of the number of layers n. We find an abrupt transition from hexagonal to orthorhombic in-plane ordering of domains when n is increased from 4 to 5. As n increases further (up to 23 in this study), the symmetry of the orthorhombic phase asymptotically approaches that of the body-centered cubic (110) plane. These results are interpreted in terms of the energetics of competing packings in the bulk and at the film interfaces. Detailed structural and thermodynamic properties are obtained with self-consistent field theory.

Single-crystal diffraction from two-dimensional block copolymer arrays.

The structure of oriented 2D block copolymer single crystals is characterized by grazing-incidence small-angle x-ray diffraction, demonstrating long-range sixfold orientational order. From line shape analysis of the higher-order Bragg diffraction peaks, we determine that translational order decays algebraically with a decay exponent eta=0.2, consistent with the Kosterlitz-Thouless-Halperin-Nelson-Young theory for a 2D crystal with a shear modulus mu=2 x 10(-4) N/m.

Monte Carlo study of crystalline order and defects on weakly curved surfaces.

We numerically study the ground states of particles interacting via a repulsive Yukawa potential on two rigid substrates shaped as isolated and periodically arranged bumps characterized by a spatially varying Gaussian curvature. Below a critical aspect ratio that describes the substrate deformation, the lattice is frustrated, but defect free. A further increase of the aspect ratio triggers defect unbinding transitions that lower the total potential energy by introducing dislocations either in isolation or within grain boundaries. In the presence of very strong deformations, isolated disclinations are nucleated. We show that the character and spatial distribution of defects observed in the ground state reflect the symmetries and periodicity of the two model surfaces investigated in this study.

The effects of network structure on the resistance of silane coupling agent layers to water-assisted crack growth.

Silane adhesion promoters are commonly used to improve the adhesion, durability, and corrosion resistance of polymer-oxide interfaces. The current study investigates a model interface consisting of the natural oxide of(100) Si and an epoxy cured from diglycidyl ether ofbisphenol A (DGEBA) and triethylenetetraamine (TETA). The thickness of (3-glycidoxypropyl)trimethoxysilane (GPS) films placed between the two materials provided the structural variable. Five surface treatments were investigated: a bare interface, a rough monolayer film, a smooth monolayer film, a 5 nm thick film, and a 10 nm thick film. Previous neutron reflection experiments revealed large extension ratios (>2) when the 5 and 10 nm thick GPS films were exposed to deuterated nitrobenzene vapor. Despite the larger extension ratio for the 5 nm thick film, the epoxy/Si fracture energy (Gc) was equal to that of the 10 nm thick film under ambient conditions. Even the smooth monolayer exhibited the same Gc. Only when the monolayer included a significant number of agglomerates did the Gc drop to levels closer to that of the bare interface. When immersed in water at room temperature for 1 week, the threshold energy release rate (Gth) was nearly equal to Gc for the smooth monolayer, 5 nm thick film, and 10 nm thick film. While the Gth for all three films decreased with increasing water temperature, the Gth of the smooth monolayer decreased more rapidly. The bare interface was similarly sensitive to temperature; however, the Gth of the rough monolayer did not change significantly as the temperature was raised. Despite the influence of pH on hydrolysis, the Gth was insensitive to the pH of the water for all surface treatments.

Immigrant women and the emergency department: the juncture with welfare and immigration reform.

This article discusses the Personal Responsibility and Work Opportunity Reconciliation Act and the Illegal Immigration Reform and Immigrant Responsibility Act and their potential impact on immigrant women's access to medical services. Current federal mandates assuring access to emergency medical services and new restrictions on financing of health care under federal programs such as Medicaid and Medicare would appear to be on a collision course. Both acts specifically reaffirm federal law on delivery of emergency services without addressing the financing of that care. Unfunded mandates in an era of diminished ability to shift costs onto insured patients are problematic for the institutions that provide uncompensated care. Specific protections for victims of domestic violence are also discussed.

Self-administration of medication by patients and family members during hospitalization.

The current trend of shorter hospital stays has heightened concern about the adequacy of preparation of patients and their families to understand and follow prescribed medication regimens properly following discharge. Cooperative Care, an education-intensive unit incorporating a living-in family member or friend acting as a 'care partner,' has had a self-administration of medication program (SAM) for the past 16 years. This paper describes SAM and reports on two studies of its effectiveness. The first was a 1-week survey of all patients (151) admitted to the unit. 126 (83.4%) were taking a mean of five medications, with a range of one to 17. Of those, 102 (80.9%) were able to participate in SAM independently, and 11 (8.7%) were on SAM with supervision by their care partners. The second study reviewed medication administration errors within Cooperative Care and the traditional nursing units of Tisch Hospital over a 4-year period (1991-1994). Cooperative Care accounted for 19.4% of discharges (22,164/114,206) and 10.3% of patient days (97,037/944,230), but only 4.6% of medication errors (80/1723). The medication error rate per 1000 discharges was 3.6 for Cooperative Care, and 17.8 for the traditional units. Comparative error rates per 10,000 medication orders were 3.06 at Cooperative Care and 4.01 on the traditional units. 74.8% of Cooperative Care patients were on SAM, but only 30% of the errors were attributed to patients or care partners. The other errors were attributed to nursing staff (50%), equipment defects (12.5%) or pharmacists (5%). Our data indicate that SAM during hospitalization is a safe and effective modality of care.