[Older care receivers with chronic pain : Cross-sectional study of gender-specific pain intensity and home-care provision in the city environment]. / Ältere Pflegebedürftige mit chronischen Schmerzen : Querschnittsstudie zur geschlechtsspezifischen Schmerzintensität und Versorgung in der großstädtischen Häuslichkeit.

BACKGROUND: Pain prevalence rates of up to 53% are found among older home-care recipients (aged ≥ 60 years). Of people affected by pain in Germany, care recipients comprise a relevant group with prevalence rates of around 70%. The available information on gender-specific pain experience shows a range of differing findings. OBJECTIVE: Our objective was to determine pain parameters of older care receivers in the big city environment who are capable of self-reporting, taking into account gender differences and relevant aspects of medical care and medication. MATERIAL AND METHODS: A cross-sectional study (structured interviews) was carried out among older (≥65 years) home-care recipients (German Social Security Code SGB XI) in Berlin, with chronic pain (n = 225), capable of self-reporting (MMST ≥ 18). Pain parameters were determined using the German version of the brief pain inventory (BPI-NHR). Multiple regression analysis was applied to test and explain how the severest pain was influenced by sociodemographic and medical parameters, mental and physical restrictions, and analgesic provision. RESULTS: Analyses showed an average pain intensity of 5.3 (SD ± 2.0). The severest pain averaged 7.0 (SD ± 2.2). Few indications of significant gender-based differences were found (e.g. pain location, number of medications). The final model identified the number of pain locations (≥14), everyday abilities, and pain medication (as needed, none) as being associated with the severest pain. Treatment achieved pain relief of over 70% in only 24.6% of cases among pain-affected care receivers. CONCLUSION: The findings indicate a significant level of pain experienced by older home-care recipients. Interdisciplinary care concepts are urgently needed.

Impact of motion artefacts and motion-artefact correction on diagnostic accuracy of apical periodontitis in CBCT images: an ex vivo study in human cadavers.

AIM: To assess the impact of motion artefacts and motion-artefact correction on diagnostic accuracy of apical periodontitis (AP) in CBCT images. METHODOLOGY: Based on clinical and radiographic inspection of 40 formalin-fixated human jaw specimens, 77 roots in 45 teeth (molars and premolars), with various disease and treatment state, were selected. The specimens were mounted on a robot simulating 3-mm movement types (nodding, lateral rotation and tremor). CBCT images with and without (controls) movements were acquired in four CBCT units: without motion-artefact correction in Cranex 3Dx, Orthophos SL 3D, and Promax 3D Mid, and with motion-artefact correction in Promax 3D Mid and X1. Three observers blindly assessed (i) whether the images were interpretable and (ii) if AP was present (5-step probability index). Histopathology provided the reference standard for presence of AP. Weighted Kappa statistics described inter-observer agreement. Estimates of diagnostic accuracy were assessed by means of receiver operator characteristic (ROC) curve analysis. Area under the curve (AUC) provided a measure of accuracy, and paired-sample AUC difference tests compared differences amongst the CBCT units and movement types. RESULTS: Observer agreement was substantial for control images, moderate for motion-artefact corrected images and fair for images without motion-artefact correction. When movement was present, motion-artefact correction reduced the percentage of images scored as noninterpretable or with uncertain disease state (score 3 in the 5-step probability index). Control images were not perfectly accurate (both false-positive and false-negative results were present; AUC 0.750-0.799). Images acquired with movement and without motion-artefact correction (AUC 0.541-0.709) were associated with significantly lower accuracy than control images (P < 0.05). With motion-artefact correction, accuracy was comparable to that observed in control images (AUC 0.732-0.790). CONCLUSIONS: Diagnostic accuracy of apical periodontitis in CBCT images was dependent on the presence of motion artefacts (i.e. lower accuracy associated with the presence of movement). Motion-artefact correction systems positively influenced image interpretability and diagnostic accuracy.

[Prevalence of peripheral vestibular diseases in children in Germany]. / Prävalenz peripher-vestibulärer Erkrankungen bei Kindern in Deutschland.

INTRODUCTION: Dizziness is a common complaint among patients; however, a lack of valid data concerning age and gender distribution of dizziness disorders among children under the age of 15 years can preclude effective diagnosis and treatment. The goal of this study was to describe the prevalence and gender distribution of three classical peripheral vestibular disorders; benign paroxysmal positional vertigo (BPPV), vestibular neuritis (VN), and Menière's disease (MD) as well as unspecific dizziness (UV) in children between 0 and 15 years of age, using state sponsored health insurance data. METHODS: A population-based epidemiological survey based on confirmed International Classification of Diseases (ICD) 10 codes of all persons aged 0-15 years in a national population was performed. Outcome measures were age and gender distribution and prevalence of BPPV, VN, and MD in this population. RESULTS: Dizziness diagnosed as being of peripheral vestibular origin was found in 1414 patients. The prevalence of peripheral vestibular disorders was found to be 15.16 per 100,000 individuals. The BPPV was coded most frequently with a prevalence of 10.21 per 100,000 individuals, followed by VN with a prevalence of 3.5 per 100,000 and MD at 1.54 per 100,000. CONCLUSION: Peripheral vestibular disorders can occur in childhood and the prevalence increases with age. In childhood, girls and boys are similarly affected. Peripheral vestibular disorders should be taken into consideration when a young child presents with vertigo or dizziness and are even more important when a child presents with unclear symptoms, as very young children might not be able to adequately verbalize dizziness and vertigo. For that reason peripheral vestibular disorders in childhood are probably underdiagnosed.

Impact of cone beam computed tomography on periapical assessment and treatment planning five to eleven years after surgical endodontic retreatment.

AIM: To evaluate how additional information from Cone Beam CT (CBCT) impacts on periapical assessment and treatment planning based on clinical examination and periapical radiographs (PR) in cases followed up five to eleven years after surgical endodontic retreatment (SER). METHODOLOGY: Patients receiving SER during 2004-2010 were reinvited for follow-up examination including clinical examination, PR, and CBCT. In total, 108 patients (119 teeth) were reinvited, 74 patients (83 teeth) accepted to participate. Three observers initially assessed PR according to the four-scaled, increasing disease severity criteria by Rud et al. (International Journal of Oral Surgery, 1, 1972 and 195) and Molven et al. (International Journal of Oral and Maxillofacial Surgery, 16, and 432): 'Radiographic assessment A'. By including clinical information 'Treatment plan A' was made as follows: 1) no treatment, 2) further observation, 3) SER reoperation (SER-R), or 4) extraction. Hereafter, the CBCT volume was assessed and the information incorporated for 'Radiographic assessment B' followed by 'Treatment plan B'. Agreement between radiographic assessments and between treatment plans was recorded and assessed statistically by Stuart-Maxwell test for marginal homogeneity. RESULTS: Nine teeth had been extracted; thus, the final analysis included 74 teeth (66 patients). The radiographic assessment was changed as a result of the CBCT evaluation in 38 cases (51.4%), of which 35 (47.3%) were to a higher Rud & Molven score, P < 0.001. The treatment plan was changed for 18 teeth (24.3%). For 14 teeth (18.9%), the change was from no treatment or further observation to a more invasive treatment plan (SER-R or extraction), P = 0.005. CONCLUSION: The use of CBCT for long-term follow-up after SER led to more cases diagnosed with persisting or recurrent apical periodontitis and hence often to the recommendation of a more invasive treatment modality.

Influence of MP 29-02 on ciliary beat frequency in human epithelial cells in vitro.

PURPOSE: MP 29-02, which contains fluticasone propionate and azelastine hydrochloride, is used as a topical nasal application for the treatment of seasonal and perennial allergic rhinitis. Although a multitude of data is available on the clinical symptom reduction and treatment safety of MP 29-02, the effect of MP 29-02 on ciliary beat frequency (CBF) has not been evaluated thus far. METHODS: MP 29-02-containing solution was applied at concentrations of 2.5, 5, 10, and 20% to 14 healthy subjects, and nasal ciliated epithelial cells were then visualized using a phase-contrast microscope. CBF was measured after the application of MP 29-02. For a comparison, fluticasone propionate was used. CBF measurements were then performed for 15 min at 22 °C. Ringer's solution was applied as a negative control. RESULTS: MP 29-02 significantly reduced CBF at all the tested concentrations compared with that of the control group within the observation time. At a 2.5% concentration, MP 29-02 significantly reduced CBF from 6.81 Hz (SD ± 1.35 Hz) at baseline to 4.88 Hz (SD ± 1.52 Hz, p < 0.001) after 15 min. In contrast, for fluticasone propionate, a significant reduction was observed only with the 20% concentration after 5, 10, and 15 min. CONCLUSIONS: MP 29-09 significantly reduced CB, with an almost linear relationship between the MP 29-09 concentration and reduction in CBF. For fluticasone propionate, a significant reduction of CBF was observed only at the highest analyzed concentration. The findings have implications for the long-term use of the MP 29-02. Yet, further clinical studies are needed to confirm these results in vivo, especially in patients with seasonal or perennial allergic rhinits.

Prediction of periapical status and tooth extraction.

AIM: To describe and analyse risk factors associated with prediction of periapical status, assessed using the full-scale Periapical Index (PAI) supplemented with extraction as outcome variable. METHODOLOGY: In 1997-1998, 616 randomly selected individuals from Aarhus County, Denmark, underwent a full-mouth radiographic survey. All 616 were re-invited in 2003-2004 and in 2008-2009, when 473 and 363 persons, respectively, consented and attended a new radiographic examination. The study population of the present investigation included 330 persons who had participated in all three examinations, and 143 persons who had participated in the first and second examination only. Using the full-mouth radiographic survey and interview information, the following variables were assessed: on person level - age, gender, smoking habits and number of teeth; on tooth level - presence of tooth, PAI, root filling, caries, marginal bone level, restoration, jaw and tooth group. The outcome variable was the 5 score PAI supplemented with extraction. The observation period was 5 years. Ordered logistic regression analyses were carried out for root filled and non-root filled teeth separately. The Regional Committee of Ethics approved the study. RESULTS: For both root filled teeth and non-root filled teeth, the baseline PAI score was the most important predictive factor of periapical status and extraction (P < 0.0001). Non-root filled teeth had in general a better outcome than root filled teeth. However, in non-root filled teeth, several other factors had a significant influence on the outcome, and the risk estimates were larger and showed a more pronounced variation between the different categories of predictive factors. For root filled teeth few variables, other than baseline PAI score, influenced the outcome significantly. CONCLUSION: The full-scale PAI was the strongest predictive factor of periapical status or extraction even when adjusted for additional factors, such as marginal bone level. A high baseline PAI score increased the risk for an impaired outcome. The large difference in risk estimates for non-root filled compared to root filled teeth documents the importance of separate analyses/studies for identification and quantification of predictive factors associated with periapical status and extraction of a tooth.

Use of micro-computed tomography for the assessment of periapical lesions in small rodents: a systematic review.

This systematic review aimed to evaluate the literature on the acquisition-, reconstruction- and analysis parameters of micro-computed tomography (micro-CT) for the assessment of periapical lesions in rats and mice, and to illustrate the effect of variation in these parameters. The PubMed database was searched from 2000 to January 2015 (English-language publications) for reports on the use of micro-CT to evaluate periapical lesions in rats and mice. QUADAS criteria were used to rate the quality of the studies. To illustrate the effect of variations in acquisition-, reconstruction-, and analysis parameters on images of periapical lesions, micro-CT examination of two hemi-mandibles of mice, with periapical lesions around the first molar was undertaken. Twenty-one studies were identified, which analysed periapical lesions in rats or mice using micro-CT. According to the QUADAS, no study was classified as high-, seven were classified as moderate-, and 14 as low quality. The effect of variation in parameters was that voxel size may interfere with image sharpness, reconstruction may interfere with image sharpness and contrast, and inadequate plane orientation may alter the size of the periapical lesion. Nonpersonalized ROIs resulted in areas that were not part of the periapical lesion. Changing the limits of the threshold for bone-tissue visualization increased lesion size. There is no defined protocol for acquiring and analysing micro-CT images of periapical lesions in rats and mice. Furthermore, acquisition-, reconstruction- and analysis parameters are not adequately explained, which may compromise the scientific impact of the studies.

Mupirocin reduces ciliary beat frequency of human nasal epithelial cells.

Mupirocin is used worldwide for topical treatment of infected skin lesions, impetigo, and especially for nasal decolonization of patients with carriage of Staphylococci, including methicillin-resistant Staphylococcus aureus. Nevertheless, data regarding the effects of mupirocin on the nasal mucosa, in particular on ciliary beat frequency (CBF), is lacking to date. We tested the CBF of ciliated nasal epithelial cells under the influence of Mupirocin-calcium dissolved in tert-butyl alcohol (TBA) containing media in different concentrations comparable to clinical use. Ringer's lactate solution and TBA served as negative control. Cells were visualized with a phase contrast microscope, and the CBF was measured with the SAVA system's region of interest method. Mupirocin-calcium dissolved in TBA led to a statistically significant time- and concentration-dependent decrease in CBF compared to the negative control. TBA addition without mupirocin also led to a significant decrease in CBF, although to a lesser extent than mupirocin/TBA. In conclusion, CBF of human nasal epithelia is significantly reduced by mupirocin-calcium-containing solutions in therapeutic concentrations. Due to our results in this study, mupirocin as a nasal decolonization agent should be used only with care, with a strictly set medical indication, and additional care measures should be considered.

Food web efficiency differs between humic and clear water lake communities in response to nutrients and light.

This study demonstrates that clear and humic freshwater pelagic communities respond differently to the same environmental stressors, i.e. nutrient and light availability. Thus, effects on humic communities cannot be generalized from existing knowledge about these environmental stressors on clear water communities. Small humic lakes are the most numerous type of lake in the boreal zone, but little is known about how these lakes will respond to increased inflows of nutrients and terrestrial dissolved organic C (t-DOC) due to climate change and increased human impacts. Therefore, we compared the effects of nutrient addition and light availability on pelagic humic and clear water lake communities in a mesocosm experiment. When nutrients were added, phytoplankton production (PPr) increased in both communities, but pelagic energy mobilization (PEM) and bacterial production (BP) only increased in the humic community. At low light conditions, the addition of nutrients led to increased PPr only in the humic community, suggesting that, in contrast to the clear water community, humic phytoplankton were already adapted to lower ambient light levels. Low light significantly reduced PPr and PEM in the clear water community, but without reducing total zooplankton production, which resulted in a doubling of food web efficiency (FWE = total zooplankton production/PEM). However, total zooplankton production was not correlated with PEM, PPr, BP, PPr:BP or C:nutrient stoichiometry for either community type. Therefore, other factors such as food chain length, food quality, ultra-violet radiation or duration of the experiment, must have determined total zooplankton production and ultimately FWE.

Cone beam computed tomography and periapical lesions: a systematic review analysing studies on diagnostic efficacy by a hierarchical model.

AIM: To evaluate using a systematic review approach the diagnostic efficacy of CBCT for periapical lesions, focusing on the evidence level of the included studies using a six-tiered hierarchical model. METHODOLOGY: The MEDLINE bibliographic database was searched from 2000 to July 2013 for studies evaluating the potential of CBCT imaging in the diagnosis and planning of treatment for periapical lesions. The search strategy was limited to English language publications using the following combined terms in the search strategy: apical pathology or endodontic pathology or periapical or lesion or healing and CBCT or cone beam CT. The diagnostic efficacy level of the studies was assessed independently by four reviewers. RESULTS: The search identified 25 publications that qualitatively or quantitatively assessed the use of CBCT for the diagnosis of periapical lesions, in which the methodology/results comprised at least one of the following parameters: the methods, the imaging protocols or qualitative/quantitative information on how CBCT influenced the diagnosis and/or treatment plan. CONCLUSION: From the assessed studies, it can be concluded that although there is a tendency for a higher accuracy for periapical lesion detection using CBCT compared to two-dimensional imaging methods, no studies have been conducted that justify the standard use of CBCT in diagnosing periapical lesions. In addition, it should be considered that, at the present time, the efficacy of CBCT as the diagnostic imaging method for periapical lesions has been assessed merely at low diagnostic efficacy levels.

Prognostic value of the full-scale Periapical Index.

AIM: To evaluate whether the full-scale Periapical Index (PAI) can predict the periapical status over time in nonroot filled and root filled teeth. METHODOLOGY: Full-mouth radiographic surveys of a random sample from a general population were performed in 1997, 2003 and 2008. The present investigation included 330 persons who participated in all three examinations and 143 persons who participated in the first and second examination. At each examination, the presence or absence of a tooth and of a root filling was recorded, and a PAI score (1-5) was assigned to all teeth. Retreatment of a root filling was recorded for root filled teeth. Statistical analysis was carried out using ordinal logistic regression and logistic regression and computed as Wald's tests. RESULTS: At baseline, nonroot filled teeth had lower PAI scores than root filled teeth (P < 0.0001). A high baseline PAI increased the risk of extraction for both root filled (P < 0.001) and nonroot filled teeth (P < 0.001). At 5-year follow-up, PAI scores were higher when baseline PAI scores had been higher. The overall pattern for root filled and nonroot filled teeth was similar, however, the differences were statistically significant (P < 0.001). In particular, the follow-up PAI score for nonroot filled teeth with baseline PAI score 1 or 2 was significantly lower than that of root filled teeth (P < 0.001). For root filled teeth with baseline PAI score 3, 4 or 5, the trend was reversed as they overall had slightly lower PAI scores at follow-up (P = 0.023). CONCLUSION: Repeated radiographic assessments of teeth using the full-scale PAI reveal that each of the five scores had distinct prognostic value for the course of periapical disease over a 5-year period for both nonroot filled and root filled teeth.

[Current aspects of ototoxicity : Local ototoxic effects, diagnosis, prevention, and treatment]. / Aktuelle Aspekte zur Ototoxizität : Lokale ototoxische Wirkungen, Diagnostik, Prävention und Therapie.

The otorhinolaryngologist is often involved in an interdisciplinary approach to diagnose ototoxic side effects. Under certain conditions, chemical agents-particularly drugs-can have ototoxic effects. This is not only true for systemic administration, but also for local application (e.g., transdermal and transtympanal). Identifying and avoiding ototoxicity is still a challenge in clinical practice. The audiological monitoring of patients receiving potentially cochleotoxic drugs is now standardized. For diagnosis of suspected vestibulotoxic effects, the video head impulse test and vestibular evoked myogenic potentials seem to be suitable procedures for objective assessment. The early detection of such ototoxic effects has important implications for the prevention of hearing and balance disorders. Recent studies show that intratympanic delivery of medications might play an important role in the limitation of ototoxically induced hearing loss. In peripheral vestibulopathies with episodic vertigo, which strongly affect quality of life, ototoxic effects can be used for therapeutic purposes.

[Current aspects of ototoxicity. Ototoxic substances and their effects]. / Aktuelle Aspekte zur Ototoxizität : Ototoxische Substanzen und deren Effekte.

Ototoxicity describes reversible or irreversible disorders of inner ear functions due to the influence of chemical, biological, or physical substances. Ototoxicity should be kept in mind during differential diagnosis of hearing loss, tinnitus, dizziness, and vertigo. In clinical practice, drug-induced ototoxic effects play a major role. The otorhinolaryngologist should also be involved in interdisciplinary cooperation, e.g., during treatment with antineoplastic chemotherapeutic agents with potential ototoxic side effects. In clinical practice, multimedication and interactions between different agents can complicate precise correlation in individual cases. Recent studies also show that noncellular components, such as otoconia, are extremely sensitive to chemical attacks.

[Frequency-specific analysis of the hVOR Prior of Cochlear Implant Operation]. / Frequenzspezifische Untersuchung des hVOR im Vorfeld einer CI-Operation.

Dizziness is one of the most common postoperative complications after a cochlear-implant (CI) surgery. With our prospective, matched-paired controlled study, we could demonstrate that patients with distinctive sensorineural hearing loss--even without any complaints of dizziness--already have a reduced horizontal vestibular-ocular-reflex (hVOR). Compared to controls, CI patients presented with a significantly reduced gain. 9 out of 17 CI patients showed physiological results in rotatory testing and video head thrust testing. One patient presented with pathological results in both tests. Remarkably, there were 2 patients who presented with pathological head impulse testing but normal values in rotatory testing and 5 patients who showed normal gains in video head impulse testing but abnormal rotatory tests. These findings clearly show the importance of a differentiated, frequency-dependent pre-operative vestibular assessment including rotatory testing and video-head impulse testing. Additionally, only an accurate pre-operative vestibular testing allows evaluating possible post-operative dizziness related complications and should be documented precisely, also for forensic reasons. This is the key to differentiate post-operative dizziness from an pre-operatively existing vestibular disorder that possibly might not be clinically apparent by the time of testing.

Should cavitation in proximal surfaces be reported in cone beam computed tomography examination?

AIM: A clinical study was done to assess the clinical diagnostic accuracy of cone beam computed tomography (CBCT) in detecting proximal cavitated carious lesions in order to determine whether cavitation should be reported when a CBCT examination is available. MATERIALS AND METHODS: 79 adjacent proximal surfaces without restorations in permanent teeth were examined. Patients suspected to have carious lesions after a visual clinical and a bitewing examination participated in a CBCT examination (Kodak 9000 3D, 5 × 3.7 cm field of view, voxel size 0.07 mm). Ethical approval and informed consent were obtained according to the Helsinki Declaration. Radiographic assessment recording lesions with or without cavitation was performed by two observers in bitewings and CBCT sections. Orthodontic separators were placed interdentally between two lesion-suspected surfaces. The separator was removed after 3 days and the surfaces recorded as cavitated (yes/no), i.e. validated clinically. Differences between the two radiographic modalities (sensitivity, specificity and overall accuracy) were estimated by analyzing the binary data in a generalized linear model. RESULTS: For both observers, sensitivity was significantly higher for CBCT than for bitewings (average difference 33%, p < 0.001) while specificity was not significantly different between the methods (p = 0.19). The overall accuracy was also significantly higher for CBCT (p < 0.001). CONCLUSION: CBCT was more accurate in detecting cavitation in proximal surfaces than bitewing radiographs; therefore a CBCT examination performed for other clinical applications should also be assessed for proximal surface cavities in teeth without restorations, and when detected, this pathology must be part of the dentist's report.

Ten-year follow-up of root filled teeth: a radiographic study of a Danish population.

AIM: To assess the long-term outcome of root filled teeth in a general adult population examined in 1997, 2003 and 2008. METHODOLOGY: The study provides longitudinal, observational information on endodontic status for 327 randomly selected individuals from a general Danish population receiving three consecutive full-mouth radiographic examinations. The association between root filling quality, periapical disease and the long-term outcome of the root filling and the root filled tooth was assessed using GEE methodology and tests for trend. RESULTS: Overall 13% of the root filled teeth had been extracted, 12% had received a revision of the root filling and 42% of root filled teeth present in 2008 had apical periodontitis (AP) after the 10-year follow-up period. The probability of persistent AP was higher if the root filling was either short or long (P = 0.001), if there were voids (P < 0.001), or if there were radiographic signs of overhang or open margin of the restoration (P = 0.01). Further, the probability of extraction was high if there were radiographic signs of overhang or open margin of the restoration (P = 0.008) and if the overall root filling quality was inadequate (test for trend, P = 0.03). CONCLUSIONS: The root filling quality primarily affected the risk of persistent AP and to a smaller extent the risk of extraction, whereas the quality of the coronal restoration primarily affected the risk of extraction and to a smaller extent the risk of persistent AP. If adjusted for AP present at the initial examination, the associations were less pronounced both in relation to extraction and persistence of AP.

Radiographic diagnosis of dental restoration misfit: a systematic review.

The objective of this study was to perform a systematic review on the use of radiographic methods for the diagnosis of misfit in dental prostheses and restorations. The MEDLINE bibliographic database was searched from 1950 to February 2014 for reports on the radiographic diagnosis of misfits. The search strategy was limited to English-language publications using the following combined MeSH terms in the search strategy: (Dental Restoration OR Dental Prosthesis OR Crown OR Inlays OR Dental Abutments) and (Dental Leakage OR Prosthesis Fitting OR Dental Marginal Adaptation OR Surface Properties) and (Radiography, Dental OR Radiography, Dental, Digital OR Cone-Beam Computed Tomography). Twenty-eight publications were identified and read in full text, and 14 studies fulfilled criteria for inclusion. Information regarding the use of radiographic methods for the diagnosis of misfits in dental prosthesis and restorations, and in which the methodology/results comprised information regarding how the sample was collected/prepared, the method, imaging protocol, presence of a reference test and the outcomes were evaluated. QUADAS criteria was used to rate the studies in high, moderate or low quality. The evidence supporting the use of radiographic methods for the diagnosis of misfits in dental prosthesis and restorations is limited to low-/moderate-quality studies. The well-established intra-oral orthogonal projection is still under investigation and considered the most appropriate method, both when evaluating the relation between dental restoration to tooth and abutment to implant. Studies using digital radiographs have not evaluated the effect of image post-processing, and tomography has not been evaluated.

Quality of root fillings performed with two root filling techniques. An in vitro study using micro-CT.

OBJECTIVE: The aim of this study was to compare the presence of voids in root fillings performed in oval and ribbon-shaped canals with two root filling techniques, lateral compaction technique (LCT) or hybrid technique (HT), a combination of a gutta-percha masterpoint and thermoplastic gutta-percha. Furthermore, the obturation time for the two techniques was evaluated. MATERIALS AND METHODS: Sixty-seven roots with oval and ribbon-shaped canals were prepared using Profile Ni-Ti rotary files. After preparation, the roots were randomly allocated to two groups according to root filling technique. All roots were filled with AH plus and gutta-percha. Group 1 was filled using LCT (n = 34) and group 2 was filled using HT (n = 33). The obturation time was measured in 30 cases evenly distributed between the two techniques. Voids in relation to the root canal fillings were assessed using cross-section images from Micro-computed Tomography scans. RESULTS: All root canal fillings had voids. Permutation test showed no statistically significant difference between the two root filling techniques in relation to presence of voids (p = 0.092). A statistically significant difference in obturation time between the two techniques was found (p < 0.001). CONCLUSION: The present study found no statistically significant difference in percentage of voids between two root filling techniques. A 40% reduction in obturation time was found for the HT compared to the LCT.

Protection of Rpe65-deficient mice identifies rhodopsin as a mediator of light-induced retinal degeneration.

Light-induced apoptosis of photoreceptors represents an animal model for retinal degeneration. Major human diseases that affect vision, such as age-related macular degeneration (AMD) and some forms of retinitis pigmentosa (RP), may be promoted by light. The receptor mediating light damage, however, has not yet been conclusively identified; candidate molecules include prostaglandin synthase, cytochrome oxidase, rhodopsin, and opsins of the cones and the retinal pigment epithelium (PE). We exposed to bright light two groups of genetically altered mice that lack the visual pigment rhodopsin (Rpe65-/- and Rho-/-). The gene Rpe65 is specifically expressed in the PE and essential for the re-isomerization of all-trans retinol in the visual cycle and thus for the regeneration of rhodopsin after bleaching. Rho-/- mice do not express the apoprotein opsin in photoreceptors, which, consequently, do not contain rhodopsin. We show that photoreceptors lacking rhodopsin in these mice are completely protected against light-induced apoptosis. The transcription factor AP-1, a central element in the apoptotic response to light, is not activated in the absence of rhodopsin, indicating that rhodopsin is essential for the generation or transduction of the intracellular death signal induced by light.

New views on RPE65 deficiency: the rod system is the source of vision in a mouse model of Leber congenital amaurosis.

Leber congenital amaurosis (LCA) is the most serious form of the autosomal recessive childhood-onset retinal dystrophies. Mutations in the gene encoding RPE65, a protein vital for regeneration of the visual pigment rhodopsin in the retinal pigment epithelium, account for 10-15% of LCA cases. Whereas previous studies of RPE65 deficiency in both animal models and patients attributed remaining visual function to cones, we show here that light-evoked retinal responses in fact originate from rods. For this purpose, we selectively impaired either rod or cone function in Rpe65-/- mice by generating double- mutant mice with models of pure cone function (rhodopsin-deficient mice; Rho-/-) and pure rod function (cyclic nucleotide-gated channel alpha3-deficient mice; Cnga3-/-). The electroretinograms (ERGs) of Rpe65-/- and Rpe65-/-Cnga3-/- mice were almost identical, whereas there was no assessable response in Rpe65-/-Rho-/- mice. Thus, we conclude that the rod system is the source of vision in RPE65 deficiency. Furthermore, we found that lack of RPE65 enables rods to mimic cone function by responding under normally cone-isolating lighting conditions. We propose as a mechanism decreased rod sensitivity due to a reduction in rhodopsin content to less than 1%. In general, the dissection of pathophysiological processes in animal models through the introduction of additional, selective mutations is a promising concept in functional genetics.