Removal of enamel caries with an air abrasion powder

This study compared the efficiency of air abrasion on enamel caries with selective enamel powder (SEP) or with alumina powder and a negative and positive control group. Ninety-three extracted molars with non-cavitated incipient enamel lesions were selected. After embedding the roots in resin, each lesion was sectioned perpendicular to the surface and photographed. Each lesion was classified microscopically as having or not having dentin involvement. The lesions were distributed into four groups with an equal number of enamel caries with or without dentin involvement. Each group was treated differently: Group 1 had SEP abrasion, Group 2 had alumina abrasion, Group 3 had sodium bicarbonate abrasion (negative control) and Group 4 had bur treatment (positive control). The surface was rephotographed after treatment. Superimposition of the photographs identified areas of "correct-excavation," "under-excavation" and "over-excavation." There were no statistical differences between lesions treated with or without dentin involvement for Groups 2 through 4. However, in the SEP group, all measured areas were significantly influenced by dentin involvement. In pairwise comparisons, no statistical differences were found between the alumina and bur groups. The SEP group, however, showed statistically significant differences for each area compared to the alumina group in enamel caries without dentin involvement. SEP performed as well as alumina and bur in lesions with dentin involvement. SEP is different in its ablative properties toward caries with dentin involvement or no dentin involvement. In terms of dental treatment, SEP seems to have a diagnostic potential for enamel lesions before operative intervention in patients with high caries risk.

Performance of laser fluorescence devices, visual and radiographic examination for the detection of occlusal caries in primary molars

The aim of this in vitro study was to compare the performance of two laser fluorescence devices (LF, LFpen), conventional visual criteria (VE), ICDAS and radiographic examination on occlusal surfaces of primary teeth. Thirty-seven primary human molars were selected from a pool of extracted teeth, which were stored frozen at -20°C until use. Teeth were assessed twice by two experienced examiners using laser fluorescence devices (LF and LFpen), conventional visual criteria, ICDAS and bitewing radiographs, with a 2-week interval between measurements. After measurement, the teeth were histologically prepared and assessed for caries extension. The highest sensitivity was observed for ICDAS at D(1) and D(3) thresholds, with no statistically significant difference when compared to the LF devices, except at the D(3) threshold. Bitewing radiographs presented the lowest values of sensitivity. Specificity at D(1) was higher for LFpen (0.90) and for VE at D(3) (0.94). When VE was combined with LFpen the post-test probabilities were the highest (94.0% and 89.2% at D(1) and D(3) thresholds, respectively). High values were observed for the combination of ICDAS and LFpen (92.0% and 80.0%, respectively). LF and LFpen showed the highest values of ICC for interexaminer reproducibility. However, regarding ICDAS, BW and VE, intraexaminer reproducibility was not the same for the two examiners. After primary visual inspection using ICDAS or not, the use of LFpen may aid in the detection of occlusal caries in primary teeth. Bitewing radiographs may be indicated only for approximal caries detection.

Osteoporosis and bisphosphonates-related osteonecrosis of the jaw: Not just a sporadic coincidence - a multi-centre study

Bisphosphonates (BPs) are powerful drugs that inhibit bone metabolism. Adverse side effects are rare but potentially severe such as bisphosphonate-related osteonecrosis of the jaw (BRONJ). To date, research has primarily focused on the development and progression of BRONJ in cancer patients with bone metastasis, who have received high dosages of BPs intravenously. However, a potential dilemma may arise from a far larger cohort, namely the millions of osteoporosis patients on long-term oral BP therapy.

Late Infiltration of Post-orthodontic White Spot Lesions

White spot lesion (WSL) infiltration has been recommended immediately after debonding of orthodontic brackets. It is however not clear if established inactive WSLs can also be masked through infiltrationOrthodontic treatment of a 19-year-old patient had to be terminated prematurely due to development of multiple WSLs of varying severity. Three months after debonding, the patient presented for lesion infiltration. After etching with 15% HCl gel and re-wetting of the dried surfaces it seemed that a good outcome could be expected. Lesion infiltration led to complete masking of less severe WSLs. The visual appearance of moderate and severe WSLs was improved but they were still visible after treatment.Inactive WSLs may not represent an increased caries risk, but patients are often bothered esthetically. Infiltration by repeated etching might be a viable approach even for inactive WSLs. Controlled clinical trials are needed to investigate the long-term performance of this technique.

Influence of examiner's clinical experience on the reproducibility and accuracy of radiographic examination in detecting occlusal caries

The aim of this in vitro study was to assess the influence of varying examiner's clinical experience on the reproducibility and accuracy of radiographic examination for occlusal caries detection. Standardized bitewing radiographs were obtained from 166 permanent molars. Radiographic examination was performed by final-year dental students from two universities (A, n = 5; B, n = 5) and by dentists with 5 to 7 years of experience who work in two different countries (C, n = 5; D, n = 5). All examinations were repeated after 1-week interval. The teeth were histologically prepared and assessed for caries extension. For intraexaminer reproducibility, the unweighted kappa values were: A (0.11-0.40), B (0.12-0.33), C (0.47-0.58), and D (0.42-0.71). Interexaminer reproducibility statistics were computed based on means ± SD of unweighted kappa values: A (0.07 ± 0.05), B (0.12 ± 0.09), C (0.24 ± 0.08), and D (0.33 ± 0.10). Sensitivity, specificity, and accuracy were calculated at D(1) and D(3) thresholds and compared by performing McNemar test (p = 0.05). D(1) sensitivity ranged between 0.29 and 0.75 and specificity between 0.24 and 0.85. D(3) specificity was moderate to high (between 0.62 and 0.95) for all groups, with statistically significant difference between the dentists groups (C and D). Sensitivity was low to moderate (between 0.21 and 0.57) with statistically significant difference for groups B and D. Accuracy was similar for all groups (0.55). Spearman's correlations were: A (0.12), B (0.24), C (0.30), and D (0.38). In conclusion, the reproducibility of radiographic examination was influenced by the examiner's clinical experience, training, and dental education as well as the accuracy in detecting occlusal caries.

Determination of Pelvic Orientation from Ultrasound Images Using Patch-SSMs and a Hierarchical Speed of Sound Compensation Strategy

In the field of computer assisted orthopedic surgery (CAOS) the anterior pelvic plane (APP) is a common concept to determine the pelvic orientation by digitizing distinct pelvic landmarks. As percutaneous palpation is - especially for obese patients - known to be error-prone, B-mode ultrasound (US) imaging could provide an alternative means. Several concepts of using ultrasound imaging to determine the APP landmarks have been introduced. In this paper we present a novel technique, which uses local patch statistical shape models (SSMs) and a hierarchical speed of sound compensation strategy for an accurate determination of the APP. These patches are independently matched and instantiated with respect to associated point clouds derived from the acquired ultrasound images. Potential inaccuracies due to the assumption of a constant speed of sound are compensated by an extended reconstruction scheme. We validated our method with in-vitro studies using a plastic bone covered with a soft-tissue simulation phantom and with a preliminary cadaver trial.

Observation of ventilation-induced Spo(2) oscillations in pigs: first step to noninvasive detection of cyclic recruitment of atelectasis?

High arterial partial oxygen pressure (Pao(2)) oscillations within the respiratory cycle were described recently in experimental acute lung injury. This phenomenon has been related to cyclic recruitment of atelectasis and varying pulmonary shunt fractions. Noninvasive detection of Spo(2) (oxygen saturation measured by pulse oximetry) as an indicator of cyclic collapse of atelectasis, instead of recording Pao(2) oscillations, could be of clinical interest in critical care. Spo(2) oscillations were recorded continuously in three different cases of lung damage to demonstrate the technical feasibility of this approach. To deduce Pao(2) from Spo(2), a mathematical model of the hemoglobin dissociation curve including left and right shifts was derived from the literature and adapted to the dynamic changes of oxygenation. Calculated Pao(2) amplitudes (derived from Spo(2) measurements) were compared to simultaneously measured fast changes of Pao(2), using a current standard method (fluorescence quenching of ruthenium). Peripheral hemoglobin saturation was capable to capture changes of Spo(2) within each respiratory cycle. For the first time, Spo(2) oscillations due to cyclic recruitment of atelectasis within a respiratory cycle were determined by photoplethysmography, a technology that can be readily applied noninvasively in clinical routine. A mathematic model to calculate the respective Pao(2) changes was developed and its applicability tested.

One-Step (18)F-Labeling of Carbohydrate-Conjugated Octreotate-Derivatives Containing a Silicon-Fluoride-Acceptor (SiFA): In Vitro and in Vivo Evaluation as Tumor Imaging Agents for Positron Emission Tomography (PET)

The synthesis, radiolabeling, and initial evaluation of new silicon-fluoride acceptor (SiFA) derivatized octreotate derivatives is reported. So far, the main drawback of the SiFA technology for the synthesis of PET-radiotracers is the high lipophilicity of the resulting radiopharmaceutical. Consequently, we synthesized new SiFA-octreotate analogues derivatized with Fmoc-NH-PEG-COOH, Fmoc-Asn(Ac?AcNH-?-Glc)-OH, and SiFA-aldehyde (SIFA-A). The substances could be labeled in high yields (38 ± 4%) and specific activities between 29 and 56 GBq/?mol in short synthesis times of less than 30 min (e.o.b.). The in vitro evaluation of the synthesized conjugates displayed a sst2 receptor affinity (IC?? = 3.3 ± 0.3 nM) comparable to that of somatostatin-28. As a measure of lipophilicity of the conjugates, the log P(ow) was determined and found to be 0.96 for SiFA-Asn(AcNH-?-Glc)-PEG-Tyr³-octreotate and 1.23 for SiFA-Asn(AcNH-?-Glc)-Tyr³-octreotate, which is considerably lower than for SiFA-Tyr³-octreotate (log P(ow) = 1.59). The initial in vivo evaluation of [¹?F]SiFA-Asn(AcNH-?-Glc)-PEG-Tyr³-octreotate revealed a significant uptake of radiotracer in the tumor tissue of AR42J tumor-bearing nude mice of 7.7% ID/g tissue weight. These results show that the high lipophilicity of the SiFA moiety can be compensated by applying hydrophilic moieties. Using this approach, a tumor-affine SiFA-containing peptide could successfully be used for receptor imaging for the first time in this proof of concept study.