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NaOH-stabilized NaOCl solutions have a higher alkaline capacity and are thus more proteolytic than standard counterparts.

OBJECTIVES Narrowed radicular pulp spaces are frequently observed in teeth wearing extended restorations. The present study investigates whether the narrowing of particularly the radicular pulp space can be attributed to coronal restorations. MATERIALS AND METHODS The study is based on an anonymized copy of the cone-beam computed tomography (CBCT) database from the Center of Dental Medicine of the University of Zurich. One hundred CBCT scans were selected out of 7317 data sets to match either a crowned (group A; n = 50) or a filled tooth (group B; n = 50) with a contralateral healthy, unrestored, and caries-free control tooth at the same position, respectively. Cross-sectional images were adjusted in the coronal, middle, and apical root third of each subjected tooth. Screenshots were taken in that position and analyzed. The area occupied by the pulp space was determined as percentage area of the whole root diameter on each cross section. The resulting values were compared between restored and control teeth. RESULTS In both groups (crowned and filled teeth) and in all the three root thirds, the radicular pulp space was significantly narrower in the restored teeth compared to the control teeth. The strongest narrowing effect was observed in the coronal root third and it decreased towards the apical root third (both groups). CONCLUSIONS Teeth with coronal restorations show within the limitations of the present study a significant narrowing of their radicular pulp space. CLINICAL RELEVANCE The asserted narrowing could have a complicating effect if root canal treatment becomes necessary in those teeth. Abstract:Objectives: Narrowed radicular pulp spaces are frequently observed in teeth wearing extended restorations. The present study investigates whether the narrowing of particularly the radicular pulp space can be attributed to coronal restorations. Materials and Methods:The study is based on an anonymized copy of the cone-beam computed tomography (CBCT) database from the center of dental medicine of the university of zurich. One hundred CBCT scans were selected out of 7317 data sets to match either a crowned (group A; n=50) or a filled tooth (group B; n=50) with a contralateral healthy, unrestored, and caries-free control tooth at the same position, respectively. Cross-sectional images were adjusted in the coronal, middle and apical root third of each subjected tooth. Screenshots were taken in that position and analyzed. The area occupied by the pulp space was determined as percentage area of the whole root diameter on each cross-section. The resulting values were compared between restored and control teeth. Results:In both groups (crowned and filled teeth) and in all three root-thirds, the radicular pulp space was significantly narrower in the restored teeth compared to control teeth. The strongest narrowing effect was observed in the coronal root third and it decreased towards the apical root third (both groups). Conclusions:Teeth with coronal restorations show within the limitations of the present stu...

ObjectivesThe aim of this series of studies was the development and validation of a new model for evaluation of dentinal hypersensitivity (DH) therapies.Materials and methodsRoots from extracted human teeth were sealed with a flowable composite. In the cervical area, a 3-mm-wide circular window was ground through the seal 1 mm deep into dentine. The pulp lumen was connected to a reservoir of artificial dentinal fluid (ADF) containing protein, mineral salts and methylene blue. At increased pulpal pressure, the ADF released through the said window was collected in containers each with 20 ml of physiologic saline for a consecutive series of 30-min intervals and ADF concentration (absorption) was determined photometrically. The model was verified by three experiments. In experiment 1, the lower limit of quantification (LLoQ, coefficient of variation = 20 % and difference of 5 standard deviations (SD) from blank) of ADF in physiologic saline was determined by measuring the absorption of 15 dilutions of ADF in physiologic saline (containing 0.625 ng to 12.5 μg methylene blue/ml) photometrically for ten times. In experiment 2, long-term linearity of ADF perfusion/outflow was investigated using 11 specimens. The ADF released through the window was collected in the said containers separately for each consecutive interval of 30 min for up to 240 min. Absorption was determined and analysed by linear regression over time. In experiment 3, perfusion before (2×) and after single treatment according to the following three groups was measured: BisGMA-based sealant (Seal&Protect®), an acidic fluoride solution (elmex fluid®) and control (no treatment).ResultsIn experiment 1, the LLoQ was 0.005 μg methylene blue/ml. In experiment 2, permeability was different within the specimens and decreased highly linearly with time, allowing the prediction of future values. In experiment 3, Seal&Protect® completely occluded dentinal tubules. elmex fluid® increased tubular permeability by about 30 % compared to control.ConclusionsA model comprising the use of artificial dentinal fluid was developed and validated allowing screening of therapeutic agents for the treatment of DH through reliable measurement of permeability of cervical root dentine.Clinical relevanceThe described in vitro model allows evaluation of potential agents for the treatment of DH at the clinically relevant cervical region of human teeth.

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