Assessing the Sealing Performance and Clinical Outcomes of Endodontic Treatment in Patients with Chronic Apical Periodontitis Using Epoxy Resin and Calcium Salicylate Seals.

Background and Objectives: Recognizing the significance of a hermetic apical seal for successful root canal treatment, the present investigation aimed to evaluate two sealing materials through an in vitro analysis, as well as to ascertain the clinical outcomes of patients treated with these two sealers in an in vivo setting. Materials and Methods: For the in vitro part of the study, two control groups of thirty monoradicular teeth were obturated with two sealers. Then, the sealers' performance was tested based on a predefined protocol. Group A included 30 patients treated with an epoxy oligomer resin-based sealer (Adseal, MetaBiomed), while Group S comprised 30 patients treated with a polymeric calcium salicylate-based sealer (Sealapex, Kerr). Samples were sectioned and evaluated under the microscope to determine the sealer's tightness by measuring the dye penetration into the root canal filling. For the in vivo part, a prospective study was designed to include 60 patients with chronic apical periodontitis in two endodontic treatment groups, using the same two sealers. Results: The in vitro analysis found that dye penetration in Group A was 0.82 mm (±0.428), while in Group S, the dye penetration was statistically significantly deeper, being 1.23 mm (±0.353). In the in vivo part of the study, the periapical index (PAI) significantly decreased 6 months after endodontic treatment, with 80.0% of patients in Group A having a PAI score of 2 compared to only 56.7% in Group S (p-value = 0.018). Similarly, tooth mobility scores significantly decreased after treatment, but with no difference between groups. The marginal bone loss decreased significantly more in the Adseal group compared to the Sealapex group (23.3% vs. 50.0%, p-value = 0.032). At the same time, 40.0% of patients in Group S had failed tooth healing compared to only 13.3% in Group A (p-value = 0.048). Conclusions: The in vitro study showed that Adseal had a better sealing capacity and a lower degree of dye penetration compared to Sealapex. However, on clinical evaluation in the in vivo study, both patient groups exhibited significant improvements in periapical index, tooth mobility scores, and pain reduction following endodontic treatment. Nevertheless, patients treated with Adseal showed a significantly greater improvement in PAI values, tooth mobility, and teeth healing after treatment. Overall, Adseal, as an endodontic sealer, may provide better sealing capabilities and enhanced clinical outcomes in the treatment of chronic apical periodontitis.

Evaluation of the Shaping Ability of Three Thermally Treated Nickel-Titanium Endodontic Instruments on Standardized 3D-printed Dental Replicas Using Cone-Beam Computed Tomography.

Background and Objectives: The aim of the present study is to compare the efficacy of three root canal preparation systems in the shaping of 3D-printed root canal replicas of single rooted teeth. Materials and Methods: Sixty 3D-printed root canal replicas were produced and divided into three groups, each consisting of twenty samples. Each group was shaped with a different instrument: Reciproc Blue R25/08 (VDW GmbH, Munich, Gemany), WaveOne Gold Primary 25/07 (Dentsply Sirona, Ballaigues, Switzerland), and ProTaper Gold F2 25/08 (Denstply Sirona). To ensure the reproducibility of pre- and post-operative CBCT images of the root canals, the endodontic printed replicas were placed in a mould of silicon impression material. A cone-beam computed tomography (CBCT) software was used to compare pre- and post-instrumentation images collected at three levels of the root canal length: 3, 6, and 9 mm from the apical foramen. The amount of transportation, centring ability, and curvature angle after shaping were evaluated for each system. The results were statistically analysed and compared using one-way analysis of variance (ANOVA). Results: Regarding the transportation of the root canal after shaping, significant differences between groups at 3 mm (p = 0.010721) and 6 mm (p = 0.000046) were recorded in the mesio-distal direction, while in the bucco-lingual significant differences were only observed at 6 mm (p = 0.000554). Reciproc Blue removed more dentin from the mesial and buccal wall of the root canal. When evaluating the centring ability of the three systems, significant differences were observed between the groups at the level of 9 mm (p = 0.037258) in the mesio-distal direction, and at the level of 6 mm (p = 0.038197) in the bucco-lingual direction. Significant differences of the canal curvature angle after shaping were also observed between groups (p = 0.000001). Reciproc Blue straightened the curvature the most, while ProTaper Gold the least. Conclusions: All systems produced minor root canal transportation. No instrument was able to achieve a perfect centring preparation of the root canal. All systems produced a small degree of root canal straightening.

En-face optical coherence tomography analysis of gold and silver nanoparticles in endodontic irrigating solutions: An in vitro study.

Optical coherence tomography (OCT) is a non-invasive, non-radioactive optical diagnostic method based on low-coherence interferometry, which achieves images with different orientation. In dentistry, its major advantage is represented by the localization and characterization of the smallest defects in hard dental tissues, dental materials and of the smallest details in dental anatomy (supplementary canals, recesses, isthmuses, or intra-radicular connections). The aim of the present in vitro study was to evaluate using c-scan en-face optical coherence tomography, the optical opacity, and the distribution inside the root canal lumen of several extracted human teeth of silver and gold nanoparticles from special irrigating solutions used in endodontic treatment. Twelve root canals from 5 human teeth were instrumented using the ProTaper Universal system after initial negotiation with hand K-files ISO no. 10 and rotary nickel-titanium PathFile instruments. An initial c-scan OCT analysis was performed for each sample to confirm that the root canal lumen was empty from radiopaque materials (Group 1). Teeth were first irrigated with NanoCare Plus (Group 2) and then with NanoCare Gold (Group 3) and C-scans were repeated after each irrigation method. The OCT investigation started at the tooth apex, at a depth of 1 mm from its tip. Subsequently, 100 slices of 10 microns were obtained from each root canal. Images were captured and then analyzed with ImageJ software to calculate the level of grey inside the root canal lumen. The highest values of grey were obtained in the samples irrigated with NanoCare Gold after NanoCare Plus (Group 3). The present study proved that both nanoparticles inserted in root canal irrigants were evidenced through OCT imagistic analysis due to their optical opacity, which allowed their highlighting in an empty root canal lumen, after the endodontic treatment was performed and the root canal was cleaned and shaped using specific protocols.

External cervical resorption: Radiological diagnosis and literature (Review).

External cervical resorption (ECR) is a relatively unknown and insidious pathology characterized by the loss of hard dental tissues such as: Enamel, cementum and dentine due to clastic function. It begins as a localized resorptive process that initiates on the area of the root beneath the epithelial attachment and the coronal part of the alveolar process, involving vital and non-vital tissues. Despite the fact that there are several potential predisposing factors related to ECR, its aetiology still remains poorly understood and more research is needed to establish the cause-and-effect relationship of all the etiological factors. Improved radiographic detection using cone-beam computed tomography (CBCT) is required in order to correctly classify and assess this entity. This provides a three-dimensional insight into the lesion, regarding the location, the size, the depth and the circumferential spread of the ECR defect. It also allows establishment of the most efficacious treatment plan and management. The purpose of this literature review is to cover the relevant literature concerning the etiology, pathogenesis, clinical and radiological presentation and management of ECRs (based on the CBCT findings).

Conservative Approach in the Management of Large Periapical Cyst-Like Lesions. A Report of Two Cases.

Background and Objectives: Periapical cystic lesions are a pathology frequently addressed to endodontic specialists. Although their therapy is still not standardized, the treatment should be as conservative as possible and by endodontic means, as they are lesions of endodontic origin. The present case report describes two cases of upper central incisors with large cyst-like periapical lesions, and their one-year follow up. Materials and Methods: Endodontic orthograde treatment was performed under copious irrigation with sodium hypochlorite, in association with calcium hydroxide as an intra-canal medication for both teeth. Root canal filling was achieved in a separate appointment using the continuous wave of condensation technique. A decompression procedure was used in association with endodontic therapy in the second case to reduce the pressure inside the cystic lesion and to allow its drainage, and only because the root canal could not be dried three weeks after medication. Initial cone beam computed tomography (CBCT) investigations, as well as at the one-year follow up, were used to compare the evolution of the lesion. Results: Both cases had a favorable outcome. New bone formation in the periapical region and complete resolution of the lesion was observed at the one-year control in the first case. In the second case, although the lesion was still not completely healed at 12 months, a significant reduction in its size could be observed, showing active signs of healing. Conclusions: Endodontic treatment is the first choice option in the management of teeth with pulpal necrosis and large periapical cystic-like lesions. Decompression is the only surgical procedure recommended when the canals cannot be dried and obturated. Large surgical interventions are unnecessary in cases where endodontic treatment can be performed.

Information Needs of Patients Diagnosed with Head and Neck Cancer Undergoing Radiation Therapy: a Survey of Patient Satisfaction.

Research suggests that the information needs of patients diagnosed with head and neck cancer can be particularly complex, given the frequent need for multidisciplinary treatments and resulting potential for profound functional impairments. This study was designed to identify head and neck cancer patients' reported informational needs and to evaluate their satisfaction with the written information they received. The study was divided into 2 phases: phase 1, prior to development of a new educational pamphlet, and phase 2, after its implementation. A survey was designed to evaluate several measures including content, amount, understanding, and timing of information delivery. It was distributed at two points during patients' treatment pathway for each phase: at their last radiation appointment and at their posttreatment follow-up appointment. Participant responses after the revised pamphlet indicated greater preparedness before their first treatment, as well as increased satisfaction with treatment option information. Most were satisfied with information timing, but about a third did indicate that additional information would have been helpful at variable time points. Open-ended responses demonstrated that overall, patients do still desire more information, particularly on side effect and self-care management information. While patients with head and neck cancer appear to be generally satisfied with the written information received, our findings suggest that there is still considerable variability in how the information is understood, when it should be delivered, and in which areas more would have been beneficial. These findings underscore the need to consider how best to balance available resources in order to provide more tailored yet comprehensive education for this group of patients.

Endodontic fillings evaluated using en face OCT, microCT and SEM.

OBJECTIVES: The goal of endodontic therapy is mechanically cleaning and shaping the root canal system, the removal of organic and inorganic debris followed by sealing with permanent filling materials. MATERIALS AND METHODS: Therefore, the aim of this in vitro study was to engage three imagistic methods: (i) en face (ef) time domain (TD) optical coherence tomography (OCT), (ii) micro-computed tomography (µCT), and (iii) scanning electron microscopy (SEM), in terms of their efficiency in assessing the quality of endodontic fillings. So far, is settled that efOCT images can identify defects∕voids in several of the investigated root canal fillings and identify gaps of 50 µm. RESULTS: The results delivered by µCT technology also showed several imperfections of the endodontic filling but also at the interfaces formed by the sealer and the root canal walls. SEM investigations highlights the complex form of the interface formed the endodontic filling material and the walls of the root canal, as well as shortcomings of the materials from several samples. Gaps of 50 µm are identified with efOCT. CONCLUSIONS: The net advantage of OCT technology, in respect to the other two technologies consists in its non-invasiveness. The OCT axial resolution is also sufficient to see the material gaps. Another advantage of efOCT investigations is that they allow real-time imaging of complex arrangement at the interfaces of the filling material with dentinal root.

A qualitative and semiquantitative SEM study of the morphology of the biofilm on root surfaces of human teeth with endodontic-periodontal lesions.

Over the last decades, scanning electron microscopy (SEM) proved to be invaluable for ultrastructural investigation, allowing imaging of the overall appearance and/or specific features of oral biofilms, e.g., microbial colonies and individual cells, glycocalyx, the presence of inorganic products. The aim of this study was the observation and evaluation of the morphology of the biofilm of endodontic-periodontal lesions (EPL) with a modified protocol involving a simplified histologic sample preparation and a low-vacuum SEM examination method. Twenty-one teeth with endodontic-periodontal involvement, extracted for periodontal reasons, were carefully washed with saline, underwent fixation in modified Karnovsky solution and were dehydrated in alcohol series. Samples were examined under low-vacuum SEM. Radicular surfaces were evaluated qualitatively and semiquantitatively for several characteristics, including the presence of bacterial types, the biofilm morphology and the content of root resorptions. Radicular surfaces were divided in four conventional zones Surfaces were evaluated for several characteristics: Presence of bacterial types, biofilm morphology, presence of root resorptions. High-quality images, relevant for endodontic-periodontal biofilms were collected. Continuous, established biofilm was found on all examined surfaces, its detection varying from 19% of the samples on the wall of cemental cone to 52.3% on the radicular surface of the periodontal pocket. Observed microorganisms included cocci, rods an filaments. Spirils and motile bacteria were only accidentally found. SEM investigation of surfaces involved in EPL revealed less surfaces covered by mature biofilm (in only 28.5% of the samples in the 'transition zone'), especially rods and filaments associated with cemental resorptions and calculus. Biofilm elements were better represented in periodontal pockets than in other zones of EPL (detected in up to 81% of the samples). A strong correlation between mature biofilm and the presence of cocci appears on all investigated zones (P<0.01). Microbiota appeared to be morphologically similar in apical and periodontal areas, especially in old EPL.

Changes in clinical and microbiological parameters of the periodontium during initial stages of orthodontic movement in patients with treated severe periodontitis: A longitudinal site-level analysis.

Applying orthodontic braces makes oral hygiene difficult and increases plaque accumulation, frequently resulting in gingival inflammation. In patients with previous severe periodontitis, this inflammation overlaps with the pre-existing inflammatory challenge and can lead to further progression of periodontal attachment loss. The aim of this study was to assess longitudinal site-level changes as mirrored by clinical and microbiological parameters during the initial remodeling of alveolar bone and the periodontal ligament, produced as an effect of light orthodontic forces in adult patients with severe periodontal disease that underwent standard (non-surgical and conventional surgical) periodontal therapy. Thirteen patients with previously treated severe generalized periodontitis were given fixed orthodontic appliances for re-alignment of teeth misaligned or displaced during the course of periodontitis. Before insertion of orthodontic appliances and at 2, 4, and 6 months of treatment, periodontal clinical parameters were recorded in the same deepest residual pocket of at least 3 mm in each patient. The same pocket was sampled at baseline and after 6 months of orthodontic treatment for the frequency of positive detection of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tanerella forsythia (Tf), Treponema denticola (Td). An average reduction in Pocket Depth by 0.2 mm at the end of the assessment period was identified. The only clinical parameter with statistically significant improvement was bleeding on probing. The frequency of detection of Aa, Pg, Pi, and Tf was not significantly different between baseline and 6 months of treatment, while a marginally significant increase of Td was found. There were no significant differences in the clinical parameters or microflora in the initial phase of orthodontic treatment in patients with reduced periodontal support. By correlating clinical and microbiological data, we concluded that the presence of periopathogens do not negatively influence periodontal health during orthodontic treatment in adult patients treated for severe periodontitis.

PET/CT of breast cancer regional nodal recurrences: an evaluation of contouring atlases.

BACKGROUND: To validate the Radiation Therapy Oncology Group (RTOG) and European Society for Radiotherapy and Oncology (ESTRO) breast cancer nodal clinical target volumes (CTVs) and to investigate the Radiotherapy Comparative Effectiveness Consortium (RADCOMP) Posterior Neck volume in relation to regional nodal recurrences (RNR). METHODS: From a population-based database, 69 patients were identified who developed RNR after curative treatment for breast cancer. RNRs were detected with 18-fluorodeoxyglucose-positron emission tomography-computed tomography (PET/CT). All patients were treatment-naïve for RNR when imaged. The RTOG and ESTRO nodal CTVs and RADCOMP Posterior Neck volumes were contoured onto a template patient's CT. RNRs were contoured on each PET/CT and deformed onto the template patient's CT. Each RNR was represented by a 5 mm diameter epicentre, and categorized as 'inside', 'marginal' or 'outside' the CTV boundaries. RESULTS: Sixty-nine patients with 226 nodes (median 2, range 1-11) were eligible for inclusion. Thirty patients had received adjuvant tangent and regional nodal radiotherapy, 16 tangent-only radiotherapy and 23 no adjuvant radiotherapy. For the RTOG CTVs, the RNR epicentres were 70% (158/226) inside, 4% (8/226) marginal and 27% (60/226) outside. They included the full extent of the RNR epicentres in 38% (26/69) of patients. Addition of the RADCOMP Posterior Neck volume increased complete RNR coverage to 48% (33/69) of patients. For the ESTRO CTVs, the RNR epicentres were 73% (165/226) inside, 2% (4/226) marginal and 25% (57/226) outside. They included the full extent of the RNR epicentres in 57% (39/69) of patients. Addition of the RADCOMP Posterior Neck volume increased complete RNR coverage to 70% (48/69) of patients. CONCLUSIONS: The RTOG and ESTRO breast cancer nodal CTVs do not fully cover all potential areas of RNR, but the ESTRO nodal CTVs provided full coverage of all RNR epicentres in 19% more patients than the RTOG nodal CTVs. With addition of the RADCOMP Posterior Neck volume to the ESTRO CTVs, 70% of patients had full coverage of all RNR epicentres.

Examining Radiation Treatment Appointment Times at a Canadian Cancer Centre: A Timing Study.

INTRODUCTION: Technological advancements in radiation therapy have led to more complex treatment techniques such as volumetric modulated arc therapy, and in turn, more daily image verification. As treatment complexity increases, it is important to consider what effect this may have on treatment time. Additional factors that may influence treatment times are patient-centered care and mobility status. The aim of this study is to determine optimal radiation treatment appointment times based on site, technique, imaging requirements, and patient needs. METHODS: Data from 535 fractions of radiation treatments were collected and analyzed between June 2016 and July 2017 by a team of eight radiation therapists at BC Cancer Vancouver Centre. Data collectors documented a number of data points, including treatment unit, scheduled appointment time, scheduled appointment duration (booked in 12 minute increments), treatment site, treatment technique, imaging modality, pre-treatment-related and post-treatment-related activity time, patient mobility status, etc. Student's t-test was performed for each site/technique to determine if the mean total treatment time was significantly different from the standard appointment time for that site. A two-sample unpaired t-test assuming unequal variance was used to compare average treatment times of the same site with different imaging modalities. Student's t-test was also used to compare average treatment times for ambulatory patients versus patients requiring some form of mobility assistance. RESULTS: Average treatment times for 6 of the 10 sites used for data analysis were longer than standard booked times and showed statistical significance (prostate/prostate bed: n = 82, P < .001; chest: n = 32, P < .001, palliative 1 treatment site: n = 28, P < .05, gyne pelvis only treatment: n = 25, P < .001, head & neck: n = 56, P < .001, and rectum: n = 28, P < 0.05). The breast/chest wall + nodes site had a significantly shorter treatment time than the standard booked appointment time (n = 87, P < .001). Analysis of the prostate/prostate bed imaging showed a significant difference between daily cone beam computed tomography and daily kilovoltage treatment time, with cone beam computed tomography imaging taking 3.83 ± 1.36 (P < .001) minutes longer on average than kilovoltage imaging. Average treatment time for patients requiring mobility assistance was 20% longer than for patients requiring no assistance (P = .02). CONCLUSION: The majority of the most common sites and techniques treated at our centre were inappropriately booked. Radiation therapy appointment durations are influenced by several factors, including site, technique complexity, imaging, and patient care. It is recommended that radiation treatment centres evaluate appointment times regularly as technology, treatment delivery, and professional practice standards evolve to ensure high-quality patient care.

Staffing Levels and Workload for Radiation Therapists in Canada.

PURPOSE: The safe delivery of radiation therapy is dependent in part on the provision and organization of oncology professionals. General recommendations for staffing of radiation oncologists, medical physicists, and radiation therapists have been published, but most of these provide little detail, especially in the case of radiation therapists (RTs). In Canada, there are no guidelines or national standards for the staffing of RTs, and there is a paucity of Canadian data on the existing staffing levels of RTs and the models used to establish these levels. This project sought to identify and compare the staffing models used for Canadian RTs, and the staffing levels and workload resulting from these models. METHODS AND MATERIALS: In January 2016, a survey was sent to managers of the 46 radiation treatment centres in Canada. This survey sought information on a range of staffing and practice variables for the fiscal year 2014/2015. Respondents were requested to provide the staffing model used for RTs at each centre and enough additional information to calculate the staffing levels and workload resulting from their staffing model. The survey included further variables that had the potential to influence staffing levels and workload, and centres were compared to establish if these variables did indeed impact staffing. RESULTS: Of the 46 centres contacted, 37 centres responded, representing an 80.4% response rate. Survey results showed there are a variety of ways used to determine staffing across the country. Twenty of the 37 responding centres include some type of workload measurement in their staffing model, whereas 17 centres base staffing solely on historic levels or operating funds. There is a great deal of variation in the staffing levels and workload of RTs in Canada, with staff at some centres planning and treating twice the number of patients as RTs at other centres. Radiation therapist staffing levels at most radiation treatment centres in Canada are below the level recommended in recent publications. Differences in staffing levels or workload could not be accounted for by treatment complexity, number of specialty programs, use of relief staff, or number of RTs working in specialty nontreatment roles. CONCLUSIONS: A high degree of variability in staffing levels and workload exists for RTs in Canada, which is not explained by differences in patterns of practice. It is likely that workload for RTs exceed safe levels at some Canadian centres. It is recommended that treatment centres use an up-to-date staffing model for RTs and continue to review staffing levels at regular intervals.

Hyaluronic Acid/Bone Substitute Complex Implanted on Chick Embryo Chorioallantoic Membrane Induces Osteoblastic Differentiation and Angiogenesis, but not Inflammation.

Microscopic and molecular events related to alveolar ridge augmentation are less known because of the lack of experimental models and limited molecular markers used to evaluate this process. We propose here the chick embryo chorioallantoic membrane (CAM) as an in vivo model to study the interaction between CAM and bone substitutes (B) combined with hyaluronic acid (BH), saline solution (BHS and BS, respectively), or both, aiming to point out the microscopic and molecular events assessed by Runt-related transcription factor 2 (RUNX 2), osteonectin (SPARC), and Bone Morphogenic Protein 4 (BMP4). The BH complex induced osteoprogenitor and osteoblastic differentiation of CAM mesenchymal cells, certified by the RUNX2 +, BMP4 +, and SPARC + phenotypes capable of bone matrix synthesis and mineralization. A strong angiogenic response without inflammation was detected on microscopic specimens of the BH combination compared with an inflammatory induced angiogenesis for the BS and BHS combinations. A multilayered organization of the BH complex grafted on CAM was detected with a differential expression of RUNX2, BMP4, and SPARC. The BH complex induced CAM mesenchymal cells differentiation through osteoblastic lineage with a sustained angiogenic response not related with inflammation. Thus, bone granules resuspended in hyaluronic acid seem to be the best combination for a proper non-inflammatory response in alveolar ridge augmentation. The CAM model allows us to assess the early events of the bone substitutes⁻mesenchymal cells interaction related to osteoblastic differentiation, an important step in alveolar ridge augmentation.

Patterns of Practice in Canadian Radiation Treatment Centres: Results of a National Survey.

PURPOSE: Radiation therapy has changed rapidly over the past decade due to the application of technological advances. A survey was conducted of radiation treatment centres in Canada to establish current patterns of practice across the country. Areas of inquiry included treatment techniques and image verification, as well as roles and responsibilities of radiation therapists (RTs). METHODS AND MATERIALS: In January 2016, a survey was sent to managers of the 46 radiation treatment centres in Canada. This survey sought information on a range of staffing and practice variables for the fiscal year 2014/2015. RESULTS: Of the 46 centres contacted, 37 centres responded, representing an 80.4% response rate. Survey results showed that the use of volumetric arc therapy and intensity-modulated radiation therapy is common across Canada for several anatomic sites, as well as the use of daily pretreatment image verification. A high degree of variability exists for imaging modality (two dimensional vs. three dimensional) for some sites, including brain, head and neck, and lung. RTs' responsibilities have expanded uniformly across the country, with RTs involved in organ-at-risk contouring and on-treatment image approval at the majority of centres. Despite this role expansion, specialty roles in areas of quality and applications expertise are still rare. CONCLUSIONS: Radiation therapy in Canada has transitioned to high-technology treatment techniques with relative consistency across the country. There is, however, variation in the imaging modality used for daily verification. Canada may benefit from consensus guidelines on the application of three-dimensional imaging for treatment verification. While RTs have expanded their responsibilities, role definition for RTs working in supervisory or supporting positions has not kept pace at many centres and it is unclear if RTs are supported in their expanded accountabilities.

Severely altered post-traumatic internal morphology of upper incisors associated with biologic width violation - the combined conservative approach.

This is the report of a case of four upper incisors with multiple internal/external resorptions after a falling accident in the childhood and subsequent violation of the biologic width by incorrect individual coronal restorations. Endodontic orthograde retreatment was performed and mineral trioxide aggregate (MTA) was placed as apical plug and to repair the large internal resorption. In order to re-establish the biologic width, a controlled surgical crown-lengthening procedure was performed. The expression of matrix metalloproteinase (MMP)-9 in the gingival tissue was used as a biomarker for the presence of inflammation in the hypertrophied gingiva. The one-year control revealed the cessation of the resorptive activities and the stability of the periodontium. The choice for a conservative combined treatment was essential in maintaining the affected teeth in an esthetically challenging area.

Influence of inorganic filler content on the radiopacity of dental resin cements.

Digital radiography was used to measure the radiopacity of 18 resin cements to determine the influence of inorganic filler content on radiopacity. Four disk specimens (n=4) of each light-curing cement were digitally radiographed alongside an aluminum step wedge using an intraoral sensor (XIOS Plus, Sirona, Germany), and their mean gray value measured. Percentage of filler by weight was determined using an analytical combustion furnace. Data were statistically analyzed using one-way ANOVA and Tukey's test (α=0.05). All materials were more radiopaque than dentin and 12 materials were more radiopaque than enamel. Filler percentage ranged between 17.36 to 53.56 vol% and radiopacity between 1.02 to 3.40 mm Al. There were no statistically significant differences in inorganic filler percentage and radiopacity among the different shades of the same material (p>0.05), but the highest radiopacity was measured for the material which contained a higher percentage of filler.

Photomicrographic evaluation of the apical sealing capacity of three types of gutta-percha master cones: an in vitro study.

The purpose of this study was to compare the apical sealing capacity of three types of gutta-percha master cones of the same apical size and different tapers following root canal preparation with nickel-titanium ProTaper Universal rotary instruments and microstructural replication with System B and Obtura III. Thirty extracted human incisors having one single straight root canal (type I Weine) were instrumented with rotary ProTaper to an F3 (30/.09) and gauged to confirm a final apical size of #30. Teeth were divided into three groups (n = 10) to be obturated as follows: Group 1: master cone Meta 0.06 taper/AH Plus, Group 2: master cone fine-medium Autofit 0.08 taper/AH Plus, and Group 3: master cone ProTaper F3 0.09 taper/AH Plus. The chosen technique was the continuous wave of compaction (System B and Obtura III). Teeth were embedded in acrylic and incrementally reduced at 0.5 and 1.0 mm from the apical foramina in a grinding machine for metallographic samples. Sections were examined and digitally photographed under a metallographic optical microscope in normal and polarized light and the images were processed. The total cross-sectional area of the root canal, the gutta-percha/sealer/voids' areas were quantified for each sample and statistically compared using one-way ANOVA and Kruskal-Wallis tests. No statistically significant differences between groups were observed (P > 0.05); however, the mean percentage of the gutta-percha-filled area was slightly higher in Group 1 at both levels of observation. Despite different tapers, all the three types of cones provided a good sealing capacity in the last apical millimeter of the root canal, with good gutta-percha-sealer ratio and few or no voids.

How accurate replicates the Thermafil System the morphology of the apical endodontic space? An ex vivo study.

AIM: To evaluate the morphology of the root canal in its apical third and the capacity of the Thermafil System to reproduce the entire morphology of the cleaned and shaped root canal. MATERIALS AND METHODS: Thirty-two roots of periodontally compromised teeth were prepared using the ProTaper System to an apical size 30 and filled with the Thermafil obturation technique and sealer. The roots were surgically amputated and prepared for metallographic evaluation by incremental reductions of 0.5 mm each, starting with the apical foramen. Photomicrographs of each section were taken at a magnification of 500x and 100x. The images were analyzed and processed. The position of the apical foramen with respect to the anatomical apex was identified and marked. Additional morphological details as lateral canals and recesses were also recorded. The cross-sectioned area of the canal and gutta-percha, the total perimeter, the shaped perimeter and the filled perimeter were recorded for each sample and the results were expressed as percentages. Multiple images of successive sections were used to create a 3D reconstruction of the apical anatomy of the tooth. The ANOVA test was performed to assess mean differences between evaluations of perimeters/areas at different levels. RESULTS: The anatomical apical foramen was found at the tip of the root in 50% of the evaluated samples. In the remaining samples, the foramen was located between 0.5 and 2.5 mm from the centre of the apex. Lateral canals, which opened in accessory foramens, were recorded in 25% of the evaluated samples. Statistical significant differences (p<0.05) were found between different levels of preparation and obturation. CONCLUSIONS: The complex morphology of the apical third of the root canal is satisfactory microstructurally replicated by the Thermafil System. Moreover, polarized light microscopy and the 3D reconstruction offered a discriminative vision of morphological details as lateral canals, recesses, the gutta-percha and debris.

Computer-assisted photomicrographic evaluation of root canal morphology after removal of the filling material during retreatment.

AIM: The purpose of this study was to evaluate the morphology of the apical third of the root canal and the effectiveness of rotary instrumentation for the removal of lateral condensed gutta-percha during endodontic retreatment. MATERIALS AND METHODS: Thirty roots with canals with regular morphology were prepared to apical size #30 and were filled with gutta-percha/AHPlus using lateral condensation. Digital radiographs of teeth were captured. After two weeks, canals were retreated to size 40 using ProTaper rotary instruments, without solvent. Roots were embedded in resin blocks and reduced incrementally at four different apical levels (at 0.5, 1.0, 1.5 and 2.0 mm from the apical foramen). The sectioned surfaces were observed under a metallographic optical microscope and digital micrographic images were captured and processed. Perimeter covered with root-filling residue was expressed as percentage of total canal perimeter for all specimens. RESULTS: Residue percentage was greater at 2.00 mm from apical level than at other levels. Most residue of filling material in all specimens was observed at 0.5 and at 2.0 mm from apex. The use of ProTaper instruments allowed the removal of gutta-percha and AHPlus sealer in the apical 2 mm in average 50% of the cases. CONCLUSIONS: The resulting morphology of the prepared canals allowed root fillings performed with gutta-percha and AHPlus sealer that were efficiently removed by using rotary instruments. More material residue was found adhering to the canal walls in the apical segments of canals. The removal of this residue was enhanced by apical enlargement beyond the diameter of the canal before retreatment.

Manganese(III) porphyrin-based potentiometric sensors for diclofenac assay in pharmaceutical preparations.

Two manganese(III) porphyrins: manganese(III) tetraphenylporphyrin chloride and manganese(III)-tetrakis(3-hydroxyphenyl)porphyrin chloride were tested as ionophores for the construction of new diclofenac-selective electrodes. The electroactive material was incorporated either in PVC or a sol-gel matrix. The effect of different plasticizers and additives (anionic and cationic) on the potentiometric response was studied. The best results were obtained for the PVC membrane plasticized with dioctylphtalate and having sodium tetraphenylborate as a lipophilic anionic additive incorporated. The sensor response was linear in the concentration range 3 × 10(-6) - 1 × 10(-2) M with a slope of -59.7 mV/dec diclofenac, a detection limit of 1.5 × 10(-6) M and very good selectivity coefficients. It was used for the determination of diclofenac in pharmaceutical preparations, by direct potentiometry. The results were compared with those obtained by the HPLC reference method and a good agreement was found between the two methods.