1,721,001 research outputs found
The effects of scaling and root planing on the marginal gap and microleakage of indirect composite crowns prepared with different finish lines: An in vitro study
No full textThe present in vitro study aimed to assess the effects of root surface mechanical instrumentation on the marginal integrity and adaptation of resin composite crowns. The following null hypotheses were tested: no differences exist between finish line and 1) marginal gap or 2) marginal microleakage before and after manual mechanical periodontal maintenance.
A total of 56 intact human mandibular molars were randomly distributed into four groups and subjected to standardized tooth preparations for indirect composite crowns with different marginal finish lines (90 degrees shoulder, beveled 90 degrees shoulder, feather edge, chamfer). One-half of the specimens was used as a control and remained untreated, and the remaining half was subjected to root surface procedures simulating five years of semestral mechanical supportive periodontal treatment. The marginal gap and microleakage were evaluated and statistically analyzed.
The specimens used as controls showed lower mean marginal gaps than those subjected to the simulated periodontal treatment, whereas the latter showed lower microleakage than the control crowns. Statistically significant differences were recorded for both the experimental variables.
The root surface procedures resulted in altered surfaces of the composite crowns. The marginal gap increased after the treatment, whereas the marginal microleakage was reduced. The 90 degrees shoulder and the chamfer preparation could be considered a viable option to fabricate composite crowns, but the beveled 90 degrees shoulder and the feather edge should not be recommended
Do nanofilled/nanohybrid composites allow for better clinical performance of direct restorations than traditional microhybrid composites? a systematic review
Full text linkThis systematic review was carried out to assess the clinical effectiveness of nanofilled and nanohybrid composites used for direct restorations in comparison with microhybrid composites. The guidelines for the preferred reporting items for systematic reviews and meta-analyses were followed. A search of articles published from July 1996 to February 2017 was performed in PubMed, SciVerse Scopus, Latin American and Caribbean Health Sciences, the Scientific Electronic Library Online, and the Cochrane Library. The present review selected only randomized controlled trials comparing the clinical performance of a nanofilled or nanohybrid composite for direct restorations with that of a microhybrid composite. The research found 201 studies. Twenty-one articles fulfilled the criteria of the present review. However, the included studies were characterized by great methodological diversities. As a general trend, nanofilled and nanohybrid composites were found to be capable of clinical performance, marginal quality, and resistance to wear similar to that of traditional composites without showing improved surface characteristics. The risk of bias of included studies was judged unclear or high. The clinical performance of nanofilled/nanohybrid composites was found to be comparable to that of traditional composites in the posterior area. The data concerning anterior and cervical restorations were insufficient. With regard to the esthetic properties, there is a compelling need for studies on anterior teeth in which the operators are kept unaware of the restorative material. Nanofilled/nanohybrid composites seem to be a valid alternative to traditional microhybrid composites, and at the moment, there is low-level evidence attesting a lack of their superiority
Modified surgical extrusion of severely compromised teeth for rehabilitative and/or regenerative purposes
No full textMultidisciplinary Management and Pulp Vitality Preservation of a Tooth With Extensive Iatrogenic Furcal Root Perforation and Biologic Width Violation
No full textThis article describes the case of a vital molar tooth with a vast furcal iatrogenic root perforation and biologic width violation, which was successfully managed by a multidisciplinary approach aimed at preserving pulp vitality. The root perforation was cleaned and then sealed with mineral trioxide aggregate, which was positioned onto the pulp at the canal orifices. After one month, the patient was not reporting symptoms, and the tooth was positively responding to the thermal test. The tooth was orthodontically extruded, subjected to minimally invasive crown lengthening, and prepared to receive a full-crown restoration. Radiotransparent composite resin was chosen as a permanent restorative material to better monitor possible endodontic complications at the coronal level. The patient's tooth was followed up for eight years uneventfully. The present case is an example of the possibility to subject a root-repaired tooth with fully formed apices to conservative yet complex multidisciplinary treatment while maintaining pulp vitality
Filling ability of three variants of the single-cone technique with bioceramic sealer: a micro-computed tomography study
No full textThe present study evaluated the quality of single-cone root canal fillings with bioceramic (BC) sealer using three different techniques by means of micro-computed tomography (micro-CT). The canals of 30 extracted single-rooted permanent teeth were shaped with R40 Reciproc blue files and filled with the single-cone technique (SCT). BioRoot RCS BC sealer was placed inside the canals with one of the following master cones: R40 cone to working length (RWL, n = 10); R40 cone trimmed 1 mm short of working length (RWL-1, n = 10); non-standardized gutta-percha cone to working length (NSWL, n = 10). A quantitative and qualitative micro-CT analysis assessed the filling quality and internal/external voids formation. Collected data underwent statistical analysis by multivariate one-way analysis of variance (α = 0.05). In all groups, the voids were minimal and prevalently external. The NSWL and RWL-1 groups had increased sealer ratios in the whole canal and the apical canal portion, respectively. The lowest amounts of voids were found in the RWL group; the void volumes were slightly greater in the RWL-1 mm and NSWL groups, especially at the apical level. Two alternative SCTs showed satisfactory filling ability, uniform distribution of the BC sealer, and a minimally increased voids formation compared to the standard SCT with dedicated cone. The two tested alternative SCTs could take advantage of the beneficial characteristics of the BC sealer, which evenly filled the endodontic space, ideally sealing both the major and the accessory communications with the periodontium. [Figure not available: see fulltext.
CROWN-TO-ROOT RATIO IN ENDODONTIC SURGERY: A SURVIVAL STUDY
Full text linkAim: to assess the influence of the crown height (CH), root length (RL) and crown-to-root ratio (CRR) on the survival of te- eth subjected to surgical endodontic retreatment and classi- fied as periapically healed.
Methods: a single operator performed all the endodontic mi- crosurgery interventions. The present analysis selected the te- eth classified as ‘‘complete periapical healing’’ according to the Molven-Halse-Grung scale. The periapical radiographs were analyzed by two independent calibrated examiners, who measured CH and RL in a blind manner. The CRR was calcula- ted as the ratio of the two variables CH and RL. The measure- ments were performed by comparing the post-operative radio- graphs (t0) with those taken for a previous retrospective analysis (t1) and the most recent available (t2). An independent
statistician conducted a survival analysis using Kaplan-Meier plots and a log-rank test (a = 0.05).
Results: thirty-eight patients were evaluated, each one contri- buting to the study with a single tooth. The mean follow-up pe- riod was 5,96 ± 3,36 years. Comparing the CRR and RL values between t1 and t2, the difference was found statistically signifi- cant (p = 0.03). Survival was improved for the teeth with roots longer than 7 mm. There were no statistically significant diffe- rences among the remaining comparisons.
Conclusions: root length ≥ 7mm exhibited better chances of long-term survival. Over time, a risk of further decrease of cli- nical RL due to periodontal disease and consequent increase of CRR could be critical by a mechanical point of view. Other studies are needed
Influence of different motions on the cyclic fatigue resistance of Reciproc and Reciproc Blue endodontic instruments
Full text linkThe aim of this study was to evaluate the cyclic fatigue resistance of Reciproc (RCP) and RPC Blue (RCPB) instruments used in continuous rotation, RECIPROC mode, and WAVEONE mode. Materials and Methods: Sixty RCP and 60 RCPB R25 files were used. For each file type, three groups (n = 20) were defined depending on the used kinematics: continuous rotation, RECIPROC mode, and WAVEONE mode. A stainless-steel artificial canal with 60 angle and 5-mm radius of curvature was milled reproducing the size and taper of the used files. The test device was electrically heated to 35C to simulate the clinical environment. All files were reciprocated or rotated until fracture. The time to failure and the length of the fractured fragments were measured. A fractographic examination was performed by scanning the electron microscopy to confirm the cause of fracture. Collected data underwent a two-way analysis of variance (a = 0.05). Results: RCPB files exhibited better cyclic fatigue resistance than RCP. The RECIPROC motion yielded greater cyclic fatigue resistance than the WAVEONE movement; the least resistance was observed in the continuous rotation groups. No significant differences were found among groups in terms of length of the fractured fragment. The fractographic analysis confirmed that all scanned samples separated due to cyclic fatigue. Conclusions: Within the limitation of the present study, the RECIPROC mode increased the cyclic fatigue resistance of the tested instruments compared to WAVEONE mode and continuous rotation. To prevent RCP and RCPB file separation, motion kinematics other than the native RECIPROC movement should be discouraged in the clinical setting
Three-year randomized clinical trial on the effectiveness of two integrated techniques for the treatment of maxillary central incisors with periapical pathosis
No full textAim To assess the effectiveness of two integrated shaping and filling techniques for the treatment of maxillary central incisors affected by chronic apical periodontitis.
Methodology The trial enrolled 60 patients with a maxillary central incisors needing root canal treatment affected by chronic apical periodontitis with periapical radiolucency smaller than 5 mm in diameter. Block-randomization was undertaken to allocate the patients to two treatment groups with different canal shaping and filling protocols: group 1 (G1, n = 30), Revo-S/One Step Obturator; group 2 (G2, n = 30) GTX/GTX Obturator. An independent examiner evaluated the patients at baseline, after 6, 12, 24 and 36 months by performing percussion and palpation tests. At the same time points, standardized periapical radiographs were taken to score the radiographic healing according to a previously published scale. For this analysis, the level of agreement with regard to the scores assigned by two blind evaluators was tested by weighted kappa statistics. Comparability of baseline clinical data, as well as the differences between the two groups and among time points concerning clinical and radiographic data were evaluated with non-parametric tests (p < 0.05).
Results All the patients were re-evaluated after 3 years. One patient per group complained of mild symptoms at the end of the observation period. Radiographic healing was progressive during the follow-up. The lesions were classified as totally healed, partially healed and not healed in 93.3%, 3.3% and 3.3% of cases in G1 and in 93.3%, 0% and 6.7% of cases in G2. The differences between groups were not significant (p > 0.05).
Conclusions The two integrated endodontic systems were equally effective in achieving high three-year success rates in the treatment of maxillary central incisors with chronic apical periodontitis
Surgical extrusion: A dental technique
No full textThis article describes a technique for surgically extruding severely compromised roots needing prosthetic rehabilitation. Unlike previously described approaches, the technique does not require advanced clinical skills or equipment, may reduce the risk of tooth or bone fracture during the luxation maneuvers, and does not seem to interfere with the alveolar socket healing process
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