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1.
Int J Dent Hyg ; 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38487950

RESUMO

OBJECTIVES: To evaluate the most effective method for mechanical inter-dental plaque removal between inter-dental brushes (IDB) and dental floss (DF), in addition to toothbrushing in patients affected by peri-implant mucositis (PIM); to identify possible factors related to the patient or to the single implant-supported element that could influence plaque accumulation and inflammation of peri-implant tissues. METHODS: Forty patients with PIM were recruited. They were randomly assigned to two different groups depending on inter-dental device used (IDB or DF). At baseline (T0), interproximal area (IA), interproximal emergence angle of the implant crown (A°) and manual dexterity (evaluated with Purdue Pegboard) have been recorded. At 14 days (T1), the inter-dental cleaning devices have been inverted between groups. After 14 days (T2), the Plaque Index (PI) and Gingival Index (GI) have been recorded. A questionnaire has been submitted to a patient for the analysis of preferences at T0, T1 and T2. RESULTS: Both inter-dental cleaning devices were effective in reducing PI and GI in the inter-dental area after 14 days of use. GI reduction was influenced by manual dexterity of the dominant hand. No significant differences were found for PI and GI at the variation of IA and A°. CONCLUSION: IDB was the most effective method for inter-dental plaque removal in all subjects regardless of their manual dexterity. DF seems to be more effective than IDB only in subjects with good dexterity.

2.
Microsc Res Tech ; 86(10): 1345-1352, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37066970

RESUMO

To compare the shaping ability of Procodile and R6 Reziflow instruments used in reciprocating motion in severely curved root canals, assessed with micro-computed tomography (µCT). Fourteen extracted human mandibular first molars were randomly assigned to two instrumentation techniques (n = 14 mesial root canals): Procodile or R6 Reziflow. For both groups, root canals were prepared to the working length up to a size 25, .06 taper. Molars were virtually divided into apical, middle and coronal thirds and µCT was used to scan all samples pre- and post-root canal. Canal transportation, centring ability, volume, surface area and unprepared area were evaluated. Geometrical parameter changes were compared with preoperative values (one-way analyses of variance and Tukey multiple comparison post-hoc test) between groups and Student t-test within groups (α = 0.05) Significantly less transportation was observed associated with the Procodile technique in the molar's coronal third compared to the R6 Reziflow technique (p < .05). No significant differences in root canal centring ability, volume, surface area and unprepared area were observed. Procodile showed a lower percentage increase of surface area compared to R6 Reziflow (p < .05). The Procodile and R6 Reziflow techniques applied to first molar root canal performed similarly except for the less transportation observed in the coronal third using Procodile. RESEARCH HIGHLIGHTS: MicroCT analysis of canal geometry before and after instrumentation revealed that Procodile and R6 Reziflow showed a similar shaping ability to shape curved root canals without substantially modifications of the original tooth anatomy.


Assuntos
Cavidade Pulpar , Níquel , Humanos , Microtomografia por Raio-X/métodos , Cavidade Pulpar/diagnóstico por imagem , Titânio , Preparo de Canal Radicular/métodos , Desenho de Equipamento
3.
Aust Endod J ; 48(3): 423-430, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35665570

RESUMO

To evaluate the filling ability of two orthograde obturation techniques followed by the apical resection with or without retrograde obturation through micro-computed tomography (CT). Thirty-two single-rooted permanent teeth were prepared and randomised into four groups (n = 8) according to the orthograde obturation technique (single cone technique [SCT] and mineral trioxide aggregate placement) combined or not with retrograde obturation. The volume of voids (VoV) within the entire endodontic space, the apical 3 mm, and 1 mm after root resection was calculated by micro-CT. Statistical analysis showed no significant difference among the groups regarding the total VoV in all root canals, as well as within the apical 1 mm after root resection. The SCT and apical resection without retrograde filling showed significantly better results in terms of VoV at the apical 3 mm after root resection. Within the study limitations, SCT associated with apical resection without retrograde preparation exhibited a similar or less amount of voids than the other groups.


Assuntos
Materiais Restauradores do Canal Radicular , Microtomografia por Raio-X , Materiais Restauradores do Canal Radicular/uso terapêutico , Obturação Retrógrada/métodos , Apicectomia/métodos , Raiz Dentária , Obturação do Canal Radicular/métodos , Cavidade Pulpar/diagnóstico por imagem , Cavidade Pulpar/cirurgia , Preparo de Canal Radicular/métodos
4.
Aust Endod J ; 48(3): 415-422, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34928535

RESUMO

This study analysed the bioceramic sealer cleaning ability of two chemo-mechanical systems in intact and restored teeth. Thirty-two single-rooted teeth were used, and half of them restored with a pre-endodontic composite restoration (PCR). All samples were instrumented with a size 40 Reciproc Blue file and filled with BioRoot RCS. Canals were retreated using the R40 and then R50 Reciproc Blue. The samples were divided into four experimental groups (n = 8): intact teeth/passive ultrasonic irrigation (PUI) (G1), intact teeth/shock wave-enhanced emission photoacoustic streaming (SWEEPS) (G2), PCR/PUI (G3) and PCR/SWEEPS (G4). The samples were scanned by micro-CT before and after retreatment, and the volume of remaining filling material was evaluated. The minor percentage of residues were observed in G2, with a volume of 0.447 ± 0.356% of the endodontic space (P < 0.001). The Reciproc/SWEEPS technique showed the better performance in intact teeth compared with PUI technique. Pre-endodontic restoration did not significantly affect the effectiveness of sealer removal.


Assuntos
Materiais Restauradores do Canal Radicular , Obturação do Canal Radicular , Obturação do Canal Radicular/métodos , Guta-Percha , Materiais Restauradores do Canal Radicular/química , Cavidade Pulpar , Preparo de Canal Radicular/métodos , Retratamento
5.
Materials (Basel) ; 14(19)2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34640251

RESUMO

This study aimed to examine the penetration depth into dentinal tubules of some chelating agents. The 17% EDTA and two preparations containing surfactants (Smear Clear, Bioakt Endo) were tested. Surface tension and liquid viscosity were measured using a Dynamic Contact Angle Analyzer and a Haake rotational rheometer. To measure the penetration depth inside dentinal tubules, thirty maxillary central incisors were selected from a pool of extracted human permanent teeth and allocated to three experimental groups (10 samples each), as well as were mechanically shaped and cleansed with 5.25% NaOCl, followed by each of the chelators being labeled with 0.1 wt % Rhodamine B according to final irrigation protocol established. The samples were embedded in an epoxy resin, after which 200 µm thick transverse sections were obtained at 2, 5, and 8 mm from the apex with a saw microtome. The specimens were then observed using a confocal laser microscope (CLSM) and the penetration of the labeled solution was measured in every third of each sample. Statistical analysis was performed using ANOVA or Kruskal-Wallis tests according to the distribution of data, evaluated with the Shapiro-Wilk normality test. Viscosity and surface tension tests have shown that BioAKT Endo has the lowest values compared to EDTA and Smear Clear. The medium penetration depth did not significantly differ among the three irrigants, while it increased considerably from the apical to the coronal level in all groups. Additionally, the maximum penetration depth increased significantly from the apical to coronal level, while among groups, BioAKT Endo showed the highest values at the apical and middle level compared to the other irrigants. No significant differences were observed among the three groups in medium and maximum penetration depths when the entire root was considered. New irrigants containing surfactants show reduced surface tension and, in one case (BioAKT Endo), viscosity. The lowering of the surface tension allows for better penetration of liquids into dentinal tubules than EDTA alone, thus improving the cleaning of the root canal system.

6.
Artigo em Inglês | MEDLINE | ID: mdl-34076645

RESUMO

The influence of the layer thickness and composite shade on the final color of Ceram.X composites (Dentsply Sirona) was tested, selecting five intermediate-translucency Ceram.X Universal shades, three high-translucency Ceram.X Duo "enamel" shades, and four low-translucency Ceram.X Duo "dentin" shades. Using cylindrical molds, 850 specimens were obtained, representing the whole array of possible Universal single specimens (in seven thicknesses, ranging from 1.0 to 4.0 mm in 0.5-mm increments) and Duo combinations. The CIELAB coordinates of each specimen were determined with a spectrophotometer. Different thicknesses and composites were compared with Clark's ΔE. The difference in color among specimens of different thicknesses was material-dependent. The thickness and shade of the composite markedly affected the color yield of the Ceram.X system. For each shade of the Universal systems, only one Duo enamel-dentin combination corresponded.


Assuntos
Resinas Compostas , Materiais Dentários , Cor , Esmalte Dentário , Humanos , Teste de Materiais , Espectrofotometria
7.
Minerva Dent Oral Sci ; 70(5): 173-179, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33908746

RESUMO

BACKGROUND: The aim of this study was to determine the knowledge of periodontal health and prevention of periodontal diseases of a pool of pharmacists working in Friuli Venezia Giulia. METHODS: A 22-questions questionnaire about oral health was sent by mail to all the pharmacies working in Friuli Venezia Giulia and to the most known associations of pharmacists. The data were collected and analyzed by Google Forms software. RESULTS: One-hundred sixty-four questionnaires were analyzed. Ninety-one percent of the pharmacists assert to give advice about prevention and treatment of oral affection during professional practice, but 97% never attended university courses about it. Only 21% took part in postgraduate courses about oral health. Most of them have not enough notions about periodontal disease. CONCLUSIONS: The findings from this study highlight that pharmacists have not enough knowledge about periodontal disease and its treatment but every day they provide advice about oral health. It would be appropriate a better organization of postgraduate courses about oral health and prevention of periodontal diseases.


Assuntos
Farmácias , Farmacêuticos , Estudos Transversais , Humanos , Saúde Bucal , Inquéritos e Questionários
8.
J Prosthet Dent ; 125(1): 23-28, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32067754

RESUMO

This 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.


Assuntos
Processo Alveolar , Alvéolo Dental , Extração Dentária
9.
J Mater Sci Mater Med ; 31(12): 127, 2020 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-33247779

RESUMO

The aim of the present study was to characterize nanohybrid and nanofilled composites in terms of degree of conversion (DC), rate of cure (RC), microhardness (Vickers hardness number; VHN), depth of cure, and contraction stress (CS). Ceram.X® universal- A3, duo enamel E2, and duo dentin D3 composites were compared to Tetric EvoCeram® and FiltekTMSupreme XTE composites of equivalent dentin and enamel shades under a 40 s photopolymerization protocol. DC was measured by infrared spectroscopy, calculating RC from the kinetic curve. Top and bottom VHN were determined using a Vickers indenter, and bottom/top surface ratio (Vickers hardness ratio; VHR) calculated. CS vs. time was assessed by a universal testing machine and normalized for the specimen bonding area. All materials showed DC < 60%, Ceram.X® composites reaching higher values than the other composites of corresponding shades. RC at 5 s of photopolymerization was always higher than that at 10 s. All the Ceram.X® composites and the lighter-shaded Tetric EvoCeram® and FiltekTMSupreme XTE composites reached the RC plateau after 25 s, the remaining materials showed a slower kinetic trend. Tetric EvoCeram® and FiltekTMSupreme XTE composites displayed the softest and the hardest surfaces, respectively. Differently from darker-shaded materials, the universal and the three enamel-shaded composites resulted optimally cured (VHR > 80%). The tested composites differed in CS both during and after light cure, Tetric EvoCeram® and FiltekTMSupreme XTE composites displaying the highest and the lowest CS, respectively. Only the Ceram.X® universal-A3 reached a CS plateau value. The tested composites exhibited material-dependent chemo-mechanical properties. Increasing the curing time and/or reducing the composite layer thickness for dentin-shaded composites appears advisable.


Assuntos
Lâmpadas de Polimerização Dentária , Restauração Dentária Permanente , Dureza/efeitos dos fármacos , Força Compressiva/efeitos da radiação , Dureza/efeitos da radiação , Cinética , Luz , Teste de Materiais , Microesferas , Nanocompostos/química , Nanocompostos/efeitos da radiação , Polimerização/efeitos da radiação , Estresse Mecânico , Propriedades de Superfície/efeitos da radiação
10.
J Mater Sci Mater Med ; 31(11): 91, 2020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-33089362

RESUMO

The 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.


Assuntos
Cerâmica/química , Guta-Percha/química , Materiais Restauradores do Canal Radicular , Obturação do Canal Radicular/métodos , Microtomografia por Raio-X/métodos , Cavidade Pulpar , Endodontia/instrumentação , Endodontia/métodos , Humanos , Teste de Materiais , Dente Molar , Periodonto/metabolismo
11.
Artigo em Inglês | MEDLINE | ID: mdl-32925999

RESUMO

The aim of this study was to investigate which factors play a major role in the healing of Class II mandibular furcation defects treated with different surgical techniques. Twenty-five systemically healthy subjects with periodontitis stage III grade B and Class II buccal mandibular furcation involvement received one of the following open flap debridement approaches: Group 1 (n = 10), no further treatment; Group 2 (n = 10), piezoelectric contouring of the furcation roof; Group 3 (n = 9), piezoelectric contouring of the furcation roof and bone grafting; Group 4 (n = 10), piezoelectric contouring of the furcation roof and bone grafting with coronally positioned flap. Clinical and radiologic variables-bleeding on probing, probing depth (PPD), vertical and horizontal bone level (CAL and PH), gingival recession, root trunk length, radicular separation, and furcation perimeter (FP)-were evaluated at baseline and 180 days and 1 year after surgery. All clinical parameters were statistically analyzed. Surgical techniques caused clinical (CAL, PPD, PH) and radiographic (FP) improvements. Regenerative techniques and the coronally positioned flap yielded a major radiographic reduction of furcation areas. All therapies resulted in significant horizontal and vertical PPD reduction and CAL gain.


Assuntos
Defeitos da Furca/cirurgia , Regeneração Tecidual Guiada Periodontal , Humanos , Mandíbula/cirurgia , Dente Molar/cirurgia , Índice Periodontal , Resultado do Tratamento
12.
J Oral Implantol ; 45(4): 259-266, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31532728

RESUMO

The primary objective of the present in vitro study was to evaluate the influence of implant site preparation technique (drills vs ultrasonic instrumentation) on the primary stability of short dental implants with two different designs inserted in simulated low-quality cancellous bone. Eighty implant sites were prepared in custom-made solid rigid polyurethane blocks with two different low cancellous bone densities (5 or 15 pounds per cubic foot [PCF]), equally distributed between piezoelectric (Surgysonic Moto, Esacrom, Italy) and conventional drilling techniques. Two short implant systems (Prama and Syra, Sweden & Martina) were tested by inserting 40 fixtures of each system (both 6.0 mm length and 5.0 mm diameter), divided in the four subgroups (drills/5 PCF density; drills/15 PCF density; piezo/5 PCF density; piezo/15 PCF density). Insertion torque (Ncm), implant stability quotient values, removal torque (Ncm), and surgical time were recorded. Data were analyzed by 3-way ANOVA and Scheffé's test (α = 0.05). With slight variations among the considered dependent variables, overall high primary implant stability was observed across all subgroups. Piezoelectric instrumentation allowed for comparable or slightly superior primary stability in comparison with the drilling procedures in both implant systems. The Prama implants group showed the highest mean reverse torque and Syra implants the highest implant stability quotient values. Piezoelectric implant site preparation took prolonged operative time compared to conventional preparation with drills; among the drilling procedures, Syra system required fewer surgical steps and shorter operative time.


Assuntos
Implantação Dentária Endóssea , Implantes Dentários , Densidade Óssea , Poliuretanos , Torque
13.
Spec Care Dentist ; 39(5): 491-496, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31267568

RESUMO

AIMS: Apraxia may hinder oral self-care and is associated with poor oral hygiene. Intersecting Pentagons Test (IPT) is a simple screening tool for constructional apraxia (CA) that tests the ability to copy a bidimensional figure. In this study we investigated whether IPT is useful to identify subjects that need interventions to support oral health in a cohort of geriatric inpatients. METHODS AND RESULTS: We assessed oral health through the decayed, missing or filled teeth index, plaque index, and periodontal screening and recording tool. We inquired about autonomy in oral hygiene activities through a standardized questionnaire. Among subjects with CA (273 out of 478 hospitalized subjects aged > 65 years) we found a higher prevalence of edentulism (P = 0.04), periodontal disease (PD) (P = 0.03), and dependence in oral hygiene activities (P < 0.001). Only 34.8% of nonautonomous apraxic patients had a caregiver that supplied oral care. In an age and sex-adjusted generalized linear model, IPT proved to be an independent predictor of dependence in oral care, reaching 61.5% sensitivity in identifying dependent patients. CONCLUSION: Among elderly inpatients, there is a significant association between IPT results, poor oral health status, and dependence in oral hygiene activities. Positivity to IPT should prompt proper device counseling and caregiver education.


Assuntos
Saúde Bucal , Higiene Bucal , Idoso , Apraxias , Estudos Transversais , Índice de Placa Dentária , Humanos
14.
J Oral Implantol ; 2019 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-31008684

RESUMO

The primary objective of the present in vitro study was to evaluate the influence of implant site preparation technique (drills vs. ultrasonic instrumentation) on the primary stability of short dental implants with two different designs inserted in simulated low quality cancellous bone. Eighty implant sites were prepared in custom-made solid rigid polyurethane blocks with two different low cancellous bone densities (5 or 15 pounds per cubic foot, PCF), equally distributed between piezoelectric (Surgysonic Moto, Esacrom, Italy) and conventional drilling techniques. Two short implant systems (Prama and Syra, Sweden & Martina) were tested by inserting 40 fixtures of each system (both 6.0 mm length and 5.0 mm diameter), divided in the four subgroups (drills/5 PCF density; drills/15 PCF density; piezo/5 PCF density; piezo/15 PCF density). Insertion torque (Ncm), implant stability quotient values, removal torque (Ncm) and surgical time were recorded. Data were analyzed by three-way ANOVA and Scheffé's test (α=0.05). With slight variations among the considered dependent variables, overall high primary implant stability was observed across all subgroups. Piezoelectric instrumentation allowed for comparable or slightly superior primary stability in comparison with the drilling procedures in both implant systems. Prama implants group showed the highest mean reverse torque, Syra implants the highest implant stability quotient values. Piezoelectric implant site preparation took prolonged operative time compared to conventional preparation with drills; among the drilling procedures, Syra system requires fewer surgical steps and shorter operative time.

15.
J Esthet Restor Dent ; 31(3): 280-289, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30790399

RESUMO

OBJECTIVES: To evaluate the fracture resistance and marginal quality of maxillary molars restored using lithium disilicate glass-ceramic (LDG) occlusal veneers with two preparation designs. METHODS: Sixteen extracted maxillary molars were assigned to two groups (n = 8). In group 1 (G1), the teeth received a preparation for a conservative full-coverage occlusal veneer restoration with a 90° rounded shoulder margin. In group 2 (G2), the teeth underwent a 1-mm cusp reduction with a marginal chamfer. LDG restorations (IPS e.max CAD) were obtained with the Cerec 3 CAD/CAM system and luted with Variolink II cement. After thermomechanical aging (1 250 000 cycles), the specimens were loaded to fracture. A semiquantitative marginal seal evaluation was performed observing resin replicas of the specimens at the scanning electron microscope. Cement thickness was assessed at the stereomicroscope on sectioned specimens. Collected data were statistically analyzed by parametric and nonparametric tests. RESULTS: The maximum load to fracture was 2395.01 ± 150.96 N in G1 and 2408.39 ± 112.66 N in G2. Most of the observed specimens exhibited restorable fractures and continuous margins. Cement thickness was 132 ± 38 µm in G1 and 150 ± 41 µm in G2. No differences between the groups emerged. CONCLUSION: This study demonstrated similar satisfactory performance of the two considered preparations designs for occlusal veneer with LDG. CLINICAL SIGNIFICANCE: A new minimally invasive occlusal veneer preparation with marginal chamfer exhibited promising fracture resistance and marginal adaptation that were comparable to those of a standard conservative preparation for the restoration of molars with CAD/CAM lithium disilicate occlusal veneers.


Assuntos
Porcelana Dentária , Falha de Restauração Dentária , Cerâmica , Desenho Assistido por Computador , Cimentos Dentários , Análise do Estresse Dentário , Teste de Materiais
16.
J Conserv Dent ; 22(5): 449-453, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-33082660

RESUMO

AIM: The 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 35°C 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 (α = 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.

17.
Odontology ; 107(2): 196-201, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30255216

RESUMO

The aim of the present study was to evaluate the difference in cyclic fatigue resistance between OneCurve (OC) and OneShape (OS) endodontic single-file NiTi systems in a severely curved artificial canal. After sample size calculation (α = 0.01; ß = 0.20; σ = 20.0; δ = 20.0), 25 OC and 25 OS files were used. An artificial canal with 60° angle and 5-mm radius of curvature was milled in a stainless-steel block reproducing the size and taper of the files used. The test device was electrically heated to maintain the environmental temperature at 37 °C. All files were rotated until fracture; the time to failure was recorded and the number of cycles to fracture (NCF) calculated. The length of the fractured fragments was measured too. Fractographic examination and cross-sectional area calculation were performed by scanning electron microscopy analysis (SEM). Data were statistically analyzed using an independent sample t test. The significance level was set at 0.01. Statistical analysis showed that OC files exhibited significantly greater cyclic fatigue resistance than OS (p < 0.001), with 721 ± 89 NCF and 301 ± 38 NCF, respectively. No significant difference was found in the length of the fractured fragments (p > 0.01). SEM fractographic analysis confirmed that all the scanned samples separated due to cyclic fatigue. Within the limitations of the present study, OC endodontic instruments resisted to cyclic fatigue better than OS. The improved mechanical resistance of OC could be related to new NiTi alloy used for their manufacturing.


Assuntos
Instrumentos Odontológicos , Titânio , Ligas Dentárias , Desenho de Equipamento , Falha de Equipamento , Teste de Materiais , Microscopia Eletrônica de Varredura , Preparo de Canal Radicular , Estresse Mecânico
18.
Aust Endod J ; 45(1): 72-78, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30113117

RESUMO

This study assessed the effectiveness of modern endodontic shaping and filling procedures on mesiobuccal roots of maxillary molars with two canals. The canals of 20 mesiobuccal roots were treated with Mtwo rotary files, passive ultrasonic irrigation and Guttafusion obturators. X-ray computed microtomography analysis was carried out prior to treatment, after canal shaping and after canal filling to determine the alterations of the canal volume before and after the instrumentation, the volume of the hard tissue debris, and percentage of the volume occupied by filling materials. The shaping instruments and filling materials reached only partially the endodontic space of the second mesiobuccal canal and the accessory endodontic structures. Canal irregularities, ramifications, and interconnections were accumulation sites of hard tissue debris. This study demonstrated that rotary files, passive ultrasonic irrigation and carrier-based filling systems could be partially effective for the treatment of the mesiobuccal canals and their accessory endodontic structures.


Assuntos
Cavidade Pulpar , Preparo de Canal Radicular , Dente Molar , Obturação do Canal Radicular , Microtomografia por Raio-X
19.
J Biomed Res ; 2018 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-30007953

RESUMO

It has been shown that stem cells are able to calcify both in vitro and in vivo once implanted under the skin, if conveniently differentiated. Nowadays, however, a study on their efficiency in osseous regeneration does not exist in scientific literature and this very task is the real aim of the present experimentation. Five different defects of 6 mm in diameter and 2 mm in depth were created in the calvaria of 8 white New Zealand rabbits. Four defects were regenerated using 2 different conveniently modified scaffolds (Bio-Oss® Block and Bio-Oss Collagen®, Geistlich), with and without the aid of stem cells. After the insertion, the part was covered with a collagen membrane fixed by 5 modified titan pins (Altapin®). The defect in the front was left empty on purpose as an internal control to each animal. Two animals were sacrificed respectively after 2, 4, 6, 10 weeks. The samples were evaluated with micro-CT and histological analysis. Micro-CT analysis revealed that the quantity of new bone for samples with Bio-Oss® Block and stem cells was higher than for samples with Bio-Oss® Block alone. Histological analysis showed that regeneration occurred in an optimal way in every sample treated with scaffolds. The findings indicated that the use of adult stem cells combined with scaffolds accelerated some steps in normal osseous regeneration.

20.
Open Dent J ; 10: 131-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27335614

RESUMO

BACKGROUND: Researchers have recently drawn attention to the analysis of gingival crevicular fluid (GCF) and peri-implant sulcus fluid (PISF) for the implementation of the diagnosis of periodontal and peri-implant disease. Nevertheless, the measurements of volume and biomarkers concentration can be critically biased when data collected from studies with parallel group design are compared, given the technical difficulties, methodological variables, as well as the variability of crevicular fluid characteristics among different individuals. OBJECTIVE: The aim of the present study was to assess the GCF and PISF volumes in healthy and diseased sites belonging to the same patient. METHOD: Ten patients presenting a periodontally healthy tooth, a tooth with periodontitis, an implant with healthy peri-implant tissues and an implant with peri-implantitis were enrolled. Samples of GCF and PISF were collected from each site of interest and their volume measured with a Periotron 8000 device. Non-parametric statistical analysis was performed to test the significance of the differences in GCF and PISF volumes between i) sites of teeth and dental implants with the same condition of health or disease and ii) healthy and diseased sites of both teeth and dental implants subgroups. The correlation between probing pocket depth (PPD) and fluid production was also tested (p<0.05). RESULTS: Healthy periodontal and peri-implant tissues produced comparable amounts of fluid that was significantly lower than in diseased sites (p<0.05). In the presence of diagnosed disease, the volumes of GCF and PISF were similar, too. The correlation between PPD and fluid production was significant only in healthy sites (PPD/GCF, ρ=0.890, p<0.001; PPD/PISF, ρ=0.810; p<0.005). CONCLUSION: The periodontal and peri-implant tissues behaved similarly in terms of fluid production in condition of both health and active disease.

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