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1.
Int J Periodontics Restorative Dent ; 37(2): e149-e153, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28196171

RESUMO

This study evaluated use of a solid-state laser to avoid the flap technique and suturing. An Er:YAG laser was used in 26 consecutive patients referred for osseous crown lengthening in 32 posterior teeth. The distance from the planned restoration margin to the alveolar crest (B) satisfied a 3-mm dentogingival complex. No tissue necrosis and no significant change in the distance from the gingival margin to B or probing depth were detected at 3 and 6 months. Minimally invasive Er:YAG laser surgery decreases the time needed to establish the gingival margin necessary for definitive restoration.


Assuntos
Processo Alveolar/cirurgia , Aumento da Coroa Clínica/métodos , Terapia a Laser/métodos , Lasers de Estado Sólido , Adulto , Processo Alveolar/anatomia & histologia , Alveolectomia/métodos , Aumento da Coroa Clínica/instrumentação , Planejamento de Prótese Dentária , Estética Dentária , Feminino , Seguimentos , Gengiva/anatomia & histologia , Gengiva/patologia , Gengivoplastia , Humanos , Terapia a Laser/instrumentação , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Índice Periodontal , Bolsa Periodontal , Retalhos Cirúrgicos/efeitos adversos , Taiwan , Dente/anatomia & histologia , Coroa do Dente , Resultado do Tratamento , Cicatrização
2.
Laser Ther ; 20(4): 273-7, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-24155537

RESUMO

BACKGROUND AND AIM: Although intentional replantation for extraoral treatment is a solution for complicated endodontic cases, it is accompanied with risk of root resorption which is most likely due to extraction trauma and infected remnants. Laser therapies have long been proved for bactericidal and biostimulation effects. In the present case, a pulpitis combined severe periodontal destruction molar was extracted with an Er:YAG laser for thorough degranulation and disinfection. Before the extraction and right after the treatment, low level laser therapy (LLLT) with 810nm diode was applied for biostimulation. RESULT: Patient reported no post operative pain after laser treatment. Clinical follow-up showed uneventful healing, and excellent bone regeneration. CONCLUSION: The Er:YAG laser coupled with low level laser therapy (810 nm diode) has shown to assist and improve intentional replantation in disinfection procedure, and it may preserve more vital cells and enhance bioregeneration for less operative pain and better healing.

3.
Dent Mater ; 23(5): 570-8, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-16820200

RESUMO

OBJECTIVES: As the bond strength of composite resin to Er,Cr:YSGG laser-irradiated dentin has not yet been evaluated, the objectives of this study were to investigate the tensile bond strength and to analyze the resin-dentin interface among bur-cut/acid-etched, Er,Cr:YSGG laser-ablated/acid-etched and Er,Cr:YSGG laser-ablated human dentin. METHODS: Crown dentin disks prepared from extracted human third permanent molars were used for the observation of surface morphological changes by scanning electron microscope (SEM). The laser energy parameters were 3.5 W and 20 Hz with water spray (air pressure level, 80%; water pressure level, maximum level). Another group of crown dentin disks were prepared for composite resin restoration and observation of resin-dentin bond interface after demineralization in 6N hydrochloric acid (HCl) for 1 min and deproteinization in 1% sodium hypochlorite solution (NaOCl) for 10 min. The tensile bond strengths of the three groups were measured by a universal testing machine at a crosshead speed of 0.5 mm/min. Fracture types at the dentin-resin interface were analyzed using the digital stereoscopic microscope and fractured surfaces of the debonded specimens were examined by SEM. RESULTS: All three groups showed that the treated surfaces were free of dentin debris and smear layer. The peritubular dentin protruded from the surrounding intertubular dentin after laser irradiation. The dentin-resin interface treated with Er,Cr:YSGG laser irradiation and acid etching demonstrated numerous resin tags converging into a bulge and then diverging again. The length of resin tags was greater than 100 microm. The tensile bond strengths of bur-cut/acid-etched, laser-ablated/acid-etched and laser-ablated human dentin were 5.37+/-1.51, 5.17+/-1.41 and 3.29+/-0.86 MPa, respectively. No statistical significance was found between the bur-cut/acid-etched and laser-ablated/acid-etched groups. The predominant fracture modes of bur-cut/acid-etched, laser-ablated/acid-etched and laser-ablated human dentin were Type 1 (50%), Type 2 (70%) and Type 1 (70%), respectively. SIGNIFICANCE: Er,Cr:YSGG laser irradiation affects adversely adhesion of resin to dentin but acid etching following laser irradiation could increase the tensile bond strength as high as that of bur-cut/acid-etched human dentin.


Assuntos
Resinas Compostas/química , Colagem Dentária , Dentina/ultraestrutura , Lasers , Condicionamento Ácido do Dente , Adolescente , Adulto , Preparo da Cavidade Dentária/instrumentação , Preparo da Cavidade Dentária/métodos , Adesivos Dentinários/química , Humanos , Teste de Materiais , Metacrilatos/química , Microscopia Eletrônica de Varredura , Cimentos de Resina/química , Camada de Esfregaço , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração , Água/química
4.
Atherosclerosis ; 191(2): 250-8, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16797553

RESUMO

Sanguinarine is a plant alkaloid present in the root of Sanguinaria canadensis and Poppy fumaria species. Sanguinarine has been used as an antiseptic mouth rinse and a toothpaste additive to reduce dental plaque and gingival inflammation. In this study, we investigated the antiplatelet effects of sanguinarine, aiming to extend its potential pharmacological applications. Sanguinarine inhibited platelet aggregation induced by arachidonic acid (AA), collagen, U46619 and sub-threshold concentration of thrombin (0.05 U/ml) with IC(50) concentrations of 8.3, 7.7, 8.6 and 4.4 microM, respectively. Sanguinarine (5-10 microM) inhibited 10-31% of platelet TXB(2) production, but not platelet aggregation induced by higher concentration of thrombin (0.1 U/ml). SQ29548, a thromboxane receptor antagonist, inhibited the AA-induced platelet aggregation but not TXB(2) production. Sanguinarine suppressed cyclooxygenase-1 (COX-1) activity (IC(50)=28 microM), whereas its effect on COX-2 activity was minimal. Sanguinarine (8, 10 microM) further inhibited the AA-induced Ca(2+) mobilization by 27-62%. In addition, SQ22536, an adenylate cyclase inhibitor, attenuated the inhibitory effect of sanguinarine toward AA-induced platelet Ca(2+) mobilization and aggregation. These results suggest that sanguinarine is a potent antiplatelet agent, which activates adenylate cyclase, inhibits platelet Ca(2+) mobilization, TXB(2) production as well as suppresses COX-1 enzyme activity. Sanguinarine may have therapeutic potential for treatment of cardiovascular diseases related to platelet aggregation.


Assuntos
Alcaloides/farmacologia , Benzofenantridinas/farmacologia , Plaquetas/efeitos dos fármacos , Cálcio/metabolismo , AMP Cíclico/metabolismo , Inibidores de Ciclo-Oxigenase/farmacologia , Isoquinolinas/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Tromboxano B2/metabolismo , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacologia , Adenilil Ciclases/metabolismo , Animais , Ácido Araquidônico/farmacologia , Plaquetas/metabolismo , Colágeno/farmacologia , Ciclo-Oxigenase 1/metabolismo , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Técnicas In Vitro , Coelhos , Receptores de Tromboxanos/efeitos dos fármacos , Receptores de Tromboxanos/metabolismo , Trombina/farmacologia
5.
Artigo em Inglês | MEDLINE | ID: mdl-16997112

RESUMO

The purpose of this prospective randomized study was to investigate the manifestations and efficiency of mandibular block (MB) using a standardized method. In this study, 123 patients requiring MB were randomly assigned to receive MB using a repeated measures design. Mandibular block was administered in each patient by using 2.1 mL of 2% lidocaine with 1:100 000 epinephrine for the inferior alveolar nerve, lingual nerve, and/or buccal nerve. Clinical parameters including the electric pulp test and test for soft tissue sensation using a sharp dental explorer were assessed on both the operated side and contralateral side before and 5, 10, and 15 minutes after injection, and at the end of surgical procedure. Results of the test of the contralateral tooth served as the control group. No response to the electric pulp test at a maximum output (80 readings) was used as the criterion for pulpal anesthesia. Results obtained with electric pulp test and sharp explorer test were not significantly different during various intervals on the contralateral side, indicating the reliability of this standardized method for assessing MB. The MB technique achieved a high rate of subjective numbness (100%) according to the perception of the patients of overall numbness and lip numbness. Overall anesthetic success rates of pulpal anesthesia were 5.7% for the central incisor, 38.2% for the canine, 55.3% for the first premolar, and 90.2% for the first molar. No significant difference was found in the efficiency of anesthesia related to sex or age of the patients. A slower onset of pulpal anesthesia after MB was found for the anterior teeth than for the posterior teeth. This study suggests that the use of a standardized method might produce a clearer and more comprehensive evaluation of the efficiency and manifestations of MB.


Assuntos
Anestesia Dentária/normas , Teste da Polpa Dentária , Bloqueio Nervoso/normas , Adolescente , Adulto , Anestesia Dentária/métodos , Anestésicos Locais/administração & dosagem , Bochecha/inervação , Distribuição de Qui-Quadrado , Criança , Feminino , Humanos , Injeções , Lidocaína/administração & dosagem , Nervo Lingual , Masculino , Nervo Mandibular , Pessoa de Meia-Idade , Bloqueio Nervoso/métodos , Estudos Prospectivos , Padrões de Referência
6.
Dent Mater J ; 25(2): 247-52, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16916225

RESUMO

The purpose of this study was to investigate the application of nondestructive testing in cyclic fatigue evaluation of endodontic ProFile nickel-titanium (NiTi) rotary instruments. As-received ProFile instruments were made to rotate freely in sloped metal blocks by a contra-angle handpiece mounted on a testing machine. Rotation was interrupted periodically, and the instrument removed and engaged onto a device to monitor its stiffness by using two strain gauges in four different directions. This monitoring method has the potential to be developed into a convenient, nondestructive turnkey system that allows in situ assessment of the integrity of NiTi instruments in the clinic. Upon fracture, which was indicated by a change in instrument stiffness, the fractured surface would be examined under a scanning electron microscope. Microscopic evaluation indicated a small area of fatigue fracture with a large area of final ductile fracture, whereby the latter was the major cyclic failure mode. Based on the results of this study, we concluded that a potential nondestructive integrity assessment method for NiTi rotary instruments was developed.


Assuntos
Ligas Dentárias , Análise do Estresse Dentário/métodos , Níquel , Preparo de Canal Radicular/instrumentação , Titânio , Análise do Estresse Dentário/instrumentação , Análise de Falha de Equipamento/métodos , Rotação , Estresse Mecânico , Transdutores
7.
J Formos Med Assoc ; 105(6): 522-6, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16801043

RESUMO

Mineral trioxide aggregate (MTA) has been widely used to repair various kinds of tooth perforations, but its use for obturation of the entire root canal has not been reported. We report two cases of tooth perforation successfully repaired with MTA. The first patient was a 78-year-old male with calcified canal and pulp floor perforation in the left maxillary first premolar. After bypass of the calcified palatal canal, both buccal and palatal canals were filled with gutta percha, and the pulp floor perforation was repaired with MTA. Clinical success with no evident radicular lesion was found at the 18-month follow-up. The second patient was a 51-year-old female with a stripping perforation in a C-shaped root canal of the right mandibular second molar detected after removal of a post. Following root canal debridement and calcium hydroxide therapy to control inflammation at the stripping perforation site, apical and furcation bone healing were observed by radiographic examination. The stripping perforation was repaired by obturation of the entire C-shaped root canal with MTA. Observation at the 9-month follow-up revealed bone healing without any clinical symptoms and signs. These cases suggest that MTA is an alternative root canal obturation material for treatment of stripping perforation in a C-shaped root canal and for repair of pulp floor perforation.


Assuntos
Compostos de Alumínio/uso terapêutico , Compostos de Cálcio/uso terapêutico , Cavidade Pulpar/lesões , Óxidos/uso terapêutico , Materiais Restauradores do Canal Radicular/uso terapêutico , Silicatos/uso terapêutico , Traumatismos Dentários/terapia , Idoso , Combinação de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
8.
J Formos Med Assoc ; 105(4): 318-28, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16618612

RESUMO

BACKGROUND: The craniofacial growth patterns of untreated individuals with skeletal Class III malocclusion have rarely been systemically investigated. This study used morphometric techniques to investigate the growth characteristics of the mandible in individuals with skeletal Class III malocclusion. METHODS: Lateral cephalometric head films of 294 individuals with untreated skeletal Class III malocclusion (134 males, 160 females) were selected and divided into five triennial age groups (T1-T5) and by gender to identify the morphologic characteristics and sexual dimorphism in changes of mandibular growth. Procrustes, thin-plate spline, and finite element analyses were performed for localization of differences in shape and size changes. Maximum and minimum principal axes were drawn to express the directions of shape changes. RESULTS: From T1 (age 6-8 years) to T4 (age 15-17 years), the distribution of localized size and shape changes of the mandible was very similar between the two genders. From T1 to T2 (age 9-11 years), significant lengthening of the condylar region was noted (23.4-39.7%). From T2 to T3 (age 12-14 years), the greatest size and shape change occurred at the condylar head (27.4-34.9%). From T3 to T4, the greatest size and shape changes occurred in the symphyseal region (23.6-42.1%). From T4 to T5 (age>or=18 years), significant sexual dimorphism was found in the distribution and amount of localized size and shape changes. Females displayed little growth increments during T4. Despite differences in the remodeling process, the whole mandibular configurations of both genders exhibited similarly significant upward and forward deformation from T4 to T5. CONCLUSION: We conclude that thin-plate spline analysis and the finite element morphometric method are efficient for the localization and quantification of size and shape changes that occur during mandibular growth. Plots of maximum and minimum principal directions can provide useful information about the trends of growth changes.


Assuntos
Má Oclusão Classe III de Angle/fisiopatologia , Mandíbula/fisiopatologia , Adolescente , Cefalometria , Criança , Feminino , Análise de Elementos Finitos , Humanos , Masculino , Má Oclusão Classe III de Angle/diagnóstico por imagem , Mandíbula/diagnóstico por imagem , Desenvolvimento Maxilofacial , Radiografia
9.
Artigo em Inglês | MEDLINE | ID: mdl-16545712

RESUMO

OBJECTIVES: The issue of existence of malignancy within oral leukoplakia has seldom been addressed in Taiwan. The aims of this study were to investigate the prevalence of carcinoma and dysplasia within oral leukoplakia at the time of clinical diagnosis and to identify the associated risk factors in Taiwan. STUDY DESIGN: The prevalence rate of malignancy and dysplasia in 1046 oral leukoplakias at a university hospital was calculated. Univariate and multivariate analyses by the Mantel-Haenszel method and multiple logistic regression model were performed to examine risk factors associated with the presence of carcinoma and dysplasia within the lesions. RESULTS: The prevalence rate of carcinoma was 12.9%. The relative risks for the presence of malignancy in leukoplakias on the tongue/floor of mouth and with nonhomogeneous appearance were 2.72- and 28.13-fold by multivariate logistic regression analysis, when compared with those on buccal mucosa and lesions having homogeneous surface (both P < .05). In contrast, patients who both smoked and chewed betel quid had a significantly lower risk for carcinoma than the abstainers (P < .05). A synergistic effect between the 2 major risk factors of clinical appearance and lesion site was evident. Nonhomogeneous leukoplakia on tongue/floor of mouth had a 43.10-fold higher risk compared to homogeneous lesions located on buccal mucosa or other sites (P < .05). However, homogeneous leukoplakia in buccal mucosa or other sites of the oral cavity still had the possibility of having carcinoma within the lesion. The prevalence of dysplasia was 45.6% among the noncancerous leukoplakias with risk factors similar to those for carcinoma. CONCLUSIONS: Our results demonstrate that some leukoplakias contain a malignant component. Lesions with certain features are more prone to carcinoma, but no clinical attributes can bring certitude. Therefore, all oral leukoplakias should be submitted to microscopic analysis before any definite treatment or long-term follow-up.


Assuntos
Carcinoma de Células Escamosas/epidemiologia , Leucoplasia Oral/epidemiologia , Neoplasias Bucais/epidemiologia , Lesões Pré-Cancerosas/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Areca/efeitos adversos , Carcinoma de Células Escamosas/etiologia , Carcinoma de Células Escamosas/patologia , Carcinoma Verrucoso/epidemiologia , Carcinoma Verrucoso/etiologia , Carcinoma Verrucoso/patologia , Transformação Celular Neoplásica , Feminino , Humanos , Leucoplasia Oral/etiologia , Leucoplasia Oral/patologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Mucosa Bucal/patologia , Neoplasias Bucais/etiologia , Neoplasias Bucais/patologia , Razão de Chances , Lesões Pré-Cancerosas/etiologia , Lesões Pré-Cancerosas/patologia , Prevalência , Fatores de Risco , Razão de Masculinidade , Inquéritos e Questionários , Taiwan/epidemiologia
10.
Lasers Surg Med ; 38(1): 62-9, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16444695

RESUMO

BACKGROUND AND OBJECTIVES: A reliable method to eradicate the bacteria of residual carious dentin has not yet been developed. The aim of this study was to evaluate the antibacterial effect of a diode laser on Streptococcus mutans through different thickness (500, 1,000, and 2,000 microm) of human dentin. The thermal effect of laser irradiation was also investigated. STUDY DESIGN/MATERIALS AND METHODS: Dentin specimens were inoculated with 2 microl of S. mutans on one side and irradiated by a diode laser on the other side with a power output ranging from 0.5 to 7 W. The laser tip was swept with the whole irradiation area of 7 mm x 3 mm at a speed of about 10 mm/second with a total irradiation time of 30 seconds. Cooling with distilled water (30 ml/minute) was applied simultaneously during laser irradiation. After laser irradiation, the bacteria was removed from the dentin surfaces and cultured for 48 hours at 37 degrees C anaerobically to assess the colony forming units (CFU) per ml. The morphology of the lased bacteria and the temperature rise during laser irradiation were observed by scanning electron microscope (SEM) and measured by thermocouple, respectively. RESULTS: The results revealed that 7 W of laser power could kill 97.7% of CFU through 500 microm thickness of dentin. However, the bactericidal efficiency was significantly reduced as the dentin thickness was increased. The morphological changes of lased bacteria ranged from less affected such as loss of their wall bands and existence of minicells to more severely degenerated, such as disintegration and fusion of cells with pores on the cell wall. Only the dentin specimens with a thickness of 500 microm exhibited a temperature rise greater than 5.5 degrees C after receiving 5 or 7 W of laser irradiation. CONCLUSIONS: A diode laser can eliminate the Streptococcus mutans of the residual carious dentin without inducing high pulpal temperature rise when the remaining dentin thickness is greater than 1 mm.


Assuntos
Cárie Dentária/microbiologia , Dentina/microbiologia , Terapia com Luz de Baixa Intensidade , Streptococcus mutans/efeitos da radiação , Dentina/efeitos da radiação , Dentina/ultraestrutura , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Estatísticas não Paramétricas
11.
Br J Pharmacol ; 147(2): 188-98, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16299551

RESUMO

1.--Thrombin is activated during gingival tissue injury and inflammation. Thrombin (platelet)-rich plasma has been used for periodontal regeneration with success. Thrombin and other bacterial proteases also affect the functions of adjacent periodontal cells via stimulation of protease-activated receptors (PARs). 2.--We noted that thrombin (0.1-2 U ml(-1)), human, and frog PAR-1 agonist peptide (20-240 microM) induced the gingival fibroblast (GF)-populated collagen gel contraction within 2 h of exposure. However, PAR-2, PAR-3, and PAR-4 agonist peptide (20-240 microM) showed little effect on collagen gel contraction. U73122 (phospholipase C inhibitor) and 2-APB (IP3 antagonist) were effective in inhibition of GF contraction. 3.--Thrombin-induced GF contraction was inhibited by 5 mM EGTA (an extracellular calcium chelator) and verapamil (an L-type calcium channel blocker). In addition, W7 (10 and 25 microM, a calcium/calmodulin (CaM) inhibitor), ML-7 (50 microM, myosin light chain kinase (MLCK) inhibitor), and HA1077 (100 microM, Rho kinase inhibitor) completely inhibited the thrombin-induced collagen gel contraction. Thrombin also induced the phosphorylation of ERK1/ERK2 and elevated the Rho-GTP levels in GF. 4.--However, U0126 only partially inhibited the thrombin-induced GF contraction. Similarly, wortmannin (100 nM), LY294002 (20 microM) (two PI3K inhibitor) and genistein also showed partial inhibition. Moreover, NAC was not able to suppress the GF contraction, as supported by the slight decrease in reactive oxygen species production in GF by thrombin. 5.--Thrombin also stimulated metalloproteinase-2 (MMP-2) and MMP-3 production in GF. But addition of GM6001 or 1,10-phenanthroline, two MMP inhibitors, could not inhibit the thrombin-induced GF contraction. 6.--These results indicate that thrombin is crucial in the periodontal inflammation and wound healing by promoting GF contraction. This event is mainly mediated via PAR-1 activation, PLC activation, extracellular calcium influx via L-type calcium channel, and the calcium/CaM-MLCK and Rho kinase activation pathway.


Assuntos
Colágeno/fisiologia , Fibroblastos/fisiologia , Gengiva/citologia , Trombina/fisiologia , Cálcio/metabolismo , Proteínas Quinases Dependentes de Cálcio-Calmodulina/antagonistas & inibidores , Tamanho Celular , Células Cultivadas , Ativação Enzimática , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Géis , Humanos , Metaloproteases/biossíntese , Quinase de Cadeia Leve de Miosina/antagonistas & inibidores , Oxirredução , Peptídeos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Receptores Ativados por Proteinase/agonistas , Transdução de Sinais , Fosfolipases Tipo C/fisiologia , Proteínas rho de Ligação ao GTP/metabolismo
12.
J Surg Oncol ; 91(1): 41-7, 2005 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-15999357

RESUMO

BACKGROUND AND OBJECTIVES: While betel quid (BQ) chewing is clearly the most avoidable risk factor of squamous cell carcinoma of buccal mucosa (BMSCC), little is known about the influence of this habit on the prognosis of BMSCC. METHODS: We surveyed 280 patients with BMSCC who were treated during an 8-year period in a cohort study to assess the independent predictive value of pretreatment BQ chewing habit on the prognosis by univariate and multivariate analysis. RESULTS: We found by univariate analysis that sex, age, clinical stage, smoking, and BQ chewing significantly affected the patients' prognosis and only age, clinical stage, and BQ chewing had significant influence on prognosis by multivariate analysis (P < 0.05). Further analysis revealed that the prognostic effect of BQ chewing changed in a dose- and time-dependent manner. The risk of death was 31.4-fold higher in heavy user (duration >30 years, daily consumption >30 quids, age of start <20 years old) when compared to those who chewed BQ to a milder degree (duration <10 years, daily consumption <15 quids, age of start > or =20 years old ) (P < 0.001). CONCLUSIONS: Pretreatment BQ chewing habit worsens the prognosis of BMSCC in Taiwan. BQ chewing is a prognostic indicator that can be used in conjunction with clinical staging to help plan the treatment for the patients.


Assuntos
Areca , Carcinoma de Células Escamosas/etiologia , Mastigação , Mucosa Bucal , Neoplasias Bucais/etiologia , Adulto , Idoso , Consumo de Bebidas Alcoólicas , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/mortalidade , Neoplasias Bucais/patologia , Neoplasias Bucais/cirurgia , Análise Multivariada , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Prognóstico , Fatores de Risco , Fumar , Taxa de Sobrevida
13.
Dent Mater ; 21(6): 511-9, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15904693

RESUMO

OBJECTIVES: An ideal material has yet to be discovered that can completely treat dentin hypersensitivity. However, if a highly biocompatible material such as bioglass, could be melted by laser irradiation to achieve better sealing depth for dentinal tubules, it may subsequently bond to dentin structures under a physiological environment and offer a prolonged therapeutic effect. METHODS: The authors used four types of energy parameters to melt the composition-modified bioglass. These four types were 30 Hz, 330 mJ/pulse (G+ mode), 30 Hz, 160 mJ/pulse (G- mode), 10 Hz, 400 mJ/pulse (D+ mode), and 10 Hz, 200 mJ/pulse (D- mode). The temperature elevation, occlusive depth of bioglass, and phase changes in the bioglass after laser irradiation were evaluated by means of scanning electron microscope (SEM), thermometer, and X-ray diffractometer (XRD). RESULTS: The occlusive depths of 2 and 10 microm in the dentinal tubules were achieved when the bioglass underwent 30 Hz, 160 mJ/pulse (G- mode) and 30 Hz, 330 mJ/pulse (G+ mode) of laser treatments, respectively. The bioglass experienced a temperature increase of less than 600 degrees C, and no phase transformation was observed after Nd:YAP laser irradiation. SIGNIFICANCE: The melting point of a composition-modified bioglass could be reduced and its use plus Nd:YAP laser have the potential in clinical use to treat dentin hypersensitivity.


Assuntos
Cerâmica/uso terapêutico , Cimentos Dentários/uso terapêutico , Sensibilidade da Dentina/terapia , Terapia a Laser , Cristalografia por Raios X , Permeabilidade da Dentina , Temperatura Alta , Humanos , Microscopia Eletrônica de Varredura , Dente Molar , Neodímio
14.
Artigo em Inglês | MEDLINE | ID: mdl-15772596

RESUMO

OBJECTIVE: The aim of the study was to examine the expressions of p53 and proliferating cell nuclear antigen (PCNA) in oral lichen planus (OLP) in relation to its clinical behavior and the patients' oral habits. STUDY DESIGN: Immunohistochemical study was carried out to investigate the expressions of p53 and PCNA in 56 OLP specimens. The results were correlated with the clinical behavior of the disease and the patients' oral habits. The expression rates were further compared with those of normal oral mucosa (NOM), epithelial hyperkeratosis (EH), epithelial dysplasia (ED), and squamous cell carcinoma (SCC). RESULTS: The staining rate of p53 (28.6%) and PCNA labeling index (LI) (27.6 +/- 8.8%) in OLP were similar to those in EH ( P = .868, .074, respectively), but higher than those of NOM and lower than those of ED and SCC (all P < .05). In OLP, no significant correlations were found between p53 or PCNA expression and the patients' age, gender, lesion duration, location, size, number of site, presence of pain, presence of local irritant, and the habits of alcohol drinking and cigarette smoking (all P > .05). In addition, the mean PCNA LI of p53+ cases was close to that of p53- cases (P = .38). However, the staining rate of p53 in OLP was higher in areca quid (AQ) chewers compared to abstainers (P = .001), and the mean PCNA LI in atrophic cases was higher than that in hypertrophic cases (P = .029). Interestingly, the staining rate of p53 and mean PCNA LI were significantly increased in AQ chewers with atrophic OLP (100%, 36.7% +/- 9.0%, respectively), which were similar to those in ED and SCC (all P > .05). CONCLUSIONS: Although this study could not confirm the precancerous nature of OLP by the relatively low p53 and PCNA expression, the results do suggest that atrophic form OLP and patients with AQ chewing habit may have a higher disease activity in view of higher expression rates of p53 and PCNA in the lesions.


Assuntos
Areca/efeitos adversos , Líquen Plano Bucal/metabolismo , Antígeno Nuclear de Célula em Proliferação/biossíntese , Transtornos Relacionados ao Uso de Substâncias/complicações , Proteína Supressora de Tumor p53/biossíntese , Adolescente , Adulto , Idoso , Análise de Variância , Carcinoma de Células Escamosas/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Líquen Plano Bucal/complicações , Líquen Plano Bucal/patologia , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Mucosa Bucal/metabolismo , Neoplasias Bucais/metabolismo , Lesões Pré-Cancerosas/metabolismo , Antígeno Nuclear de Célula em Proliferação/análise , Transtornos Relacionados ao Uso de Substâncias/etiologia , Transtornos Relacionados ao Uso de Substâncias/metabolismo , Proteína Supressora de Tumor p53/análise
15.
Lasers Surg Med ; 36(3): 225-33, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15685604

RESUMO

BACKGROUND AND OBJECTIVES: The purpose of this study was to investigate the long-term effect of Nd:YAG laser irradiation on cultured human periodontal fibroblasts (hPF). STUDY DESIGN/MATERIALS AND METHODS: The cultured hPF were irradiated by pulsed Nd:YAG laser. The power delivery was 50 mJ x 10 pps (pulse per second) with irradiation duration 60, 120, 180, or 240 seconds. The viability and collagen content of laser-irradiated hPF were assessed on day 5 after laser treatment. Light microscope and transmission electron microscope (TEM) were used to observe cytomorphological change. The irradiated hPF cultured in mineralizing medium for 28 days were examined by alizarin red S and Von Kossa stain. RESULTS: The cellular viability and collagen content of hPF decreased after Nd:YAG laser irradiation. Cell damage was noted with retraction of cellular processes, loss of normal architecture, and lysis of some cells. However, survived hPF proliferated and migrated to the cell-debris-associated deposits. The electron-dense cytoplasm and amorphous organelles in laser-damaged cells was revealed by TEM. In vitro mineralization was demonstrated in the long-term laser-irradiated hPF cultured in mineralizing medium. CONCLUSION: Nd:YAG laser irradiation induced partial loss of cellular viability and collagen content. The co-existence of viable cells and progressive degeneration of laser-damaged cells was associated with the in vitro mineralization of hPF.


Assuntos
Fibroblastos/efeitos da radiação , Lasers , Ligamento Periodontal/efeitos da radiação , Calcificação Fisiológica/efeitos da radiação , Células Cultivadas , Colágeno/efeitos da radiação , Relação Dose-Resposta à Radiação , Fibroblastos/ultraestrutura , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Transmissão , Ligamento Periodontal/citologia
16.
Toxicology ; 208(1): 95-104, 2005 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-15664436

RESUMO

Cresol is a well-known environmental pollutant, toluene metabolite, uremic toxicant and accidental poisoning product. Formocresol, a preparation of formalin and cresol, is also used as a root canal medicament and for pulpotomy of primary teeth. However, little is known about its effect on cardiovascular system. In this study, m-cresol inhibited the AA-induced platelet aggregation by 43-97% at concentrations ranging from 0.25 to 1 mM. Collagen-induced platelet aggregation was also inhibited by 0.25-1 mM of m-cresol by 47-98%. Accordingly, o-cresol (0.1-0.5 mM) also inhibited the AA-induced platelet aggregation by 46-96% and the collagen-induced platelet aggregation by 35-88% at concentrations of 0.1-1 mM. AA- and collagen-induced platelet thromboxane B(2) (TXB(2)) production was inhibited by even 0.1 mM of m-cresol with 88 and 54% of inhibition, respectively. The o-cresol (0.1 mM) also inhibited the AA- and collagen-induced platelet TXB(2) production with 91 and 97% respectively. Although m- and o-cresol (<1 mM) showed little effect on thrombin-induced platelet aggregation, they effectively inhibited the thrombin-induced platelet TXB(2) production. The m-cresol (2 and 5 mM) inhibited the COX-1 activity by 55-99%, but showed little effect on COX-2 enzyme activity. Moreover, o-cresol (0.5 and 1 mM) inhibited the COX-1 activity by 40-95%. COX-2 enzyme activity was inhibited by 68% at a concentration of 5 mM o-cresol. These results indicate that acute cresol-poisoning, direct root canal medication with formocresol or long-term occupational exposure to cresol and toluene may potentially suppress blood clot formation and lead to tissue hemorrhage via inhibition of platelet aggregation, TXB(2) production and COX enzyme activity.


Assuntos
Cresóis/toxicidade , Inibidores de Ciclo-Oxigenase/toxicidade , Poluentes Ambientais/toxicidade , Inibidores da Agregação Plaquetária/toxicidade , Tromboxano B2/antagonistas & inibidores , Animais , Plaquetas/efeitos dos fármacos , Plaquetas/enzimologia , Células Cultivadas , Ciclo-Oxigenase 1 , Ciclo-Oxigenase 2 , Inibidores de Ciclo-Oxigenase 2 , Relação Dose-Resposta a Droga , Ativação Plaquetária/efeitos dos fármacos , Prostaglandina-Endoperóxido Sintases/metabolismo , Coelhos , Tromboxano B2/biossíntese
17.
J Formos Med Assoc ; 104(11): 830-8, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16496063

RESUMO

BACKGROUND AND PURPOSE: Previous studies investigating the effects of core or post on the fracture strength of teeth often omitted the periodontal ligament (PDL) because its physical properties are difficult to reliably quantify. This study investigated the effects of various PDL elastic moduli on the stress distribution around a central incisor and surrounding alveolar bone using 3-dimensional finite element stress analyses. METHODS: Four 3-dimensional finite element models of an upper central incisor and the dento-alveolar complex were established. Five models were constructed, including: no PDL, as well as a PDL with elastic moduli of 6.9 MPa, 68.9 MPa, and 1750 MPa. Two loading conditions were simulated, one with protrusive force and one with intrusive force. Protrusive loading was generated using a point force of 200 N at 45 degrees inclination to the longitudinal axis of the incisor applied on the lingual side. Intrusive loading was generated using a point force of 200 N applied perpendicular to the incisal edge. RESULTS: The absence of a PDL had detrimental effects on the surrounding bone, because the applied stress remained concentrated at the bone crest and cervical third of the root. A PDL with a lower elastic modulus, on the other hand, helped to alleviate the magnitude of stress throughout the surrounding bone and the bone crest, in particular, by distributing the stress deeper towards the apical region. The stress distribution at the crown was unaffected by variations in the PDL elastic modulus. CONCLUSIONS: PDL with a lower elastic modulus can help protect the alveolar bone crest from stress concentration.


Assuntos
Processo Alveolar/fisiologia , Análise do Estresse Dentário , Incisivo/fisiologia , Ligamento Periodontal/fisiologia , Elasticidade , Análise de Elementos Finitos , Humanos
18.
Dent Mater J ; 24(4): 562-9, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16445019

RESUMO

Sealing of exposed dentinal tubules is generally considered the most effective strategy to treat dentin hypersensitivity. On this account, we fabricated a DP-bioglass paste that created a homogeneous blockage on open dentinal tubules and formed a deep precipitate within dentinal tubules. DP-bioglass paste was prepared by mixing 20% to 60% phosphoric acid and DP-bioglass to treat dentin surfaces. CO2 laser irradiation was used to melt the DP-bioglass paste. The results demonstrated that 30% phosphoric acid was the optimum concentration to produce homogeneous occlusion on exposed dentinal tubules and 60 microm of sealing depth. CO2 laser irradiation could melt the DP-bioglass paste and create about 10 microm of sealing depth. Moreover, temperature rise during CO2 laser irradiation was only 4.86 +/- 0.47 degrees C. The results presented in this work suggested that DP-bioglass paste could produce considerable sealing depth in dentinal tubules with the potential of prolonging the therapeutic effect efficaciously.


Assuntos
Cimentos Dentários/uso terapêutico , Sensibilidade da Dentina/tratamento farmacológico , Adolescente , Adulto , Cristalografia por Raios X , Cimentos Dentários/química , Cimentos Dentários/farmacologia , Dentina/ultraestrutura , Permeabilidade da Dentina/efeitos dos fármacos , Temperatura Alta , Humanos , Lasers , Microscopia Eletrônica de Varredura , Dente Molar , Ácidos Fosfóricos , Espectrometria por Raios X
19.
Artigo em Inglês | MEDLINE | ID: mdl-15356465

RESUMO

OBJECTIVES: The aim of the study was to investigate the effectiveness of an educational program on the reduction of the incidence of wrong-site tooth extraction at the outpatient department of a university hospital in Taiwan. STUDY DESIGN: Data collected from cases of wrong-site tooth extraction during 1996 to 1998 were used to develop a specific educational intervention that was implemented from 1999 to 2001. The annual incidence of erroneous extraction was compared between the preintervention and intervention periods. The factors contributing to wrong tooth extraction were also analyzed. RESULTS: The annual incidence rates of erroneous extraction from 1996 to 1998 were 0.026%, 0.025%, and 0.046%, respectively. During the intervention period from 1999 to 2001, wrong-site tooth extraction did not occur at the department. There was a significant difference in the incidence of erroneous extraction between the preintervention and intervention periods (P<.01). Cognitive failure was the most frequent form of active failure responsible for wrong-site tooth extraction, whereas communication and training were found to be major latent factors contributing to these errors. CONCLUSIONS: Our results suggest the effectiveness of an educational program comprising case-based materials, information feedback, and clinical guidelines in reducing the incidence of wrong-site tooth extraction.


Assuntos
Erros Médicos/prevenção & controle , Extração Dentária/efeitos adversos , Adolescente , Adulto , Cognição , Comunicação , Educação em Odontologia/métodos , Feminino , Humanos , Masculino , Erros Médicos/estatística & dados numéricos , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Terminologia como Assunto , Dente , Extração Dentária/estatística & dados numéricos , Redação
20.
Photomed Laser Surg ; 22(4): 330-4, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15345177

RESUMO

OBJECTIVE: The aim of this study was to investigate the phase, compositional, and morphological changes of Er:YAG laser-irradiated dentin. BACKGROUND DATA: To date, nothing comprehensive has been reported about the phase and compositional changes of human dentin after Er:YAG laser irradiation. METHODS: The human dentin was irradiated by Er:YAG laser with irradiation energies from 300 mJ/pulse-10 pps-10 sec to 700 mJ/pulse-10 pps-10 sec with and without water spray. After irradiation, the specimens were analyzed by means of x-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). RESULTS: After exposure to Er:YAG laser, dentin showed no phase changes on the x-ray diffractometer. In Fourier transform infrared analysis, two absorption bands at 2200 and 2015 cm(-1) could be traced on dentin treated by Er:YAG laser with irradiation energies beyond 300 mJ/pulse-10 pps-10 sec and without water spray. The OH(-) band disappeared at 1630 cm(-1). Scanning electron micrographs revealed that laser energy of 500 mJ/pulse-10 pps-10 sec was sufficient to prompt melting and recrystallization of dentin crystals. CONCLUSIONS: Our study demonstrated that Er:YAG laser irradiation on dentin with water spray would not significantly change the structure and composition. Therefore, water cooling is important for reducing the thermal effect of Er:YAG laser.


Assuntos
Dentina/efeitos da radiação , Dentina/ultraestrutura , Terapia com Luz de Baixa Intensidade/métodos , Espectroscopia de Infravermelho com Transformada de Fourier , Microanálise por Sonda Eletrônica , Érbio , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Dente Molar , Sensibilidade e Especificidade , Relação Estrutura-Atividade
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