Er:YAG Laser for Surgical Crown Lengthening: A 6-Month Clinical Study.

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.

Laser assisted tooth replantation case report.

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.

Evaluation of mandibular block using a standardized method.

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.

Application of nondestructive testing in cyclic fatigue evaluation of endodontic Ni-Ti rotary instruments.

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.

Tensile bond strength of Er,Cr:YSGG laser-irradiated human dentin and analysis of dentin-resin interface.

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.

Treatment of pulp floor and stripping perforation by mineral trioxide aggregate.

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.

Antiplatelet effect of sanguinarine is correlated to calcium mobilization, thromboxane and cAMP production.

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.

Morphometric analysis of mandibular growth in skeletal Class III malocclusion.

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.

Carcinoma and dysplasia in oral leukoplakias in Taiwan: prevalence and risk factors.

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.

Effects of various periodontal ligament elastic moduli on the stress distribution of a central incisor and surrounding alveolar bone.

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.

In vitro study of DP-bioglass paste for treatment of dentin hypersensitivity.

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.

Bactericidal effects of diode laser on Streptococcus mutans after irradiation through different thickness of dentin.

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.

Signaling mechanism of thrombin-induced gingival fibroblast-populated collagen gel contraction.

1.--Thrombin is activated during gingival tissue injury and inflammation. Thrombin (platelet)-rich plasma has been used for periodontal regeneration with success.

Univariate and multivariate analysis of prognostic significance of betel quid chewing in squamous cell carcinoma of buccal mucosa in Taiwan.

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.

In vitro study of dentin hypersensitivity treated by Nd:YAP laser and bioglass.

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.

Higher expressions of p53 and proliferating cell nuclear antigen (PCNA) in atrophic oral lichen planus and patients with areca quid chewing.

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.

Long-term effect of pulsed Nd:YAG laser irradiation on cultured human periodontal fibroblasts.

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.

Inhibition of cyclooxygenase activity, platelet aggregation and thromboxane B2 production by two environmental toxicants: m- and o-cresol.

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.

Effects of root-end filling materials and eugenol on mitochondrial dehydrogenase activity and cytotoxicity to human periodontal ligament fibroblasts.

Various root-end filling materials have been used to prevent the entry of root-canal pathogens into periapical regions. Five root-end filling materials were compared regarding the cytotoxicity, apoptosis, and mitochondrial dehydrogenase (MDH) activities of human periodontal ligament (PDL) fibroblasts, with the use of a novel transwell culture system. Exposure to IRM (a ZnO eugenol-based intermediate restorative material), a 2-ethoxybenzoic acid cement (Super EBA), and amalgam for 3 days inhibited the MDH activity of PDL fibroblasts as indicated by decrease in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) reduction by 97%, 95%, and 51%, respectively.

Effectiveness of an educational program in reducing the incidence of wrong-site tooth extraction.

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.

Structural changes of Er:YAG laser-irradiated human dentin.

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.

Thermal effect and morphological changes induced by Er:YAG laser with two kinds of fiber tips to enlarge the root canals.

Objective: The aim of this study was to assess the application of Er:YAG laser root canal preparation using two fiber tip systems.

Background Data: Previous studies have not shown the thermal effect of Er:YAG laser using cone-shaped fiber tip.

Materials And Methods: The ability of Er:YAG laser to enlarge root canals at a pulse energy set at 30 or 20 mJ and constant pulse rate of 10 pps (pulses per second) was tested.

Successful treatment of oral verrucous hyperplasia with topical 5-aminolevulinic acid-mediated photodynamic therapy.

Previous studies have shown a selective accumulation of 5-aminolevulinic acid (ALA)-derived protoporphrin IX (PpIX) in oral premalignant and malignant tissues. This provides a biologic rationale for the clinical use of ALA-mediated PDT (ALA-PDT) for oral premalignant and malignant lesions. In this study, five patients with oral verrucous hyperplasia (OVH) were treated with a new protocol of ALA-PDT composed of multiple 3-min irradiations with a light emitting diode (LED) red light at 635+/-5 nm separated with several 3-min rests for a total of 1000 s (fluence rate, 100 mW/cm(2); light exposure dose, 100 J/cm(2)) after topical application of 20% ALA for 1.

Morphologic study of Nd:YAG laser usage in treatment of dentinal hypersensitivity.

Our previous in vitro study indicated that Nd:YAG laser irradiation on dentin could melt normal dentin surface and close the exposed dentinal tubule orifices without creating surface cracks. This study evaluated the morphologic changes of hypersensitive dentin after Nd:YAG laser irradiation. Thirty patients with clinically diagnosed cervical dentin hypersensitive teeth were treated with a Nd:YAG laser of 30 mJ intensity at 10 pulses per second for 2 min.

The role of organic tissue on the punch shear strength of human dentin.

Objectives: The tendency to fracture of human teeth has been attributed to numerous reasons, including pulpless tooth dehydration, tooth structure degeneration, and excessive spreader loading. To date, however, no consistent data has been gathered to ascertain the effect of organic tissue on the biomechanical properties of human dentin. This study explored the influences of organic tissue removal on the morphological changes and punch shear strength by means of low vacuum wet scanning electron microscope (Wet-SEM) and punch shear apparatus.