Effect of different smear layers on the bonding performance and durability of four adhesive systems / 中国组织工程研究

BACKGROUND: When the tooth surface is treated with a rotary or manual instrument, a smudge layer is formed on the enamel and dentin by debris generated by cutting and abrasion. The bonding interface between the adhesive and the dentin is considered as a weak part in the direct repair process. To clarify the effect of smear layer on different kinds of adhesive is significantly important for dentists to select and correctly use the adhesive in clinical treatment. OBJECTIVE: To evaluate the effect of different diamond burs on the dentin bonding performance of four adhesive systems to dentin after 24 hours and 100 days of artificial saliva-storage. METHODS: Adhesive systems were: (1) VSA (Optibond Versa, Kerr); (2) AIO (Optibond All in One, Kerr); (3) SBU (Single bond Universal, 3M); (4) GLU (Bond 5, Gluma, Heraeus). In present study, 80 extracted human molars were randomly divided into four groups and each group is divided into 4 subgroups. Dentin surfaces were prepared by: (1) 600-grit SiC-paper (control group); (2) super-fine diamond bur; (3) regular diamond bur; (4) coarse diamond bur. Bonding agent was applied according to each manufacturer’s instruction. After light-curing, dentin surfaces were built-up with resin composite (A2, CHARISMA, Heraeus). The micro-tensile bond strength was determined after 24 hours and 100 days of storage in artificial saliva at 37 °C. The fractured surfaces on dentin side were observed by scanning electron microscope. RESULTS AND CONCLUSION: (1) Storage for 24 hours: There was no significant difference among groups under VSA and GLU. Under SBU and AIO, the bond strength in the coarse diamond bur group was significantly lower than that in the control group (P 0. 05). Using coarse diamond bur, the bond strength in the VSA group had significant difference compared with the AIO, GLU and SBU groups (P 0. 05). (2) Storage for 100 days, there was no significant difference among groups under VSA and GLU. Under SBU, the bond strength in the coarse diamond bur group was significantly lower than that in the control group (P 0. 05). Using regular diamond bur, the bond strength showed no significant difference in the GLU group compared with the SBU, and VSA groups (P > 0. 05). Using coarse diamond bur, the bond strength had no significant difference between VSA and AIO groups (P < 0. 05). (3) Using VSA, the bond strength in each group at 100 days showed significant difference compared with that at 24 hours (P < 0. 05). (4)Compared with immersed for 24 hours, the ratio of bond interface and combined crack in the VSA, SBU and GLU groups after immersed for 100 days was increased, especially the VSA group. Compared with the other groups, the ratio of bond interface and combined crack in the GLU group after immersed for 24 hours and 100 days both increased by 50%. (5) These results indicate that preparation by different burs produces different smear layers, which has significant effect to self-etching adhesive system and has no significant effect to total-etching adhesive system. Storage time makes effect on different adhesives.

The influence of different surface treatment protocols and bonding agents on the repair microtensile bond strength of six-month' aged composite: An in vitro study / A influência de diferentes protocolos de tratamento de superfície e agentes de união na resistência de união à microtração de reparo de compósito envelhecido por seis meses: um estudo in vitro

Objective: To compare the effect of three surface treatment protocols and two intermediate agents on repairing aged composite, regarding microtensile bond strength (µTBS) and mode of fracture, at two time intervals. Material and methods: Six-monthaged microhybrid composite blocks, were randomly distributed into three groups, subjected to; Fine, Super Fine grit diamond burs or Erbium- Yag Laser surface treatment. Each block had both One Coat bond SL (Bond) and Brilliant Flow flowable composite (Flow) intermediate agents, alongside. Blocks were incrementally repaired using nanohybrid composite, cut into beams, then randomly subjected either immediately (IM) to µTBS test or after thermocycling (TC) for 5000 cycle. Mode of failure was determined using stereomicroscope. Data were analyzed through three-way ANOVA followed by pairwise comparison with Bonferroni correction. Kruskal Wallis test compared groups for failure mode analysis (α=0.05) Results: Super Fine grit showed the highest mean µTBScompared to control for both intermediate agents, IM and after TC at P<0.05. No difference between Fine grit and Laser application for all groups (P>0.05). IM, Bond showed the highest µTBS compared to TC, Flow for all tested groups. Beams roughened with Fine and Super Fine burs showed significantly lower adhesive failures than those roughened with Laser. Flow suffers significantly higher adhesive failure than those with Bond. For TC tested groups; beams with Super Fine bur and Bond showed significantly lower adhesive failure at P=0.029. Conclusion: Super Fine grit and Bond provide the highest µTBS and the least adhesive failure; moreover TC resulted in significant decrease in µTBS (AU)

Objetivo: Comparar o efeito de três protocolos de tratamento de superfície e dois agentes intermediários no reparo de compósito envelhecido, quanto à resistência à microtração (µTBS) e modo de fratura, em dois intervalos de tempo. Material e métodos: Blocos de compósito microhíbrido envelhecidos por seis meses, foram distribuídos aleatoriamente em três grupos, submetidos a; Pontas diamantadas de granulação Fina, Superfina ou tratamento de superfície com laser de Erbio-Yag. Cada bloco tinha ambos os agentes intermediários One Coat bond SL (Adesivo) ao lado de Brilliant Flow (Resina Fluida). Os blocos foram reparados de forma incremental usando compósito nanohíbrido, cortados em palitose, em seguida, submetidos aleatoriamente imediatamente (IM) ao teste de µTBS ou após termociclagem (TC) por 5000 ciclos. O modo de falha foi determinado usando estereomicroscópio. Os dados foram analisados por meio de ANOVA de três fatores, seguida de comparação pareada com correção de Bonferroni. O teste de Kruskal Wallis comparou os grupos para análise do modo de falha (α = 0,05). Resultados: a granulação Super fina apresentou a maior média de µTBS em comparação com o controle para ambos os agentes intermediários, IM e após TC (P <0,05). Não houve diferença entre granulação fina e aplicação de laser para todos os grupos (P> 0,05). IM, Adesivo apresentou a µTBS mais alta em comparação com TC, Resina Fluida para todos os grupos testados. Os palitos asperizados com pontas de granulações Fina e Superfina apresentaram falhas adesivas significativamente menores do que as asperizadas com Laser. Resina Fluida sofreu falhas adesivas significativamente maiores do que aquelas com Adesivo. Para grupos testados TC; palitos tratados com ponta Superfina e Adesivo apresentaram falha adesiva significativamente menor com P = 0,029. Conclusão: a granulação Superfina e o Adesivo fornecem a maior µTBS e o mínimo de falha adesiva; além disso, o TC resultou em uma diminuição significativa da µTBS. (AU)

Chemical constituents of underground parts of Astragalus tatsienensis var. incanus / 中草药

Objective To study the chemical constituents of the underground parts of Astragalus tatsienensis var. incanus. Methods The compounds were separated and purified by RP18, Sephadex LH-20 column chromatography, as well as preparative liquid chromatography. The structures of the isolated compounds were determined by means of modern spectroscopic analysis and physicochemical properties. Results Four compounds were isolated from the methanol extract of the underground part of A. tatsienensis var. incanus, and identified as 3β-O-α-L-rhamnopyranosyl (1→2)-β-D-galactopyranosyl (1→2)-β-D-glucuronopyranosyl- 22β-hydroxy-11-oxo-olean-12-ene (1), hyperoside (2), wighteone (3), and 4-hydroxybenzoic acid (4). Conclusion Compounds 2-4 are isolated from this plant for the first time, and compound 1 is a new triterpene glycosides compound, named astratatincoside A.

The Effect of Multiple Sterilisation Cycles on Cutting Efficiency of a Diamond Bur

@#Introduction: Sterilisation is an essential step in the reprocessing of reusable dental instruments including burs that have become contaminated, or potentially contaminated. Transmission of disease or infection may happen as an effect of improper sterilisation of the reused instruments. Dental burs are one of the essential tools in any conservative dental procedures, which undergo multiple sterilisation cycles before being discarded. However, repeated sterilisation process is associated with the reduction in cutting efficiency of a bur that is potentially due to corrosion. Thus, this study aims to compare the effect of two sterilisation methods on cutting efficiency of a diamond bur that is commonly used in dental procedures. Methods: 30 fissure diamond burs were randomly divided into three sterilisation groups: Group A (dry heat), B (steam under pressure) and C (control). Each bur was used to cut teeth for 45 seconds for ten cycles. Between cuts, the burs underwent sterilisation based on their sterilisation groups. Amount of cutting weight was measured after each cut. Results: This study shows that no significant difference (p>0.05) in the cutting efficiency of the burs following sterilisation of Groups A and B. However, there is a significant mean difference (p<0.05) of cutting efficiency between burs in Groups A, B, and C. Conclusion: Multiple sterilisation cycles is one of the factors that contribute to the cutting ability and effectiveness of a bur. However, there is no significant difference between dry heat and steam under pressure sterilisation methods toward the cutting efficiency of a bur.

What is the changing frequency of diamond burs?

PURPOSE: The purpose of this study was to determine the changing frequency of a diamond bur after multiple usages on 3 different surfaces. MATERIALS AND METHODS: Human premolar teeth (N = 26), disc shaped direct metal laser sintered CoCr (N = 3) and zirconia specimens (N = 3) were used in this study. Groups named basically as Group T for teeth, Group M for CoCr, and Group Z for zirconia. Round tapered black-band diamond bur was used. The specimens were randomly divided into three groups and placed with a special assembly onto the surveyor. 1, 5, and 10 preparation protocols were performed to the first, second, and third sub-groups, respectively. The subgroups were named according to preparation numbers (1, 5, 10). The mentioned bur of each group was then used at another horizontal preparation on a new tooth sample. The same procedure was used for CoCr and zirconia disc specimens. All of the bur surfaces were evaluated using roughness analysis. Then, horizontal tooth preparation surfaces were examined under both stereomicroscope and SEM. The depth maps of tooth surfaces were also obtained from digital stereomicroscopic images. The results were statistically analyzed using One-Way ANOVA, and the Tukey HSD post-hoc tests (α=.05). RESULTS: All of the groups were significantly different from the control group (P < .001). There was no significant difference between groups Z5 and Z10 (P=.928). Significant differences were found among groups T5, M5, and Z5 (P < .001). CONCLUSION: Diamond burs wear after multiple use and they should be changed after 5 teeth preparations at most. A diamond bur should not be used for teeth preparation after try-in procedures of metal or zirconia substructures.

Study of the relationships between bur diameter and dental implant diameter / Estudio de las relaciones entre diámetro de fresas y diámetro de implantes dentales

The bur used to construct the bed where a dental implant is installed is extremely important to treatment success. The aim of this investigation was to analyze the relationship between bur diameter and implant diameter in different areas. A descriptive study was designed to analyze 5 commercial brands currently on the market. The manufacturer's instructions were followed to establish the size and type of bur indicated for the study implants, which were regular, with a width between 3.5 mm and 4.0 mm and a length from 12 mm to 13 mm. Drilling from the most apical region, the first measurement of width was established 3 mm cervically, the lower middle measurement 6 mm cervically, the upper middle measurement at 9 mm and the cervical measurement at 12 mm. A scanning electron microscope was used standardized for all measurements; the data were analyzed using the Shapiro-Wilk test and the t-test, having considering a value of p<0.05 for significant differences. At apical level, all the implants were wider than the bur. The greatest differences between bur width and implant were observed at cervical level, maintaining a relation where the implant was always wider. In medium-sized areas, it was observed that in some systems the burs have a larger diameter than the study implants. A significant relation was established in the apical, upper middle and cervical areas. Bur morphology is related to implant morphology; no implant system is the same as another in terms of the implant-bur relation.

La relación entre la fresa utilizada para construir el lecho donde se instala el implante dental tiene alta importancia en el éxito del tratamiento. El objetivo de esta investigación fue analizar la relación entre el diámetro de fresa y el diámetro de implantes en diferentes áreas. Se diseñó un estudio descriptivo analizando utilizando 5 marcas comerciales vigentes en el mercado; se siguió las instrucciones del fabricante para establecer el tamaño y tipo de fresa indicada para el implante en análisis, los cuales fueron de tipo regular considerando medidas en ancho de entre 3,5 mm y 4,0 mm y en largo de 12 mm a 13 mm. Desde la región mas apical de implantes y fresar se estableció 3 mm hacia cervical la primera medición de ancho, 6 mm hacia cervical la medición media inferior, a 9 mm la medición media superior y a 12 mm la medición cervical; para esta medición se utilizó microscopio electrónico de barrido estandarizado para todas las mediciones; los datos fueron analizados con pruebas estadísticas de Shapiro-Wilk y la prueba t-test, considerando un valor de p<0,05 para considerar diferencias significativas. A nivel apical, todos los implantes fueron mas anchos que las fresas utilizadas. A nivel cervical es donde se observan las mayores diferencias entre el ancho de la fresa y del implante manteniendo una relación donde el implante siempre es mas ancho. En áreas medianas, se observó que en algunos sistemas las fresas son de mayor diametro a los implantes analizados. Se estableció relación significativa en las regiones apical, media superior y cervical. La morfología de fresas presenta relación con la morfología implantaría; ningún sistema de implantes es igual a otro en términos de relación implante y fresa.

Chemical constituents of Ajuga ovalifolia var. calantha / 中草药

Objective To investigate the chemical constituents of Ajuga ovalifolia var. calantha. Methods The 95% ethanol extract from the whole herb of A. ovalifolia var. calantha was separated and purified by column chromatography over silica gel, Sephadex LH-20, ODS, and RP-HPLC. Their chemical structures were identified on the basis of physicochemical characteristics and spectral analyses. Results Thirteen compounds were isolated and identified as (16S)-12,16-epoxy-11,14-dihydroxy-17 (15→16)-abeo-abieta- 8,11,13-trien-7-one (1), ajuforrestin B (2), ajudecumin A (3), 14,15-dihydroajugapitin (4), cyasterone (5), β-sitosterol (6), acacetin (7), apigenin (8), luteolin (9), scopoletin (10), isoscopoletin (11), 4-hydroxy-3-methoxy-benzaldehyde (12), and acetovanillon (13). Conclusion Compounds 1 and 10-13 are reported from the genus Ajuga Linn., and compounds 2-5 and 7 are isolated from this plant for the first time. Single crystal X-ray diffraction experiment is carried out for compound 1, and the crystal structure data of single crystal X-ray diffraction of compound 1 is obtained for the first time.

Chemical constituents from Incarvillea delavayi / 中草药

Objective: To investigate the chemical constituents from the whole plant of Incarvillea delavayi. Methods: The whole plant of I. delavayi was extracted by 90% ethanol. Various chromatography methods were employed to separate the chemical constituents, and the structures were identified by comprehensive spectroscopic analysis. Results: Fourteen compounds, including cyclohexanethanoids, monoterpene alkaloids, and triterpenoids, were obtained from the 90% ethanol extract of I. delavayi. Their structures were identified as 5-hydroxyethyl-6-hydroxyl-3-methyl benzofuran (1), cleroindicin B (2), 3,4,5-trimethoxyl benzoic acid ethyl ester (3), 3,4,5-trimethoxyl benzoic acid methyl ester (4), 6-hydroxyl dihydrobenzofuran (5), 2-(4'-ethoxyphenyl)-ethanol (6), tecomine (7), (+)-epidihydrotecomanine (8), 5-hydroxy skytanthine (9), δ-skytanthine (10), isoincarvilline (11), mairine B (12), coelobillardierine (13), and 3β-acetyl oleanolic acid (14). Conclusion: Compound 1 is identified as new compound and named as delavayol A, while compounds 3-6, 9-11, and 13 are isolated from the titled plant for the first time.

Evaluación de un nuevo método de remoción quirúrgica de implantes oseointegrados considerados en fallo / Evaluation of a new surgical removal method of failed integrated implants

OBJETIVO El objetivo del presente estudio descriptivo es la valoración de un nuevo método de remoción de implantes oseointegrados bajo una técnica mínimamente invasiva. MATERIALES Y MÉTODOS El estudio fue desarrollado sobre un grupo de 66 implantes oseointegrados de conexión interna y externa diagnosticados en falla, a los cuales se les indicó su remoción quirúrgica por presentar un diagnóstico radiográfico de pérdida ósea periimplantaria, mal posicionamiento quirúrgico con imposibilidad de rehabilitación protésica o daño del elemento de retención protésico del implante. El procedimiento quirúrgico, el cual es de carácter ambulatorio, fue llevado a cabo en un pabellón bajo anestesia local. Como primera opción de remoción quirúrgica, el procedimiento consistió en la utilización de instrumental de remoción a contra-torque, sin la apertura de un colgajo de espesor total, y como segunda opción de remoción quirúrgica la utilización de una fresa trefina, para lo cual fue necesario realizar un colgajo de espesor total que expusiera el lecho implantario. RESULTADOS Se removieron un total de 66 implantes oseointegrados, todos bajo la primera modalidad de remoción a contra-torque con el nuevo instrumento, sin colgajo y sin la necesidad de usar fresa trefina. CONCLUSIONES Con las limitaciones de este estudio preliminar planteamos que la utilización del nuevo instrumento de remoción a contra-torque de implantes oseointegrados en fallo se vislumbra como una muy buena alternativa de remoción quirúrgica mínimamente invasiva, disminuyendo los riesgos quirúrgicos del uso de una fresa trefina, el daño a los tejidos aledaños.

OBJECTIVE The aim of this study is the evaluation of a new removal method of osseointegrated implants under a minimally invasive technique. MATERIALS AND METHODS The study was conducted on a group of 66 osseointegrated internal and external connection implants that were considered unsuccesful. The surgical removal was indicated after radiologically confirming peri-implant bone loss, and poor positioning which made the prosthetic rehabilitation impossible, or would damage the prosthetic implant retainer. The surgical procedure was developed in an operating room under local anesthesia. As first surgical removal option, the procedure consisted of the use of a removal instrument that works against torque and which does not need a full thickness flap to reach the surgical site; and as a second surgical removal option a trephine bur was used. For this option, a full thickness flap was performed in order to expose the surgical site. RESULTS A total of 66 osseointegrated implants were removed under the first mode, with no full thickness flaps or Trephine burs required. CONCLUSIONS Within the limitations of this preliminary study, we propose that the use of this new, against torque, removal instrument of osseointegrated implants in failure is seen as a very good alternative to invasive surgical removal techniques, reducing surgical risks.

Evaluation of shear bond strength with different enamel pretreatments: An in vitro study.

Context: Bonding procedures are time consuming and debonding of brackets is a common problem encountered in orthodontics. Aims: The purpose of this in vitro study was to evaluate the shear bond strength (SBS) with different enamel pretreatment (acid etching, air abrasion, and bur abrasion) to enhance the bonding performance. Subjects and Methods: A total of 60 extracted premolars for orthodontic purposes were randomly assigned to three groups based on conditioning method: Group I ‑ conventional etching with 37% phosphoric acid; Group II ‑ air abrasion with 50 μm aluminum oxide; and Group III ‑ bur abrasion with diamond fissure (#330, MANI, Dia‑Burs, New Jersey, USA). After storing the specimens for 24 h in distilled water at 37°C, SBS was measured with Universal testing machine (Lloyd Universal testing machine‑Model No. L.R 100K, UK). The shear force at a crosshead speed of 1 mm/min was transmitted to brackets. The adhesive remnant index (ARIs) scores were recorded after bracket failure. Statistical Analysis Used: Descriptive statistics, multiple comparisons of the SBS of different groups, were performed by analysis of variance. The Tukey’s test was used to evaluate differences in ARI scores between groups. All statistical evaluations were calculated using the Statistical Package for Social Sciences Windows, release 10.0.0 (SPSS Inc., Chicago, Illinois, USA). Results: The analysis of SBS variance (P < 0.01) and Chi‑square test of ARIs scores (P < 0.01) revealed significant differences among three groups tested. The SBS in Group I (mean: 8.822 ± 0.92 MPa) and Group III (mean: 6.015 ± 0.87 MPa) was significantly higher than Group II (mean: 3.824 ± 0.57 MPa). The ARI was used to evaluate the residual adhesive on the enamel after bracket removal. The Tukey’s test was used to evaluate differences in the ARI scores among the groups. Conclusions: The current findings indicate that enamel surface preparation using bur abrasion results in a significant higher than air abrasion; within the limitations of this study recommend bur abrasion as a viable alternative to acid etching.

Enamel pretreatment with Er:YAG laser: effects on the microleakage of fissure sealant in fluorosed teeth

OBJECTIVES: The purpose of this in vitro study was to evaluate the microleakage and penetration of fissure sealant in permanent molar teeth with fluorosis after pretreatment of the occlusal surface. MATERIALS AND METHODS: A total of 120 third molars with mild dental fluorosis were randomly divided into 6 groups (n = 20). The tooth surfaces were sealed with an unfilled resin fissure sealant (FS) material. The experimental groups included: 1) phosphoric acid etching (AE) + FS (control); 2) AE + One-Step Plus (OS, Bisco) + FS; 3) bur + AE + FS; 4) bur + AE + OS + FS; 5) Er:YAG laser + AE + FS; and 6) Er:YAG laser + AE + OS + FS. After thermocycling, the teeth were immersed in 0.5% fuchsin and sectioned. Proportions of mircoleakage (PM) and unfilled area (PUA) were measured by digital microscope. RESULTS: Overall, there were significant differences among all groups in the PM (p = 0.00). Group 3 showed the greatest PM, and was significantly different from groups 2 to 6 (p < 0.05). Group 6 showed the lowest PM. Pretreatment with Er:YAG with or without adhesive led to less PM than bur pretreatment. There were no significant differences among groups in PUA. CONCLUSIONS: Conventional acid etching provided a similar degree of occlusal seal in teeth with fluorosis compared to those pretreated with a bur or Er:YAG laser. Pretreatment of pits and fissures with Er:YAG in teeth with fluorosis may be an alternative method before fissure sealant application.

Influência do modelo e marca de ponta diamantada na resistência flexural / Influence of model and brand of diamond bur in flexural strength

Introdução: As pontas diamantadas são instrumentos rotatórios abrasivos utilizados principalmente na odontologia restauradora para realização de preparos dentários e acabamentos de restaurações. Estes instrumentos são formados por uma haste metálica, eixo intermediário e ponta ativa. Objetivo: Mensurar a resistência flexural da haste e intermediário de pontas diamantadas de seis marcas comerciais diferentes disponíveis no mercado brasileiro. Materiais e Métodos: utilizou- se 60 pontas diamantadas, sendo 30 pontas 2200 (n=5) e 30 pontas 2130 (n=5), das marcas KG Sorensen, Option, Microdont, FAVA, Zeep, Vortex. Os instrumentos rotatórios foram posicionados em dispositivo que permitiu que suas extremidades fossem apoiadas sobre bases metálicas; submetidas à Máquina Universal de Ensaio (EMIC), para mensurara força máxima aplicada em um deslocamento de 3 mm. Para o padrão de falha, verificou-se se as pontas sofreram dobras ou fraturas totais. Resultado: os instrumentos rotatórios da marca KG Sorensen destacaram-se em todos os testes, apresentando elevados valores de resistência flexural tanto para haste quanto para intermediário; não apresentando nenhuma falha do tipo fratura total. A marca Option apresentou o maior índice de instrumentos com falha do tipo fratura total.Conclusão: não existe padronização da resistência flexural entre as marcas comercias, sendo que a utilização de instrumentos com baixa resistência pode ocasionar maiores taxas de falha, danificando o equipamento ou causar injurias aos tecidos do paciente.

Introduction: The diamond burs are rotary abrasives instruments primarily used in restorative dentistry to perform dental preparations and finishing restorations. These instruments consist of shank, intermediate shaft and head. Objective: To measure the flexural strength of the shank and intermediate shaft diamond burs of six different commercial brands available in the Brazilian market. Methods: 60 diamond burs, 30 burs 2200(n = 5) and 30 burs 2135 (n = 5), of brands KG Sorensen, Option, Microdont, FAVA, Zeep, Vortex were used. The rotary instruments were placed in the device that allowed its ends were supportedon metal bases; submitted to Universal Testing Machine (EMIC), to measure the maximum force applied a displacement of 3mm. For the standard fault, it was found that the burs suffered bends or total fractures. Results: It was observed that the rotary instruments KG Sorensen, stood out all tests, showing high values of flexural strength for shank and intermediate shaft; showing no fault of type fracture total. Option had the highestrate of failure type instruments with total fracture. Conclusion: There is no standardization between the flexural trademarks, and the use of instruments with low resistance may cause higher rates of failure, damaging the equipment or cause injuries to the tissues of the patient.

Influence of ultrasound and diamond burs treatments on microtensile bond strength.

Objective: To compare surface treatments with CVDentUS ® ultrasound tips (UT) and KGSorensen ® diamond burs (DB) on etched (e) and non-etched (n/e) dentin. The microtensile bond strength (μTBS) was measured and fractography was assessed by scanning electron microscope (SEM). Materials and Methods: Sixteen molars were divided into four groups of four teeth each according to treatment (DB-n/e; DB-e; UT-n/e; UT-e). The teeth were restored, sectioned into samples for μTBS (n=40) and tested on a EMIC DL-2000 universal machine (0.5 mm/min) and analyzed by SEM for fracture classification. Statistical Analysis: For analysis of the data on μTBS, the two-way ANOVA, using treatment and acid etching as fixed factor, and the Tukey test were used (α=0.05). To failures classification in cohesive in dentin (CD); cohesive in composite resin (CC); cohesive interfacial on base or top of hybrid layer (CBT); cohesive in adhesive (CA); mixed (M); interfacial on smear layer (S) the Fisher's exact test (α=0.05) was performed. Results: The mean values of μTBS (in MPa) in the different groups were as follows: UT-e: 45.31±8.16; DB-e: 34.04±9.29; UT-n/e: 15.17±3.71; and DB-n/e: 9.86±3.80. On analysis of the SEM micrographs, the DB-n/e group showed total obstruction of dentinal tubules; the UT-n/e group showed partial desobstruction of dentinal tubules and irregular surface; the DB-e group showed complete desobstruction of dentinal tubules; and the UT-e group showed complete desobstruction of dentinal tubules and irregular surface. Conclusion: The combination of ultrasound treatment and acid etching provides high values of μTBS. An association exists between CA/CC failures and the UT method, CBT failure and the DB method, CBT/CC failures and etching, S failure and non-etching.

A comparison of root surface instrumentation using manual, ultrasonic and rotary instruments: An in vitro study using scanning electron microscopy.

Background: The commonly accepted idea concerning root planing is that excessive removal of cementum is not necessary for removal of endotoxins. The ideal instrument should enable the removal of all extraneous substances from the root surfaces, without causing any iatrogenic effects. Aim: To compare the remaining calculus, loss of tooth substance, and roughness of root surface after root planing with Gracey curette, ultrasonic instrument (Slimline® insert FSI-SLI-10S), and DesmoClean® rotary bur. Materials and Methods: The efficiency of calculus removal, the amount of lost tooth substance, and root surface roughness resulting from the use of hand curette, ultrasonic instrument, and rotary bur on 36 extracted mandibular incisors were examined by SEM. We used three indices to measure the changes: Remaining calculus index (RCI), Loss of tooth substance index (LTSI), and Roughness loss of tooth substance index (RLTSI). Twelve samples were treated with each instrument. The time required for instrumentation was also noted. Statistical Analysis: Kruskal-Wallis ANOVA was used for multiple group comparisons and the Mann-Whitney test for group-wise comparisons. Analysis was carried out with SPSS® software (version 13). Results and Conclusion: The RCI and LTSI showed nonsignificant differences between the three groups. RLTSI showed a significant difference between Slimline™ and hand curette as well as Slimline™ and Desmo-Clean™. Slimline™ showed the least mean scores for RCI, LTSI, and RLTSI. Thus, even though the difference was not statistically significant, Slimline™ insert was shown to be better than the other methods as assessed by the indices scores and the instrumentation time.

Phenols in Rhododendron primulaeflorum Bur. et Franch / 中国药学杂志

OBJECTIVE: To study the phenols in the young branches and leaves of Rhododendron primulaeflorum Bur. et Franch. METHODS: The constituents were separated and purified by chromatographic methods, and their structures were elucidated by spectroscopic methods and chemical analyses. RESULTS: Eight known phenol compounds, cannabichromeorcinic acid(1), methylorsellinate(2), orsellinic acid(3), orcinol-O-β-D-glucopyranoside(4), 2, 6-dimethoxy-4-hydroxyphenyl-1-O-β-D-glucopyranoside(5), lyoniside(6), 4, 6-dihydroxy-2-O-(β-D-glucopyran-osyl) acetophenone(7) and 3, 5-dihydroxy-4-O-(β-D-glucopyranosyl) acetophenone(8) were isolated from the plant. CONCLUSION: All of the compounds except compound 2 were isolated from this plant for the first time. Copyright 2012 by the Chinese Pharmaceutical Association.

Técnica pessoal para obtenção de enxertos ósseos cranianos / Personal technique to harvest skull bone grafts

O objetivo deste artigo foi relatar o desenvolvimento de técnica pessoal para obtenção de enxerto ósseo da calota craniana e divulgá-la entre os neurocirurgiões brasileiros. Essa técnica foi empregada em 101 pacientes que apresentavam necessidade de reconstrução óssea da maxila e/ou da mandíbula. A técnica apresenta o diferencial de determinação da profundidade do crânio por meio de trepanações parciais realizadas na região anterior e posterior do osso parietal para, posteriormente, realizar a remoção do enxerto. Como conclusão, a técnica mostra-se segura e eficiente e pode ser aplicada a qualquer paciente que necessita de cirurgia reconstrutiva.

The objective of this paper was to report the development of personal technique to harvest skull bone graft and spread it to Brazilian neurosurgeons. This technique was used in 101 patients who needed reconstructive surgery prior dental implants. The technique presents like differentiate the clinical determination of thickness of cranium prior the osteotomy. This technique, like conclusion, is safe and efficient and can be applied in any reconstructive surgery.

An experimental study of cutting efficiency of air-driven diamond burs on human tooth / 대한치과보철학회지

PURPOSE: The purpose of this study was to investigate the cutting efficiency of coarse grit diamond burs with air-turbine handpiece on natural tooth. MATERIALS AND METHODS: Four groups of coarse grit diamond bur were selected: Komet (A), Shofu (B), Premier (C), and Mani (D). The extracted maxillary central incisors were used, and ten cuts were made on each specimen, using the rotary diamond burs. The surface of each bur was measured at the upper, middle, and bottom of the bur with confocal laser scanning microscope and imaged with SEM. The data were analyzed with one-way ANOVA and t-test at the significance level of 0.05. RESULTS: The surface roughness was measured. At the A diamond bur, the Sa values were 52.93 microm, 48.32 microm, 46.79 microm, 45.06 microm, and 43.43 microm for control, test 1, 2, 3, and 4 respectively. The Sa values were 50.68 microm, 45.62 microm, 44.41 microm, 44.10 microm, and 42.46 microm for B diamond bur, 58.02 microm, 55.53 microm, 52.22 microm, 48.26 microm, and 45.36 microm for C diamond bur, and 50.11 microm, 46.73 microm, 45.46 microm, 42.58 microm, and 41.80 microm for D diamond bur. Surface roughness after each bur use showed significant changes, but no significant difference was found in surface roughness change between bur systems. CONCLUSIONS: Surface roughness in the same bur system showed significant differences after each tooth preparation. However no statistically significant differences were found in surface roughness between bur systems. The SEM images between control and test 4 showed the abraded particles.

Microshear bond strength of a self-etching primer adhesive to enamel according to the type of bur / 대한치과보존학회지

OBJECTIVES: The purpose of this study was to compare the microshear bond strength (uSBS) to enamel prepared with different burs and to determine what type of bur were chosen when a self-etching primer adhesive was used. MATERIALS AND METHODS: Enamel of forty-two human molars were used. They were divided into one of six groups (n = 7), Group 1, coarse (125 - 150 microm) diamond bur; Group 2, standard (106 - 125 microm) diamond bur; Group 3, fine (53 - 63 microm) diamond bur; Group 4, extrafine (20 - 30 microm) diamond bur; Group 5, plain-cut carbide bur (no. 245); Group 6, cross-cut carbide bur (no. 557). Clearfil SE Bond and Clearfil AP-X (Kuraray Medical Inc.) was bonded to enamel surface. The bonded specimens were subjected to uSBS testing. RESULTS: The uSBS of Group 4 was the highest among groups and it was significantly higher than that of Groups 1, 2, 3, and 6 (p < 0.05), but it was not significantly different from that of Group 5. CONCLUSIONS: Different burs used on enamel surface affected the microshear bond strengths of a self-etching primer adhesive to the enamel surface. In the case of Clearfil SE Bond, extrafine diamond and plain-cut carbide bur are recommended for bonding to enamel.

Anterior cervical decompression technique via intervertebral space under microscope / 第二军医大学学报

Objective To discuss the technique of the anterior cervical decompression via intervertebral space under microscope. Methods A total of 271 patients with cervical disc herniation underwent anterior microsurgical decompression and intervertebral fusion from Jun. 2000.6 to Dec. 2005. The patients included 178 cases with single level herniation, 71 with double level ones, and 22 with three level ones. MRI images showed slight or medium anterior compression with slight abnormal changes within spinal cord in all cases. The main equipment included operation microscope for neurosurgery and high speed bur. The annular fibrous and osteophytes were removed by high speed bur to expose and clean the degenerative nucleus pulpous. We lifted the posterior longitudinal ligament (PLL) with tension using a hook-like stripper and cut it; then the residual PLL and posterior bony edges were removed. Results There were no severe complications such as injuries of the spinal cord, nerve root or blood vessels. The average intraoperative blood loss was (126 + 29. 4) ml and the mean operative time was (62+12. 4) min. The average time for the patients to get off bed was (1. 8 + 0. 4) days. The nerve functions were improved in all patients after operation, with the excellent nerve function found in 69 cases, good in 157 cases, fair in 27 cases, and poor in 18 cases according to JOA scores. Conclusion Anterior cervical decompression via intervertebral space under microscope is suitable for treatment of pathological changes of the intervertebral space; delicate manipulation under microscope and high speed bur can contribute to a successful operation; and the anatomy of intervertebral space is more suitable for the biomechanics of the cervical vertebrate.

Comparison of new bone forming activity after osteotomy using Er:YAG laser and conventional bur in rabbit mandible