Tooth sectioning for coronectomy: how to perform?

OBJECTIVES: The aim of this study was to determine the increase in heat production, preparation time, and cutting surface quality of conventional, high-speed rotating instruments and piezoelectric preparation for coronectomy procedures. MATERIALS AND METHODS: One hundred intact extracted molars were sectioned horizontally, sub-totally, 1 mm under the cemento-enamel line with five methods: (1) tungsten carbide torpedo (TcT), (2) round (TcR) drills using a conventional speed surgical straight handpiece (< 40,000 min-1), (3) tungsten carbide fissure (TcF), (4) diamond torpedo (DT) drills using a surgical high-speed, contra-angle handpiece (~ 120,000 min-1), or (5) a saw-like piezoelectric tip (PT). Temperatures, preparation times, and cutting surface irregularities were registered and the differences were analyzed with ANOVA, Tukey's HSD post hoc test (temperature, time) and with chi-square test (irregular surface). RESULTS: Rotating instruments produced a maximal temperature increase of less than 1 °C. TcF produced the least heat (ΔT = - 3.92 °C to the baseline), while PT produced significantly the highest temperature increases (ΔT = 12.38 °C, p < 0.001). Tungsten carbide drills were the fastest for coronectomy (from 55.9 to 64.3 s), while DT (169.7 s) while PT (146.8 s) were significantly slower. TcT and TcR drills produced an irregular root surface more frequently. CONCLUSIONS: During coronectomy, rotating instruments produced entirely acceptable heat, while PT produced unacceptable temperatures. Tungsten carbide drills performed coronectomies effectively, but the diamond torpedo and PT seemed clinically questionable. Considering heat, speed, and the cutting surface quality simultaneously, TcF in a surgical high-speed handpiece seems to be the best choice for coronectomy. CLINICAL RELEVANCE: The correct insert can significantly reduce excessive heat and operation time during coronectomy procedures.

Ensaio clínico randomizado e cruzado entre a piezocirurgia e a técnica convencional rotatória para a exodontia de terceiros molares inferiores / Randomized crossover clinical trial between piezocirurgia and conventional technique for inferior third molar extraction

A exodontia de terceiros molares inclusos produz um grau significativo de traumatismo para os tecidos moles e estruturas ósseas da cavidade oral, consequentemente resultando em uma reação inflamatória. Esta reação gera diversos sinais e sintomas clínicos pós operatórios como: dor, edema e limitação de abertura bucal que fazem parte da resposta inflamatória reparadora, mas que se exacerbada pode levar a grandes desconfortos. O objetivo do presente estudo foi verificar comparativamente a piezocirurgia e a técnica convencional rotatória quanto a variabilidade dos principais parâmetros clínicos, sistêmicos e locais, no pré, trans e no pós operatório da exodontias de terceiros molares inferiores. Foi realizado um estudo clínico randomizado, cruzado em 20 pacientes saudáveis com necessidade de exodontia de terceiros molares inclusos e/ou impactados bilateralmente de mesma dificuldade cirúrgica. O lado a ser operado foi alocado randomicamente para técnica ultrassônica ou rotatória. Foram analisadas as alterações hemodinâmicas, pressão arterial, frequência cardíaca e saturação de oxigênio pré, trans e pós operatórias. Os desfechos locais foram coletados no dia do procedimento e 24 horas após a cirurgia, nesse contexto foi investigada a máxima abertura bucal em milímetros e o edema facial em pontos anatômicos pré estabelecidos. A análise de dor foi registrada pelo próprio paciente por meio da escala visual analógica em ficha padronizada, assim como a quantidade de analgésicos consumida e os níveis de ansiedade. Os resultados mostraram que o tempo trans operatório pelo uso da piezocirurgia foi maior. Não houve grande variabilidade nos parâmetros hemodinâmicos. A técnica ultrassônica provocou limitação de abertura de boca semelhante à técnica convencional. Gerou menor edema pós operatório em uma das dimensões lineares. Não promoveu níveis menores de dor pós operatória, além disso pode aumentar o grau de ansiedade do paciente. Concluímos que para as osteotomias nas exodontias de terceiros molares inferiores, a piezocirurgia mostrou ser comparável a técnica convencional. O emprego de uma ou outra técnica deve ser uma opção pessoal do cirurgião.

Evaluación de la calidad de las obturaciones endodónticas realizadas por estudiantes de posgrado, en molares superiores, con técnicas de instrumentación manual y rotatoria / Evaluation of the quality of root canal fillings made bypostgraduate students in upper molars with manualand rotary instrumentation techniques

Objetivo: el objetivo de este estudio fue evaluar la calidad de las obturaciones endodónticas en molares superiores instrumentados con técnicas manuales y rotatorias, por estudiantes de posgrado. Materiales y métodos: para este estudio, se analizaron las radiografías de endodoncias que fueron realizadas durante un año por alumnos de un curso de posgrado en endodoncia, en primeros y segundos molares superiores, con ténicas de instrumentación manual y rotatoria y posteriormente obturadas con técnica de condensación lateral. Se analizó la calidad de las obturaciones endodónticas en función de la longitud y la homogeneidad de la masa de gutapercha. Resultados: el 53,6 por ciento de las obturaciones estaba dentro de los límites del conducto radicular y en el 65,2 por ciento de los casos, la homogeneidad fue incorrecta. En cuanto a la longitud, no se verificaron diferencias estadísticamente significativas entre las técnicas, como ocurrió con la homogeneidad (p<0,05). La frecuencia de inadecuados en ewsta última fue mayor para la técnica manual. La mayor cantidad de fallas en la obturación se registró en el conducto mesiovestibular. Conclusión: la calidad de las obturaciones no depende de la técnica de instrumentación empleada, sino de la experiencia del profesional interviniente y del tipo de conducto radicular tratado.(AU)

Aim: the aim of this study was to evaluate the quality ofendodontic fillings in upper molars instrumented with manualand rotary techniques by posgraduate students.Materials and methods: Radiographs of first and secondupper molars root canal treatments performed by studentsof a posgraduate endodontic course during a year wereanalyzed. Either manual or rotary instrumentation techniqueswere used and obturation was carried out using lateral condensation.Quality of endodontic obturation was analyzed accordingto length and homogeneity.Results: There were acceptable lengths of root canalfillings in 53.6% and homogeneity was incorrect in 65.2% ofthe cases. There was no statistically significance difference betweentechniques for the case of length, but there were statisticallysignificance difference for homogenity (p>0.05). Moredefective obturations were registered in the mesiobuccal canal.Conclusion: Independent of the instrumentation technique,the quality of root fillings is inherent to the professionalexperience and the type of root canal treated.

Fracture Forces of Dentin after Surface Treatment with High Speed Drill Compared to Er:YAG and Er,Cr:YSGG Laser Irradiation.

Dental tooth restorative procedures may weaken the structural integrity of the tooth, with the possibility of leading to fracture. In this study we present findings of coronal dentin strength after different techniques of surface modification. The fracture strength of dentin beams after superficial material removal with a fine diamond bur high speed drill hand piece, Er:YAG (2.94 µm, 8 J/cm(2)), and Er,Cr:YSGG (2.78 µm, 7.8 J/cm(2)) laser irradiation slightly above the ablation threshold was measured by a four-point bending apparatus. Untreated dentin beams served as a control. A total of 58 dentin beams were manufactured from sterilized human extracted molars using the coronal part of the available dentin. Mean values of fracture strength were calculated as 82.0 ± 27.3 MPa for the control group (n = 10), 104.5 ± 26.3 MPa for high speed drill treatment (n = 10), 96.1 ± 28.1 MPa for Er,Cr:YSGG laser irradiation (n = 20), and 89.1 ± 36.3 MPa for Er:YAG laser irradiation (n = 18). Independent Student's t-tests showed no significant difference between each two groups (p > 0.05). Within the parameter settings and the limits of the experimental setup used in this study, both lasers systems as well as the high speed drill do not significantly weaken coronal dentin after surface treatment.

Cross sectional: use of coolant for high-speed tooth preparation: a survey of pediatric dentist members of the American Academy of Pediatric Dentistry.

PURPOSE: To report the findings of a survey to determine the educational experiences, opinions and clinical practices relative to the use of coolant during cavity preparation of pediatric dentist members of the American Academy of Pediatric Dentistry (AAPD) and to determine whether teaching policies influenced the type of coolant used in private practice. METHODS: Four thousand fifty surveys were emailed to AAPD members and included questions regarding demographics and predoctoral, graduate, and current practice policies for the use of dry cutting. RESULTS: Returned survey numbered 1730 for a response rate of 43%. Fifteen percent were taught the concept of dry cutting in their predoctoral programs and 34% in their specialty, programs. Sixty percent never or rarely prepare teeth without water coolant. Slightly more than 40% prepared teeth with air coolant alone. Patient behavior (25%) and sedation (21%) were reported as determining factors for cutting dry. Thirty-one percent of private practice clinicians and 34% of part time academics use dry cutting, while only 15% of full time academicians use the technique (P<0.0001). CONCLUSIONS: Respondents tend to use the technique they were taught during their residency. Use of dry cutting was more likely to be utilized during sedations or general anesthesia to avoid airway compromise.

Comparative study of the cutting efficiency and working life of carbide burs.

PURPOSE: The aim of this study was to establish the wear and cutting efficiency of tungsten carbide burs from different manufacturers by performing cutting tests with machinable glass ceramic. MATERIALS AND METHODS: Cutting tests were performed with 70 tungsten carbide burs from seven manufacturers: (A) Coltene/Whaledent, (B) CEI, (C) Meisinger, (D) Axis, (E) Komet, (F) Kerr, (G) Edenta. All groups were examined under scanning electron microscope (SEM) before and after the cutting efficiency test for similarities and differences. A specially designed cutting device was used. An electric handpiece was operated at 200,000 rpm with a 120 ml/min coolant water supply rate. The burs were tested under a 165 g constant load using 3 mm wide Macor ceramic as substrate. For each bur the cutting procedure involved a total of five cuts of 3 minutes on every cut, with a total cutting time for each bur of 15 minutes. Data were analyzed using one-way ANOVA at 95.0% confidence level. RESULTS: Significant differences (p < 0.05) were found in the mean cutting rates of the different groups. Groups A and B showed the highest cutting rates. Higher cutting rates were associated with a longer bur lifespan. SEM photomicrographs of the burs and substrates revealed significant changes on the surfaces after the cutting process. CONCLUSIONS: The morphology characteristics of tungsten carbide burs are related to their effectiveness. The group that presented the worst working life also showed substantial wear on its surface according to the results of SEM.

Comparação da resistência à fadiga por torção das limas de níquel-titânio PathFile com outras limas pequenas de conicidade de 0, 02mm / Comparison of the torsional fatigue resistance of PathFile nickel-titanium files with other small 0.02 mm taper files

Esse estudo teve por objetivo comparar a resistência à fadiga por torção das seguintes limas de conicidade de 0,02mm: PathFile #13, #16 e #19; ProFile #15 e #20; K3 #15 e #20; Quantec LX #15 e #20; e Liberator #15 e #20. Métodos: foram testados 11 grupos, com 20 limas cada. As limas foram fixadas a um torcímetro e submetidas a rotação até fraturar. O torque máximo e o grau de rotação antes da fratura foram registrados. Limas com tamanhos de ponta semelhante foram comparadas entre si para identificar diferenças significativas. O teste ANOVA de uma via e o teste post hoc de Tukey foram usados para identificar diferenças estatisticamente significativas (p < 0,05) entre os grupos. Resultados: as limas Liberator #15 e #20 tiveram fraturas ao torque significativamente mais baixas do que todas as outras limas semelhantes, enquanto a PathFile #16 teve fratura ao torque significativamente mais alta do que as limas #15 com as quais foi comparada. Conclusão: os resultados do teste de resistência à fadiga por torção das limas Path File foram comparativamente melhores do que os de outras limas pequenas com conicidade de 0,02mm.

Subcutaneous emphysema to the head and neck resulting from a dental crown preparation.

CASE REPORT: A 59-year-old African-American female presents with subcutaneous emphysema to the head and neck region resulting from routine dental treatment with a high speed air-driven handpiece. The patient had a chief complaint of generalized edema, dysphagia and pain to her face and neck. The patient subsequently was admitted to the intensive care unit for airway monitoring. PURPOSE: To alert the dental community about the incidence of iatrogenic subcutaneous emphysema from a routine dental procedure, and how to recognize and manage its occurrence.

An evaluation of dental operative simulation materials.

The study was to evaluate the performance of different materials used in dental operative simulation and compare them with those of natural teeth. Three typical phantom teeth materials were compared with extracted permanent teeth by a nanoindentation system and evaluated by students and registered dentists on the drilling sensation of the materials. Moreover, the tool life (machinability) of new cylindrical diamond burs on cutting the sample materials was tested and the burs were observed. Although student and dentist evaluations were scattered and inconclusive, it was found that elastic modulus (E) and hardness (H) were not the main factors in determining the drilling sensation of the materials. The sensation of drilling is a reflection of cutting force and power consumption.An ideal material for dental simulation should be able to generate similar drilling resistance to that of natural tooth, which is the machinability of the material.

Predicting in vivo failure of rotary nickel-titanium endodontic instruments under cyclic fatigue.

The aim of this study was to examine the lifespan or number of cycles to failure of tapered rotary nickel-titanium (Ni-Ti) endodontic instruments. Simulated root canals with different curvatures were used to determine a relation between canal curvature and instrument lifespan. Using a novel mathematical model for the deformation of pseudoelastic Ni-Ti alloy, it was shown that maximum stress need not necessarily occur at the outer layer. On the basis of this observation, the Coffin-Manson relation was modified with parameters determined from this experiment. Results showed that the number of cycles to failure was influenced by the angle and radius of canal curvature and the size of instrument at the beginning of canal curvature. The resulting quantitative mathematical relation could be used to predict the lifespan of rotary Ni-Ti endodontic instruments under clinical conditions and thereby reduce the incidence of instrument failure in vivo.

Ultrasonic margin preparation for fixed prosthodontics: a pilot study.

PURPOSE: Atraumatic, oscillating ultrasonic instruments have recently been developed for prosthodontic margin finishing. This in vitro observational pilot study aimed to compare the condition of crown preparation margins finished using new ultrasonic instruments with margins finished with conventional rotary instruments. METHODS: Two extracted human canine teeth were prepared for crowns. A split-tooth model was used to refine the margins: half of the margin was finished with conventional rotary instruments, the other with ultrasonic instruments. The profiles of the margins were observed using scanning electron microscopy, and a quantitative comparison of surface roughness was obtained using surface roughness analysis software. RESULTS: The margins finished with the ultrasonic instruments exhibited a better-defined axial wall/margin angle and a smoother marginal surface. Rotary instruments produced a sharper and more continuous external line angle. Two-dimensional surface roughness analysis showed that the margins produced with the ultrasonic instruments were approximately half as rough as the margins prepared with the conventional rotary instruments. CONCLUSION: The ultrasonic instruments produce margins in better condition than the current standard and appear to have some practical advantages. CLINICAL SIGNIFICANCE: Preparations for fixed prosthodontics finished with these ultrasonic instruments created better-defined margins, which could result in more successful prostheses.

Comparison of different grinding procedures on the flexural strength of zirconia.

STATEMENT OF PROBLEM: The surface of zirconia ceramic is damaged during grinding, which may affect the mechanical properties of the material. PURPOSE: The purpose of this study was to compare the biaxial flexural strength of zirconia after different grinding procedures and to measure the temperature rise from grinding. MATERIAL AND METHODS: Forty disk-shaped zirconia specimens (15 × 1.2 mm) with a smaller disk in the center of each disk (1 × 3 mm) were divided into 4 groups (n=10). The specimens were ground with a high-speed handpiece and micromotor with 2 different grinding protocols, continual grinding and periodic grinding (10 seconds grinding with 10 seconds duration), until the smaller disk was removed. Control specimens without the center disk (n=10) were analyzed without grinding. The biaxial flexural strengths of the disks were determined in a universal testing machine at a crosshead speed of 0.5 mm/min. The fracture strength (MPa) was recorded, and the results were analyzed using a 1-way ANOVA, Tukey HSD test, Student's t test, and Pearson correlation test (α=05). RESULTS: All grinding procedures significantly decreased flexural strength (P<.01). The mean flexural strength of the high-speed handpiece groups was higher (815 MPa) than that of the micromotor groups (718 MPa). The temperature values obtained from micromotor grinding (127°C) were significantly higher than those from high-speed handpiece grinding (63°C) (P<.01). CONCLUSIONS: Grinding zirconia decreased flexural strength. Zirconia material ground with a high-speed handpiece run continually caused the least reduction in flexural strength.

Efecto del laser de baja intensidad en el tejido pulpar durante el movimiento ortodóncico / Effect of low level laser on dental pulp tissue during orthodontic movement

Low level laser application in orthodontics attempts to accelerate the induced orthodontic movement and to dissipate the dental discomfort during treatment. The recognition of its biological foundation is a fundamental issue to understand the effect of all tissues involved in the irradiated zone.There have been research findings on the cell proliferation and empowerment of cell functions, promotion of bone remodeling, and decreasing of the local swelling and pain during orthodontic treatments. However, the positive results of the laser application on cells involved in the orthodontic movement have not widely been investigated.Literature indicates a lack of research finding on the effect of low laser therapy on the dentin-pulp complex, which demands randomized controlled trials. For these reasons, the aim of this paper attempts to compile the main publications done regarding the effect of low level laser therapy on dental pulp tissue...(AU)

La aplicación del laser de baja intensidad en Ortodoncia, busca acelerar el movimiento dental inducido y manejar la sensación dolorosa durante el curso del tratamiento. El conocimiento de su fundamento biológico, es un aspecto fundamental para comprender el efecto de todos los tejidos involucrados en las zonas irradiadas.Se han reportado hallazgos acerca de cambios en las proliferaciones celulares y potencialización de sus funciones, promoción del remodelado óseo, disminución de la inflamación local y alivio del dolor durante los tratamientos de ortodoncia. Sin embargo, los resultados positivos de la aplicación del láser de baja intensidad en las células involucradas en el movimiento ortodóncico no han sido ampliamente investigados. La literatura indica falta de investigaciones acerca del efecto de la terapia láser de baja intensidad en el complejo dentino-pulpar, por tanto se requieren estudios aleatoriamente controlados sobre el tema. El objetivo de esta revisión es recopilar las publicaciones que reportan el efecto del laser de baja intensidad sobre el tejido pulpar...(AU)

Perda de corte da lima protaper quanto a esterilização e número de uso / Analysis the cutting loss of instruments protaper in relation the number of use and effect of sterilization

Objetivo: Este estudo propõe-se avaliar a perda de corte do instrumento rotatório ProTaper® em função do número de uso e esterilização em autoclave. Método: Foram estudados 10 canais simulados de resina acrílica transparente com ângulo de curvatura de 45º, valendo-se de instrumentos Protaper® de numeração S1, S2, F1, F2 e F3, substituindo o Sx pelas brocas de Largo #1. Os blocos foram pesados em balança analítica digital, anotando-se o peso inicial. A seguir, houve o preparo com motor elétrico Endo Pro-Torque® da Driller com reverso automático submetido ao ajuste e controle da velocidade em 350 rpm, torque de 1N, com engate para contra-ângulo modelo Kavo®, tomando-se o cuidado de padronizar o tempo de ação de cada instrumento em 3 minutos. Usou-se o creme de Endo-PTC durante o preparo do canal simulado e após seu tempo de ação, lavava-se o canal com hipoclorito de sódio. Depois, o bloco era lavado com detergente neutro, seco com gaze, canal aspirado, seco com cone de papel absorvente, pesado, anotando-se o peso final. A cada uso as limas rotatórias eram limpas com gaze embebido em álcool e, posteriormente, lavadas com detergente neutro e secas também com gaze e levadas em envelope descartável para processo de esterilização em autoclave com ciclo de 20 minutos. Resultados: Os instrumentos utilizados perderam a sua capacidade de corte em função do número de uso. Conclusão: O instrumento perde a capacidade de corte em função do uso, e só a partir do sé¬timo uso, o instrumento ProTaper® perde consideravelmente sua efetividade, recomendando-se seu descarte

Aims: This investigation aims to evaluate the cutting loss and sterilization of rotary ProTaper® instrument for sterilization process in autoclave. Method: Were studied ten substrate resin simulated canals blocks numbered 1 to 10 with angle of 45º. Before and after instrumentation were used with ProTaper® files numbering S1, S2, F1, F2, F3, is substituting for the Sx Largo drills # 1. These blocks were weighted using an analytical digital scale model Mettler AJ 100 and following it were analyzed of the amount of resin removed in each sample were noted both initial and final weight. The instrumentation was made with Endo-Pro-Torque engine-driven Driller system with automatic reverse and speed control in 350 rpm, torque 1N using stop watch for standardize the 3 minutes time of each instrument. Cream Endo-PTC was used during instrumentation e after that, washing the canals with 5mL the distillate water with plastic syringe. The blocks were washed with detergent, dry with gauze, aspirated canal, dried with paper absorbent points, weighted and noted final weight. In each use the files were clean with gauze alcohol soaked and later washed with detergent and dried with gauze and put in recipient discard able for sterilization in autoclave Sercon model during 20 minutes. Results: The instruments used have lost the cutting ability in relation to the number of use. Conclusions: It?s concluded that occurred a loss of efficiency of the cutting instrument, however the instrument ProTaper loses its cutting ability in use only after the seventh use and thus it?s recommended its discard

Learn-a-prep II as a predictor of psychomotor performance in a restorative dentistry course.

This investigation assessed whether early student performance with a dental handpiece on a didactic training aid known as the Learn-A-Prep II (LAP II) was predictive of performance on subsequent practical examinations in a preclinical restorative dentistry course. Eighty-one first-year students were given initial handpiece training and formative feedback using the LAP II and were then instructed to independently prepare four LAP II patterns within the pattern lines and at a specified depth. Performance on the LAP II was compared with the summative assessment on two subsequent amalgam preparation practical examinations given at the middle (Class II) and end (Complex) of the course. Pattern preparation within the lines did not significantly improve the likelihood of receiving an A or B on the Class II practical (p=0.53) or on the Complex practical (p=0.37). Students who had an acceptable depth on the LAP II were 3.73 times more likely to receive an A or B on the Class II practical than those students who did not have acceptable depth (p=0.03). Performance at an acceptable depth did not significantly improve the likelihood of receiving an A or B on the Complex practical (p=0.15). The LAP II may aid in identification of students who would benefit from early intervention with additional focused instruction.

Heat production during different ultrasonic and conventional osteotomy preparations for dental implants.

OBJECTIVES: The purpose of this study was to evaluate the intraosseous temperature changes during ultrasonic and conventional implant site preparation in vitro with respect to the effect of load and irrigation volume. MATERIAL AND METHODS: Implant sites were prepared using two different ultrasonic devices (Piezosurgery, Mectron Medical Technology and VarioSurg, NSK) and one conventional device (Straumann) at loads of 5, 8, 15 and 20 N and with irrigation volumes of 20, 50 and 80 ml/min. During implant site preparation, temperatures were measured in fresh, equally tempered bovine ribs using two thermocouples placed at a distance of 1.5 mm around the drilling site in cortical and cancellous bone. The preparation time was recorded. RESULTS: The heat production and time required for implant site preparation using both ultrasonic devices were significantly higher than those for conventional drilling (P<0.01). Increased loading had no effect on heat production. A higher irrigation volume was associated with a diminished temperature increase in the cortical bone for ultrasonic but not for conventional drilling, which resulted in significantly lower temperatures in cortical as compared with cancellous bone during ultrasonic implant site preparation. CONCLUSIONS: Ultrasonic implant site preparation is more time consuming and generates higher bone temperatures than conventional drilling. However, with the levels of irrigation, ultrasonic implant site preparation can be an equally safe method.

Topography and presence of a smear layer in deciduous molars prepared with high-speed cutting and ultrasonic abrasion: an in-vitro study.

OBJECTIVE: The aim of this in-vitro study was to compare the effect of high-speed cutting (HS) with ultrasonic abrasion (US) concerning the internal topography and the presence of a smear layer in a cavity preparation performed in healthy deciduous molars. MATERIAL AND METHODS: Seven first deciduous molars were used. Two occlusal cavity preparation were done, one in the medial fossula and another in the distal fossula, which were chosen randomly. One preparation was carried out with a diamond point adapted to the HS system (GI), while a chemical vapor deposition (CVD) point adapted to a US device (GII) was used for the other preparation. Subsequently, all samples (n = 14) were cleaved to observe the inside and then prepared for evaluation using scanning electron photomicroscopy. The internal topography of the prepared cavities was descriptively analyzed. In order to assess the presence of a smear layer, scores were tabulated using the 2000 GMC program and analyzed using the Mann-Whitney test. RESULTS: Concerning the internal topography, the presence of striae was verified in both groups. In the GI group they were finer, found in a greater number, and with narrower spaces between them. In the GII group, the striae were undulating, similar to the effect of wheels on sand, and with wider spaces between them. As regards the presence of a smear layer, there was no statistically significant difference between the groups (P > 0.05). CONCLUSIONS: In view of the methodology employed, it may be concluded that cavity preparation with a CVD point in a US abrasion system led to the formation of fewer striae and both devices promoted the marked presence of a smear layer, obstructing dentinal tubuli.

An evaluation of different caries removal techniques in primary teeth: a comparitive clinical study.

OBJECTIVE: To compare the efficacy of caries removal, time taken and to evaluate the pain threshold experienced by the patient during various caries removal methods. STUDY DESIGN: Eighty patients between the age groups of 5-9 years were selected and caries removal was done by hand instruments, airotor, carisolv and papacarie. The efficacy, time taken and the pain threshold was evaluated during the caries removal by Ericson D et al scale, visual analogue scale respectively. RESULTS: Highly significant relation (< 0.05) was observed when intergroup comparison was made using one way analysis of variance (ANOVA). CONCLUSION: It was concluded that chemomechanical removal of caries with Papacarie and Carisolv were found to be effective measures of caries removal and could be considered as viable alternatives to painful procedures like Airotor in management of dental caries especially in children.