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Biomedical subjects

P R Wesselink

Publications and source records attributed to P R Wesselink.

At least 19 recordsLinked to original sources
PubMed2007

The evaluation of removal of calcium hydroxide paste from an artificial standardized groove in the apical root canal using different irrigation methodologies.

AIM: To evaluate the capacity to remove a calcium hydroxide (Ca(OH)2) paste from the root canal and to evaluate the efficacy of Ca(OH)2 removal during passive ultrasonic irrigation using either sodium hypochlorite (NaOCl) or water as an irrigant. METHODOLOGY: Sixteen mandibular premolars were used. Each root was prepared to the apical foramen using GT instruments of size 30, 0.06 taper. Each root was split longitudinally. In one half of the root, a groove was cut in the canal wall 2-6 mm from the apex which was then filled with a Ca(OH)2 paste. Subsequently the roots were reassembled. In group 1 (n = 16), the teeth were ultrasonically irrigated using 50 mL 2.0% NaOCl as the irrigant. Group 2 (n = 16) was treated in the same manner as group 1, but using 50 mL water in place of the NaOCl. In group 3 (n = 16), the teeth were irrigated by syringe injection of 50 mL 2.0% NaOCl. The quantity of remaining Ca(OH)2 in the groove was scored and the data analysed with Kruskal-Wallis and Mann-Whitney tests. RESULTS: The difference in remaining Ca(OH)2 between all groups was statistically significant (P < 0.001). Group 1 had significantly lower scores than group 2 (P < 0.001) and group 3 (P = 0.002), but there was no significant difference between groups 2 and 3 (P = 0.765). CONCLUSIONS: Passive ultrasonic irrigation with 2% NaOCl was more effective in removing Ca(OH)2 paste from artificial root canal grooves than syringe delivery of 2% NaOCl or water as irrigant.

Calcium Hydroxide↗
PubMed2006

Consequences of and strategies to deal with residual post-treatment root canal infection.

Bacterial sampling of prepared root canals is used to determine the presence and character of the remaining microbiota. However, it is likely that current sampling techniques only identify organisms in the main branches of the root canal system whereas it is unlikely that they can sample areas beyond the apical end-point of preparation and filling, or in lateral canals, canal extensions, apical ramifications, isthmuses and within dentinal tubules. Thus, it may be impossible by current techniques to identify residual post-treatment root canal infection. In histologic observations of root apices, bacteria have been found in inaccessible inter-canal isthmuses and accessory canals often in the form of biofilms. There is no in vivo evidence to support the assumption that these bacteria can be entombed effectively in the canal system by the root filling and thus be rendered harmless. As a consequence of this residual root infection, post-treatment apical periodontitis, which may be radiographically undetectable, may persist or develop as a defence mechanism to prevent the systemic spread of bacteria and/or their byproducts to other sites of the body. Histologic observation of root apices with surrounding bone removed from either patients or human cadavers has demonstrated that post-treatment apical periodontitis is associated with 50-90% of root filled human teeth. Thus, if the objective of root canal treatment is to eliminate apical periodontitis at a histological level, current treatment procedures are inadequate. It is essential that our knowledge of the local and systemic consequences of both residual post-treatment root infection and post-treatment apical periodontitis be improved. The continued development of treatments that can effectively eliminate root infection is therefore a priority in clinical endodontic research. Post-treatment disease following root canal treatment is most often associated with poor quality procedures that do not remove intra-canal infection; this scenario can be corrected via a nonsurgical approach. However, infection remaining in the inaccessible apical areas, extraradicular infection including apically extruded dentine debris with bacteria present in dentinal tubules, true radicular cysts, and foreign body reactions require a surgical intervention.

Bacterial Infections↗
PubMed2006

The influence of volume, type of irrigant and flushing method on removing artificially placed dentine debris from the apical root canal during passive ultrasonic irrigation.

AIM: To determine the influence of volume, irrigant and method of flushing on the removal of artificially-placed dentine debris from the apical part of root canals during passive ultrasonic irrigation. METHODOLOGY: Access cavities were prepared in 15 canine teeth and their root canals instrumented to size 20, 0.10 taper. Each root was split longitudinally, forming two halves. A groove was cut in the canal wall 2-6 mm from the apex in each half which was then filled with dentine debris prior to the roots being reassembled. All canals were ultrasonically irrigated, using a size 15, 0.02 taper smooth wire to a length of 21 mm that was placed in the canal to the apical foramen. In group 1 the canal was flushed with a continuous flow of 50 mL 2% sodium hypochlorite (NaOCl). In group 2 the continuous flow was not used but the canal was flushed with 12 mL 2% NaOCl, at a rate of 2 mL 30 s-1 using a syringe. Group 3 was treated in the same way as group 2 but the canal was flushed with 6 mL 2% NaOCl, at a rate of 2 mL min-1. Group 4 was treated in the same way as group 1 but water was used as the irrigant. Before and after irrigation, images of the grooves were captured and stored. The quantity of dentine debris in the groove was evaluated. The differences in debris scores between the experimental groups were analysed with the Kruskal-Wallis test and the Mann-Whitney U-test. The level of significance was set at P=0.05. RESULTS: The difference between all groups was statistically significant (K-W test P<0.001). Groups 1, 2 and 3 differed significantly from group 4 (P<0.001); there was no significant difference between groups 1, 2 and 3 (P=0.550). CONCLUSIONS: Syringe delivery of 2% NaOCl (6 and 12 mL) was as effective as a continuous flow of 2% NaOCl (50 mL). Water was not effective in removing dentine debris from grooves in the apical portion of root canals.

Cuspid↗
PubMed2006

Leakage along apical root fillings with and without smear layer using two different leakage models: a two-month longitudinal ex vivo study.

AIM: To compare two different experimental models when measuring leakage along root fillings with or without smear layer. METHODOLOGY: One hundred and twenty single-rooted teeth were prepared to size 50 and allocated to two groups: fluid transport model (n = 60) and glucose penetration model (n = 60). The roots in each group were divided into three subgroups of 20 teeth each. Smear layer was left in place in group 1 but removed in groups 2 and 3. In groups 1 and 2 canals were filled with laterally compacted gutta-percha cones and AH 26. Group 3 was laterally compacted with Resilon cones and Epiphany sealer. The coronal portion of the filling was removed to assure only 4 mm of filling remained in the canal. Leakage of glucose was evaluated by measuring its concentration once a week for a total period of 56 days using a glucose penetration model. Fluid transport was evaluated by measuring the movement of an air-bubble using a fluid transport model, 1 and 8 weeks after canal filling. Differences between the groups in glucose concentrations and fluid transport were statistically analysed with the Kruskal-Wallis and the Mann-Whitney tests. The level of significance was set at alpha = 0.05. RESULTS: Glucose penetration was significantly different between the three groups after the first 8 days (P < 0.05). Resilon leaked the most throughout the experiment period. No significant difference (P > 0.05) existed between the two gutta-percha groups at all time intervals (Mann-Whitney test). In the fluid transportation model, no statistically significant differences were observed between all three experimental groups (P > 0.05) at either 1 or 8 weeks after filling (Kruskal-Wallis test). CONCLUSIONS: Under the conditions of this study, the glucose penetration model was more sensitive in detecting leakage along root fillings. Removing the smear layer before filling did not improve the sealing of the apical 4 mm of filling. Resilon allowed more glucose penetration but the same amount of fluid transport as the gutta-percha root fillings.

Dental Leakage↗
PubMed2005

An evaluation of the quality of root fillings in mandibular incisors and maxillary and mandibular canines using different methodologies.

OBJECTIVES: To evaluate the quality of root fillings in mandibular incisors and maxillary and mandibular canines using different methodologies of evaluation, namely radiographs, the fluid transport test and the percentage of gutta-percha (PGP), and to determine if a correlation occurs between the results of the different methodologies used. METHODS: One group of mandibular incisors with oval canals (n=20) and one group of maxillary and mandibular canines (n=20) were instrumented and obturated by cold lateral compaction using AH 26 as the sealer. The filled roots were bucco-lingually and mesio-distally radiographed. Using a scoring system, the quality of each root filling was radiographically evaluated, the higher the score the poorer the quality. Fluid transport along the root filling was then measured using a fluid transportation device. Each root was horizontally sectioned 4 and 6mm from the apex. Images of the cross-sections were taken, using a microscope and a digital camera. Images were scanned into a PC as TIFF images. Using a KS 100 Imaging system the canal area and the gutta-percha filled areas were measured. The percentage of gutta-percha filled areas was calculated. RESULTS: Considering the radiographic scores of the two different projections together the score was significantly higher for the mandibular incisors than for the canines (P=0.039). The radiographic score was significantly higher for the mesio-distal radiograph in comparison with the bucco-lingual radiograph (P=0.0001), for the canines as well as the incisors. Using only the bucco-lingual radiograph there was no significant difference between the mandibular incisors and the canines (P=0.992). The mandibular incisors displayed significantly more fluid transport than the canines (P=0.049). A significantly greater percentage of gutta-percha filled areas was found in the cross-sections of canines as compared to the cross-sections of mandibular incisors (P=0.000001). The correlation between the radiographic score of the mesio-distal radiograph and the PGP 4 and 6mm was significant (P=0.013). There was no significant correlation between the FT and the radiograph or the FT and the PGP. CONCLUSIONS: The quality of the root fillings in oval canal-mandibular incisors may be compromised.

Bismuth↗
PubMed2005

A comparison between a smooth wire and a K-file in removing artificially placed dentine debris from root canals in resin blocks during ultrasonic irrigation.

AIM: To compare the efficacy of a smooth wire with a conventional K-file, in removing dentine debris from grooves in root canals made in resin blocks, during ultrasonic irrigation. METHODOLOGY: Each resin block containing a standard simulated canal was split longitudinally through the canal, forming two halves. In one canal wall, a standard groove 4 mm in length, 0.2 mm in width and 0.5 mm in depth was cut 2-6 mm from the apical end of the canal, to simulate uninstrumented canal extensions. Each groove was filled with fresh dentine debris mixed with 2% NaOCl to simulate a situation when dentine debris accumulates in uninstrumented canal extensions. Each canal was reassembled by joining the two halves of the resin block by means of wires and sticky wax. In each canal ultrasonic irrigation was performed for 3 min using 2% NaOCl as irrigant. In one group (n = 20) a conventional K-file size 15 was used. In the other group (n = 20) a smooth wire was used which had the same length and diameter as the size 15 K-file. Before and after irrigation, images of each half of the canal with a groove were taken, using a microscope and a digital camera, after which they were scanned into a PC as TIFF images. The quantity of dentine debris in the groove was evaluated using a scoring system: the higher the score, the larger the amount of debris remaining. The score data were analysed by means of the Mann-Whitney U-test. RESULTS: After ultrasonic irrigation, the debris was completely removed from the groove in 35 canals (87.5%), and there was no significant difference between the groups (P = 0.429). CONCLUSIONS: Using a smooth wire during ultrasonic irrigation is as effective as a size 15 K-file in removal of artificially placed dentine debris in grooves in simulated root canals in resin blocks.

Dental Instruments↗
PubMed2005

The efficacy of ultrasonic irrigation to remove artificially placed dentine debris from human root canals prepared using instruments of varying taper.

AIM: To investigate the influence of the taper of root canals on the effectiveness of ultrasonic irrigation to remove artificially placed dentine debris. METHOD: Forty-four maxillary and mandibular canines were selected after bucco-lingual and mesio-distal radiographs indicated that their internal diameters were smaller than the diameters of a size 20, .06 taper System GT instrument (Dentsply Maillefer, Ballaigues, Switzerland). These canines were divided into three groups and prepared using either size 20, .06 taper System GT instruments, size 20, .08 taper or size 20, .10 taper System GT instruments. Each root was then split longitudinally through the canal, forming two halves. In one canal wall, a standard groove was cut 2-6 mm from the apex, to simulate un-instrumented canal extensions. Each groove was filled with dentine debris mixed with 2% NaOCl to simulate a situation when dentine debris accumulates in the un-instrumented canal extensions. Each canal was reassembled by joining the two halves of the teeth by means of wires and sticky wax. In each canal ultrasonic irrigation was performed with a size 15 K file using 2% NaOCl as an irrigant. Before and after irrigation, images of each half of the canal with a groove were taken using a microscope and a digital camera, after which they were scanned into a PC as TIFF images. The quantity of dentine debris in the groove was evaluated using a scoring system: the higher the score, the larger the amount of debris. The scores before and after irrigation were compared. The differences in percentage of score reduction between the three groups were analysed by means of one-way anova. RESULTS: After ultrasonic irrigation, the debris score reduced by 74, 81 and 93%, respectively, in the size 20, .06, 20, .08 and 20, .10 taper groups. However, the difference amongst groups was not statistically significant (P = 0.078). CONCLUSION: There was a tendency that ultrasonic irrigation was more effective in removing artificially placed dentine debris from simulated canal extensions from canals with greater tapers.

Analysis of Variance↗
PubMed2005

[Local and potential systemic consequences of endodontic root infection].

In root infections, bacteria are present not only in planktonic cells but also in biofilms, which are more resistant to host defence mechanisms and disinfectans. Apical periodontitis, which may be radiographically undetectable, may develop or persist as a host defence mechanism to prevent the systemic spread of bacteria and their by-products to other sites of the body. The risk of spreading microorganisms and septic emboli is present especially in compromised hosts; furthermore, long-standing inflammation may have systemic effects and affect general health. Effective procedures should be developed to minimize the burden of root infection.

Bacterial Infections↗
PubMed2005

[Root canal preparation: shaping and cleaning of the root canal].

Primary shaping is of paramount importance for a succesfull root canal treatment. In this article the basis principles of apical terminus location, shape, size and diameter are discussed. The use of NiTi instruments and crown-down preparation techniques are explained.

Dental Instruments↗
PubMed2005

[Pain during and after root canal treatment].

Toothache can be prevented or remedied with a root canal treatment. Unfortunately a root canal treatment can also be the cause of pain. During a root canal treatment pain can be suppressed by local anesthesia, the use of the airotor, the attitude of the dentist and his communication with the patient. Afterpain has three causes: damage and iatrogenic apical periodontitis, pulpitis and continuing apical periodontitis. In this article the possible treatment of pain by a root canal treatment are extensively discussed.

Analgesics↗
PubMed2005

[The filling of the root canal system].

There are many techniques and materials to fill the root canal system. In this paper a number of the most popular techniques and materials is discussed mainly with the purpose to give an overview, and to understand the advantages and disadvantages of the various types of root fillings. Discussed are sealers based on zinc oxide-eugenol, synthetics and those that adhere to dentine or to which medicaments have been added. Of the various filling techniques the cone cementation techniques like single cone and lateral compaction are discussed, while of the warm techniques the lateral, vertical, and thermomechanical compaction as well as injection and core carrier techniques are described.

Drug Compounding↗
PubMed2004

Comparison of mandibular premolars and canines with respect to their resistance to vertical root fracture.

OBJECTIVE: To compare the force required to vertically fracture uninstrumented and instrumented mandibular premolars and canines. METHODS: Two groups of single round-canal mandibular premolars and two groups of single oval-canal mandibular premolars were selected after radiographs indicated an internal long:short diameter of 1 or >2 at a level 5 mm from the apex. In addition, two groups of maxillary and mandibular canines were selected. The root canals of three of these groups (one from each category) were conventionally enlarged using same-sized instruments, while the other three groups were uninstrumented. Each root was mounted in an acrylic resin cylinder, and the force required to cause vertical root fracture (VRF) was measured using an Instron tester. RESULTS: No significant difference in resistance to VRF was found between the round- and oval-canal premolars with (p = 0.9) or without (p = 0.6) instrumentation. The average force required to fracture the uninstrumented premolars and canines was 698 and 566 N, respectively. The average force required to fracture the instrumented premolars and canines was 490 and 554 N, respectively. The force required to fracture the instrumented premolars and canines was 30% (p < 0.05) and 2% (p = 0.9) lower, respectively, than that required to fracture their uninstrumented counterparts. CONCLUSIONS: The instrumented mandibular premolars have a higher risk to fracture than the uninstrumented mandibular premolars.

Bicuspid↗
PubMed2004

The effectiveness of syringe irrigation and ultrasonics to remove debris from simulated irregularities within prepared root canal walls.

AIM: To compare the ability of syringe irrigation and ultrasonic irrigation to remove artificially placed dentine debris from simulated canal irregularities within prepared root canals. METHODOLOGY: After canal enlargement, twelve canines were split longitudinally into two halves. On the wall of one half of each root canal a standard groove of 4 mm in length, 0.2 mm in width and 0.5 mm in depth was cut, 2-6 mm from the apex, to simulate uninstrumented canal extensions. On the wall of the other half, three standard saucer-shaped depressions of 0.3 mm in diameter and 0.5 mm in depth were cut at 2, 4 and 6 mm from the apex to simulate uninstrumented canal irregularities. Each groove and depression were filled with dentine debris mixed with 2% NaOCl to simulate a situation when dentine debris accumulates in uninstrumented canal extensions and irregularities during canal preparation. Each tooth was re-assembled by reconnecting the two halves, using wire and an impression putty material. Two per cent NaOCl was then delivered into each canal either using syringe irrigation (n = 8) or using ultrasonic irrigation (n = 8). Before and after irrigation, images of the two halves of the canal wall were taken, using a microscope and a digital camera, after which they were scanned into a PC as TIFF images. The amount of remaining dentine debris in the grooves and depressions was evaluated by using a scoring system between 0-3: the higher the score, the more the debris. The data were analysed by means of the Mann-Whitney U-test. RESULTS: Both forms of irrigation reduced the debris score significantly. The debris score was statistically significantly lower after ultrasonic irrigation than after syringe irrigation (P = 0.002 for grooves, P = 0.047 for depressions). CONCLUSION: Ultrasonic irrigation ex vivo is more effective than syringe irrigation in removing artificially created dentine debris placed in simulated uninstrumented extensions and irregularities in straight, wide root canals.

Cuspid↗
PubMed2004

The efficacy of ultrasonic irrigation to remove artificially placed dentine debris from different-sized simulated plastic root canals.

AIM: To investigate the influence of diameter and taper of root canals on the effectiveness of ultrasonic irrigation to remove artificially placed dentine debris from simulated uninstrumented extensions in simulated root canals. METHOD: Three groups of standard canals were cut in resin blocks using either size 20, .04 taper ProFile instruments, size 20, .06 Greater Taper (GT) rotary instruments or size 20, .08 GT instruments, respectively. Each resin block was then split longitudinally through the canal, forming two halves. In one canal wall, a standard groove 4 mm in length was cut 2-6 mm from the apical end of the canal, to simulate uninstrumented canal extensions. Each groove was filled with dentine debris mixed with 2% NaOCl to simulate a situation when dentine debris accumulates in the uninstrumented canal extensions. Each canal was reassembled by joining the two halves of the resin block by means of wires and sticky wax. In each canal ultrasonic irrigation was performed for 3 min using 2% NaOCl as irrigant. Before and after irrigation, images of each half of the canal with a groove were taken using a microscope and a digital camera, after which they were scanned into a PC as TIFF images. The quantity of dentine debris in the groove was evaluated using a scoring system: the higher the score, the larger the amount of debris remaining. The score data were analysed by means of Kruskal-Wallis and Mann-Whitney U-tests. RESULTS: After ultrasonic irrigation, the debris score for the size 20,.04 taper group was significantly higher than that for the size 20,.06 group (P = 0.040) and the size 20,.08 group (P = 0.006) groups. However, no significant difference was found between the size 20,.06 and the size 20,.08 groups (P = 0.320). CONCLUSION: In simulated plastic root canals, the diameter and taper of root canal influenced the effectiveness of ultrasonic irrigation to remove artificially placed dentine debris.

Dental Instruments↗
PubMed2004

Effect of dentinal fluid composition on dentin demineralization in vitro.

Dentin demineralization is reduced by perfusion with water. We hypothesized that a simulated dentinal fluid (SDF) that contains albumin, in addition to electrolytes, would be more effective in reducing dentin demineralization than water alone, and this effect would increase with increasing flow rate of SDF. Perfusion rate in tooth segments that carried buccal cervical dentin windows was measured in a fluid transport set-up. These windows were then demineralized under perfusion with water, or SDF at 1.47 kPa for 31 days. We analyzed integrated mineral loss and lesion depth with the use of transverse microradiography (TMR), which revealed that 38% more mineral dissolved from dentin lesions perfused with water than from those perfused with SDF. The former were also 18% deeper. Flow rate of dentinal fluid showed no correlation with demineralization. We concluded that composition of dentinal fluid is an important determinant of the rate of lesion formation and progression in dentin.

Albumins↗
PubMed2004

[Solvents for the removal of gutta-percha from root canals. 1. Efficacy].

The removal of gutta-percha and sealer from endodontically treated root canals may prompt the use of organic solvents. In the present article a number of possible solvents are described and, based upon the literature, their efficacy is assessed. Some solvents, amongst which chloroform, xylene and halothane are almost equally efficient, although all leave a debris of gutta-percha and sealer in the root canals behind. Only chloroform solves AH26 and most probably AH-plus, but very slowly. Eucalyptol and turpentine oil are slow dissolvers. Orange oil and limonene are promising. The data on other solvents, if candidates at all, are scarce. The choice of a solvent is co-determined by factors such as toxicity and sensitisation, which will be described in a second publication.

Gutta-Percha↗
PubMed2004

[Solvents for the removal of gutta-percha from root canals. 2. Side effects of chloroform, halothane and xylene].

High concentrations of organic solvents have adverse effects on the health of professional workers. In endodontics, halothane, chloroform and xylene are used to dissolve gutta-percha from root canals. It is therefore questioned whether the use of these solvents could affect the health of patients or of the dental team. It seems warranted to conclude that the amounts and concentrations of chloroform, xylene and halothane such as used in endodontic retreatment, are low and therefore are safe. However, the dentist should be aware of possible hypersensitivity induced by previous application of halothane as a narcotic.

Chloroform↗