Biomedical subjects
Martin Trope
Publications and source records attributed to Martin Trope.
Success of an alternative for interim management of irreversible pulpitis.
BACKGROUND: Extraction and endodontic therapy are treatment options for irreversible pulpitis. Extraction often is chosen for financial reasons. The authors conducted a study to investigate an alternative interim therapy. METHODS: The authors recruited patients (N = 73) with irreversible pulpitis and whose teeth were restorable but who opted for extraction owing to financial reasons. After undergoing pulpotomy, the teeth were restored by random assignment with one of two intermediate restorative materials: Caulk IRM (Dentsply Caulk, Milford, Del.) (Group I, n = 38) or an IRM base with glass ionomer core (Fuji IX GP, GC America, Alsip, Ill.) (Group II, n = 35). The authors monitored the teeth over six and 12 months for pain, integrity of restoration and radiographic periapical status by densitometric analysis. RESULTS: By six months, 10 percent of subjects remaining in the study (Group I, n = 27; Group II, n = 25) reported pain; by 12 months, 22 percent (Group I, n = 22; Group II, n = 18) reported pain. A two-tailed Fisher exact test showed no significant difference (P > or = .05) between groups at either time interval. No apical radiographic change was noted in 49 percent of teeth at six months (Group I, n = 18; Group II, n = 19) and 42 percent at 12 months (Group I, n = 16; Group II, n = 15). Chi2 analysis demonstrated no significant differences (P > or = .05) between groups. Seven of 22 restorations in Group I and four of 18 in Group II required repair at 12 months with no statistical difference (chi2 analysis, P > or = .05). CONCLUSIONS: The interim treatment of eugenol pulpotomy using either restorative material reliably prevented pain for six months. For longer periods, both restorations may require repair. CLINICAL IMPLICATIONS: This option should preserve the integrity of the arch and extend the use of the tooth while the patient finds the means to finance complete endodontic treatment.
Fracture resistance of roots endodontically treated with a new resin filling material.
BACKGROUND: The authors evaluated the fracture resistance of endodontically treated teeth filled with either gutta-percha or a new resin-based obturation material. METHODS: The authors prepared and randomly divided 80 single-canal extracted teeth into five groups: lateral and vertical condensation with gutta-percha, lateral and vertical condensation with the new resin-based obturation material, and a control group with no filling material. The specimens were stored in 100 percent humidity for two weeks, mounted in polyester resin and loaded to failure. RESULTS: The authors found statistically significant differences among the experimental groups (P < .05). The groups with the new material displayed higher mean fracture loads and the gutta-percha groups lower mean fracture load values than the control unfilled group. However, the differences were not significant. The groups with the new material displayed significantly higher mean fracture loads than gutta-percha groups independent of the filling technique used. CONCLUSIONS: Filling the canals with the new resin-based obturation material increased the in vitro resistance to fracture of endodontically treated single-canal extracted teeth when compared with standard gutta-percha techniques. CLINICAL IMPLICATIONS; If other properties of the new resin-based obturation material compare favorably with those of gutta-percha for filling the root canal, it should be considered as a replacement for gutta-percha, as the results of this study indicate that it could provide enhanced resistance to tooth fracture.
Gutta-percha--the end of an era?
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Effect of catalase supplementation in storage media for avulsed teeth.
The type of liquid medium used to store avulsed teeth prior to replantation has been shown to affect the long-term prognosis. One possibility is that some storage media contain hydrogen peroxide (H2O2) that may be toxic to periodontal ligament cells. Therefore, the aim of this study was to determine if the addition of catalase to storage media improved the prognosis of replanted dog teeth. Forty-eight mongrel premolar roots were endodontically treated, extracted, randomly divided and placed into one of four storage media: Hank's balanced salt solution (HBSS), containing no antioxidant); Viaspan, containing the antioxidant, glutathione, or the same two media supplemented with catalase(100 U ml(-1)) for 1, 5, or 26 h prior to replantation. After 2 months, the dogs were euthanized and the roots histologically examined to evaluate the attachment tissues. Regardless of the storage medium used, overall healing was excellent and only 4% of the roots displayed inflammatory or replacement resorption. When roots from the different storage media were compared, those stored in HBSS were found to display the highest incidence of surface resorption (55.7%). Supplementation of HBSS with catalase resulted in a lower level of surface resorption (48.6%) that was statistically significant (P < 0.05). Roots stored in Viaspan - or + catalase displayed even lower levels of surface resorption (41.3 and 38.2%, respectively). The improvement observed with catalase-supplemented HBSS was confined to the 45-min incubation period; only Viaspan - or + catalase reduced surface resorption at the 5- and 26-h incubations. Collectively, these data demonstrate that roots stored in media containing antioxidant activity undergo less surface resorption. These results suggest that low levels of H2O2 in storage media for avulsed teeth may adversely affect periodontal ligament cells.
The effect of short-term calcium hydroxide treatment on dentin bond strengths to composite resin.
The purpose of this study was to evaluate the influence of calcium hydroxide (Ca(OH)2) treatment on the bond strengths to dentin of a resin-based composite material. Two distinct dental adhesives, Prime & Bond (P&B) NT and Single Bond (SB) were used. One hundred and twenty-seven bovine incisors were mounted in acrylic, ground flat to expose middle dentin, polished to 600-grit, and randomly assigned to 10 groups: (i) 0 days, no Ca(OH)2, P&B NT; (ii) 7 days, no Ca(OH)2, P&B NT; (iii) 7 days, Ca(OH)2, P&B NT; (iv) 30 days, no Ca(OH)2, P&B NT; (v) 30 days, Ca(OH)2, P&B NT; (vi) 0 days, no Ca(OH)2, SB; (vii) 7 days, no Ca(OH)2, SB; (viii) 7 days, Ca(OH)2, SB; (ix) 30 days, no Ca(OH)2, SB; (x) 30 days, Ca(OH)2, SB. All specimens were stored in an incubator at 37 degrees C. Specimens were then retrieved and the dentin surface was rinsed with air/water spray from a triple syringe. Dentin was etched with 37% phosphoric acid (PA) for 15 s, rinsed, blot dried, and coated with adhesive according to manufacturer's instructions. The adhesive was light cured for 10 s, and Filtek Z250 was applied to the surface with a #5 gelatin capsule and light cured for 160 s. Shear bond strengths were measured for each specimen in an Instron unit at a cross-head speed of 0.5 mm min(-1). The data were subjected to anova and Duncan post-hoc tests. Mean shear bond strengths for P&B NT ranged from 8.02 to 11.79 MPa. There was no significant difference between P&B NT groups treated with or without Ca(OH)2 at any time interval. Mean shear bond strengths for SB ranged from 14.70 to 19.54 MPa. No significant difference was found between SB groups treated with or without Ca(OH)2 at 7 days. At 30 days, SB with Ca(OH)2 was significantly higher than SB without Ca(OH)2. Short-term Ca(OH)2 treatment had no detrimental effect on dentin bond strengths to the ethanol or acetone-based adhesive resin systems tested.
Effect of endodontic instrument taper on post retention.
The purpose of this study was to evaluate the effect of various tapers of canal preparations on the retention of posts. Ninety human central or lateral mandibular incisors were prepared by removing the clinical crown at the CEJ and instrumenting the canals with instruments of varying tapers. The groups comprising 10 teeth each were divided as follows: Taper 0.02 Ni-Ti hand files (control), Taper 0.04 ProFile Series 29, Taper 0.06 ProFile Series 29, Taper 0.08 ProFile GT Rotary, Taper 0.10 ProFile GT Rotary, Taper 0.12 ProFile GT Rotary, Taper 0.08* ProFile GT Rotary 0.08 taper with #50/.12 taper in coronal third, Taper 0.10* ProFile GT Rotary 0.10 taper with #50/.12 taper in coronal third, Taper 0.12* ProFile GT Rotary 0.12 taper with #50/.12 taper in coronal third. Canals were filled with gutta-percha and AH 26 sealer using lateral condensation. Gutta-percha was removed with a heated 5/7 plugger until a level of 5 mm of gutta-percha was left in the apical segment of the root. Post channel preparation was made to the appropriate size with minimal change in canal shape with the Premier IntegraPost drill, and the corresponding IntegraPost was cemented with 3M Vitremer cement. The roots were fixed in copper rings with mounting plaster and mounted on an Instron TT machine. The posts were subjected to gradually increasing vertical tensile force until dislodgment of the post occurred. Force (lb) required to dislodge the post was obtained for each tooth, and the average force of the groups was compared using a one-way ANOVA with Tukey's multiple comparisons. The highest resistance to dislodgment was obtained with Taper 0.04 (79.10 +/- 10.73), whereas the lowest was obtained by the Taper 0.02 (18.70 +/- 13.44). No statistical difference was found between six of the groups: Taper 0.08*, Taper 0.10, Taper 0.12*, Taper 0.10*, Taper 0.12, and Taper 0.06. Taper 0.08 was statistically inferior to Taper 0.04 but not Taper 0.02. The 0.04 taper seems to be the best taper for maximal resistance to post dislodgment.
Clinical management of the avulsed tooth: present strategies and future directions.
The aim of this review article is to supplement the recently published International Association of Dental Traumatology (IADT) guidelines on treatment of the avulsed tooth. A thorough discussion on the reasoning behind each guideline is presented. In addition, the author's views on alternate treatment strategies and future directions, along with recent research on the subject of the avulsed tooth, are also presented.
The effectiveness of increased apical enlargement in reducing intracanal bacteria.
It has been suggested that the apical portion of a root canal is not adequately disinfected by typical instrumentation regimens. The purpose of this study was to determine whether instrumentation to sizes larger than typically used would more effectively remove culturable bacteria from the canal. Forty patients with clinical and radiographic evidence of apical periodontitis were recruited from the endodontic clinic. Mandibular cuspids (n = 2), bicuspids (n = 11), and molars (mesial roots) (n = 27) were selected for the study. Bacterial sampling was performed upon access and after each of two consecutive instrumentations. The first instrumentation utilized 1% NaOCI and 0.04 taper ProFile rotary files. The cuspid and bicuspid canals were instrumented to a #8 size and the molar canals to a #7 size. The second instrumentation utilized LightSpeed files and 1% NaOCl irrigation for further enlargement of the apical third. Typically, molars were instrumented to size 60 and cuspid/bicuspid canals to size 80. Our findings show that 100% of the cuspid/bicuspid canals and 81.5% of the molar canals were rendered bacteria-free after the first instrumentation sizes. The molar results improved to 89% after the second instrumentation. Of the (59.3%) molar mesial canals without a clinically detectable communication, 93% were rendered bacteria-free with the first instrumentation. Using a Wilcoxon rank sum test, statistically significant differences (p < 0.0001) were found between the initial sample and the samples after the first and second instrumentations. The differences between the samples that followed the two instrumentation regimens were not significant (p = 0.0617). It is concluded that simple root canal systems (without multiple canal communications) may be rendered bacteria-free when preparation of this type is utilized.
Capping the inflamed pulp under different clinical conditions.
BACKGROUND: A great deal of controversy exists regarding the reliability of capping the inflamed pulp. In particular, the use of calcium hydroxide as a capping agent has come into question. In this study, hard tissue barrier formation after inflamed pulps were capped directly or after partial pulpotomy was compared with calcium hydroxide or bonded resin and with no additional seal or an IRM surface seal. Seventy teeth in five dogs were used. Ten untreated teeth were used as negative controls. In 60 teeth, pulpal inflammation was induced by preparing a cavity close to the pulp and sealing a cotton pellet soaked in plaque in it for 1 to 2 weeks. The cavities were then re-entered and extended to expose the pulps. MATERIALS AND METHODS: In half the teeth (n = 30) a partial pulpotomy was performed and in the other half (n = 30) pulpal treatment was performed on the superficial exposed pulp. Both pulpal treatment groups received the same restorative procedures: (1) calcium hydroxide + amalgam + IRM surface seal; (2) OptiBond Solo, Prodigy with IRM surface seal; or (3) OptiBond Solo, Prodigy without IRM surface seal. The presence, absence, and quality of a hard tissue barrier were evaluated histologically. RESULTS: The calcium hydroxide groups were statistically superior to all other groups. The IRM surface seal resulted in significantly better healing. Although there was no statistically significant difference between direct pulp capping and partial pulpotomy with the numbers in this study, power statistics indicated that in clinical practice a partial pulpotomy would be preferable. CLINICAL SIGNIFICANCE The results of this study suggest that a partial pulpotomy, calcium hydroxide medicament, and a bacteria-tight coronal restoration represent a viable technique for capping the inflamed pulp.