Immediate esthetic management of a catastrophically fractured anterior.

A quick, failsafe method for the esthetic replacement of a catastrophically fractured anterior tooth was presented. This method required minimal armamentarium and no anesthesia. In addition, it employed a technique that is not technique sensitive. The patient and the dental team both benefit by resolving the esthetic crisis using simple methods and excellent time resource management.

Retention of posts luted with phosphate monomer-based composite cement in canals obturated using a eugenol sealer.

PURPOSE: To examine the effect post-obturation sequencing had on retention of endodontic posts luted with a phosphate monomer-based resin cement into canals previously obturated using a eugenol-based sealer. MATERIALS AND METHODS: 64 single-rooted teeth were decoronated, and root canals were filed, cleaned, and shaped with a size 5 Gates Glidden drill and 0.12 taper rotary instrumentation. Teeth were then divided into 4 groups of 16 specimens each. Group 1 was not obturated, and served as a control. The other three groups were obturated with gutta percha and a eugenol-based sealer. Post space preparation and post cementation were completed at three different post-obturation intervals - immediate (Group 2), 1 week (Group 3), and 4 weeks (Group 4). Ten-mm deep post spaces were prepared with a size 6 Gates Glidden drill, and size 5 Paraposts were cemented with Panavia 21 OP. Following 48-hour of storage, specimens were mounted in PVC pipe with acrylic, and the posts were removed in tensile mode using a universal testing machine at 1 mm min(-1), with data recorded in kilograms. RESULTS: Group 1 (controls) mean = 61.80, SD = 16.21; Group 2 (immediate) mean = 38.70, SD = 12.97; Group 3 (1 week) mean = 43.15, SD = 14.66; Group 4 (4 weeks) mean = 18.82, SD = 8.00. Using ANOVA and Bonferroni tests, Group 1 demonstrated significantly greater mean retention strength values than Groups 2 and 3 (P < 0.05), which in turn had significantly greater mean retention strength values than Group 4 (P < 0.05).

Effect of prolonged water storage and repeated thermocycling on the reinforcing ability of refrigerated Amalgambond Plus/High Performance Additive in third molars with large mesio-occlusodistal amalgam restorations.

OBJECTIVE: This in vitro investigation examined what effect prolonged water immersion and repeated thermocycling had on the fracture strength of extracted third molars restored with refrigerated Amalgambond Plus with High Performance Additive (AB+/HPA) and Tytin amalgam. MATERIALS AND METHODS: Mesio-occlusodistal (MOD) channels were prepared in one member from each of 19 contralateral pairs. After restoration, specimens were stored in water for 6 months, with thermocycling repeated every 2 months. Specimens were fractured in a universal testing machine, and the data were analyzed. Secondary effects of tooth location and tooth size were also examined. RESULTS: Fracture strengths of prepared/restored teeth were not statistically different from those of intact contralateral pairs (p > 0.05). Maxillary teeth had lower fracture strengths than mandibular teeth, and tooth size had no effect on fracture strength. CONCLUSIONS: Extracted molars with large MOD amalgam restorations bonded with refrigerated AB+/HPA had fracture strengths equivalent to those of intact contralateral pairs after 6 months of water storage and repeated thermocycling.

Effect of thermocycling on the fracture strength of intact third molars stored for two different time periods.

OBJECTIVE: This study investigated the effect of thermocycling on the fracture strength of intact, extracted molars stored for two different intervals before testing. METHODS: Thirty-eight recently extracted molars and 38 molars stored for 1 to 5 years were each randomly separated to create four subgroups. One subgroup from each storage interval was thermocycled 1,000 times from 5 to 55 degrees C using 30-second dwell times, and then all teeth were fractured using a universal testing machine. RESULTS: Thermocycled recently extracted molars had significantly lower mean fracture strengths than nonthermocycled recently extracted molars (p < 0.001). No other pairwise comparisons were statistically significant. CONCLUSION: Thermocycling significantly reduced the fracture strength of recently extracted third molars. However, no significant differences in fracture strength were seen with molars stored for 1 to 5 years before thermocycling.

Effects of a refrigerated amalgam bonding system on fracture resistance.

This in vitro study evaluated the effectiveness of using an amalgam bonding system at refrigerated temperature to regain fracture resistance in molars with large mesial-occlusal-distal restorations. Nineteen pairs of homologous contralateral pairs of third molars were used, with control teeth remaining intact. Although the bonded amalgam group developed 81% of the fracture strength values of the intact teeth, the intact teeth were found to have significantly higher fracture strength values (p = 0.0326, paired t-test).

Shear bond strength of bis-acryl composite provisional material repaired with flowable composite.

BACKGROUND: Time and expense are considerable when refabrication of a bis-acryl composite provisional prosthesis is required, so an effective method of repair is desirable. Attempts at self-repair have been ineffective, and no reports of repair specific to bis-acryl composites were found in the literature. PURPOSE: To investigate the strength of a bis-acryl composite repair using flowable composite after two surface treatments and three storage conditions. MATERIALS AND METHODS: Thirty specimens of bis-acryl composite were made and divided into six groups. Half of the specimens received air abrasion only, and half received air abrasion followed by application of an intermediate bonding resin. A flowable composite was then applied to all specimens. Following three different storage conditions, the flowable composite was debonded using a universal testing machine in tensile mode. RESULTS: All specimens failed cohesively within the bis-acryl composite rather than at the repair interface. Surface treatment with air abrasion alone resulted in significantly higher shear bond strength values than when air abrasion and intermediate bonding resin were combined. Bond strength values were significantly higher in thermocycled specimens than in air-dried specimens. CONCLUSIONS: Use of air abrasion followed by application of flowable composite proved to be a successful technique for bis-acryl composite repair. CLINICAL SIGNIFICANCE: Repair of bis-acryl composite provisional material with a flowable composite is effective, expedient, and inexpensive.

Retention strengths of five luting cements on prefabricated dowels after root canal obturation with a zinc oxide/eugenol sealer: 1. Dowel space preparation/cementation at one week after obturation.

PURPOSE: This investigation examined the effect of 5 different cements on the retention strength of prefabricated endodontic dowels placed into root canals previously obturated with gutta percha and a zinc oxide/eugenol (ZOE) sealer. MATERIALS AND METHODS: Ninety-six single-rooted teeth were decoronated, filed, cleaned, sequentially shaped, and divided into 6 groups of 16 specimens each. Five of the groups were then obturated with gutta percha and a ZOE sealer. One group was not obturated and served as the control group. Dowel space preparation and dowel cementation for all groups were completed 1 week later. Ten-mm deep dowel spaces were prepared using size 6 Gates Glidden drills. Size 5 Paraposts were then cemented with 5 different cements: Panavia 21 for group 1 (unobturated controls) and group 2; Ketac-Cem glass ionomer for group 3; Fleck's zinc phosphate for group 4; Parapost (composite) Cement for group 5; and C&B Metabond 4-META for group 6. After 48 hours, the dowels were removed using a universal testing machine in tensile mode at 1 mm min(-1). RESULTS: The following results were found (all values in kg): group 1 (controls; Panavia 21) mean = 61.81, 95% CI = +/-8.65; group 2 (Panavia 21), mean=43.15, 95% CI = +/-7.81; group 3 (Ketac-Cem), mean =34.45, 95% CI = +/-4.93; group 4 (zinc phosphate), mean = 25.07, 95% CI = +/-5.03; group 5 (Parapost Cement), mean = 24.99, 95% CI = +/-5.35. None of the group 6 (C&B Metabond) specimens developed measurable bond strengths, so this group was excluded from parametric statistical analyses. An analysis of variance (ANOVA) showed a significant effect of group; pairwise multiple comparison procedures (Tukey test) showed that group 1 (controls) had significantly greater retention than all other groups (p <0.001); group 2 (Panavia 21) had significantly greater retention than groups 4 (zinc phosphate) and 5 (Parapost cement) (p <0.001). None of the other pairwise comparisons were statistically different. CONCLUSION: Paraposts cemented with Panavia 21 in unobturated root canals exhibited significantly higher retention than Paraposts luted with Panavia 21 and 4 different cements into dowel spaces prepared 1 week after obturation with gutta percha/ZOE sealer (p <0.001). Among the obturated groups, Panavia 21 cement (group 2) demonstrated significantly greater retention of Paraposts than zinc phosphate (group 4) and Parapost composite (group 5) cements (p <0.001). Ketac-Cem glass ionomer cement (group 3) had intermediate retention values that were not statistically different than those of groups 2, 4, and 5 (p >0.05). The 4-META cement, C&B Metabond, failed to polymerize.

Effect of dowel space preparation and composite cement thickness on retention of a prefabricated dowel.

PURPOSE: This investigation examined what effect cement thickness had on retention of prefabricated endodontic dowels luted with a composite resin cement (Panavia 21 OP; J Morita, Irvine, CA) into canals previously obturated with gutta percha and a eugenol-based sealer. MATERIALS AND METHODS: Sixty-four single-rooted teeth were decoronated, filed, cleaned, and sequentially shaped with sizes 2-5 Gates Glidden drills (Dentsply/Maillefer, Tulsa, OK) and 0.12 taper rotary instrumentation. Teeth were then divided into 4 groups of 16 specimens each. All specimens were obturated with gutta percha and a eugenol-based sealer. Dowel space preparation and dowel cementation were completed 1 week after obturation. Ten-millimeter-deep dowel spaces were prepared using dowel drills with 4 different diameters: size 5 Parapost drill (Group 1; Coltene/Whaledent, Mahwah, NJ); size 5.5 Parapost drill (Group 2; Coltene/Whaledent); size 6 Gates Glidden drill (Group 3; Dentsply/Maillefer); size 6 Parapost drill (Group 4; Coltene/Whaledent). Size 5 Paraposts were then cemented with Panavia 21 OP. After 48 hours of storage, specimens were mounted in polyvinyl chloride (PVC) pipe with acrylic, and the dowels were removed in tensile mode using a universal testing machine at 1 mm/min, with data recorded in kilograms. RESULTS: (all values in kilograms) Group 1 (Parapost 5) mean = 15.07, 95% confidence interval (CI) = +/-6.11; Group 2 (Parapost 5.5) mean = 25.60, 95% CI = +/-7.39; Group 3 (Gates-Glidden 6) mean = 43.15, 95% CI = +/-7.81; Group 4 (Parapost 6) mean = 37.75, 95% CI = +/-6.35. Analysis of variance and Bonferroni tests revealed that Group 3 had significantly greater mean retention strength values than Group 1 and Group 2 (p <.05), and that Group 4 had significantly greater mean retention strength values than Group 1 (p <.05). CONCLUSIONS: Paraposts cemented with Panavia 21 OP showed significantly greater retention in oversized dowel spaces compared with dowel spaces prepared with the manufacturers' matched dowel-drill set.

Use of yellow plastic food wrap to retard composite resin polymerization.

BACKGROUND: Dental chair lights can rapidly polymerize light-reactive composites beyond the point of workability, preventing adequate time for the shaping and sculpting of large direct composite restorations. PURPOSE: The purpose of this study was to determine whether yellow plastic food wrap placed over a dental chair light would perceptibly retard the polymerization rate of a light-cured composite (Esthet-X, shade A1, Dentsply/Caulk, Milford, DE, USA). MATERIALS AND METHODS: Zero, one, and two thicknesses of yellow plastic food wrap (Reynolds Metals Company, Richmond, VA, USA) were, in turn, used in the following scenarios: (1) placed in a spectrophotometer and compared for percentage transmission of 470 nm light; (2) placed over a curing unit light wand and compared for milliwatts of output on a radiometer; (3) placed over a dental chair light positioned 64 cm from 0.22 mm thick composite specimens, with Fourier Transform Infrared Spectrometry readings made every 40 seconds to measure degree of composite polymerization; (4) placed over a dental chair light positioned 64 cm from a direct veneer preparation (clinical simulation), which was then restored by four experienced clinicians who reported working times. RESULTS: Results for the scenarios were as follows: (1) zero sheets 100%, one sheet 34%, two sheets 6%; (2) zero sheets 580 mW, one sheet 190 mW, two sheets 20 mW; (3) percent conversion at 80 seconds--zero sheets 8%, one sheet 0.65%, two sheets 0.76%; percent conversion at 120 seconds--zero sheets 19.11%, one sheet 12.22%, two sheets 0.42%; (4) mean working times--zero sheets 34 seconds, one sheet 72 seconds, two sheets 155 seconds. CONCLUSIONS: Yellow plastic food wrap placed over a dental chair light markedly extended the working time of a light-cured composite in each of four assessments performed. Two sheets of plastic wrap were more than twice as effective as one sheet. CLINICAL SIGNIFICANCE: The suggested filtering technique with yellow plastic wrap placed over a dental chair light is a highly effective, expedient, and inexpensive method for increasing the working time of light-cured composites.