Stainless steel crowns as a restoration for permanent posterior teeth in people with special needs: A retrospective study.

BACKGROUND: Limited information exists regarding the use of stainless steel crowns (SSCs) in permanent teeth. The objective of this retrospective cohort study was to present the long-term clinical outcomes of the SSC compared with those of amalgam and composite resin restorations and the SSC radiographic outcomes in a special-needs population. METHODS: This study included 271 patients with at least 1 SSC restoration from the Mount Sinai Hospital Dentistry Clinic for Persons with Special Needs in Toronto, Ontario, Canada. A total of 2,621 posterior permanent tooth restorations were documented: 766 SSCs, 1,651 amalgam restorations, and 204 composite resin restorations. Clinical analysis included patient demographics, treatment parameters, and outcome assessments for each restoration recorded. Radiographic analysis of SSC restorations included 127 bite-wing radiographs and 118 periapical radiographs, measurement of interproximal bone loss, and assessment of periapical status using the Periapical Index Scale. RESULTS: The 10-year survival rates for new SSC and amalgam restorations were 79.2% and 63.5%, respectively. The 91 SSC failures included 2 recementations, 33 replacements, and 56 extractions. Primary diagnoses at the time of failure included chronic periodontal disease (25) and loose or lost SSCs (24). Of the 528 failed conventional restorations that were replaced, 60% were replaced with SSCs. The mean alveolar bone loss from mesial and distal sites was 1.36 millimeters and 1.40 mm, respectively. Therefore, 93% of the sites recorded were less than 2 mm and classified as healthy. All pre-SCC and post-SSC periapical radiographs had healthy Periapical Index Scale scores (1 or 2) recorded over an average duration of 8.4 years (1-29.1 years). CONCLUSIONS: SSCs are a durable treatment option for the restoration of the posterior permanent dentition. PRACTICAL IMPLICATIONS: Posterior permanent teeth restored with stainless steel crowns can be expected to last for 10 years and represent a viable treatment choice for severely carious or fractured posterior permanent teeth.

Ectopic Eruption of the Permanent Maxillary First Molar: Predictive Factors for Irreversible Outcome.

PURPOSE: The purpose of this study was to determine the rate of self-correction and predictive factors for irreversible outcome of mesial ectopic eruption of permanent maxillary first molars (EE), in a sample population where no interceptive treatment was initiated. METHODS: Charts of patients diagnosed with EE were reviewed, and radiographs were analyzed for predictive factors reported in the literature. RESULTS: Sixty-five EE were included in the study; 46 (71 percent) self-corrected, of which one-third occurred after age nine years. Space loss, with an average of approximately three mm, occurred in 18 EE (28 percent). Increased magnitude of impaction, degree of resorption of the primary second molar, severe lock, and bilateral occurrence were positively correlated with irreversible EE. Multiple regression analysis was positive for increased magnitude of impaction when adjusted for gender and bilateral occurrence. CONCLUSION: Spontaneous self-correction occurred in 71 percent of permanent maxillary first molars with ectopic eruption; one third of self-corrections occurred after nine years of age. Delaying treatment of ectopic eruption of permanent maxillary first molars may be a viable option when the outcome is uncertain. Increased magnitude of impaction was the most reliable predictor associated with irreversible outcome.

A retrospective study of a modified 1-minute formocresol pulpotomy technique part 1: clinical and radiographic findings.

PURPOSE: The purpose of this study was to assess the clinical and radiographic outcomes of a 1-minute application of full-strength Buckley's formocresol with concurrent hemostasis using the medicated cotton pledget in human primary teeth. METHODS: Using a retrospective chart review, clinical and radiographic data were available for 557 primary molars in 320 patients. Descriptive statistics and survival analysis were used to assess outcomes. RESULTS: Overall clinical success, radiographic success, and cumulative 5-year survival rates were approximately 99%, 90%, and 87%, respectively. Internal root resorption (∼5%) and pulp canal obliteration (∼2%) were the most frequently observed radiographic failures. Thirty-nine teeth were extracted due to clinical and or radiographic failure. Mandibular molars were 6 times more prone to radiographic failure than maxillary molars. CONCLUSIONS: Success rates for the modified technique are comparable to techniques that use the 5-minute diluted or full-strength solutions reported in the literature. This 1-minute full-strength formocresol technique is an acceptable alternative to published traditional techniques.

A retrospective study of a modified 1-minute formocresol pulpotomy technique part 2: effect on exfoliation times and successors.

PURPOSE: The purposes of this study were to evaluate the: effect of a 1-minute application of full-strength Buckley's formocresol with concur- rent hemostasis using the medicated cotton pledget in human primary teeth on their successors; and exfoliation times compared to the contralateral nonpulpotomized tooth. METHODS: Using a retrospective chart review, clinical and radiographic data were available for 557 primary molars in 320 patients. RESULTS: There was no difference between treated and control teeth in the number of enamel defects of succedaneous teeth (P<.45). Approximately 66% exfoliated at the same time as their contralateral counterpart and approximately 29% exfoliated earlier (P<.001). CONCLUSIONS: This 1-minute technique showed a tendency toward early exfoliation, but no effect on clinical management, and no increase in incidence of defects on succedaneous teeth was observed. The 1-minute full-strength formocresol technique may be considered an acceptable alternative to the 5-minute formocresol pulpotomy.

Shear bond strengths of orthodontic brackets cemented to bovine enamel with composite and resin-modified glass ionomer cements.

PURPOSE: The purpose of this in vitro study was to determine the effects of short- and long-term storage on the shear bond strength of metal, polycarbonate, and ceramic orthodontic bracket bases using autopolymerizing resin composite and resin-modified glass ionomer cements (RMGIC). The glass ionomer cement was applied in both a wet and a dry environment. METHODS: With a method developed in the authors' laboratory, orthodontic brackets were cemented under constant pressure to embedded bovine incisor enamel. All cements were mixed and applied in accordance with the manufacturer's instructions. The specimens were stored in water at 37 degrees C for 24 hours, 7 days, or 180 days. After the lapse of each time interval, they were shear tested to failure. The shear bond strengths (SBSs) were converted to megapascals (MPa). An adhesive remnant index (ARI) was used to record the site of the residual cement. RESULTS: There were no precipitous increases or decreases in SBS over a lapsed time of 180 days, although some variations occurred between 24 hours and 7 days. Similar findings were recorded for ARI. CONCLUSIONS: The bracket base-cement combinations produce clinically sustainable SBSs over time. Selection of the cement may be important in patients who exhibit a high risk for caries.

The influence of orthodontic bracket base design on shear bond strength.

Many bracket base designs and adhesive materials are in clinical use today. Bases have evolved from perforated metal bases to the present foil mesh bases, and treatments range from none, to spraying metal alloy onto the base, to the most common treatment of microetching. The purpose of this study was to determine the effect of orthodontic bracket base design on mean shear bond strength 1 hour or 24 hours after bonding. For each time group, 12 specimens of 6 types of metal brackets were bonded to bovine incisors with Transbond XT (3M Unitek, Monrovia, Calif) light-cured composite resin. Brackets were debonded 1 hour or 24 hours later, and the shear bond strength was recorded. Six debonded brackets of each type from each time group were selected at random and sandblasted. All the teeth were cleaned, and half were rebonded with used brackets, and half were rebonded with new brackets. Bond strength was measured again, 1 hour or 24 hours later. Representative specimens were inspected under the scanning electron microscope. Bracket base design significantly affected mean shear bond strength. Speed (60-gauge, microetched foil-mesh base; Strite Industries, Cambridge, Ontario, Canada) had the highest bond strength at 1 hour; followed by Time (machined, integral, microetched base with mechanical undercuts; American Orthodontics, Sheboygan, Wis); American Master Series (80-gauge foil-mesh base; American Orthodontics); Ovation Roth (80-gauge layered onto 150-gauge, microetched foil-mesh base; GAC, Central Islip, NY); Orthos Optimesh XRT (100-gauge microetched foil-mesh base; Ormco, Orange, Calif); and, finally, the nickel-free brackets (injection molded, 100-gauge, microetched, foil-mesh base; World Class Technology, McMinnville, Ore). The 24-hour results were similar except that Time had the highest mean shear bond strength (ANOVA, P <.05). Chairside sandblasting significantly affected the 1-hour, but not the 24-hour, mean shear bond strengths (ANOVA, P <.05). Sandblasting appears to be an effective method of cleaning bracket bases before rebonding.

Factors that affect the shear bond strength of multiple component and single bottle adhesives to dentin.

PURPOSE: To examine the effects of thermocycling and the long-term integrity of the bonds between adhesive and resin composite to bovine dentin using multi-step and single bottle adhesive systems. MATERIALS AND METHODS: Dentin bonding sites were prepared using water irrigated #600 grit SiC paper on bovine incisor crowns mounted in acrylic resin. A 4 mm diameter area of dentin was etched, rinsed, left visibly moist and adhesives applied according to the manufacturers' instructions. The adhesives were: Scotchbond Multipurpose, Single Bond, All Bond 2, One Step, and Prime & Bond 2.1. Cylinders of Z100 resin composite 4 mm in diameter were positioned over the adhesive and visible light-cured. Bonded specimens were divided into five groups each containing 12 samples and: (1) stored in water for 24 hours; (2) stored in water for 7 days; (3) stored in water for 270 days; (4) thermocycled after 24 hours and stored for a total lapsed time of 7 days; (5) stored in water for 6.5 days, and thermocycled for a total lapsed time of 7 days. All storage temperatures were 37 degrees C. All specimens were shear (SBS) tested to failure at the end of each storage period, the results converted to MPa and the mode of fracture failure recorded. RESULTS: The SBS for all five adhesives deteriorated over time; the effects of thermocycling were shown to be variable and dependant upon the adhesive; the modes of fracture failure were shown to be adhesive/cohesive or mixed; after long-term (270 days) storage there was an increased tendency for adhesive/cohesive fracture failure.