Quintessence International, 02/1999

Objective: An investigation was undertaken to assess potential predisposing factors to invasive cervical resorption. Method and materials: A group of 222 patients with a total of 257 teeth displaying varying degrees of invasive cervical resorption were analyzed. Potential predisposing factors, including trauma, intracoronal bleaching, surgery, orthodontics, periodontal root scaling or planing, bruxism, delayed eruption, developmental defects, and restorations were assessed from the patients' history and oral examination. Results: Of the potential predisposing factors identified, orthodontics was the most common sole factor, constituting 21.2% of patients and 24.1% of teeth examined. Other factors were present in an additional 5.0% of orthodontically treated patients (4.3% of teeth), and these consisted principally of trauma and/or intracoronal bleaching. Trauma was the second most frequent sole factor (14.0% of patients and 15.1% of teeth). Trauma in combination with intracoronal bleaching, orthodontics, or delayed eruption constituted an additional 11.2% of patients (10.6% of teeth). Intracoronal bleaching was found to be the sole potential predisposing factor in 4.5% of patients and 3.9% of teeth, and an additional 10.4% of patients and 9.7% of teeth showed a combination of intracoronal bleaching with trauma and/or orthodontics. Surgery, particularly involving the cementoenamel junction area, was a sole potential predisposing factor in 6.3% of patients and 5.4% of teeth. Periodontal therapy, including deep root scaling and planing, showed a low incidence, as did other factors, such as bruxism and developmental defects. The prsence of an intracoronal restoration was the only identifiable factor in 15.3% of patients and 14.4% of teeth, while 15.0% of patients and 16.4% of teeth showed no identifiable potential predisposing factors. Conclusion: These results indicated a strong association between invasive cervical resorption and orthodontic treatment, trauma, and intracoronal bleaching, either alone or in combination.

Objective: The purpose of this study was to carry out a clinical evaluation of the treatment of invasive cervical resorption. Method and materials: Topical application of a 90% aqueous solution of trichloracetic acid, curettage, nonsurgical root canal treatment where necessary, and restoration with glass-ionomer cement were performed on 94 patients with a total of 101 affected teeth. A minimum of 3 years' follow-up was required, unless failure occurred before that time, in which case that treatment was included. Teeth were divided into four classes, depending on the extent of the resorptive process. Class 1 represented the least invasive resorptive lesion, near the cervical area with shallow penetration into dentin, while class 4 represented the most invasive resorptive process, which had extended beyond the coronal third of the root. Results: In all class 1 and class 2 cases, the results showed complete success, judged by an absence of resorption or signs of periapical or periodontal pathosis. When overall success rate in class 3 lesions was 77.8%. Only 12.5% of teeth in class 4 were free of resorption and deemed to be clinically sound. Conclusion: The treatment regimen was successful in class 1 and class 2 cases, reasonably successful in class 3 cases, and generally unsuccessful in class 4 resorptions, where alternative treatment is recommended. Diagnosis of lesions at an early stage is, therefore, highly desirable

Cemental tear is a rare but probably underdiagnosed condition that may be a factor in rapid periodontal breakdown. The present case report describes the regenerative treatment of a periodontal lesion around a mandibular canine in a 50-year-old woman. The preoperative radiograph revealed a small cemental tear within an intrabony lesion. The three-wall bony lesion was treated with a barrier membrane and followed for 3 years. Periodontal pocket reduction was 5.5 mm, and attachment gain amounted to 3.5 to 4.5 mm. Standardized radiographs showed remarkable, 1.6-mm bone fill of the intrabony lesion. Also, a band of keratinized tissue had formed.

Objective: This study was intended to quantify the marginal leakage of three glass-ionomer - resin composite hybri d materials and compare it with the leakage exhibited by a glass-ionomer cement and a bonded resin composite system. Mathod and materials: Standardized Class V cavities were prepared on root surfaces of 105 extracted human teeth, randomly assigned to five groups of 21 each, and restored with either Ketac-Fil Aplicap, Z100/Scotchbond Multi-Purpose P lus, Vitremer, Photac-Fil Aplicap, or Dyract. The teeth were thermally stressed for 500 cycles and stained with methylene blue. The microleakage was quantified spectrophotometrically, and the data were statistically analyzed with Friedman's test. Results: There were no significant differences in microleakage among the five groups. Restorations of all tested materials showed some marginal leakage in Class V cavities. Conclusion: The microleakage performance of glass-ionomer - resin composite hybrid materials was similar to those of a conventional glass-ionomer and a bonded resin composite system.

Objective: Early bond strengths produced by dentin bonding systems should be sufficient to resist the polymerization shrinkage of resin composite. This study compared the 10-minute and 24-hour shear bond strengths of six dentin bonding systems: One-Step (OS), PermaQuik (PQ), Prime & Bond 2.1 (PB), Scotchbond Multi-Purpose (SBMP), Single Bond (SB), and Tenure Quik with Fluoride (TQ). Method and materials: Each bonding system was used to bond composite to visibly moist dentin at 34 degrees C ± 2 degrees C. The specimens were debonded at 37 degrees C ± 1 degree C 10 minutes after the start of light curing of the bonding system, and the results were compared with the 24-hour bond strengths. The mode of failure was recorded Results: The 10-minute mean shear bond strengths were: OS, 16.4; PQ, 14.3; SB, 14.0; PB, 12.7; TX, 10.7; and SBMP, 9.3 MPa. The 24-hour mean shear bond strengths were OS, 23.3; PB, 20.8; SB, 20.3; PQ, 19.4; TQ, 11.2; and SBMP, 10.0 M Pa. The 10-minute mean shear bond strengths of OS, PQ, PB, and SB bonding systems were significantly less than the 24-hour values. More dentinal fractures and mixed failures were observed with OS, PQ, and PB. Systems with higher bond strengths had more resin penetration into the lateral dentinal branches. Conclusion: The 10-minute mean shear bond strengths were all less than 17 MPa, and the 10-minute bond strengths were less than the 24-hour values.