Background: Tumor shrinkage is a common end point used in screening new cytotoxic agents. The standard World Health Organization criterion for partial response is a 50% or more decrease in the sum of the products of two measurements (the maximum diameter of a tumor and the largest diameter perpendicular to this maximum diameter) of individual tumors. However, theoretically, the simple sum of the maximum diameters of individual tumors is more linearly related to cell kill than is the sum of the bidimensional products. It has been hypothesized that the calculation of bidimensional products is unnecessary, and a 30% decrease in the sum of maximum diameters of individual tumors (assuming spherical shape and equivalence to a 50% reduction in the sum of the bidimensional products) was proposed as a new criterion. We have applied the standard response and the new response criteria to the same data to determine whether the same number of responses in the same patients would result. Methods: Data from 569 patients included in eight studies of a variety of cancers were reanalyzed. The two response criteria were separately applied, and the results were compared using the statistic. The importance of confirmatory measurements and the frequency of nonspherical tumors were also examined. In addition, for a subset of 128 patients, a unidimensional criterion for disease progression (30% increase in the sum of maximum diameters) was applied and compared with the standard definition of a 25% increase in the sum of the bidimensional products. Results: Agreement between the unidimensional and bidimensional criteria was generally found to be good. The statistic for concordance for overall response was 0.95. Conclusion: We conclude that one dimensional measurement of tumor maximum diameter may be sufficient

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Objectives The authors conducted a study to determine the types, outcomes, risk factors and esthetic assessment of implants and their restorations placed in the general practices of a practice-based research network. Methods All patients who visited network practices three to five years previously and underwent placement of an implant and restoration within the practice were invited to enroll. Practitioner-investigators (P-Is) recorded the status of the implant and restoration, characteristics of the implant site and restoration, presence of peri-implant pathology and an esthetic assessment by the P-I and patient. The P-Is classified implants as failures if the original implant was missing or had been replaced, the implant was mobile or elicited pain on percussion, there was overt clinical or radiographic evidence of pathology or excessive bone loss (> 0.2 millimeter per year after an initial bone loss of 2 mm). They classified restorations as failures if they had been replaced or if there was abutment or restoration fracture. Results The authors enrolled 922 implants and patients from 87 practices, with a mean (standard deviation) follow-up of 4.2 (0.6) years. Of the 920 implants for which complete data records were available, 64 (7.0 percent) were classified as failures when excessive bone loss was excluded from the analysis. When excessive bone loss was included, 172 implants (18.7 percent) were classified as failures. According to the results of univariate analysis, a history of severe periodontitis, sites with preexisting inflammation or type IV bone, cases of immediate implant placement and placement in the incisor or canine region were associated with implant failure. According to the results of multivariate analysis, sites with preexisting inflammation (odds ratio [OR] = 2.17; 95 percent confidence interval [CI], 1.41–3.34]) or type IV bone (OR = 1.99; 95 percent CI, 1.12–3.55) were associated with a greater risk of implant failure. Of the 908 surviving implants, 20 (2.2 percent) had restorations replaced or judged as needing to be replaced. The majority of P-Is and patients were satisfied with the esthetic outcomes for both the implant and restoration. Conclusions These results suggest that implant survival and success rates in general dental practices may be lower than those reported in studies conducted in academic or specialty settings. Practical Implications The results of this study, generated in the private general practice setting, add to the evidence base to facilitate implant treatment planning.

Background This study investigated postoperative hypersensitivity at 1, 4, and 13 weeks following resin-based composite (RBC) restorations of occlusal caries and its relationship with prepreparation (baseline) sensitivity and preparation-related variables, including dentin caries activity, cavity dimension and volume, and lesion radiographic visibility. Methods Investigators in a practice-based research network enrolled patients with occlusal caries deemed to require operative treatment. The 45 dental practitioners then placed restorations using their preferred techniques. Complete baseline data on 665 restorations from 602 patients included patient-reported sensitivity (pre-preparation); dentists’ ranking of dentin caries on opening the enamel; measurements of preparation depth, width, and length; and patient demographics. At 1, 4, and 13 weeks post-treatment, patients anonymously reported any sensitivity to hot and cold stimuli, sweets, clenching, and chewing, as well as quality-of-life indicators related to the restorations. Results At baseline, 30% of teeth had reported sensitivities of ≥3 on an anchored scale from 0 to 10 points and were designated as appreciable hypersensitivity (AH). Appreciable hypersensitivity at baseline was related to lesion radiographic visibility and patient age but not to dentin caries activity ranking, type of posterior tooth, gender, or race/ethnicity. Patients reported on 491 restorations at 4 weeks post-treatment—18% had AH. Of those who had AH, 39% (34 of 87) had no baseline AH. With restoration, 63% of teeth with baseline AH no longer had AH. Changes in AH were not associated with preparation depth, length, width, or volume. Conclusion Patient-reported occlusal caries tooth sensitivity was high at baseline and eliminated by RBC restoration in 63% of cases; however, new sensitivity after restoration was reported in 10% of lesions that had none at pretreatment. Sensitivity was not related to preparation dimensions, volume, tooth type, or patient demographics (other than age) in these early lesions.

Background The authors undertook a study involving members of a dental practice-based research network to determine the outcome and factors associated with success and failure of endodontic therapy. Methods Members in participating practices (practitioner-investigators [P-Is]) invited the enrollment of all patients seeking treatment in the practice who had undergone primary endodontic therapy and restoration in a permanent tooth three to five years previously. If a patient had more than one tooth so treated, the P-I selected as the index tooth the tooth treated earliest during the three- to five-year period. The authors excluded from the study any teeth that served as abutments for removable partial dentures or overdentures, third molars and teeth undergoing active orthodontic endodontic therapy. The primary outcome was retention of the index tooth. Secondary outcomes, in addition to extraction, that defined failure included clinical or radiographic evidence (or both) of periapical pathosis, endodontic retreatment or pain on percussion. Results P-Is in 64 network practices enrolled 1,312 patients with a mean (standard deviation) time to follow-up of 3.9 (0.6) years. During that period, 3.3 percent of the index teeth were extracted, 2.2 percent underwent retreatment, 3.6 percent had pain on percussion and 10.6 percent had periapical radiolucencies for a combined failure rate of 19.1 percent. The presence of preoperative periapical radiolucency with a diagnosis of either irreversible pulpitis or necrotic pulp was associated with failure after multivariate analysis, as were multiple canals, male sex and Hispanic/Latino ethnicity. Conclusions These results suggest that failure rates for endodontic therapy are higher than previously reported in general practices, according to results of studies based on dental insurance claims data. Clinical Implications The results of this study can help guide the practitioner in deciding the most appropriate course of therapy for teeth with irreversible pulpitis, necrotic pulp or periapical periodontitis.