Radiotherapy Capabilities, Population, Average Income, and Health Insurance Status as Predictors of Cancer Mortality at the County Level in the United States

PURPOSE/OBJECTIVE(S)

Sufficient radiotherapy capacity at the country level is commonly seen in high income countries and is an essential factor in access to high quality cancer care. However, universal access is not always possible due to other factors beyond the commonly used parameter of machines per million population. This study aims to assess the barriers cancer patients in a high-income country face in accessing radiotherapy, and how this impacts cancer mortality.

MATERIALS/METHODS

This cross-sectional study utilized United States county level oncologic and demographic data obtained from Centers for Disease Control and Prevention and the International Atomic Energy Agency Directory of Radiotherapy Centers. Radiotherapy facilities in the United States were mapped using Geographic Information Systems software. Univariate analysis was used to identify whether distance to a radiotherapy center or various socioeconomic factors were predictive of all-cancer mortality-to-incidence ratios. Variables that were deemed to be significant (p ≤ 0.05) on univariate analysis were then included in a step-wise backwards elimination method of multiple regression analysis.

RESULTS

Among the United States counties studied, 31.3% of counties have at least one radiotherapy facility and 8.3% have five or more radiotherapy facilities. Median linear distance from a county's centroid to the nearest radiotherapy center was 36 Km and the median county all-cancer mortality to incidence ratio (MIR) was 0.37. The ratio of radiotherapy centers, linear accelerators and brachy therapy units per 1 million people were significantly associated with all-cancer MIR (p<0.05). Greater distance to radiotherapy facilities, lower county population, lower average income per county, and higher proportion of patients without health insurance were statistically significant predictors of increased all-cancer MIR (R-squared: 0.2113, F = 94.22, p<0.001).

CONCLUSION

This analysis used unique high-quality datasets to identify significant barriers to radiotherapy access that correspond to higher cancer mortality at the county level. Geographic access, personal income, and insurance status all contribute to these concerning disparities. Efforts and novel strategies to address and minimize these barriers are needed to ensure access to care and improve oncologic outcomes.

Five-year randomized controlled clinical study comparing cemented and screw-retained zirconia-based implant-supported single crowns

Objectives

To compare screw‐retained and cemented all‐ceramic implant‐supported single crowns regarding biological and technical outcomes over a 5‐year observation period.

Materials and methods

In 44 patients, 44 two‐piece dental implants were placed in single‐tooth gaps in the esthetic zone. Patients randomly received a screw‐retained (SR) or cemented (CR) all‐ceramic single crown and were then re‐examined annually up to 5 years. Outcome measures included: clinical, biological, technical, and radiographic parameters. Data were statistically analyzed with Wilcoxon–Mann–Whitney, Wilcoxon, and Fisher's exact tests.

Results

During the observation period, three patients (6.8%) were loss to follow‐up. Eight restorations (18.2%, CI (8.2%, 32.7%)) were lost due to technical (6 patients, 13.6% (CI (5.2%, 27.4%)), 2 CR and 4 SR group, intergroup p = .673; implants still present) or biological complications (2 patients, 4.5% (CI (0.6%, 16.5%)), only CR group, intergroup p = .201, both implants lost). This resulted in a survival rate of 81.2% (CI (65.9%, 90.1%)) on the restorative level (18 SR; 15 CR, 3 lost to follow‐up). At the 5‐year follow‐up, the median marginal bone levels were located slightly apical relative to the implant shoulder with 0.4 mm (0.5; 0.3) (SR) and 0.4 mm (0.8; 0.3) (CR) (intergroup p = .582). Cemented restorations demonstrated a significantly higher biological complication rate (36.8%, SR: 0.0%; intergroup p = .0022), as well as a significantly higher overall complication rate (68.4%, SR: 22.7%, intergroup p = .0049). All other outcomes did not differ significantly between the two groups (p > .05).

Conclusions

All‐ceramic single‐tooth restorations on two‐piece dental implants resulted in a relatively low survival rate. Cemented restorations were associated with a higher biological and overall complication rate than screw‐retained restorations.

Sinus Floor Elevation with Biphasic Calcium Phosphate or Deproteinized Bovine Bone Mineral: Clinical and Histomorphometric Outcomes of a Randomized Controlled Clinical Trial

PURPOSE

To clinically and histomorphometrically compare a biphasic calcium phosphate (BCP) and deproteinized bovine bone mineral (DBBM) for sinus floor elevation.

MATERIALS AND METHODS

Sinus floor elevation procedures (lateral window) were performed randomly applying either BCP (test) or DBBM (control). At 6 months, bone biopsy specimens were harvested and dental implants were placed. The proportions of new bone, residual grafting material, and nonmineralized soft tissue were calculated. Four months after implant placement, the prosthetic reconstructions were inserted and the implant survival was assessed.

RESULTS

Fifty-one patients were treated; 25 were randomly allocated to the BCP group and 26 to the DBBM group. After 6 months in 50 patients, bone biopsy specimens could be harvested, and a total of 121 implants could be placed subsequently. The histomorphometric analysis revealed a comparable percentage of new bone in both groups (BCP 35.9%, DBBM 35.4%; P > .05). The remaining grafting material was significantly lower with BCP (25.3%) compared with DBBM (45.9%; P < .001). Nonmineralized tissue was significantly higher for the BCP group (38.1%) compared with the DBBM group (18.2%; P < .001). The implant survival rate at loading was assessed at the level of the patients (96.0% for BCP and 88.8% for DBBM; P > .05) and at the level of the implants (96.9% for BCP and 94.7% for DBBM; P > .05).

CONCLUSION

Grafting with DBBM or BCP showed similar percentages of new bone 6 months after sinus floor elevation. Implant survival presented no significant difference until loading.

Reconstructive aspects: Summary and consensus statements of group 3. The 5th EAO Consensus Conference 2018

OBJECTIVES

The tasks of this working group were to evaluate the existing evidence on the efficiency and efficacy of the digital and conventional workflows for the fabrication of fixed implant reconstructions, to assess the performance of all-ceramic fixed implant reconstructions and, finally, to evaluate the outcomes of internally and externally connected implant abutments and reconstructions.

METHODS

Four reviews were available analyzing the current literature on the respective topics. One review dealt with the efficiency and efficacy of digital and conventional fabrication workflows. Two reviews analyzed the outcomes of all-ceramic fixed implant reconstructions, one focusing on single-implant reconstructions and the other evaluating multiple-unit implant fixed dental prostheses (FDPs). The fourth review evaluated the clinical outcome on external, respectively, internal implant-abutment connections. These reviews were the basis for the discussions within the group and at the plenary sessions.

RESULTS

The present consensus report gives the consensus statements, the clinical recommendations, and the implications for future research as discussed and approved by the plenum of the consensus conference. The four manuscripts by Mühlemann et al., Rabel et al., Pieralli et al., and Pjetursson et al. are published as part of the journal supplement of the present EAO consensus conference.

Is the use of digital technologies for the fabrication of implant-supported reconstructions more efficient and/or more effective than conventional techniques: A systematic review

OBJECTIVE

To identify clinical studies evaluating efficiency and/or effectiveness of digital technologies as compared to conventional manufacturing procedures for the fabrication of implant-supported reconstructions.

MATERIALS AND METHODS

A systematic search from 1990 through July 2017 was performed using the online databases Medline, Embase, and Cochrane-Central-Register-of-Controlled-Trials. Literature on efficiency and/or effectiveness during the impression session, the manufacturing process, and the delivery session were included.

RESULTS

In total, 12 clinical studies were included. No meta-analysis was performed due to a large heterogeneity of the study protocols. Nine publications reported on posterior single implant crowns (SIC) and three on full-arch reconstructions. Mean impression time with intraoral scanners ranged between 6.7 and 19.8 min, whereas the range for conventional impressions was 8.8 and 18.4 min. In a fully digital workflow (FD-WF) for posterior SIC, mean fabrication time ranged between 46.8 and 54.5 min (prefabricated abutment) and 68.0 min (customized abutment). In a hybrid workflow (H-WF) including a digitally customized abutment and a manual veneering, mean fabrication time ranged between 132.5 and 158.1 min. For a conventional porcelain-fused-to-metal-crown, a mean time of 189.8 min was reported. The mean time for the delivery of posterior SIC ranged between 7.3 and 7.4 min (FD-WF), 10.5 and 12.5 min (H-WF), and 15.3 min (conventional workflow, C-WF). The FD-WF for posterior SIC was more effective than the H-/C-WF.

CONCLUSIONS

The implementation of the studied digital technologies increased time efficiency for the laboratory fabrication of implant-supported reconstructions. For posterior SIC, the model-free fabrication, the use of prefabricated abutments, and the monolithic design was most time efficient and most effective.