Teammate familiarity and risk of injury in emergency medical services

Objective: We investigated the association between teammate familiarity and workplace injury in the emergency medical services (EMS) setting. Methods: From January 2011 to November 2013, we abstracted a mean of 29 months of shift records and Occupational Safety Health Administration injury logs from 14 EMS organisations with 37 total bases located in four US Census regions. Total teammate familiarity was calculated for each dyad as the total number of times a clinician dyad worked together over the study period. We used negative binomial regression to examine differences in injury incidence rate ratios (IRRs) by familiarity. Results: We analysed 715 826 shift records, representing 4197 EMS clinicians and 60 701 unique dyads. We determined the mean shifts per dyad was (5.9, SD 19.7), and quartiles of familiarity were 1 shift worked together over the study period, 2–3 shifts, 4–9 shifts and ≥10 shifts worked together. More than half of all dyads worked one shift together (53.9%, n=32 739), 24.8% of dyads 2–3 shifts, 11.8% worked 4–9 shifts and 9.6% worked ≥10 shifts. The overall incidence rate of injury across all organisations was 17.5 per 100 full-time equivalent (FTE), range 4.7–85.6 per 100 FTE. The raw injury rate was 33.5 per 100 FTEs for dyads with one shift of total familiarity, 14.2 for 2–3 shifts, 8.3 for 4–9 shifts and 0.3 for ≥10 shifts. Negative binomial regression confirmed that dyads with ≥10 shifts had the lowest incidence of injury (IRR 0.03; 95% CI 0.02 to 0.04). Conclusions: Familiarity between teammates varies in the EMS setting, and less familiarity is associated with greater incidence of workplace injury

Postoperative hypersensitivity and its relationship to preparation variables in Class I resin-based composite restorations:findings from the practitioners engaged in applied research and learning (PEARL) Network. Part 1.

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

Restoration variables and postoperative hypersensitivity in Class I restorations:PEARL Network findings. Part 2.

BACKGROUND: This study investigated postoperative hypersensitivity at 1, 4, and 13 weeks following resin-based composite restoration of occlusal caries as well as the relationship to materials and technique employed by PEARL Network Practitioner Investigators (P-Is). METHODS: PEARL P-Is (n = 45) enrolled patients with early occlusal caries lesions deemed to require treatment and placed restorations using their routine technique. Data on 485 restorations at 4 weeks included: baseline sensitivity; ranking of dentin caries activity; post-preparation use of antimicrobials, liners, and dentin bonding agent; type of resin-based composite (RBC) employed; whether layer or bulk fill was used; and patient demographics. Patients anonymously reported at 1, 4, and 13 weeks any sensitivity to hot, cold, sweets, clenching, and chewing as well as quality of life (QOL) related to the restoration(s). RESULTS: Appreciable hypersensitivity (AH)—ie, sensitivity of 3 or greater on an 11-point anchored scale—was reported in 30% of all 668 eligible carious teeth at baseline. Among them, 10% of study teeth with no baseline AH had developed AH at 4 weeks post-treatment. With restoration, 63% of teeth with baseline AH no longer had AH, while the remainder had no improvement. Neither change in AH nor change in greatest sensitivity was associated with use of a liner, use of flowable or hybrid RBC, or bulk or layer technique. With use of an antimicrobial, at 1 week, there was a significant but transient effect on AH (P = 0.006), which was generally not present at 4 weeks, although it continued for one product. At 4 weeks, the change in greatest sensitivity was associated with the type of dentin bonding agent, total etch or self etch, (P = 0.004). Using similar materials and techniques, P-Is had widely differing patient-reported outcomes. CONCLUSION: Patient self-reported post-restoration AH—either acquired or remaining—at 4 weeks was generally not related to the materials or techniques recorded in these small- to moderate-sized occlusal restorations. However, the change in greatest sensitivity was associated with the type of dentin bonding agent used; but the clinical significance of this difference is questionable

Dentin caries activity in early occlusal lesions selected to receive operative treatment:findings from the Practitioners Engaged in Applied Research and Learning (PEARL) Network

BACKGROUND: Members of the practice-based research network Practitioners Engaged in Applied Research and Learning (PEARL) Network investigated the dentin caries activity in early occlusal lesions and its relationship to patient age, preoperative tooth sensitivity and radio-graphic appearance, as well as its influence on preparation depth and volume. METHODS: PEARL Network practitioner-investigators (P-Is) (n = 45), general dentists who were trained but whose methods were not calibrated, conducted a study regarding postoperative hypersensitivity in resin-based composite restorations. The P-Is enrolled as study participants 613 patients with occlusal carious lesions that, in the P-Is’ clinical judgment, required restoration. The P-Is used baseline radiographs to assess the depth and extent of the lesions. Data for 671 restorations included baseline sensitivity; ranking of dentin caries activity on the opening of the enamel; radiographic visibility (n = 652); and measurements of preparation depth, width and length. RESULTS: P-Is found rapidly progressing dentin caries in 38.5 percent (258 of 671) of lesions and slowly progressing (and potentially inactive dentin) caries in the remainder of the lesions. Rapidly progressing caries was not related to the participant’s age or participant-reported preoperative hypersensitivity but was related to the lesion depth as seen radiographically (P < .001) and depth (P < .001) and volume (P < .001) of the preparation. Molars had slightly higher but not statistically significant levels of caries activity. CONCLUSION: Rapidly progressing dentin caries, while present in only 38.5 percent of lesions, was related to the lesion’s radiographic appearance but not to the participant’s age or the study tooth’s pre-operative sensitivity. CLINICAL IMPLICATIONS: On the basis of the low level of rapidly progressing dentin caries in this study population and the fact that slowly progressing caries can be inactive or remineralizing, the authors advise sealing versus operative treatment of early or shallow occlusal lesions

Treatments for hypersensitive noncarious cervical lesions: A Practitioners Engaged in Applied Research and Learning (PEARL) Network randomized clinical effectiveness study

BACKGROUND: The Practitioners Engaged in Applied Research and Learning (PEARL) Network conducted a three-armed randomized clinical study to determine the comparative effectiveness of three treatments for hypersensitive noncarious cervical lesions (NCCLs): use of a potassium nitrate dentifrice for treatment of hypersensitivity, placement of a resin-based composite restoration and placement of a sealant. METHODS: Seventeen trained practitioner-investigators (P-Is) in the PEARL Network enrolled participants (N = 304) with hypersensitive posterior NCCLs who met enrollment criteria. Participants were assigned to treatments randomly. Evaluations were conducted at baseline and at one, three and six months thereafter. Primary outcomes were the reduction or elimination of hypersensitivity as measured clinically and by means of patient-reported outcomes. RESULTS: Lesion depth and pretreatment sensitivity (mean, 5.3 on a 0- to 10-point scale) were balanced across treatments, as was sleep bruxism (present in 42.2 percent of participants). The six-month participant recall rate was 99 percent. Treatments significantly reduced mean sensitivity (P < .01), with the sealant and restoration groups displaying a significantly higher reduction (P < .01) than did the dentifrice group. The dentifrice group’s mean (standard deviation) sensitivity at six months was 2.1 (2.1); those of the sealant and restoration groups were 1.0 (1.6) and 0.8 (1.4), respectively. Patient-reported sensitivity (to cold being most pronounced) paralleled clinical measurements at each evaluation. CONCLUSIONS: Sealing and restoration treatments were effective overall in reducing NCCL hypersensitivity. The potassium nitrate dentifrice reduced sensitivity with increasing effectiveness through six months but not to the degree offered by the other treatments. PRACTICAL IMPLICATIONS: Sealant or restoration placement is an effective method of immediately reducing NCCL sensitivity. Although a potassium nitrate dentifrice did reduce sensitivity slowly across six months, at no time was the reduction commensurate with that of sealants or restorations

Effectiveness of a resin-modified glass ionomer liner in reducing hypersensitivity in posterior restorations:A study from the Practitioners Engaged in Applied Research and Learning Network

BACKGROUND: The objectives of this randomized comparative effectiveness study conducted by members of the Practitioners Engaged in Applied Research and Learning (PEARL) Network were to determine whether using a resin-modified glass ionomer (RMGI) liner reduces postoperative hypersensitivity (POH) in dentin-bonded Class I and Class II resin-based composite (RBC) restorations, as well as to identify other factors (putative risk factors) associated with increased POH. METHODS: PEARL Network practitioner-investigators (P-Is) (n = 28) were trained to assess sensitivity determination, enamel and dentin caries activity rankings, evaluation for sleep bruxism, and materials and techniques used. The P-Is enrolled 341 participants who had hypersensitive posterior lesions. Participants were randomly assigned to receive an RBC restoration with or without an RMGI liner before P-Is applied a one-step, self-etching bonding agent. P-Is conducted sensitivity evaluations at baseline, at one and four weeks after treatment, and at all visits according to patient-reported outcomes. RESULTS: P-Is collected complete data regarding 347 restorations (339 participants) at baseline, with 341 (98 percent) (333 participants) recalled at four weeks. Treatment groups were balanced across baseline characteristics and measures. RBC restorations with or without an RMGI liner had the same one-week and four-week POH outcomes, as measured clinically (by means of cold or air stimulation) and according to patient-reported outcomes. CONCLUSIONS: Use of an RMGI liner did not reduce clinically measured or patient-reported POH in moderate-depth Class I and Class II restorations. Cold and air clinical stimulation findings were similar between groups. PRACTICAL IMPLICATIONS: The time, effort and expense involved in placing an RMGI liner in these moderate-depth RBC restorations may be unnecessary, as the representative liner used did not improve hypersensitivity outcomes