Histological assessment of a novel de-epithelialization method for connective tissue grafts harvested from the palate. An experimental study in cadavers.

OBJECTIVES: This study aims to compare the histological outcomes of three distinct de-epithelialization methods used in (connective tissue grafts) CTG harvested from the palate. MATERIALS AND METHODS: An experimental study using nine cadaver head specimens was carried out to compare 3 different de-epithelialization techniques for CTG. Eighteen samples were randomly allocated to three study groups: bone scraper, diamond bur and extraoral removal with a scalpel. The main outcome variable was the graft surface percentage without epithelium remains. Additionally, the time employed, and the graft thickness were also measured. RESULTS: Sixteen CTGs were analyzed. The extraoral scalpel group presented a total surface area with no epithelium of 58.84% (22.68) and a mean de-epithelialization time of 3.7 min; the intraoral diamond bur group had 88.24% (41.3) of the surface with no epithelium and took 1.455 min, and the intraoral bone scraper showed 97.98% (5.99) of surface without epithelium and a mean time of 0.815 min (P < 0.05). Histological analysis showed significant differences between the bone scraper and the extraoral group (P = 0.009). CONCLUSION: The de-epithelialization technique with a bone scraper seems to be the most effective and fastest de-epithelialization technique for CTG. These findings need to be confirmed in future clinical studies with larger samples. CLINICAL RELEVANCE: The use of bone scrapers, could be a simple, effective and fast technique to de-epithelialize connective tissue grafts harvested from the palatal area for both novice and experienced surgeons.

Peri-implantitis in patients without regular supportive therapy: Prevalence and risk indicators.

OBJECTIVES: To determine the prevalence of peri-implant diseases in patients treated in a university setting without a regular peri-implant supportive therapy schedule, and to identify the risk indicators associated with peri-implantitis. MATERIAL AND METHODS: A retrospective cohort study was made of patients with dental implants with at least 12 months of functional loading who did not receive regular peri-implant supportive therapy. Patient- and implant-related variables were retrieved, and clinical and radiological examinations were performed. Descriptive and bivariate analyses and multilevel logistic regression analyses were performed to identify factors associated with peri-implantitis. RESULTS: A total of 213 implants in 88 patients were analyzed. The patient-level prevalence of peri-implantitis and peri-implant mucositis was 26.1% (95%CI: 16.7%-35.5%) and 44.3% (95%CI: 34.0%-54.6%), respectively. Peri-implant diseases were significantly more frequent when the width of the keratinized mucosa was < 2 mm (OR = 5.26; 95%CI: 1.24-22.26; p = 0.024), and when there was 12 month post-loading bone loss (OR = 2.96; 95%CI: 1.35-6.52; p = 0.007). CONCLUSIONS: Peri-implantitis is a common finding in patients without regular peri-implant supportive therapy (prevalence 16.7-35.5%). A thin peri-implant keratinized mucosa (< 2 mm) and a higher degree of bone remodeling after loading seem to be the main risk factors for peri-implantitis in this patient profile. CLINICAL RELEVANCE: Patients who do not engage in supportive peri-implant maintenance have a higher risk of peri-implantitis. A thin keratinized mucosa and bone loss during the first year of loading are predisposing factors for peri-implantitis.

Validity and reliability of the Spanish version of the consultation and relational empathy measure in dental students (Sp-Dent-CARE): A cross-sectional study.

INTRODUCTION: An evaluation was made of the psychometric properties of a Spanish version of the Consultation and Relational Empathy Measure (CARE) to assess relational empathy in undergraduate dental students. In addition, the influence of demographic, socio-economic and consultation-related factors upon the degree of perceived empathy and overall satisfaction was studied. MATERIALS AND METHODS: A cross-sectional study was carried out in patients seen in the Oral Surgery Unit by fourth year dental students. Dentists, specialized translators and psychologists developed the translation of the questionnaire. After a pilot test, a convenience sample of patients was included. Construct validity was tested by factor analysis using principal component analysis with varimax rotation and Kaiser standardization, and internal consistency was assessed by Cronbach's α. RESULTS: Two pilot tests were carried out with a panel of experts until the final version of the questionnaire was established. In the validation stage, 191 patients participated (92 men and 99 women), with a mean age of 52.5 ± 17 years. The mean score of the CARE measure was 47.2 ± 4.4, and 57.6% of the patients (n = 110) reported the maximum score on the questionnaire. The final version showed a 1-factor solution explaining 68.6% of the total variance, with excellent final internal consistency (α = 93.4%). CONCLUSION: The Spanish version of the CARE measure affords high reliability and validity in assessing relational empathy in dental students. Perceived empathy is related to overall satisfaction. Patient demographics and the number of visits do not influence perceived empathy.

Accuracy of dental implant placement with or without the use of a dynamic navigation assisted system: A randomized clinical trial.

OBJECTIVES: To assess dental implant placement accuracy with a dynamic computer-assisted implant surgery (dCAIS) system and a freehand approach. Secondarily, to compare the patients' perception and quality of life (QoL) with the two approaches. METHODS: A double-arm randomized clinical trial was conducted. Consecutive partially edentulous patients were randomly allocated to the dCAIS or standard freehand approach groups. Implant placement accuracy was evaluated by overlapping the preoperative and postoperative Cone Beam Computer Tomographs (CBCT) and recording linear deviations at the implant apex and platform (in mm) and angular deviations (in degrees). Questionnaires recorded self-reported satisfaction, pain and QoL during surgery and postoperatively. RESULTS: Thirty patients (22 implants) were enrolled in each group. One patient was lost to follow-up. A significant difference (p < .001) in mean angular deviation was found between the dCAIS (4.02°; 95% CI: 2.85 to 5.19) and the FH (7.97°; 95% CI: 5.36 to 10.58) groups. Linear deviations were significantly lower in the dCAIS group, except for the apex vertical deviation, where no differences were found. Although dCAIS took 14 min longer (95% CI: 6.43 to 21.24; p < .001), patients in both groups considered the surgical time acceptable. Postoperative pain and analgesic consumption during the first postoperative week were similar between groups and self-reported satisfaction was very high. CONCLUSION: dCAIS systems significantly increase the accuracy of implant placement in partially edentulous patients in comparison with the conventional freehand approach. However, they increase the surgical time significantly and do not seem to improve patient satisfaction or reduce postoperative pain.

Comparison of external, internal flat-to-flat, and conical implant abutment connections for implant-supported prostheses: A systematic review and network meta-analysis of randomized clinical trials.

STATEMENT OF PROBLEM: The implant abutment connection interface has been considered one of the major factors affecting the outcome of implant therapy. However, drawbacks of traditional meta-analyses are the inability to compare more than 2 treatments at a time, which complicates the decision-making process for dental clinicians, and the lack of a network meta-analysis. PURPOSE: The purpose of this network meta-analysis was to assess whether the implant abutment connection influences the outcome of implant-supported prostheses. MATERIAL AND METHODS: An electronic search was undertaken to identify all randomized clinical trials comparing the effect of at least 2 different implant abutment connection designs published from 2009 up to May 2020. Outcome variables were implant survival rate, peri-implant marginal bone loss, and biologic and prosthetic complication rates at 12 months after prosthetic loading. Relevant information was extracted, and quality and risk of bias assessed. Pairwise meta-analyses and network meta-analyses based on a multivariate random-effects meta-regression were performed to assess the comparisons (α=.05 for all analyses). RESULTS: For peri-implant marginal bone loss and prosthetic complications, conical interfaces were determined to be the most effective, with significant differences when compared with external hexagonal connections (P=.011 and P=.038, respectively). No significant differences were found among the implant abutment connections in terms of survival and biologic complications (P>.05 in all direct, indirect, and mixed comparisons). CONCLUSIONS: After 1 year of loading, conical connections showed lower marginal bone loss and fewer prosthetic complications than external hexagonal connections. However, the implant abutment connection design had no influence on the implant survival and biologic complication rates.

Is serum C-terminal telopeptide cross-link of type 1 collagen a reliable parameter for predicting the risk of medication-related osteonecrosis of the jaws? A systematic review and meta-analysis of diagnostic test accuracy.

OBJECTIVE: To determine the usefulness of Serum C-terminal telopeptide cross-link of type 1 collagen (sCTX) as a preoperative marker for predicting the risk of developing medication-related osteonecrosis of the jaws (MRONJ) after invasive oral surgery in patients on antiresorptive medication. MATERIALS AND METHODS: Two authors independently searched four electronic databases up to March 25, 2021, for case-control studies and prospective and retrospective cohort studies that assessed preoperative sCTX levels in patients taking antiresorptive medication who underwent oral surgery procedures. The main outcome was the number of MRONJ cases in patients with an sCTX value lower and higher than 150 pg/mL. Qualitative and quantitative data was extracted in tables and the risk of bias was assessed using the QUADAS-2 tool. Estimates of diagnostic accuracy were expressed as sensitivity, specificity, negative and positive likelihood ratio (LR - and LR +), and diagnostic odds ratio (DOR), with a 95% confidence interval (95%CI). The data were combined using random-effects models based on the inverse variance method. RESULTS: Seven studies were included in the meta-analysis. The results were as follows: sensitivity 57% (95%CI: 41-71%), specificity 72% (95%CI: 64-79%), LR + 2 (95%CI: 1.3-3.1), LR - 0.6 (95%CI: 0.4-0.9), and DOR 3.4 (95%CI: 1.5-7.7). CONCLUSIONS: The low overall performance of sCTX indicates that this parameter is not suitable for predicting MRONJ risk in patients on antiresorptive medication who need an oral surgery procedure. CLINICAL RELEVANCE: sCTX should not be considered a reliable preoperative marker to predict MRONJ development.

Probing single-tooth dental implants with and without prostheses: a cross-sectional study comparing healthy and peri-implant mucositis sites.

AIM: To evaluate differences in probing depth (PPD) with and without a prosthesis in implants without interproximal bone loss (IBL). Secondarily, to assess whether the difference in PPD measured with and without the crown was affected by diagnosis or implant location. MATERIALS AND METHODS: A cross-sectional study was conducted in patients with a single screw-retained implant-supported crown in the posterior area, without IBL. PPD and was assessed before and after crown removal. A subgroup analysis compared healthy vs. mucositis implants and premolar vs. molar locations. RESULTS: In the 62 implants analysed (23 healthy and 39 with mucositis), the PPD was 1.15 mm (SD = 1.24 mm) deeper without the prosthesis than with it (p < .001). This difference was independent of the implant location (p > .05) except for buccal sites (p = .048). The mean PPD difference for implants with mucositis was 0.95 mm (SD = 1.19 mm; p < .001) while healthy implants had a mean PPD variation of 1.47 mm (SD = 1.29 mm; p < .001). CONCLUSION: The presence of prosthesis in single-tooth implants in the posterior area without IBL seems to lead to an underestimation of PPD that appears to be significant in implants diagnosed with mucositis, although the difference is even greater in healthy implants. Further studies are needed to confirm these findings.

Accuracy assessment of dynamic computer-aided implant placement: a systematic review and meta-analysis.

OBJECTIVES: To assess the accuracy of dynamic computer-aided implant surgery (dCAIS) systems when used to place dental implants and to compare its accuracy with static computer-aided implant surgery (sCAIS) systems and freehand implant placement. MATERIALS AND METHODS: An electronic search was made to identify all relevant studies reporting on the accuracy of dCAIS systems for dental implant placement. The following PICO question was developed: "In patients or artificial models, is dental implant placement accuracy higher when dCAIS systems are used in comparison with sCAIS systems or with freehand placement? The main outcome variable was angular deviation between the central axes of the planned and final position of the implant. The data were extracted in descriptive tables, and a meta-analysis of single means was performed in order to estimate the deviations for each variable using a random-effects model. RESULTS: Out of 904 potential articles, the 24 selected assessed 9 different dynamic navigation systems. The mean angular and entry 3D global deviations for clinical studies were 3.68° (95% CI: 3.61 to 3.74; I2 = 99.4%) and 1.03 mm (95% CI: 1.01 to 1.04; I2 = 82.4%), respectively. Lower deviation values were reported in in vitro studies (mean angular deviation of 2.01° (95% CI: 1.95 to 2.07; I2 = 99.1%) and mean entry 3D global deviation of 0.46 mm (95% CI: 0.44 to 0.48 ; I2 = 98.5%). No significant differences were found between the different dCAIS systems. These systems were significantly more accurate than sCAIS systems (mean difference (MD): -0.86°; 95% CI: -1.35 to -0.36) and freehand implant placement (MD: -4.33°; 95% CI: -5.40 to -3.25). CONCLUSION: dCAIS systems allow highly accurate implant placement with a mean angular of less than 4°. However, a 2-mm safety margin should be applied, since deviations of more than 1 mm were observed. dCAIS systems increase the implant placement accuracy when compared with freehand implant placement and also seem to slightly decrease the angular deviation in comparison with sCAIS systems. CLINICAL RELEVANCE: The use of dCAIS could reduce the rate of complications since it allows a highly accurate implant placement.

Is it possible to extract lower third molars with infiltration anaesthesia techniques using articaine? A double-blind randomized clinical trial.

OBJECTIVE: To compare the efficacy and safety of inferior alveolar nerve blocks (IANB) with additional buccal infiltration (standard technique) and of buccal and lingual anaesthetic infiltration (experimental technique) for lower third molar (L3M) extractions. STUDY DESIGN: A randomised, double-blind clinical trial involving 129 L3M extractions was conducted. In the IANB group, an IANB was performed using the conventional approach, followed by a buccal injection in the extraction area. In the infiltration group (INF), an infiltration was performed in the buccal and lingual areas of the lower second molar. A 4% articaine solution was employed in all cases. The main outcome variable was anaesthetic efficacy. Other variables like intraoperative and postoperative pain, onset time and adverse events were also recorded. Descriptive and bivariate analyses of the data were made. RESULTS: 120 patients were randomised. The IANB group showed significantly higher anaesthetic efficacy than the INF group (64.4 vs. 45.8%) (odds ratio = 0.47; 95% confidence interval = 0.22-0.97; p = 0.042). No complications were observed. CONCLUSIONS: IANB with additional buccal infiltration is more suitable than the experimental technique for achieving adequate analgesia in L3M extractions. Moreover, the standard method is safe and provides a shorter onset time and lower initial postoperative pain levels.

Mechanical complications of implant-supported complete-arch restorations and impact on patient quality of life: A retrospective cohort study.

STATEMENT OF PROBLEM: Mechanical complications (for example, fractures) in implant-supported complete-arch restorations may affect the social and professional activities of the patient. However, most studies seem to overlook patient perceptions and generally do not assess the changes in the quality of life (QoL) of patients who experience these complications. PURPOSE: The purpose of this retrospective cohort study was to assess the influence of technical or mechanical complications of complete-arch implant-supported prostheses on patient perception and QoL by using the Oral Health Impact Profile (OHIP)-14. MATERIAL AND METHODS: A retrospective cohort study was formed of patients treated consecutively at a private clinic with immediately loaded complete-arch prostheses supported by a minimum of 4 implants (Replace Tapered; Nobel Biocare AB) and Multi-Unit conical abutments (Multi-Unit abutments; Nobel Biocare AB). OHIP-14 and questions regarding self-reported satisfaction were used to evaluate the influence of mechanical complications on QoL. RESULTS: Fifty-six participants (26 men and 30 women) with a mean age of 64 ±11.1 years, and 72 restored arches were included. The mean ±standard deviation follow-up time was 52 ±26 months. The prosthetic success rate was 38.8%, and the survival rate was 100% (no failure was registered). The most common complications were abutment screw loosening (43%), chipping or fracture of the veneering material (25%), and screw loosening (21%). The OHIP-14 scores were close to zero, without differences between participants with or without mechanical complications. Overall, the participants reported that the prostheses allowed good oral hygiene (94.6%) and met their expectations (89%) and that they would repeat the treatment (87.5%) and would recommend it to others (93%). CONCLUSIONS: Minor mechanical complications such as screw loosening and chipping or fracture of the veneering material were frequent events but had no impact on the satisfaction and QoL of patients with immediately loaded complete-arch implant-supported prostheses.

Influence of Different Incision Designs on Flap Extension: A Cadaveric Animal Model.

It is well known that wound dehiscence is one of the most frequent complications in guided bone regeneration. The main cause of this complication may be a lack of tension-free and primary wound closure. The aim of this study was to evaluate and compare the effect of periosteal releasing incisions (PRI) on the extension of 3 different flap designs: envelope, triangular, and trapezoidal. Twelve pig mandibles were used to quantify extension of the flap designs. The mandibles were equally and randomly distributed into the 3 flap groups. Each mandible was divided into 2 sides: 1 was subjected to a PRI and the other not. The flap was pulled with a force of 1.08 N, and the extension was recorded. The subgroups without PRI showed an average extension of 5.14 mm with no statistically significant differences among them (P = .165). The PRI provided an average extension of 7.37 mm with statistically significant differences among the subgroups (P < .001). The releasing incisions significantly increased flap extension in each flap design. The increase in extension of the trapezoidal flap with PRI was significantly greater than in the other subgroups. In cases where primary closure is required, surgeons should consider performing trapezoidal flaps with PRI in order to reduce tension.

Effect of an Informative Video on Anxiety and Hemodynamic Parameters in Patients Requiring Mandibular Third Molar Extraction: A Randomized Clinical Trial.

PURPOSE: The purpose was to determine the effect of watching an informative video about mandibular third molar (M3M) removal on patient anxiety and hemodynamic parameters. PATIENTS AND METHODS: A randomized controlled clinical trial was carried out in healthy patients (aged between 18 and 40 years) requiring M3M extraction under local anesthesia. Patients with previous tooth extractions, psychiatric disorders, or cardiac problems or patients undergoing anxiolytic or antidepressant drug treatment were excluded. Participants were randomized into 2 groups according to whether they watched an informative video about the surgical procedure (video group) or not (control group). The primary outcome variable was the difference between groups regarding patient anxiety assessed with the State-Trait Anxiety Inventory (STAI) and the Modified Dental Anxiety Scale (MDAS). The secondary outcome variables were hemodynamic parameters recorded during different moments of the surgical procedure. Descriptive, bivariate, and multivariate analyses were performed, and a repeated-measures mixed model was generated. Statistical significance was considered for P < .05. RESULTS: Fifty patients referred for M3M extraction met the inclusion criteria. The final data analysis was based on 47 patients: 25 from the video group and 22 controls. The bivariate analysis showed the video group to have a significant decrease in anxiety as measured by the MDAS (P = .006; 95% confidence interval [CI], -4.1 to -0.7) and STAI-State (P = .003; 95% CI, -13.7 to -0.7). A significantly lower heart rate was likewise found in the video group (χ2 = 4.30, df = 1, P = .038). The linear regression analysis adjusting for the STAI-Trait also showed lower dental anxiety measured by the MDAS in the video group (P = .023; 95% CI, 0.32 to 4.14). CONCLUSIONS: Providing preoperative information through an informative video about M3M removal significantly reduces patient anxiety and heart rate during the surgical procedure.

Efficacy and safety of selective COX-2 inhibitors for pain management after third molar removal: a meta-analysis of randomized clinical trials.

OBJECTIVES: To compare selective COX-2 inhibitors with ibuprofen in terms of analgesia, rescue medication consumption, and adverse effects after impacted third molar removal. MATERIALS AND METHODS: Electronic databases were searched. Single dose, double-blind, randomized, and controlled clinical trials comparing the analgesic effect of a selective COX-2 inhibitor versus at least one active control group using ibuprofen after impacted third molar removal were selected. RESULTS: Twelve studies were included for the qualitative synthesis and eight were included in the meta-analysis. No statistically significant differences were found between selective COX-2 inhibitors and ibuprofen in terms of pain relief after 6, 8, and 12 h. Rescue analgesia use after 24 h was significantly greater in the ibuprofen group than in the selective COX-2 inhibitor group. There were no statistically significant differences in the number of patients presenting one or more adverse events between the two groups, though ibuprofen intake was related with more nausea and vomiting. CONCLUSIONS: No statistically significant differences were found in terms of pain relief 6, 8, and 12 h post-medication between selective COX-2 inhibitors and ibuprofen following totally or partially impacted third molar removal. The patients who consumed selective COX-2 inhibitors needed less rescue analgesia after 24 h. The occurrence of one or more adverse events was similar in both groups, though patients who consumed ibuprofen had more nausea and vomiting. CLINICAL RELEVANCE: COX-2 inhibitors could be considered a suitable alternative to ibuprofen for pain relief after third molar extraction in patients at risk of developing nausea and vomiting. Also, COX-2 inhibitors seem to slightly reduce the need of rescue medication consumption.

Effect of crown to implant ratio and implantoplasty on the fracture resistance of narrow dental implants with marginal bone loss: an in vitro study.

BACKGROUND: Peri-implantitis is a biological complication that affects soft and hard tissues around dental implants. Implantoplasty (IP) polishes the exposed implant surface, to decontaminate it and make it less prone to bacterial colonization. This study investigates whether a higher clinical crown-to-implant-ratio (CIR) reduces implant fracture resistance and whether implants are more fracture-prone after IP in the presence of 50% of bone loss. METHODS: Forty-eight narrow platform (3.5 mm) 15 mm long titanium dental implants with a rough surface and hexagonal external connection were placed in standardized bone-like resin casts leaving 7.5 mm exposed. Half were selected for IP. The IP and control groups were each divided into 3 subgroups with different clinical CIRs (2:1, 2.5:1 and 3:1). The implant wall width measurements were calculated using the software ImageJ v.1.51 through the analysis of plain x-ray examination of all the samples using standardized mounts. A fracture test was performed and scanning electron microscopy was used to evaluate maximum compression force (Fmax) and implant fractures. RESULTS: IP significantly reduced the implant wall width (P < 0.001) in all reference points of each subgroup. Fmax was significantly higher in the 2:1 subgroup (control = 1276.16 N ± 169.75; IP = 1211.70 N ± 281.64) compared with the 2.5:1 (control = 815.22 N ± 185.58, P < 0.001; IP = 621.68 N ± 186.28, P < 0.001) and the 3:1 subgroup (control = 606.55 N ± 111.48, P < 0.001; IP = 465.95 N ± 68.57, P < 0.001). Only the 2.5:1 subgroup showed a significant reduction (P = 0.037) of the Fmax between the controls and the IP implants. Most fractures were located in the platform area. Only 5 implants with IP of the 2:1 CIR subgroup had a different fracture location (4 fractures in the implant body and 1 in the prosthetic screw). CONCLUSIONS: IP significantly reduces the fracture resistance of implants with a 2.5:1 CIR. The results also suggest that the CIR seems to be a more relevant variable when considering the resistance to fracture of implants, since significant reductions were observed when unfavorable CIR subgroups (2.5:1 and 3:1 CIR) were compared with the 2:1 CIR samples.

Does Mandibular Gonial Angle Predict Difficulty of Mandibular Third Molar Removal?

PURPOSE: Predicting the difficulty of impacted mandibular third molar (IM3M) removal remains a controversial issue because many variables have been associated with increased operation time. Thus, the main objective of this study was to assess the influence of the gonial angle on the surgical difficulty of IM3M extraction. PATIENTS AND METHODS: A prospective cohort study of patients requiring IM3M removal was conducted. The gonial angle measured with a goniometer was considered the primary predictor variable. The primary outcome variable was operation time. Difficulty also was recorded by surgeons using a 100-mm visual analog scale (VAS). Postoperative complications (pain, swelling, and trismus at 48 hours and 7 days) were registered as secondary outcome variables. A descriptive bivariate statistical analysis, Pearson correlations and scatter plots, and an explanatory multiple linear regression model were performed. Significance was set at P < .05. RESULTS: The sample comprised 60 participants (17 men and 43 women) with a mean age of 25.2 years (standard deviation, 7.1 years). No significant correlations were found between the gonial angle and operation time, VAS difficulty score, and postoperative complications. Regression analysis confirmed this lack of effect of the gonial angle. The operation time was significantly affected by surgical experience (P = .016) and patient age (P = .009), whereas the 100-mm VAS difficulty score was only related to surgical experience (P = .001). CONCLUSIONS: The gonial angle is not related to the surgical difficulty of IM3M removal. Moreover, this variable is not associated with the occurrence of postoperative complications. According to the findings in this cohort, surgical experience and patient age are the only variables significantly related to increased operation time.

Multidrug-Resistant Salmonella enterica Isolated from Food Animal and Foodstuff May Also Be Less Susceptible to Heavy Metals.

Salmonella enterica is a foodborne pathogen showing increasing multidrug resistance (MDR). We characterized the antimicrobial resistance (AMR) genotype using microarrays in a panel of 105 nontyphoidal S. enterica isolated from food animals and foodstuff. Nineteen isolates were chosen on the basis of their MDR and virulence for determination of heavy metal susceptibilities and screened by polymerase chain reaction for heavy metal resistance genes. Whole-genome sequencing (WGS) was performed on three isolates carrying clinically important AMR genes and the cdtB toxin gene to detect other heavy metal resistance mechanisms, and conjugation assays were performed to evaluate transfer of AMR/toxin genes with heavy metal resistance genes. AMR genotyping results showed isolates harbored between 1 and 12 mobile AMR genes, with 58% being classified as MDR. The tested subset of isolates showed reduced susceptibility to zinc (78%), copper (68%), silver (63%), arsenic (47%), and tellurite (26%); phenotypes that could be attributed to zitB (n = 32%), pcoA/pcoD (n = 32%), tcrB (n = 16%), arsB (n = 16%), silA/silE (n = 42%), and terF (n = 26%) genes. WGS confirmed the presence of other heavy metal resistance genes such as copA, cusA, and czcD. Isolates often harbored multiple heavy metal resistance genes. Two strains (Sal25 and Sal368) were able to conjugate with Escherichia coli J53 at a relatively high frequency (∼10-4 colony-forming units per recipient). Transformants selected in the presence of copper harbored either an IncHI2 (J53/Sal25 transconjugant) or IncF (J53/Sal368 transconjugant) plasmid with decreased susceptibilities to tellurite, zinc, copper, cobalt, arsenic, lead, mercury, and silver. blaCTX-M-1 and mcr-1 genes were also transferred to one transconjugant, and tet(M) and blaTEM-1 genes to the other. This work shows the presence of a diversity of AMR genes in this zoonotic pathogen, and suggests that heavy metals may contribute to selection of clinically important ones through the food chain, such as the plasmid-mediated colistin resistance gene mcr-1.

A metagenomic study of patients with alveolar osteitis after tooth extraction. A preliminary case-control study.

OBJECTIVE: To identify the microbiome in sockets with alveolar osteitis and compare it with a control group using metagenomic techniques. MATERIALS AND METHODS: A case-control study was conducted in subjects that had undergone a tooth extraction. Microbiological samples were taken from the sockets of 10 patients with dry socket after tooth extraction (AO group) and 10 patients in whom exodontia resulted in no postoperative complications (control group). Bacterial DNA was isolated, and the 16S rRNA gene was amplified and sequenced. Multiplexed tag-encoded sequencing of DNA from the samples was performed, and the reads were processed by Metagenomic Rapid Annotation. RESULTS: A total of 151 different species were found: 55 bacteria were only found in the AO group, 51 were specific to the control group, and 45 were common to both groups. The most frequently found genera in both groups were Prevotella. Prevotella nanceiensis, Actinomyces odontolyticus, Treponema maltophilum, Veillonella dispar, Tannerella forsythia, and Leuconostoc mesenteroides were found in several patients with alveolar osteitis, with an abundance greater than 0.5%, and were absent in all the control group samples. CONCLUSIONS: Patients who develop alveolar osteitis after dental extractions might have a different microbiota from that of patients without postoperative complications. Since this is a preliminary report, further research is needed to assess whether bacteria play an important role in the etiology of dry socket. CLINICAL RELEVANCE: This study seems to indicate that bacteria may play an important role in the alveolar osteitis etiology. Thus, new prevention and treatment strategies should be considered.

Effect of implantoplasty on fracture resistance and surface roughness of standard diameter dental implants.

OBJECTIVE: To assess the effect of implantoplasty on the fracture resistance, surface roughness, and macroscopic morphology of standard diameter (4.1 mm) external connection dental implants. MATERIALS AND METHODS: An in vitro study was conducted in 20 screw-shaped titanium dental implants with an external connection. In 10 implants, the threads and surface were removed and polished with high-speed burs (implantoplasty), while the remaining 10 implants were used as controls. The final implant dimensions were recorded. The newly polished surface quality was assessed by scanning electron microscopy (SEM) and by 3D surface roughness analysis using a confocal laser microscope. Finally, all the implants were subjected to a mechanical pressure resistance test. A descriptive analysis of the data was made. Also, Student's t tests were employed to detect differences regarding the compression tests. RESULTS: Implantoplasty was carried out for a mean time of 10 min and 48 s (standard deviation (SD) of 1 min 22 s). Macroscopically, the resulting surface had a smooth appearance, although small titanium shavings and silicon debris were present. The final surface roughness (Sa values 0.1 ± 0.02 µm) was significantly lower than that of the original (0.75 ± 0.08 µm Sa ) (p = .005). There was minimal reduction in the implant's inner body diameter (0.19 ± 0.03 mm), and no statistically significant differences were found between the test and control implants regarding the maximum resistance force (896 vs 880 N, respectively). CONCLUSIONS: Implantoplasty, although technically demanding and time-consuming, does not seem to significantly alter fracture resistance of standard diameter external connection implants. A smooth surface with Sa values below 0.1 µm can be obtained through the use of silicon polishers. A larger sample is required to confirm that implantoplasty does not significantly affect the maximum resistance force of standard diameter external connection implants.

A Probabilistic Paradigm for the Parametric Insurance of Natural Hazards.

There is a pressing need for simple and reliable risk transfer mechanisms that can pay out quickly after natural disasters without delays caused by loss estimation, and the need for long historical claims records. One such approach, known as parametric insurance, pays out when a key hazard variable exceeds a predetermined threshold. However, this approach to catastrophe risk, based on making deterministic binary predictions of loss occurrence, is susceptible to basis risk (mismatch between payouts and realized losses). A more defensible approach is to issue probabilistic predictions of loss occurrence, which then allows uncertainty to be properly quantified, communicated, and evaluated. This study proposes a generic probabilistic framework for parametric trigger modeling based on logistic regression, and idealized modeling of potential damage given knowledge of a hazard variable. We also propose various novel methods for evaluating the quality and utility of such predictions as well as more traditional trigger indices. The methodology is demonstrated by application to flood-related disasters in Jamaica from 1998 to 2016 using gridded precipitation data as the hazard variable. A hydrologically motivated transformation is proposed for calculating potential damage from daily rainfall data. Despite the simplicity of the approach, the model has substantial skill at predicting the probability of occurrence of loss days as demonstrated by traditional goodness-of-fit measures (i.e., pseudo-R2 of 0.55) as well as probabilistic verification diagnostics such as receiver operating characteristics. Using conceptual models of decisionmaker expenses, we also demonstrate that the system can provide considerable utility to involved parties, e.g., insured parties, insurers, and risk managers.

Prevalence of neuropathic pain and sensory alterations after dental implant placement in a university-based oral surgery department: A retrospective cohort study.

OBJECTIVE: To determine the prevalence and the clinical features of patients with neuropathic pain and sensory alterations after dental implant placement. BACKGROUND: Literature is very scarce concerning the prevalence of neuropathic pain after dental implant placement. PATIENTS AND METHODS: A retrospective cohort study was made in patients submitted to dental implant placement in the Dental Hospital of the University of Barcelona. A descriptive analysis of the data was made, and the 95% confidence intervals (95% CI) were calculated for the prevalences. RESULTS: The study sample was composed of 1156 subjects of whom, 1012 patients (3743 dental implants) met the study inclusion criteria. Four hundred and seventeen patients (41.2%) were male and 595 (58.8%) were female, with a mean age of 60.7 years (range 16-90 years). Three patients were diagnosed as having painful post-traumatic trigeminal neuropathy (PPTN), which corresponds to a prevalence of 0.3% (95% CI: 0%-0.6%). Additionally, 5 patients (0.5%; 95% CI: 0%-1.07%) presented trigeminal neuropathy without pain (TNWP). The combined prevalence of both disorders was 0.8% (95% CI: 0.02%-1.3%). All patients with PPTN and TNWP were 60 years old or older, with a total combined prevalence of 1.48% (95% CI: 0.46%-2.5%) in this age group. Additionally, the prevalence in this age group for women was 1.85% (95%CI: 0.38%-3.31%). CONCLUSIONS: Neuropathic pain after dental implant placement is very infrequent (0.3%) in a University Oral Surgery department. However, the presence of trigeminal neuropathies can be slightly higher and can affect up to 0.5% of patients. Older female patients seem to be more prone to this rare and disabling complication.