Exotic encounters with dental implants: managing complications with unidentified systems

Machine learning for identification of dental implant systems based on shape - A descriptive study

Aim:

To evaluate the efficacy of machine learning in identification of dental implant systems from panoramic radiographs based on the shape.

Settings and Design:

In vitro–Descriptive study

Materials and Methods:

A Dataset of digital panoramic radiographs of three dental implant systems were obtained. The images were divided into two datasets: one for training and another for testing of the machine learning models. Machine learning algorithms namely, support vector machine, logistic regression, K Nearest neighbor and X boost classifiers were trained to classify implant systems from radiographs, based on the shape using Hu and Eigen values. Performance of algorithms was evaluated by its classification accuracy using the test dataset.

Statistical Analysis Used:

Accuracy and recover operating characteristic (ROC) curve were calculated to analyze the performance of the model.

Results:

The classifiers tested in the study were able to identify the implant systems with an average accuracy of 0.67. Of the classifiers trained, logistic regression showed best overall performance followed by SVM, KNN and X boost classifiers.

Conclusions:

Machine learning models tested in the study are proficient enough to identify dental implant systems; hence we are proposing machine learning as a method for implant identification and can be generalized with a larger dataset and more cross sectional studies.

Impact of design elements of the implant supracrestal complex (ISC) on the risk of peri-implant mucositis and peri-implantitis: A critical review

OBJECTIVE

The aim of this review was to investigate the evidence correlating the emergence profile (EP) and emergence angle (EA), peri-implant tissue height, implant neck design, abutment and/or prosthesis material, retention and connection types with risk of peri-implant mucositis and peri-implantitis.

METHODS

Seven focus questions were identified, and seven electronic search queries were conducted in PubMed. Human studies reporting on bleeding on probing, probing depth or case definitions of peri-implant mucositis and peri-implantitis were included.

RESULTS

Emerging evidence with bone-level implants suggests a link between EA combined with convex EP and peri-implantitis. Depth of the peri-implant sulcus of ≥3 mm is shown to be reducing the effectiveness of treatment of established peri-implant mucositis. Modification of the prosthesis contour is shown to be an effective supplement of the anti-infective treatment of peri-implant mucositis. Limited evidence points to no difference with regard to the risk for peri-implant mucositis between tissue- and bone-level implants, as well as the material of the abutment or the prosthesis. Limited evidence suggests the use or not of prosthetic abutments in external connections and does not change the risk for peri-implantitis. Literature with regard to prosthesis retention type and risk for peri-implantitis is inconclusive.

CONCLUSIONS

Limited evidence indicates the involvement of EA, EP, sulcus depth and restricted accessibility to oral hygiene in the manifestation and/or management of peri-implant mucositis/peri-implantitis. Conclusions are limited by the lack of consensus definitions and validated outcomes measures, as well as diverse methodological approaches. Purpose-designed studies are required to clarify current observations.

Original versus nonoriginal cast-to-gold abutment-implant connection: Analysis of the internal fit and long-term fatigue performance

STATEMENT OF PROBLEM

Restoring implants with nonoriginal abutments is common. However, studies that evaluated compatible abutments with long-term fatigue performance are lacking.

PURPOSE

The purpose of this in vitro study was to assess the internal fit and the cyclic fatigue life after artificial aging of 3 implant-abutment configurations restored with 1 original and 2 compatible nonoriginal cast-to-gold abutments.

MATERIAL AND METHODS

Forty-eight original internal hexagon connection implants were connected to 3 different brands of abutments (n=16): 1 original to the implant system and the other 2 with nonoriginal abutments. Internal fit and the percentage of surface with tight contact were assessed by scanning electron microscopy in 12 cross-sectioned specimens (n=4) at 3 different areas (platform, internal, and screw). Thirty-six implant-abutment-crown specimens (n=12) were immersed in artificial saliva and thermocycled for 10 000 cycles between 5 °C and 55 °C. Subsequently, a cyclic load test, as per International Organization for Standardization (ISO) Standard 14 801, was completed in a universal testing machine at 2 Hz in air.

RESULTS

The original abutments presented the best fit and highest percentage of tight contact in the internal areas. In addition, the original abutments showed the lower cyclic fatigue strength degradation and the highest long-term success.

CONCLUSIONS

Occlusal loads are transferred more homogenously through the system when original abutments are used because of the better fit between the internal components, leading to increased fatigue resistance.

Infectious complications related to medical tourism

BACKGROUND

Medical tourism has been increasing dramatically globally, with people travelling from developed countries to low-income or middle-income countries, often to avoid high costs or long delays associated with seeking healthcare in their countries of origin. The current review summarizes healthcare-related infections associated with medical tourism, focusing on cosmetic surgery and organ transplantation.

METHODS

A systematic MEDLINE and PubMed search from January 2010 to December 2019 yielded 80 relevant articles, including 49 articles on medical tourism-related infections focusing on cosmetic surgery and organ transplantation, which were included in this reviews.

RESULTS

The literature reveals specific types of cross-border, healthcare-related infections depending on medical intervention. Destinations include low-income countries such as countries of Asia and the Indian subcontinent, middle-income countries including Central and South America, and high-income countries such as the United States and Europe. In terms of type of infections, in 36 (68%) and 15 (28.3%) studies, wound and blood-borne infections were documented, respectively, while in 21 studies (58.3%) non-tuberculous mycobacteria were isolated, including Mycobacterium abscessus, Mycobacterium chelonae, Mycobacterium senegalense and Mycobacterium fortuitum. The choices of medical tourists could have significant consequences for them and their home countries, including infectious complications and importation of pathogens, particularly antibiotic-resistant microorganisms, with public health implications.

CONCLUSIONS

There is a need for public health strategies in order to prevent morbidity and mortality as well as future management and education of patients engaging in medical tourism.

Micromorphological differences of the implant-abutment junction and in vitro load testing for three different titanium abutments on Straumann tissue level implants

BACKGROUND

The aim of this study was to investigate the micromorphological differences among three commercially available titanium abutments on Straumann implants. Furthermore, the possible impact of functional loading on the micromorphology and potential complications was investigated with the use of in vitro testing.

MATERIAL AND METHODS

Three groups of Titanium abutments (A: Straumann Variobase n = 5, B: EBI best Duo n = 5, and C: Implant Direct n = 5) were torqued on Straumann RN implants, as according to each of the manufacturer's instructions. The implant-abutment units were scanned with Micro-CT. Three units of each group were directly sliced in the microtome and photographed under different magnifications (10×-500×) through a Scanning Electron Microscope. Six units (two from each group) were restored with cement-retained crowns, subjected to 2000,000 load cycles with loads between 30 and 300 N at 2 Hz, examined through Micro-CT and finally sliced and photographed as described above. The micromorphology of each unit was studied, and the total length of tight contact (<3 μm) was calculated between the implant, abutment and screw contact areas.

RESULTS

Major morphological differences were identified between the three units, as well as differences in the extent of tight contact in all areas examined. Despite the morphological differences, the 2M cycles of loading via in vitro test did not result in any noticeable complications although some changes in the micromorphology were observed.

CONCLUSION

The examined implant-abutment units presented with major morphological differences. Two million cycles of in vitro loading did not appear to affect the stability of the units despite the micromorphological changes. These results need to be interpreted however under the limitations of the small sample size and the specific set-up of the in vitro testing.

The impact of cantilevers on biological and technical success outcomes of implant-supported fixed partial dentures. A retrospective cohort study

OBJECTIVE

To investigate the biological and technical success outcomes of implant-supported fixed dental prostheses with and without cantilevers, after a minimum of one year loading.

MATERIAL AND METHODS

One hundred and seven subjects with 128 cantilever FDPs (cFDP) supported by 132 implants were compared with 99 individuals with 144 non-cantilever FPDs (ncFDPs) supported by 203 implants. Outcomes such as marginal bone loss from FDP insertion to final follow-up as well as frequency and extent of biological and technical complications were investigated and correlated with patient, site, implant and FDP design characteristics.

RESULTS

The cFDPs were followed for average of 51 months (1551 days, SD ± 977), and ncFPDs for 49 months (1483 days, SD ± 809 days). Implant survival and success rates were 96.7% and 87.9% for implant supporting cFDPs, and 99.5% and 92.6% for ncFDPs. There was no significant difference in overall bone loss between cFDPs and ncFDPs (cantilever side: 0.58, SD ± 1.16 - non-cantilever side: 0.59, SD ± 0.99), but implants in the cantilever group lost significantly more bone in the posterior mandible (0.50 SD ± 1.3 mm for cFDPs and 0.24 SD ± 0.80 mm for ncFDPs). Within the cantilever group, cantilever arm length and implant location had an influence on bone loss. Regardless of the presence of cantilever, implants associated with technical complications had a higher rate of biological complications as well. Furthermore, the length of the cantilever arm was positively correlated with implant failure, technical complications and bone loss ≥1.5 mm (P = 0.011, <0.001, and 0.007).

CONCLUSION

Overall implants can be successfully used to support cantilever FDPs. However, there are technical and biological implications which appear inter-related.