Indiana University-Purdue University Indianapolis (IUPUI) / Understanding the factors that increase patients susceptibility to orthodontically induced root resorption is of the utmost importance to the practicing clinician. Numerous studies have been conducted that investigated contributing and etiological factors that tend to increase the amount of external apical root resorption a patient may incur during orthodontic treatment. However, there has been little research that has attempted to determine if patients treated with different slot size orthodontic brackets exhibit the same amount of external apical root resorption. The purpose of this research was to determine if patients treated with the 0.018 x 0.025 slot size bracket and patients treated with the 0.022 x 0.028 exhibited similar amounts of external apical root resorption during orthodontic treatment. Pre and Post treatment panoramic films from 91 consecutively treated orthodontic patients from a private orthodontic practice were used for this study. Each case that was included in the study had been treated with standard edgewise brackets using the Tweed-Merrifield philosophy of treatment. Forty-three cases from the 0.018 group and 48 from the 0.022 group were obtained. Each film that was analyzed was blinded prior to measuring to minimize observer bias. Mitutoyo Digimatic® calipers accurate to the nearest tenth of a millimeter were used for obtaining tooth measurements. Measurements were made from the Cemento-enamel junction and from incisal/occlusal to most apical portion of each incisor and all first molars. Statistical analysis was performed and the results showed no significant correlation between the size of the bracket and the amount of root resorption. No significant correlations existed between the groups for patient age, time in treatment, gender, and angle classification. Statistically significant differences were noted for cases in which extraction of four bicuspids was performed. Subjects belonging to the extraction group demonstrated significantly more external apical root resorption than those in which extractions were not done. This study demonstrated that the incidence of EARR that a patient may incur during treatment is independent of the size of the slot of the orthodontic bracket.

Indiana University-Purdue University Indianapolis (IUPUI) / New products are frequently developed for bonding brackets. This continuum brings about incessant studies attempting to prove or disprove their value. The need to compare the results of bond failure studies is made difficult if not impossible by the variation of published testing methods. The purpose of this study is to compare the differential effects of thermocycling, as a lab protocol, on three debonding techniques, shear-peel, tension, and torsion when using a traditional orthodontic resin adhesive. A standard orthodontic resin, Transbond™ XT (3M Unitek, Monrovia, CA) was used to bond 102 flattened 0.018-inch stainless steel brackets (3M Unitek) to flattened bovine incisors. Two step acid etching and priming (37 % phosphoric acid gel and Transbond MIP Primer, 3M Unitek) was used to prepare the enamel for bonding. During bonding, the resin thickness was held consistent. The bonding was accomplished under controlled temperature and humidity. Half of the samples were thermocycled prior to debonding. The samples were debonded in shear-peel, tension, and torsion. The data showed no significant differences between thermocycling and nonthermocycling in shear-peel or torsion, but in tension the thermocycling group had a statistically significant higher failure load. Overall, was a trend toward increased bond strength in the thermocycled group. The increase is likely the result of continued polymerization during thermocycling. The statistical difference that is noted in tension is thought to be due to the location of the highest stress being in the center of the resin pad. This would be the location of the least initial polymerization. The use of thermocycling as a lab protocol during bracket failure studies in shear-peel and torsion is not necessary when using traditional orthodontic resin.

Indiana University-Purdue University Indianapolis (IUPUI) / The search for an orthodontic bonding adhesive that has chemical adhesion to enamel and releases fluoride into the oral environment has led to experimentation with glass ionomer cements. This study compared the tensile bond strength of eight different orthodontic bracket base designs in vitro and assessed the amount of adhesive remaining on the bracket pad after debonding. Each bracket base design included in this study had unique characteristics warranting their inclusion. The groups contained brackets with 60, 80, and 100 gauge mesh pads; 100 gauge mesh sandblasted pads; perforated metal bases; Micro-Lock™ photo-etched bases; Dyna-Lock™ integral bracket/bases; and ceramic silane-coated bracket pads. Groups contained 20 to 22 specimens that were bonded to bovine incisor teeth embedded in a self-curing acrylic block that could be held in the testing machine. Pre-encapsulated glass ionomer cement (Ketac-Fil™) was the experimental adhesive. The adhesive was mixed according to the manufacturer's instructions in a dental amalgamator. The specimens were thermocycled between water oaths of 15°C and 55°C. The specimens spent 30 seconds in each bath for a total of 2,500 cycles and were stored in a humidor until debonding. After 14 days, the specimens were subjected to a tensile force using an Instron mechanical testing machine until failure occurred. The Micro-Loc™ photo-etched base had significantly higher mean tensile bond strength (p<0.05) than all other brackets tested. The ceramic brackets were unable to be tested due to the extremely weak bond strength which did not allow preparation of the samples for debonding. Following debonding, the percentage of adhesive remaining attached to the bracket base was determined using a grid in the ocular of a light microscope. In general, the site of bond failure involved the base/adhesive interface. The Dyna-Lock™ integral bracket/base and 80 gauge mesh base had a greater mean percent of adhesive remaining attached to the base. (Dyna-Lock™ 45 percent and 80 gauge mesh 43 percent vs. all other < 20 percent.) The results indicate that the bracket base design can influence the bond strength when GIC is used as an orthodontic adhesive and suggests that development of GIC with increased fracture toughness might increase bond strength.

Incipient caries lesions or white spot lesions are one of the most common clinical problems resulting from orthodontic treatment with fixed appliances. Literature has shown that infrared photothermal radiometry and modulated luminescence (PTR-LUM), used by The Canary System for caries detection, is capable of monitoring artificially created carious lesions and their evolution during demineralization. Recently, a water-based calcium aluminate glass ionomer luting cement, Ceramir, has shown bioactive surface apatite formation that may influence local remineralization. This in vitro study’s objective was to evaluate effects of bioactive cement on enamel demineralization around orthodontic brackets compared to composite resin cement. A sample of 32 caries-free extracted human teeth was collected under an IRB-exempt protocol. Orthodontic brackets were cemented to each tooth with either Transbond XT or Ceramir. A 3x3 mm window adjacent to the bracket was created with acid-resistant varnish f / Oral Biology

This thesis presents the results of an extensive study of several types of lateral bracing for solid-sawn and parallel-chord truss floor systems. Three solid-sawn floor bracing systems were evaluated: X-bridging, full-depth solid blocking, and finally, post-tensioned solid-blocking. Five different truss bracing systems were investigated: bottom-chord bracing, steel X-bracing, strong-back bracing, and the bracing combinations of X-plus bottom-chord bracing, and strong-back plus bottom chord bracing were evaluated. A total of seven, 4.9m x 4.9m floor specimens were constructed. Four 38 x 286 mm (2 x 12 inch nominal), solid-sawn wood joist floors were constructed for evaluation of the solid-sawn bracing systems. Three 305 mm (12 inch) deep, bottom-chord bearing, metal plate connected, parallel-chord truss floors were constructed to evaluate the truss floor bracing systems. Both floor systems utilized joist/truss spacings of 610 mm (24 inches) on center, and were covered with 18.3 mm (23/32 inch) thick, tongue-in-groove, plywood sheathing. The bracing systems were evaluated at different live load levels and boundary conditions. The bracing systems were subjected to both static and dynamic loadings. The effect of the bracing systems were determined based on four parameters: one static, and three dynamic. The percent change in concentrated load carried by the loaded joist was used as the static test parameter. The effect, if any, of the bracing systems on the modal resonant frequencies, separation of frequencies, and damping characteristics of the floor systems, were used as dynamic parameters. Future research and design recommendations were given in the conclusion chapter. / Master of Science

Background: All treatments, especially funded by social means, should be subject to cost-effectiveness studies to ensure that the best possible optimization decision it taken between different treatment options. Within the health care area this is a well-developed area. For odontology in general, and orthodontic treatment in specific, this is an unknown territory and cost-effectiveness studies are rare. Malocclusion can be treated with several different systems. The sales pitch from system providers for braces - such as self-ligated brackets (SLB) promises e.g. shorten treatment duration, shorter chairtime, fewer visits, but the purchase cost of SLB systems is higher. Due to lack of results from unbiased RCT there is no guidelines. It is up to the dentist to use the treatment method/system of their own choice. Purpose: The purpose of this thesis is to estimate the cost-effectiveness of SLB compared to conventional brackets (CB) to determine which of the two systems that should be considered as the preferred choice of treatment in a publicly funded system. Method: Through an incremental cost-effectiveness ratio (ICER) calculate the most costeffective system from a societal perspective which includes all costs. To estimate the health care cost, the Reference price list will be used as baseline for production cost for CB. With the use of secondary resources examine the cost driving components to estimate the production cost of SLB. To estimate the non-health care cost a matrix with downtime from work and travel costs was estimated accounting for travel to disclose the magnitude of these cost. The Outcome of the different treatment alternatives will be measured from different perspectives, such as state specific and general profiles. Treatment duration and foregone education will also be investigated. Conclusions: When all production costs for SLB has been adjusted it shows that the total cost of SLB is slightly cheaper. The reduced number of visits required, less chairtime and shorter treatment period are the positive sides of the higher purchase cost of the SLB. Most of the outcome results are not statistically significant, but there is a tendency, with better average values for SLB. SLB seems to be the cheaper and with more effective outcome though not to the extent the provider promises. The difference of treatment duration is minimal and has no significant advantage. The foregone education for the patient is not possible to quantify in monetary terms but could have significant impact depending on different geographical areas but will small differences between the systems. Hence, in lack of unbiased studies and just focusing on average values, SLB dominates CB and should be the preferred choice of treatment until new long-term studies has been published. / Bakgrund: Alla behandlingar, särskilt de som är offentligt finansierade, borde ha genomgått kostnadseffektivitetsbedömningar för att kunna fatta bästa möjliga beslut. Inom sjukhälsovård är detta ett välutvecklat område. Inom tandvård generellt, men kanske ortodonti i synnerhet, är detta ett outforskat område och kostnadseffektivitetsstudier är sällsynta. Malocklusion kan behandlas med flera olika system. Säljargument från olika tandställningsleverantörer, som t.ex. självligerande brackets (SLB) ger löften om t.ex. kortare behandlingsperiod, kortare tid i tandläkarstolen, färre besök men till en högre inköpskostnad. I brist på resultat från oberoende RCT saknas riktlinjer. Det är upp till den enskilda tandläkaren att välja den behandlingsmetod/system som hen finner bäst. Syfte: Syftet med uppsatsen är att undersöka kostnadseffektiviteten mellan SLB jämfört med konventionella brackets (CB) för att avgöra vilket av dessa två system borde anses vara föredraget behandlingsalternativ i ett offentligt finansierat system Metod: Med kostnadseffektivitetskvoten (incremental cost-effectiveness ratio, ICER) beräkna det mest kostnadseffektiva systemet från ett samhällsperspektiv som inkluderar alla kostnader. För att uppskatta direkta behandlingskostnaden kommer Referensprislistan att användas som produktionskostnadsbas. Med hjälp av sekundära källor som undersöker de kostnadsdrivande komponenterna, uppskatta produktionskostnaden för SLB. För att mäta de indirekta behandlingskostnaderna skapas en matris för att påvisa kostnaden med ställtid från arbete och resekostnader. Resultatet av de olika behandlingsalternativen kommer att mätas från olika perspektiv, såsom generella hälsoprofiler och tillståndsspecifika. Behandlingsperiod och missad utbildnings kommer också att undersökas. Slutsats: Efter det att produktionskostnaderna har blivit justerade visas att totalkostnaden för SLB är något billigare. Färre antal besök, kortare tid i behandlingsrummet är det positiva sidorna av det högre inköpspriset för SLB. De flesta av resultaten är inte statistiskt signifikanta men det finns en tendens mot bättre effekt med SLB. SLB tycks vara det billigare och mest effektiva systemet om än inte i den utsträckning som säljargumenten hävdar. Skillnaden i behandlingsperiod är minimal och har igen avgörande betydelse. Den missade utbildningen är svårligen kvantifierbar i monetära termer men kan ha en avgörande betydelse beroende på olika geografiska platser men med små skillnader mellan systemen. Följaktligen, i brist på oberoende studier och med ett fokus på medelvärde är SLB det dominerande valet över CB och borde vara det föredragna behandlingsalternativet fram till dess att nya långsiktiga forskningsrön har blivit publicerade.

Made available in DSpace on 2017-07-24T19:22:31Z (GMT). No. of bitstreams: 1 Paola Andrea Zurita Baya.pdf: 5901353 bytes, checksum: 64a11dda533f6676e318b6f0b49bd278 (MD5) Previous issue date: 2014-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study evaluated the effects of bleaching agents on adhesiveness and surface of metallic brackets. To evaluate the bond strength (BS) and adhesive remnant index (ARI) sixty specimens were confectioned, where sixty brackets were bonded to 60 Premolars with the adhesive TransbondTM XT. They were divided randomly into 3 groups (n=20), a control group (CG) wich not received bleaching agent, two experimental groups TWS and TWO where the bleaching agent hydrogen peroxide 10% (Opalescence® TrèswhiteTM Supreme) and hydrogen peroxide 8% (Opalescence® TrèswhiteTM Ortho) were applied respectively. The specimens were submitted to shearing in a universal testing machine (Kratos) with a crosshead speed of 0,5 mm/min. The ARI was evaluated with a magnifying stereomicroscope (20x). For the evaluation of surface roughness 15 new brackets were used, divided into 3 groups (n=5). These groups correspond to a control group (CG) without bleaching agent, and two experimental groups (TWS e TWO). The brackets underwent to the surface roughness test by digital rugosimeter (Surftest SJ 400). The ANOVA test showed no significant difference for the RA (p = 0.3511), Rug (p= 0.10) nor to changes in roughness (p= 0.1024). The Kruskal-Wallis test showed no significant difference for the ARI (p= 0.3732). It was concluded that the use of bleaching agents tested in this study is viable in orthodontic patients. / Este estudo avaliou os efeitos dos agentes clareadores na adesividade e na superfície de brackets metálicos. Para a avaliação da resistência adesiva (RA) e do índice de adesivo remanescente (IAR) foram confeccionados 60 corpos de prova, onde 60 brackets foram colados em 60 pré-molares humanos com o adesivo TransbondTM XT. Foram divididos aleatoriamente em 3 grupos (n=20), um grupo controle (GC) que não recebeu agente clareador, dois grupos experimentais TWS e TWO nos quais foram aplicados o agente clareador peróxido de hidrogênio 10% (Opalescence® TrèswhiteTM Supreme) e peróxido de hidrogênio 8% (Opalescence® TrèswhiteTM Ortho) respectivamente. As amostras foram submetidas a cisalhamento em uma máquina universal de ensaios mecânicos (Kratos) com velocidade de carga de 0,5 mm/min. O IAR foi avaliado com uma lupa estereomicroscópica (20x). Para à avaliação da rugosidade superficial foram utilizados 15 brackets novos, divididos em 3 grupos (n=5). Esses grupos correspondem a um grupo controle (GC) sem agente clareador e dois grupos experimentais (TWS e TWO). Os brackets foram submetidos ao teste de rugosidade superficial pelo rugosímetro digital (Surftest SJ 400, Mitutoyo) O teste ANOVA demonstrou não existir diferença significativa para a RA (p= 0,3511), Rug. (p= 0,10) e nem para alterações da rugosidade (p= 0,1024). O teste Kruskal-Wallis demonstrou não haver diferença significativa para o IAR (p= 0,3732). Concluise que o uso dos agentes clareadores testados no presente estudo é viável em pacientes ortodônticos.

Aim: To compare the 0.018-inch and 0.022-inch conventional pre-adjusted orthodontic bracket slot systems in terms of the effectiveness of levelling and alignment stage of orthodontic treatment. Design: Prospective, multi-centre randomised clinical trial. Setting: This was undertaken in the secondary care hospital environment in Tayside NHS in the United Kingdom. Subjects and methods: One hundred and five orthodontic patients were randomly allocated to treatment with either the 0.018-inch bracket slot (n= 52) and 0.022-inch bracket slot (n=53) Victory conventional pre-adjusted bracket systems (3M Unitek). The patients were treated in three centres in secondary care hospitals Tayside NHS, United Kingdom. The levelling and alignment stage of treatment was assessed from the start of treatment until the ligation of the working archwire for each bracket slot system (0.016x0.022 stainless steel for the 0.018-inch group and 0.019x0.025 stainless steel for the 0.022-inch group). Periapical radiographs were taken before the start of treatment and after 9 months in treatment for the maxillary central incisors to assess orthodontically-induced inflammatory root resorption (OIIRR). The “Smiles better” questionnaire was completed by the participants at 6 months from the start of treatment. Primary outcome measures: The duration of the levelling and alignment stage of orthodontic treatment in the maxillary and mandibular arches. Secondary outcome measures: The number of scheduled appointments for the levelling and alignment stage of orthodontic treatment in the maxillary and mandibular arches, OIIRR at 9 months from the start of treatment using periapical radiographs and patient perception of wearing orthodontic appliances. Results: The data from 92 patients (mean age 19.55 years) were analysed after the completion of their levelling and alignment stage of orthodontic treatment. An ANOVA test showed no statistically significant difference in the duration or number of scheduled appointments for the levelling and alignment stage in the maxillary and mandibular arches between the two appliance groups. Non-parametric statistical test showed no statistically significant difference in the severity of OIIRR and patient perception of wearing orthodontic appliances between the two study groups except for the soreness of teeth, where more patients in the 0.022-inch group experienced significant teeth soreness than the 0.018-inch group. Multiple regression analysis determined that 49.6% of the variance in the duration of levelling and alignment duration for the maxillary arch can be explained by five factors: alignment of ectopic tooth, scheduled appointment intervals, gender, bracket slot size system and the number of failed scheduled visits. For the mandibular arch, 50.8% of the variance in the levelling and duration of alignment can be explained by three factors: scheduled appointment intervals, arch irregularity and the number of debonded brackets. Conclusions: There is no difference in the effectiveness of the levelling and alignment stage of orthodontic treatment between the 0.018-inch or 0.022-inch conventional bracket slot systems except for the soreness of teeth.

Magister Chirurgiae Dentium - MChD (Orthodontics) / The aim of the study is to compare the frictional resistance generated between two types of self-ligating brackets; Smart-Clip Metal SL (3M Unitek) and Damon Clear SL (Ormco), with conventional stainless steel brackets, Victory Series (3M Unitek) when coupled with various stainless steel and nickel-titanium archwires. Materials and Methods: All brackets had a 0.022" slot and tested using three archwires: 0.016" nickel-titanium, 0.019 x 0.025" nickel-titanium and 0.019 x 0.025" stainless steel archwires. Friction was evaluated for the upper right quadrant of the typodont. For each testing procedure, new brackets and archwire was employed to eliminate the influence of wear. Results: The mean results showed that the Smart-Clip self-ligating brackets generated significantly lower friction than both the Damon Clear self-ligating brackets and Victory Series brackets. However, the analysis of the various bracket-archwire combinations displayed that Damon Clear SL brackets generated the lowest friction when tested with 0.016" round nickeltitanium archwire and significantly higher friction than Smart-Clip and Victory Series brackets when tested with 0.019 x 0.025" stainless steel rectangular archwires. All brackets showed higher frictional forces as the wire size increased. Clinical relevance: The production of high levels of friction during orthodontic sliding mechanics presents a clinical challenge to the orthodontists. The generation of high levels of friction may reduce the effectiveness of the mechanics, decrease tooth movement efficiency and further complicate anchorage control. The amount of friction is variable in the orthodontic system and can be altered somewhat by the orthodontist's choices.

Lastbilar som har en påbyggnation, såsom en tippbil, sopbil eller lastbil med kran, behöver ha en hjälpram fastsatt på sin chassiram för att kunna säkerställa lastbilens form och funktion. Dessa chassiramar och hjälpramar sätts ihop med olika typer av fästen. Generellt sett används stela fästen längre bak på ramen, samt flexibla fästen längre fram på ramen. Syftet med de flexibla fästena är att försöka få chassiramen att röra sig som en del av fordonets fjädringssystem, för att bland annat minska komfortstörande vibrationer. Examensarbetets syfte var att på uppdrag av Scania utreda dessa flexibla fästelement. Utifrån syftet formulerades tre huvudfrågeställningar. Den första var om det på ett analytiskt sätt gick att ta fram för- och nackdelar med de olika typer av flexibla fästelement som i nuläget används. Den andra frågeställningen var gällande åtdragningsmomentet på fästena. Skruven som sammanfogar fästet på chassiramen med fästet på hjälpramen sätts med ett väldigt lågt moment, för att undvika att fästet böjs sönder då de sätts med en glipa mellan varandra. Frågan var då hur kritiskt detta låga åtdragningsmoment var, och vad som händer om montören råkar dra åt lite för hårt. Slutligen så var den tredje frågeställningen hur mycket fästena kunde röra sig från varandra innan låsning uppkom, för att studera risken för att byrålådseffekt uppstår i fästet. För att få fram svar på dessa frågor gjordes det faktasökande i Scanias påbyggarhandbok, samt annan litteratur. För att öka förståelsen för Scanias fästen, utfördes intervjuer med personal från olika avdelningar. Det gjordes även FEM-analyser på ett vinkelfäste för att få ut spänningsbilder vid olika åtdragningsmoment. Gällande den första frågeställningen så gav faktasökande och intervjuer inte heltäckande information. Faktasökandet gav inte den sökta teoretiska bakgrunden. Intervjuerna gav en god överblick, men inte den detaljinformation som krävdes för att få ut ett adekvat resultat. Det är inte uteslutet att den detaljkunskapen finns på andra delar av Scania. Således rekommenderas vidare intervjuer och undersökning för att besvara frågan gällande inbördes för- och nackdelar mellan de flexibla fästelementen. Angående den andra frågeställningen, hur kritiskt åtdragningsmomentet var, gav FEM-analyserna spänningsbilder som visar att en viss felmarginal kan tillåtas, men inte mycket. Enligt Scanias monteringsanvisningar ska åtdragningsmomentet vara 25 Nm. Vid en ökning med 30 % på detta låga moment gick minsta säkerhetsfaktorn från 4 till 2,2. En oförsiktig montör kan nästan halvera minsta säkerhetsfaktorn i fästet. Dras däremot skruven mellan de båda vinkelfästena åt med samma moment som används för att fästa dem i ramen, 170 Nm, uppstår plastisk deformation och en vertikal förskjutning som förstör fästets flexibilitet. Angående den tredje frågeställningen, om låsning i fästet uppstår, löstes det geometriskt med hjälp av CAD-ritningar i CREO. Enligt anvisningar från Scania sätts fästena med ett lodrätt avstånd på 10 ± 5 mm mellan varandra. Detta gav två extremvärden, 5 mm samt 15 mm. Låsning uppstod fortare i fallet med 5 mm. Detta fall tillät en längsgående rörelse på 6,4 mm samt en rörelse på 5 mm i sidled innan en låsning uppstod i fästet. Det är många olika typer av dynamiska krafter som verkar på ramarna vid körning och användning av lastbilen, samt det är flera olika fästen på rad med varierande avstånd. På grund av dessa faktorer anses resultatet vara svårtolkat och således rekommenderas ytterligare utredningar samt experiment för att svara på om oönskad låsning och byrålådseffekt uppstår. / Trucks that have a superstructure, such as a dump truck, garbage truck or truck with a crane, need to have a subframe attached to their chassis frame, to be able to ensure the truck's shape and function. These chassis frames and subframes are assembled with different types of brackets. Generally, rigid brackets are used further back on the frame, as well as flexible brackets further forward on the frame. The purpose of these flexible mounts is to try to get the chassis frame to move as part of the vehicle's suspension system, to, among other things, reduce comfort-disturbing vibrations. The purpose of the thesis was to investigate these flexible mounts on behalf of Scania. Three main issues were formulated based on the purpose. The first was whether it was possible in an analytical way to identify advantages and disadvantages with the different types of flexible mounts that are currently used. The second issue was regarding the tightening torque on the brackets. The screw that joins the bracket on the chassis frame with the bracket on the subframe is set with a very low torque, to avoid the bracket being bent as they are inserted with a gap between each other. The question then was how critical this low tightening torque was, and what happens if the fitter happens to tighten a little too hard. Finally, the last question was how much the brackets could move apart before locking occurred, to study the risk of the drawer effect occurring in the bracket. To obtain answers to these questions, a fact-finding was made in Scania's bodybuilder instructions, as well as other literature. To gain an understanding of Scania's mounts, interviews were conducted with staff from various departments. FEM analysis were also performed on an angle bracket to obtain tension images at different tightening torques. Regarding the first question, fact-finding and interviews did not provide comprehensive information. The fact-finding did not provide the theoretical background that was sought after. The interviews provided a good overview, but not good enough detailed information to obtain an adequate result. It is not excluded that this detailed knowledge is available in other parts of Scania. Thus, further interviews and research is recommended to answer questions regarding advantages and disadvantages between the flexible mounts. Regarding the second question, how critical the tightening torque was, the FEM analysis provided tension images that show that a certain margin of error can be allowed, but not much. According to Scania's installation instructions, the tightening torque should be 25 Nm. With an increase of 30% at this low torque, the minimum safety factor went from 4 to 2.2. A careless fitter can almost halve the minimum safety factor in the bracket. If, on the other hand, the screw between the two angle brackets is tightened with the same torque used to fasten them to the frame, 170 Nm, plastic deformation and a vertical displacement occur which destroys the flexibility of the bracket. Regarding whether locking in the bracket occurs, it was solved geometrically with the help of CAD drawings in CREO. According to instructions from Scania, the brackets are placed at a vertical distance of 10 ± 5 mm between each other. This gave two extreme values, 5 mm and 15 mm. Locking occurred faster in the case of 5 mm. This case allowed a longitudinal movement of 6.4 mm and a lateral movement of 5 mm before a locking occurred in the bracket. There are many different types of dynamic forces that act on the frames when driving and using the truck, and there are several different mounts in a row with varying distances. Due to these factors, the results are considered difficult to interpret and thus further investigations and experiments are recommended to answer whether unwanted locking and the drawer effect occur.