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Language Journal of Clinical and Experimental Dentistry. 2018. Vol. 10, no. 9
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- Influence of different alcohol intake frequencies on alveolar bone loss in adult rats : a sem study(2018) de Souza, Daniela-Martins; Rodrigues, Vinicius-Aneas; Silva, Alan-de Aquino; Gonsalves, Vitor-Sulz; Pereira, Kauê-Alberto; Nishioka, Renato Sussumu; de Carvalho, ClaudemirAlcohol intake is associated with oral diseases and bone changes including alveolar bone loss in humans and in experimental animals. The main aim of the present study is to assess the effect of long-term alcohol intake, at different frequencies, on periodontal bone loss (PBL) in adult rats. Thirty-six (36) rats were divided into 3 groups: Control (daily water intake, n=12), daily alcohol intake (20% ethanol, n=12), and social alcohol intake (20% ethanol twice a week, n=12). The rats were sacrificed after 90 days and their right maxillae were removed. Initially, a random portion from each group was analyzed through SEM (scanning electron microscope) to assess surface topography. Next, all pieces were dissected and stained with methylene blue 1% and photographed in stereomicroscope at 10x magnification. The PBL was assessed by measuring the distance between cement-enamel junction and alveolar bone crest. Results showed higher (p=0.0368) alcohol solution amount in the daily intake group than in the twice week intake one. The SEM showed qualitatively flat bone surface in the control group, the social intake group presented surface with few minor hollows, and the daily intake group evidenced increased number and diameter of wells. The comparison between groups showed higher bone loss (p<0.05) in both frequencies than in the control, but the bone loss was lower (p<0.05) in the social alcohol intake group than in the daily intake one. Alcohol intake may cause alveolar bone loss in periodontitis-free rats depending on the frequency.
- Micro-computed tomographic evaluation of dentinal defects after root canal preparation with hyflex edm and vortex blue rotary systems(2018) Mandava, Jyothi; Yelisela, Rajiv-Kumar; Arikatla, Sampath-Kumar; Ravi, RavichandraTo evaluate the incidence of dentinal microcracks formation after root canal shaping procedures with HyFlex EDM and Vortex Blue rotary systems comparing with that of hand instrumentation using micro-computed tomography. Mandibular first molar teeth (n=60) having 50 to 200mesial root curvature were scanned using high resolution micro-CT imaging before root canal preparation to identify the presence of dentinal defects. Post-instrumentation cross-sectional images were taken and increased number and type of root defects were assessed and recorded. The data was statistically analysed by using chi-square test and McNemar?s test at a significance level of 5%. HyFlex EDM has shown greater increase in post instrumentation dentinal defects. Both rotary systems exhibited increased dentinal defects formation at coronal, middle regions which is statistically significant (P=0.042) when compared to apical region. HyFlex EDM has shown greater increase in post instrumentation dentinal defects followed by Vortex Blue rotary system and hand instrumentation resulted minimal defects.
- Evaluation of micro shear bonding strength of two universal dentin bondings to superficial dentin by self etch and etch-and-rinse strategies(2018) Daneshkazemi, Pedram; Ghasemi, Amir; Daneshkazemi, Alireza; Shafiee, FahimeUniversal bondings can be used either with the etch-and-rinse or self-etch technique. Thus, the present study was done to evaluate the micro-shear bonding strength of two types of Universal Bondings to superficial dentin i.e self-etch and etch and rinse. The samples included 70 tooth blocks taken from 35 extracted sound premolar teeth. The superficial dentin was exposed to grinding by 800 grit silicon carbide Disk. The samples were randomly divided into 5 equal groups (14 samples in each group). Scotch bond universal (3M/USA) and All bond universal (BISCO/USA) were applied by self-etch and etch and rinse technique in group 1-4 and Adper Single bond 2 (3M/USA) was used in group 5 as etch and rinse for the control group. Z250 XT (3M/USA) resin composite was bonded in tygon tube on surfaces of samples and were cured. Specimens were stored in distilled water at 37ºC for 24 h and then subjected to the micro shear bond strength test in a universal testing machine at a crosshead speed of 0.5 mm/min. The data were analyzed by two-way ANOVA and Tukey test. Failure mode was determined using a stereomicroscope under 20X magnification. Significance level was considered 0/05. The mean of micro-shear bonding strength and Standard Deviation of groups in Mega Pascal are respectively: 35.74 (6.21), 29.50 (3.89), 24.60 (3.53), 31.47 (4.73), 18.09 (3.87). The self-etch technique for Scotch bond Universal and the etch and rinse technique for All bond Universal showed higher micro shear bonding strength. Adper single bond 2 showed the lowest bond strength to a significant level in comparison to other groups (p<0.05). Failure mode was predominantly adhesive. The micro shear bonding strength of universal adhesives was highly bonding-dependent. Universal bondings had higher micro-shear bonding strength than Adper single bond 2.
- A decision analysis for periapical surgery : retrospective study(2018) Kaya, Göksel ?im?ek; Saruhan, Nesrin; Yapici, Günay; Ertas, ÜmitPeriapical surgery is now a reliable therapeutic procedure for the treatment of teeth with periapical lesions, particularly when orthograde retreatment is problematic. However, little information is available regarding treatment planning of cases referred for periapical surgery. Therefore, this study was conducted to analyze and evaluate the factors that affect the decision-making process for periapical surgery. This study retrospectively assessed clinical and radiographic data from patients undergoing periapical surgery. The factors involved in deciding to perform periapical surgery were classified into technical, biological, and combined factors. Out of 821 patients, 544 (66.3%) underwent endodontic treatment/retreatment, 204 (24.8%) were treated with coronal restorations and 60 (7.3%) were treated with post. Periapical surgery was indicated for biological reasons in 35% of patients and for technical reasons in 17.9%. The common biological factor was persistent clinical symptoms (19.7%). The most common technical cause was failure of previous endodontic treatment (66.3%). Nearly half of all periapical lesions (45%) were <5 mm in size. Periapical surgery was justified in only 434 (52.9%) subjects. We suggest that it is very important for patients to be informed and encouraged about endodontic retreatment in order to reduce unnecessary surgical procedures.
- Inflammatory fibro-epithelial hyperplasia related to a fixed implant-supported prosthesis : a case report(2018) Sánchez Torres, Alba; Mota, Inês; Alberdi Navarro, Javier; Cercadillo Ibarguren, Iñaki; Figueiredo, Rui; Valmaseda Castellón, E.The gingival overgrowth is a common finding in the clinical practice with a diverse etiology. There are no treatment guidelines defined for this oral lesions. These can provoke discomfort to the patient and often, can alter the function of the stomatologic system. This article presents a case report of a bilateral gingival overgrowth in a 68 years old woman wearing a fixed upper-arch implant-supported prosthesis placed five years ago. The clinical exam after removing the prosthesis showed an intense accumulation of plaque around the intermediate abutments associated to a mucosal enlargement with suppuration on touching the buccal area of the implant in position 1.5 and a probing depth of 8mm. The 2.4 and 2.5 implants also showed vestibular mucosal enlargement and a probing depth of 6mm. No changes were observed in the peri-implant bone level measured in the periapical radiographs. An incisional biopsy was made on second quadrant and sent for the histopathological study. The definitive diagnosis was inflammatory fibro-epithelial hyperplasia. No recurrence has been reported after a 6 month follow-up.
- Salivary glucose as a non-invasive biomarker of type 2 diabetes mellitus(2018) Tiongco, Raphael-Enrique; Bituin, Aira; Arceo, Engracia; Rivera, Nicole; Singian, EloisaEvery year, millions of people are diagnosed with Diabetes mellitus (DM) and the number of new and undiagnosed cases continue to rise. Diagnosis of diabetes is usually performed by blood glucose analysis after fasting for a certain period. However, this method uses an invasive technique that can cause discomfort and even trauma to some patients which could eventually lead to behavioral changes such as avoidance of healthcare and laboratory testing. Studies that explore the diagnostic value of salivary glucose are promising due to the non-invasiveness of the test procedures and its potential correlation with blood results. The study conducted aimed to determine if salivary glucose can be utilized as an alternative to blood glucose in the screening, diagnosis, and monitoring of type 2 diabetes mellitus (T2DM). A total of 75 participants were recruited and equally divided into 3 groups (normal fasting glucose, impaired fasting glucose, and provisional DM) based on their fasting blood glucose (FBG) level. Blood and unstimulated saliva were collected from each participant and were subjected to glucose analysis using the routine glucose oxidase-peroxidase method. Using Pearson?s correlation and linear regression, a high degree and significant correlation was observed between blood and salivary glucose (r = 0.715, p<0.001). Further analysis showed that salivary glucose is 88.5% sensitive and 61.5% specific with a positive predictive value of 45.8%, and a negative predictive value of 97.1%. Salivary glucose is comparable to blood glucose in diagnosing and monitoring T2DM and is considered more advantageous than blood due to its non-invasive nature.
- The effect of aspartame and pH changes on the erosive potential of cola drinks in bovine enamel : an in vitro study(2018) Rios, Daniela; Ionta, Franciny-Querobim; Rebelato, Rafael; Jordão, Maisa-Camillo; Wang, Linda; Magalhães, Ana-Carolina; Honório, Heitor-MarquesThe aim of this study was to clarify the mechanism behind the different erosive potential of regular and light cola drinks: pH difference and/or aspartame presence. Sixty bovine enamel blocks were randomly divided into 5 groups: RC - regular cola, RCpH - addition of base to increase regular cola pH, RCAS - addition of aspartame to regular cola, LC - light cola, and LCpH - addition of acid to decrease light cola pH. Two-thirds of the blocks surface was coated with nail varnish for reference. The samples were daily subjected to four erosive challenges for 2 minutes. Between the erosive challenges (2h) and overnight the samples were maintained in artificial saliva. The response variable was the percentage surface hardness change (%SHC) after 1st experimental day and enamel surface loss (µm) measured at the 5th day by profilometry. Data were analyzed by ANOVA and Tukey?s test (p<0.05). Independently of the cola modifications, all groups promoted similar hardness change of enamel surface. RC promoted higher enamel loss (6.69±0.71µm) than LC (4.80±0.77µm). The acid addition to light cola (LCpH: 6.60±1.78µm) significantly enhanced its erosive potential, which did not differ from RC. The base addition to regular cola (RCpH-4.00±0.64µm) resulted in similar wear to LC. The addition of aspartame to the regular cola (RCAS 5.44±0.65µm) resulted in similar wear to LC and RC. The data suggest that the pH alteration has a major impact on the erosive potential of cola drinks, however, the sweetener also has some influence.
- Soft-tissue cone-beam computed tomography (ST-CBCT) technique for the analysis of skeletal, dental and periodontal effects of orthopedic rapid maxillary expansion(2018) Furtado, Álvaro; Furtado, Gisela-Crippa; El Haje, Ossam; Rosário, Henrique-Damian; Franco, Ademir; Makeeva, Irina; Paranhos, Luiz-RenatoOrthopedic rapid maxillary expansion (RME) is a common treatment of choice for managing transverse deficiency of the maxilla. This approach may have desired and undesired skeletal, dental and periodontal effects that may be assessed clinically or through imaging techniques. This study aims to investigate the dental, skeletal and periodontal effects of orthopedic RME using the soft-tissue cone-beam computed tomography (CBCT) technique. The sample consisted of 10 patients (5males and 5 females) aged between 10 and 14 years (mean age: 12.5 years) treated with Hyrax orthopedic device. CBCT scans set for the registration of soft tissue (ST-CBCT) were taken from each patient before (T1) and 120 days after (T2) RME. Skeletal (n=10), dental (n=1) and periodontal (n=4) parameters measured in ST-CBCT were compared between T1 and T2 using t-test within a significance level of 5%. The skeletal parameters with statistically significant increase (p<0.05) in T2 were the width of the buccal alveolar bone crest, the external width of the dental arch at the level of buccal cusps, and the width of the dental arch at the level of most prominent dental surface contour. Representing the dental parameter, the inclination of the anchor teeth was statistically significant for premolars (p<0.05). The only statistically significant outcome in periodontal parameters was the decrease in buccal bone plate thickness of first molars (p<0.05). Dentists must be aware of the ST-CBCT technique for the analysis of hard and soft tissue after orthodontic and orthopedic treatments. This technique revealed that the RME reached optimal skeletal and dental effects with minimal periodontal side effects.
- Oral lichen planus and its relationship with systemic diseases. A review of evidence(2018) Cassol-Spanemberg, Juliana; Rodríguez de Rivera Campillo, M. E.; Otero Rey, Eva; Estrugo Devesa, ALbert; Jane Salas, Enric; López López, JoséOral lichen planus (OLP) is one of the most common dermatological diseases which are present in the oral cavity. It is a chronic autoimmune, mucocutaneous disease that affects the oral mucosa as well as the skin, genital mucosa and other sites. Review the relevant information to OLP and its relationship with systemic diseases. Searches were carried out in the Medline/PubMed, Lilacs, Bireme, BVS, and SciELO databases by using key-words. After an initial search that provided us with 243 papers, this number was reduced to 78 from the last seven years. One of the first criteria adopted was a selective reading of the abstracts of articles for the elimination of publications that presented less information regarding the subject proposed for this work. All the selected articles were read in their entirety by all of the authors, who came to a consensus about their level of evidence. The Scottish Intercollegiate Guidelines Network (SIGN) criteria were used as the criteria of methodological validation. Only 9 articles showed an evidence level of 1+, 2+, 3 or 4, as well as a recommendation level of A, B, C or D. Three of them were non-systematic reviews, one was a cohort study and only one was a controlled clinical trial. Three of the studies were case series, with respective sample sizes of 45, 171 and 633 patients. Several factors have been associated with OLP. Patients with OLP are carriers of a disease with systemic implications and may need the care of a multidisciplinary team. The correct diagnosis of any pathology is critical to making effective treatment and minimizes iatrogenic harm. For OLP is no different, taking into account its association with numerous systemic diseases that require special attention from health professionals. Periodic follow-up of all patients with OLP is recommended.
- Bolton ratios in Portuguese subjects among different malocclusion groups(2018) Machado, Vanessa; Botelho, João; Pereira, Dinis; Vasques, Mariana; Fernandes-Retto, Paulo; Proença, Luís; Mendes, José-João; Delgado, AnaSeveral methods have been described to estimate inter-arch tooth size relationship, such as Bolton?s ratios. The aims of this study were to verify the validity of Bolton indexes in a sample of untreated Portuguese subjects based on Angle classification and to evaluate the gender difference. 168 pre-treatment dental casts of orthodontics Portuguese subjects (59 males and 109 females) with different occlusions were used, which were selected randomly from 541 consecutively treated orthodontic patients. The mesiodistal widths from first molar to first molar were measured on each pre-treatment cast to the nearest 0.01 mm using digital caliper, and Bolton?s anterior and overall ratios were calculated. Descriptive statistics as mean, standard deviation and range were calculated. Moreover, the results were compared to Bolton?s ratios and differences based on gender and occlusion groups were evaluated by statistical inference methods. The results reveal that the mean values, standard deviation and range were larger than Bolton?s in normal occlusion group (78.3±3.5% in anterior ratio and 92.1±2.2% in overall ratio) and there were no differences between genders (p >0.05). Class I (anterior and overall ratios, p=0.001 and p<0.001, respectively), Class II/2 (anterior ratio, p=0.032) and Class III (overall ratio, p=0.041) were significantly different from Bolton?s reference data. The results showed no differences between gender and no difference between normal occlusion and malocclusion groups. Moreover, in normal occlusion group, the anterior and overall tooth size ratios was equivalent to the original Bolton?s ratios, although the mean and standard deviation were large.
- Condylar response to large mandibular advancement combined with maxillary impaction and counterclockwise rotation : a computed tomographic study(2018) do Vale, Francisco-José-Fernandes; Francisco, Inês; Scherzberg, Jessica; Guimarães, Adriana; Caramelo, Francisco; Maló, LuísaThis study aims to analyze the effectiveness of cone-beam computed tomography (CBCT) in the evaluation of the condylar position, angulation and intercondylar distance and assess the changes in these parameters before and after bimaxillary surgery, preformed with the critical movments of Le Fort I osteotomy (for impaction of the maxilla and conterclockwise rotation of the upper occlusal plane) and Bilateral Sagittal Split Osteotomy (BSSO) for mandibular advancement (> 8mm). Twenty class II patients successfully treated with BSSO of the mandible, in conjunction with Le Fort I osteotomy, were studied to evaluate the condylar changes before and after surgery. The position of the condyle was classified according to the Pullinger & Hollender?s formula in both phases. A MANOVA analysis followed by post-hoc tests were conducted to ascertain if there were statistically significant differences between pre and post surgical variables under study. The agreement of the condylar position?s classification was evaluated resorting to the Kappa statistics. There were no statistically significant differences between the values of the position and angulation of the condyles and intercondylar distance before and after surgery. There was an increase of the axial angle of the left condyle and the frontal angle of both condyles, while there was a decrease of the axial angle of the right condyle, the sagittal angle of both condyles and intercondylar distance. The CBCT is a useful method for assessing variations of condylar position in detail. It was verified that the critical movements of maxillary impaction associated with the mandibular advancement do not produce significant alterations in the mandibular condyles, however, these tend to perform a posterior and inferior movement.
- What do dental college clinicians know about oral cancer and its risk factors? An assessment among final year students, interns and faculty members in saudi arabia(2018) Jafer, Mohammed; Crutzen, Rik; Jafer, Alhassen; van den Borne, BartThe ability of health care professionals to perform oral cancer examination depends partly on their knowledge of the disease and its risk factors. This study aimed to assess and compare the knowledge of final year students, interns and faculty members regarding oral cancer and its risk factors. A 35-item questionnaire about knowledge of oral cancer and its risk factors was distributed among participants from Jazan University?s Dental School. A minimum score of 18 was the cut-off point for an acceptable total score of oral cancer knowledge [OCTS]. Descriptive statistics described the relations between demographics variables and knowledge levels of participants. The differences between OCTS, diagnostic-clinical examination knowledge [DCK] and supportive knowledge [SK] and sex and occupation were analyzed using independent t-test and ANOVAs respectively. A total of 72 students, 68 interns and 88 faculty members completed the questionnaires (N = 228); with an average age of 23.8 ± 0.9 years, 25.1 ± 1.5 years and 40.6 ± 9.1 years with 55.1% males. OCTS was 20.2 ± 3.6 out of 35. No significant difference between OCTS and participants? sex was found (t (203) = 1.342, p = .181, 95% CI for difference -.302 ?? 1.589). No significant differences in OCTS between students, interns and faculty members (F (2, 225) = 2.116, p = .123). A significant difference in SK between final year students, interns, and faculty members was founded (F (2, 194) = 5.62, p = .004). Knowledge of oral cancer and its risk factors among Jazan Dental School?s final year students, interns and faculty members is acceptable. However, due to the high rate of oral cancer in Jazan, emphasizing knowledge of oral cancer and its risk factors in the curriculum of Jazan Dental School is required.
- Effect of chlorhexidine on the durability of a new universal adhesive system(2018) Shadman, Niloofar; Farzin-Ebrahimi, Shahram; Mortazavi-Lahijani, Elaheh; Jalali, ZahraThe effect of chlorhexidine on bond durability of universal adhesives is not clear. The aim of this study was to evaluate the effect of chlorhexidine on 6-month water storage bond strength of adhesive systems. 72 freshly sound human extracted molars were selected. In each tooth both buccal and lingual sides were prepared by bur to reach superficial dentin and randomly divided into 6 groups and 12 sub-groups and bonded with Scotchbond Universal (SBU) or Scotchbond Multi-purpose (SBMP) with/without chlorhexidine (CHX) usage. Group 1: SBU, group2: SBU+CHX, group3: Etch+SBU, group4: Etch+CHX+SBU, group5: Etch+SBMP, group6: Etch+CHX+SBMP. After composite curing, water storage and thermocycling was done. Each group was divided into two subgroups. One was tested immediately, and the other was thermocycled for 5000 cycles (5-55 °C) (it was equivalent to 6 months of storage in distilled water). Shear bond strength test was done and failure modes were determined by Stereomicroscope. The data were analyzed by one-way ANOVA, Tukey post-hoc test and Paired Two test with P<0.050 as the level of significance. Shear bond strength in late SBU (Self etch) was significantly lower than late SBU [Etch and rinse (ER)], P value= 0.0001, also shear bond strength in late SBU [self-etch (SE)] was significantly lower than immediate SBU (SE), P value= 0.01. There were no significant differences between other sub-groups and conditions. The most failure mode was adhesive in all the groups. Long term bonding durability of SBU(ER) was better than SBU (SE). CHX usage had prevented bond strength decrease in SBU and SBMP in long term. CHX usage did not have any effect on immediate shear bond strength of SBU and SBMP. Immediate and late shear bond strength of SBMP with/without CHX usage was similar to SBU(SE, ER).
- The evaluation of surface sealants? effect on the color stability of Nano-hybrid composite after polishing with One-Step system (in-vitro)(2018) Khalaj, Kaveh; Soudi, Armin; Tayefi-Nasrabadi, Mahsima; Keshvad, Mohammad-AliThe clinical use of composite resins has increased substantially over the past few years due to increased esthetic demands by patients, improvements in formulation, and simplification of bonding procedures. An alternative for preventing or reducing composite discoloration is using of composite surface sealant. The purpose of this study was to determine the effect of surface sealant on color-stability of Nano-hybrid composites after polishing with one-step system. 56 disk-shaped specimens (10*2 mm) of a Nano-hybrid composite resin (VOCO,Cuxhaven,Germany) were prepared. The specimens were randomly divided in to 2 groups of 28 specimens each. The surfaces of specimens were polished with One-step system (Dimanto,VOCO,Germany ). one group of specimens assigned as control group and received no more surface treatment .surface sealant (PermaSeal,Ultradent,USA) was applied on the surface of specimens of the other group as experimental group .specimens were stored in Ringer?s solution for 24 hours at 37oC. The specimens were subjected to artificial aging with thermocycling method between coffee solution at 55°C and Ringer?s solution at 5°C for 3000 cycles. CIE L*a*b color coordinates were established using a spectrophotometer for each specimen. Statistical significance was set at p<0.05. After aging in both groups, color changing was significantly different (p<0.05) and clinically unacceptable (?E> 3.3) and there was no significant difference between the two groups in ?E. Surface sealant was not effective in improving color stability.
- Comparative in vitro study of two methods for gingival biotype assessment(2018) Sala Martí, Leticia; Alonso Pérez, Raquel; Agustín Panadero, Rubén; Ferreiroa Navarro, Alberto; Carrillo de Albornoz Sainz, AnaThe gingival thickness seems to have an important role in different dental treatments. There are different methods of quantifying this thickness, but it is not known which of them can be the most effective. The objective to assess the accuracy of two different methods for gingival thickness measurement: the transgingival needle probing (TGNP) and the tension-free caliper (TFC) in an in vitro model, by comparing them with direct physical measurements (reference standard). Gingival thickness (GT) was evaluated in 27 female pigs with four implant sites 1, 2 and 3mm from the gingival margin with three different methods: 1) transgingival needle probing 2) tension-free caliper and 3) Direct visualization after making a incision in the mucosa and measuring GT with a periodontal probe. Wilcoxon test for paired samples were used with a confident level of 95%. A total of 324 points were measured, 59% of the sites presented a thin biotype with DV, it was correctly assessed with the TGNP in 84% of the times and in 86% with the TFC. 41% of the sample presented thick biotype, 76% was the percentage measured with the TGNP and 0% of the sites evaluated with TFC resulted in this biotype. Transgingival needle probing constitutes an accurate method when measuring GT at different levels. Tension free caliper is not a good tool for assessing the gingival biotype as long as it is unable to predict thick biotype.
- Does muscular activity related to vertical facial divergence influence the time needed for orthodontic extrusion of palatally impacted maxillary canines? A retrospective study(2018) Tepedino, Michele; Iancu-Potrubacz, Maciej; Grippaudo, Cristina; Chimenti, Claudio; Laganà, GiuseppinaThe aim of the present study was to evaluate if the different muscular activity correlated to different degrees of facial divergence has an effect on the time needed to extrude a palatally impacted maxillary canine. Twenty-six patients were retrospectively selected, all treated with a specific cantilever appliance that allows extrusion of the impacted canine applying a physiologic amount of force below 0.6 N in a predictable way. For all the patients, pre-treatment cephalometric tracings were used to evaluate facial divergence through the FMA angle, the angle between the maxillary and mandibular plane, and the angles between the occlusal plane and either the maxillary and mandibular plane. Linear bivariate regression was calculated to evaluate if facial divergence can predict the time needed for canine extrusion. The linear regression model was not able to predict extrusion time from variables explaining the facial divergence. Palatally impacted maxillary canines can be treated with the application of physiologic extrusion force regardless of patients? facial divergence and muscular activity.
- Influence of voxel size on the accuracy of linear measurements of the condyle in images of cone beam computed tomography : a pilot study(2018) Costa, André Luiz Ferreira; Barbosa, Bruna-Viana; Perez-Gomes, João-Pedro; Calle, Alison-Jhisel-Mansmith; Santamaria, Mauro; Lopes, Sérgio-Lúcio-Pereira-de CastroTo analyze the influence of voxel size and exposure time on the accuracy of linear measurements of the condyle. Four macerated hemi-mandibles of pigs were scanned in nine different voxel size protocols. Three-dimensional models of the condyle were generated in order to establish a comparison between linear measurements obtained with each voxel protocol and those obtained with a caliper (gold standard). The comparison between the protocols was performed considering the average of the two measurements of the condyle in the latero-medial (LM) and antero-posterior (AP) axes and also through repeated measurement ANOVA with rank transformation. The level of significance was 5%. A significant difference was found between the protocols regarding the LM and AP variables (p-values = 0.0027 and 0.0263, respectively). In the LM axis, the protocol P6 (voxel size of 0.3 mm with scan time of 4.8 seconds) did not show statistical difference compared to the gold standard. The protocols P4 and P5 (voxel size of 0.25 mm with scan times of 14.7 and 26.9 seconds, respectively) were both statistically similar compared to caliper, although they have presented a longer scan time. In the AP axis, the protocol P8 (voxel size of 0.4 mm with time scan of 4.8 seconds) was statistically similar to the gold standard. A smaller voxel size does not necessarily mean more accuracy regarding the linear measurements of the condyle. It is possible to obtain an acceptable level of accuracy with a larger voxel size and a shorter exposure time to radiation.
