Journal of Clinical and Experimental Dentistry. 2015. Vol. 7, no. 2
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- Sunct syndrome. Report of a case and treatment update(2015) Gay Escoda, Cosme; Mayor Subirana, Gemma; Camps Font, Octavi; Berini Aytés, LeonardoShort-lasting unilateral neuralgiform headache attacks with conjuntival injection and tearing (SUNCT) is considered a rare trigeminal autonomic cephalgias, a group of primary headache disorders characterized by brief episodes of severe unilateral headache in the distribution territory of the trigeminal nerve, accompanied by prominent ipsilateral and cranial parasympathetic autonomic features. The present report describes a SUNCT syndrome in a 64-year-old male who had been diagnosed with trigeminal neuralgia several years ago. The patient reported stabbing pain in the orbital zone and in the left upper maxillary region, of great intensity, brief duration, and a frequency of 20-100 attacks a day. Pain episodes were accompanied by conjunctival injection and tearing. Based on the anamnesis, clinical examination and a magnetic resonance imaging scan, episodic SUNCT syndrome was diagnosed and pharmacological treatment with topiramate was started. This reduced the intensity and number of attacks to 3-6 a day
- Alternative surgical management of oroantral fistula using auricular cartilage(2015) Ozkan, Aydin; Durmaz, Can EnginOne of the clinical complications encountered by oral and maxillofacial surgeons is oroantral communication (OAC) with subsequent formation of oroantral fistula (OAF). Many techniques and treatment modalities have been described for the management of OAC and OAF. There are advantages and disadvantages of all these techniques. We report a 21-year-old male patient who was admitted to our department for the presence of an OAF and was treated using an auricular cartilage graft. This technique may be useful to treat OAF and to provide a solid alveolar bone site for subsequent pre-implant surgery
- Hand, foot and mouth disease: a short case report(2015) Kashyap, Roopashri Rajesh; Kashyap, Rajesh ShankerHand, foot and mouth disease, that was once considered a disease of cattle, has been emerging as a common human childhood disease in the last few years. It is a viral disease characterized by a brief febrile illness and typical vesicular rashes. In rare cases, patients may also develop neurological complications. This report describes a case of hand, foot and mouth disease, presented with typical clinical features in the South Indian region.
- Influence of orthodontic treatment on temporomandibular disorders: a systematic review(2015) Fernández, Felipe J.; Cañigral Ortiz, María Aránzazu; López Caballo, José L.; Brizuela Velasco, Aritza; Moreno Hay, Isabel; del Río Highsmith, Jaime; Vega Álvarez, José AntonioObjectives: The aim of this literature systematic review was to evaluate the possible association between malocclusions, orthodontic treatment and development of temporomandibular disorders. Material and Methods: A search was carried out on PubMed-Medline database from January 2000 to August 2013 using the keywords “ orthodontics and temporomandibular disorders ”, “ orthodontics and facial pain ” and “ malocclusion and temporomandibular disorders ”. Human studies included in the study were those assessing signs and symptoms of temporomandibular disorders in relation to orthodontic treatment. Results: The search strategy resulted in 61 articles. After selection according to the inclusion/exclusion criteria 9 articles qualified for the final analysis. The articles which linked orthodontics and development of temporomandibular disorders showed very discrepant results. Some indicated that orthodontic treatment could improve signs and symptoms of temporomandibular disorders, but none of them obtained statistically significant dif ferences. Conclusions: According to the authors examined, there is no evidence for a cause-effect relationship between orthodontic treatment and temporomandibular disorders, or that such treatment might improve or prevent them. More longitudinal studies are needed to verify any possible interrelationship
- Investigating activity of masticatory muscles in patients with hypermobile temporomandibular joints by using EMG(2015) Davoudi, Amin; Haghigaht, Abbas; Rybalov, Oleg; Shadmehr, Elham; Hatami, AminBackground: Temporomandibular joint hypermobility (TMJH) can manifest higher range of motions in mandible. The aim of this study was to investigate and compare the activity of masticatory muscle of TMJs in healthy individuals and patients with mild, moderate and severe TMJH. Material and Methods: In this clinical study, 69 patients (between the ages of 22 to 42) with manifestation of TMJH were included. The patients were divided into three groups based on their maximum mouth opening (MMO): (light) with MMO of 50-55 mm; (moderate) with MMO between 55 to 65 mm; and (severe) with MMO >65 mm. Also, 20 healthy people with profiled tomography in the last 6 months were invited as control group (healthy) with normal MMO (<50 mm). All the groups subjected to electromyogram (EMG) in 2 steps: maximal voluntary clenching (MVC) of the jaws; and during chewing of bread by using one side of the jaws voluntary. The collected data were analyzed by Student T-test and Chi-Square tests using SPSS software version 15 at significant level of 0.05. Results: Both TMJs of light, moderate and severe groups showed significant differences in frequency, time of activity and rest in comparison with healthy group during chewing and MVC (all p values < 0.01). Conclusions: Masticatory muscles activity reduced in relation with the severity of TMJH and higher excessive mouth opening.
- Measurement of the percentage of root filling in oval-shaped canals obturated with Thermafil Obturators and Beefill 2in1: in vitro study(2015) Faus Llácer, Vicente; Collado Castellanos, Nicolás; Alegre Domingo, Teresa; Dolz Solsona, María; Faus Matoses, VicenteBackground: The aim of the study was to measure the percentage of root canal fillings in long oval canals obturated with thermoplasticized gutta-percha techniques, Beefill 2in1® and Thermafil Obturators®. Material and Methods: Fifty four mandibular incisors were selected after bucco-lingual and mesio-distal radiographs showed at 5 mm from apex an internal long: short diameter ≥2. Teeth were instrumented with Protaper Universal and divided in two groups of 27. Group 1 was obturated with Thermafil Obturators® and group 2 with Beefill 2in1®. Two horizontal sections were cut at 5 and 7 mm from the apex and photographed in a stereo-microscope. The total area of the canal and filled canal in cross-sections were measured with AutoCad and the percentages of gutta-percha-sealer and voids in the canal were obtained. Results: Both systems achieved high percentage of filled canal, Thermafil 96.8% and Beefill 2in1 98.9%. The percentages of voids in both groups were very low. No significant differences were found between the two groups. The percentage obtained at 5 and 7 mm from the apex in both groups showed no significant dif ference. Conclusions: The percentages of filled canal (gutta-percha-sealer) were high and these two thermoplasticized techniques are suitable for long oval canals obturation.
- Comparison of the therapeutic effects of the dietary and topical forms of Zizyphus jujuba extract on oral mucositis induced by 5-fluorouracil: a golden hamster model(2015) Koohi Hosseinabadi, Omid; Andisheh Tadbir, Azadeh; Bahadori, Parisa; Sepehrimanesh, Masood; Mardani, Maryam; Tanideh, NaderBackground: Oral mucositis (OM) is a common inflammatory complication among cancerous patients as an ad verse effect of chemotherapy and radiotherapy. The aim of this study was to evaluate the effects and identify the appropriate route of administration of extract of Zizyphus jujuba in 5-flurouracile induced OM induction in golden hamster. Materials and Methods: In a prospective randomized double blind animal study, OM was induced in 56 male golden hamsters by 5-FU (60 mg/kg) on days 0, 5, and 10 of the study. The cheek pouch was scratched with a sterile needle on once daily on days 3 and 4. On days 14-17, 300 mg/kg dietary and 20% Z. jujuba gel and gel base groups were treated and then compared with a control group. Microscopic scores and pouch content of malondialdehyde (MDA), plus activities of superoxide dismutase and myeloperoxidase in pouch tissue were evaluated. Results: Histopathology scores of mucositis were lower in the systemic and 20% Z. jujuba gel groups than the gel base and control groups ( P <0.05). Also, lower MDA level and higher activities of MPO and SOD were detected in the systemic and 20% Z. jujuba gel groups in comparison to the gel base and control groups ( P <0.001). Conclusions: The use of Z. jujuba hydroalcoholic extract in systemic and topical forms may be associated with reduced intensity of OM, diminished concentration of MDA, and increased activity of MPO and SOD on induced OM in golden hamster undergoing 5-FU consumption
- Indirect sinus lift without bone graft material: systematic review and meta-analysis(2015) Pérez Martínez, Sara; Martorell Calatayud, Luis; Peñarrocha Oltra, David; García Mira, Berta; Peñarrocha Diago, MiguelA systematic literature review and a meta-analysis of indirect sinus lift without the use of bone graft material was performed. A PubMed search was made from January 2005 to January 2012 with keywords: “sinus lift” , “osteo-tome” , “graft” and “maxillary sinus elevation” . The inclusion criteria were: maxillary sinus lift technique with osteotomes with a minimum follow-up period of 5 months after surgery without bone graft material. 11 articles were included. The mean gain in residual crestal bone height after maxillary sinus lift without bone graft material was 3,43 mm ± 0,09 (2,5 mm – 4,4 mm). The survival rate ranged from 94% to 100%. Placement of implants with sinus lift without bone graft material, is a valid surgical technique to gain residual crestal height and placed implants in an atrophic posterior maxillary with a crestal height from 5 to 9 mm
- Mucormycosis in a healthy elderly patient presenting as oro-antral fistula: report of a rare incidence(2015) Nilesh, Kumar; Malik, Neelima A.; Belgaumi, UzmaMucormycosis is a rare opportunistic fungal infection that commonly affects patients who are immuno-compromised. It invariably presents as an acute spreading infection, with very poor prognosis if not treated promptly. We report a case of mucormycosis in immuno-competent elderly patient, presenting as oro-antral communication. Patient’s history, clinical and laboratory evaluation revealed no systemic predisposing factors. The disease was non-fulminant, localized and showed remission after local measures, without parentral anti-fungal therapy
- Pathological mandibular fracture: a severe complication of periimplantitis(2015) Naval Gias, Luis; Rodríguez Campo, Francisco José; Naval Parra, Beatriz; Sastre Pérez, JesúsNowadays, dental implant treatment is a very common option for patients even in medical compromised conditions. Some complications related to them have been described. Periimplantitis (PI) is one of the biggest concerns of these kind of treatments, probably has a multifactorial aethiology. Usually the consequences of PI are the loss of the implants and prostheses, expenses of money and time for dentists and patients. Very often PI implies the necesity of repeating the treatment . Pathological mandibular fracture due to PI is a severe but infrequent complication after dental implant treatment, especially after PI. In this study we present three cases of mandibular pathologic fractures among patients with different medical and dental records but similar management: two of them had been treated years ago of oral squamous cell carcinoma with surgery and radiotherapy, the other patient received oral bisphosphonates for osteoporosis some years after implantation. We analized the causes, consequences and posible prevention of these fractures as well as the special features of this kind of mandibular fractures and the different existing treatments.
- Tannerella forsythia is associated with increased levels of atherogenic low density lipoprotein and total cholesterol in chronic periodontitis(2015) Ardila Medina, Carlos Martín; Perez Valencia, Aide Yancelly; Rendon Osorio, Willer LeandroBackground: Accumulating evidence suggests that acute and chronic infections with periodontopathogens are associated with an increased risk of cardiovascular disease. The objective of this study was to assess whether Tannerella forsythia and Porphyromonas gingivalis are associated with increased levels of atherogenic low-density lipoprotein (LDL), high-density lipoprotein, total cholesterol (TC), triglycerides and body mass index (BMI) in chronic periodontitis patients. Material and Methods: Medical history and clinical and radiographic examination were conducted in 80 chronic periodontitis patients and 28 healthy individuals. Fasting blood samples were drawn for the measurement of the parameters of dyslipidemia. Anthropometric measurements such as height in meters and weight in kilograms were recorded. Both periodontitis and control subjects were asked to answer a questionnaire with regard to their socio- demographic and smoking status. The presence of T. forsythia , and P. gingivalis was detected using primers designed to target the respective 16S rRNA gene sequences. Results: The occurrence of T. forsythia and P. gingivalis was higher in the group of subjects with periodontitis. Superior levels of triglycerides were observed in chronic periodontitis patients compared to healthy individuals. High levels of TC in periodontitis persons were significantly associated with increased bleeding on probing. Greater mean levels of TC and LDL were shown in the presence of T. forsythia ( P <0.05). Likewise, higher proportions of patients with BMI ≥25 kg/m 2 related with T. forsythia ( P <0.05). T. forsythia was a significant discriminating factor in the multivariate linear regression model emerging as significant explanatory of increased levels of TC (β=17,879, 95% CI = 4,357-31,401; p =0.01) and LDL (β=17,162, 95% CI= 4,009-30,316; p =0.01). Conclusions: Higher levels of serum total cholesterol and LDL were observed in the occurrence of T. forsythia and the presence of this periodontopathogen may increase the atherogenic potency of low-density lipoprotein that may augment the risk for atherosclerosis in periodontal disease patients.
- Lip and oral lesions in children with Down syndrome: a controlled study(2015) Al-Maweri, Sadeq A.; Tarakji, Bassel; Al-Sufyani, Ghadah A.; Al-Shamiri, Hashem M.; Gazal, GiathBackground: Down syndrome (DS) is the most common chromosomal abnormality affecting numerous organs, including the orofacial region. The objective of the present study was to assess the prevalence of lip and oral soft tissue lesions, with particular emphasize on the incidence of fissured tongue, lip fissures and angular cheilitis, among individuals with DS in Yemen. Material and Methods: This controlled cross-sectional study included 50 children with DS (6-18 years), and 50 age- and gender-matched healthy controls. The prevalence of orofacial soft tissue lesions was evaluated in both groups. Data were analyzed by Chi-square and Fisher tests, and p <0.05 was considered to be statistically significant. Results: Ten orolabial lesions were identified among the subjects. The most frequently seen lesions were: Fissured tongue (78.0%), lip fissures (64.0%), angular cheilitis (38.0%) and Cheilitis (14.0%). The frequencies of these lesions were significantly higher in children with DS than healthy controls ( P < 0.001). Most of lip fissures were in the lower lip, and 80% of the fissures were in the midline. Conclusions: The prevalence of lip and oral lesions among individuals with DS is remarkably high. Hence, oral physicians should be more aware of the orofacial findings seen more frequently in this genetic disorder .
- Case-control study of craniomandibular disorders in patients with fibromyalgia(2015) García Moya, Eduardo José; Montiel Company, José María; Almerich Silla, José ManuelBackground: Fibromyalgia is a clinical syndrome characterized by chronic widespread pain, which is non-articular and is predominantly experienced in the muscles and vertebral column, and by extensive heightened sensitivity to local pressure at many specific points The purpose of this study was to measure differences in the level of painful symptoms and in the movements of the mandible in a group of patients who had been diagnosed as suffering from fibromyalgia, in comparison with a control group. The anxiety and subjective pain levels and their relation with mandibular mobility were also compared. Materials and Methods: A case-control study was designed. The temporomandibular joints and masticatory muscles of the cases (n=20) and controls (n=18) were examined, anxiety was assessed by the STAI index and subjective pain was measured on a visual analogue scale. The data analysis was carried out with SPSS v.19.0 software. The descriptive data were expressed as means and proportions at a 95% confidence interval. The proportions were compared with the chi-square test and the means with the Mann-Whitney U test. Pearson’s correlation coefficient was used to measure the association between quantitative variables. Results: The fibromyalgia patients (the case group) presented a higher level of pain following the musculoskeletal examination and significantly greater symptoms at the examination points. Regarding joint mobility, significant differences in mandibular opening were found (cases 43.4 mm vs controls 47.2 mm, p = 0.042). The mean pain score of the cases was significantly higher than that of the controls (4.03 vs 1.8, p = 0.001) but no significant differences were found in the anxiety index (23.8 vs 23.4). Conclusions: patients with fibromyalgia are affected to a greater extent by craniomandibular disorders, with lower mouth opening and higher pain levels than healthy persons. However, the anxiety levels of the two groups are similar.
- Toxicity test of a dental commercial composite(2015) Ponce Bravo, Santa; Ledesma Montes, Constantino; Martínez Rivera, José Luis; Garcés Ortíz, MaricelaBackground: International rules must be followed for testing biosecurity in dental materials. A new brand of restorative material appeared in the market and regulations indicated that it should be tested for toxicity. Objectives: The aim of this study was to determine the 90-day sub chronic toxicity of one triethylene glycol dimethacrylate containing composite (MEDENTAL Light-Cure Composite™) orally administered to rats according to Organization for Economic Co-Operation and Development no. 48 guidelines and the requirements specified in the ISO 10993-11. Material and Methods: Wistar rats ate the polymerized composite during 90 days and were observed to determine changes in their behavior, eye and skin signs and other attitudes such as aggressiveness, posture, walking and response to handling. After 90 days were sacrificed to ascertain blood alterations, we did special hematological tests and assessed microscopic slides from 33 different organs. Results: We recorded no significant changes in clinical behavior of the animals. Microscopic review of the H&E stained slides obtained from the analyzed organs showed no abnormal inflammatory or cytological changes and all hematological special tests were within normal limits. Conclusions: Results of this study show that under our experimental conditions the MEDENTAL Light-Cure Composite™ does not produce inflammatory or cytological changes suggestive of toxicity
- Dentofacial abnormalities among adolescents: a study on the prevalence and severity(2015) Shenoy, Rekha P.; Shenoy-Panchmal, GaneshBackground: The objectives of this investigation were to assess prevalence and severity of dentofacial abnormalities and orthodontic treatment need among adolescents in Mangalore taluk. Material and Methods: A cross-sectional study was conducted among 1340 children from randomly selected high schools. A proforma was used to record demographic data and components of the Dental Aesthetic Index [DAI] for each subject. The Chi squared test was used for analysis with p-value of < 0.05 considered statistically significant. Results: Dentofacial abnormalities (DAI scores ≥ 26) were recorded in 38.5% subjects. Mean DAI score of the study population was 24.59 ± 6.09. Female subjects presented with higher prevalence and higher mean DAI scores than their male counterparts ( p > 0.05). Assessment of severity of malocclusion between age groups revealed no differences ( p > 0.05). Orthodontic treatment was highly desirable in 11% and mandatory in 5.2% subjects. Conclusions: A high prevalence of dentofacial abnormalities was found among adolescents in Mangalore taluk pointing towards a need for designing effective programs for early diagnosis and treatment of this condition, especially among adolescents
- The relationship between tooth size discrepancy and archform classification in orthodontic patients(2015) O'Mahony, Gerard; Millett, Declan T.; Cronin, Michael S.; McIntyre, Grant T.; Barry, Mark K.Background: To determine the relationship between clinically significant tooth size discrepancies (TSD) and archform classification in orthodontic patients. Material and Methods: Two hundred and forty consecutive sets of pre-treatment orthodontic study models were scanned and landmarked. All models had permanent teeth erupted from first molar to first molar in both arches. Sixty sets of images were classified into two groups of 30 according to the presence (group 1) or absence (group 2) of a clinically significant overall or anterior TSD (>2 SD from Bolton’s original means). Mean upper and lower archforms were created for each group using a fourth degree polynomial curve. Upper and lower archforms in each group were classified as square, tapering or ovoid; their distribution was analysed using the Fisher test with a 5% level of significance. To evaluate the intra-operator error when determining archform type, the 60 archforms were re-classified by the same operator two weeks later. The unweighted Kappa statistic at 95% confidence intervals was used to determine the similarity of the classification on the two occasions. Results: Reproducibility of the classification of archform was very good (unweighted Kappa statistic of 0.83 with a 95% confidence interval of 0.73, 0.93). There was no statistically significant difference in the distribution of archform type between group 1 and group 2 for the upper ( p =0.3305) or lower ( p =0.6310) arches. Conclusions: The presence of a clinically significant TSD and archform classification do not appear to be related.
- Laser-Casein phosphopeptide effect on remineralization of early enamel lesions in primary teeth(2015) Aminabadi, Naser-Asl; Najafpour, Ebrahim; Samiei, Mohammad; Erfanparast, Leila; Anoush, Somayeh; Jamali, Zahra; Pournaghi-Azar, Fatemeh; Oskouei, Sina GhertasiBackground: The aim of this study was to assess the effect of Nd:YAG laser irradiation following casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) application on calcium and phosphate concentration and surface microhardness (SMH) of enamel surface in artificial white spot lesions of primary teeth. Material and Methods: Eighty teeth with artificial white spot lesions were randomly divided into four groups: (A) distilled and deionized water, (B) Nd:YAG laser, (C) CPP-ACP crème, & (D) CPP-ACP plus laser. SMH was measured using Vickers diamond indenter in Vickers Hardness Number (VHN). Two samples of each group were analyzed using scanning electron microscope (SEM). The results were analyzed with the SPSS 17/win. Results: The subjects of group D demonstrated a significant increase in the calcium and phosphate contents of enamel surface compared to those of groups A ( P < 0.001, P < 0.001), B ( P < 0.001, P < 0.001) and C ( P = 0.024, P = 0.04), respectively. A statistically significant difference was seen for mean VHN between groups A and B ( P = 0.002). SEM evaluations confirmed the results. Conclusions: The combination of Nd:YAG laser and CPP-ACP crème could be recommended as an effective preventive modality for remineralizing of white spot lesions in primary teeth.
- Post-fatigue fracture resistance of metal core crowns: press-on metal ceramic versus a conventional veneering system(2015) Solá Ruiz, María Fernanda; Agustín Panadero, Rubén; Campos Estellés, Carlos; Labaig Rueda, CarlosBackground: The aim of this in vitro study was to compare the mechanical failure behavior and to analyze fracture characteristics of metal ceramic crowns with two veneering systems – press-on metal (PoM) ceramic versus a conventional veneering system – subjected to static compressive loading. Material and Methods: Forty-six crowns were constructed and divided into two groups according to porcelain veneer manufacture. Group A: 23 metal copings with porcelain IPS-InLine veneering (conventional metal ceramic). Group B: 23 metal copings with IPS-InLine PoM veneering porcelain. After 120,000 fatigue cycles, the crowns were axially loaded to the moment of fracture with a universal testing machine. The fractured specimens were examined under optical stereomicroscopy and scanning electron microscope. Results: Fracture resistance values showed statistically significant differences (Student’s t-test) regarding the type of ceramic veneering technique ( p =0.001): Group A (conventional metal ceramics) obtained a mean fracture resistance of 1933.17 N, and Group B 1325.74N (Press-on metal ceramics). The most common type of fracture was adhesive failure (with metal exposure) ( p =0.000). Veneer porcelain fractured on the occlusal surface following a radial pattern. Conclusions: Metal ceramic crowns made of IPS InLine or IPS InLine PoM ceramics with different laboratory techniques all achieved above-average values for clinical survival in the oral environment according to ISO 6872. Crowns made with IPS InLine by conventional technique resisted fracture an average of 45% more than IPS InLine PoM fabricated with the press-on technique
- Dentin wettability enhancement for three irrigating solutions and their effect on push out bond strength of gutta percha / AH Plus(2015) Fahmy, Sarah Hossam; El Gendy, Abeer Abdel Hakim; El Ashry, Salma HassanBackground: The aim of this study was to investigate the effect of wettability enhancement for 17% EDTA, 2.5% sodium hypochlorite and 7% maleic acid solutions on push out bond strength of gutta percha /AH Plus to root dentin. Materials and Methods: One hundred and eight extracted single rooted human lower premolars were instrumented up to Protaper Universal F5 then irrigated with 3ml of 2.5% NaOCl after each file. Irrigants were prepared and a pilot study for determination of Tween 80 concentration yielding the lowest surface tension value in every solution was conducted. Samples were randomly divided into a control group and two experimental groups (17% EDTA and 7% Maleate), further split into eight subgroups (n=12), according to Tween 80 implementation sequence. Roots were obturated using gutta percha and AH plus by lateral condensation. Bond strength was measured by push out test. Mode of failure was then evaluated quantitatively by stereomicroscopy. Data were statistically analyzed using one way ANOVA followed by Tukey-Kramer for multiple comparisons. Results: Control group showed the lowest values. Maleic acid subgroups showed significantly higher overall values than EDTA subgroups ( P <0.05). Protocols implementing surfactant containing NaOCl showed significantly lower values than plain counterparts. Failure pattern was predominantly cohesive for plain regimens and the ones implementing Tween 80 in maleic acid solutions with plain NaOCl. Conclusions: Tween 80 addition to demineralizing irrigants increased the bond strength values. Surfactant containing NaOCl solutions yielded lower bond strength than plain ones
- Magnitude and distribution of stresses in composite resin and sound dentine interface with mechanical retentions(2015) Kuramochi, Gisaku; Borie, Eduardo; Orsi, Iara Augusta; Del Sol, MarianoBackground: Adhesive systems are constantly subjected to mechanical and chemical stresses that negatively impact the integrity and durability of the dentine-adhesive interface. Despite the lack of evidence to support or reject the clinical indication for mechanical retention, the potential further contribution of these preparations to the behavior of the composite resin-sound dentine bond has been rarely addressed. The authors evaluated by finite element analysis the effect of mechanical retention on the magnitude and distribution of stresses in a composite resin-sound dentin bonding interface when subjected to tensile and shear forces. Material and Methods: A three-dimensional model was created based on three cylindrical volumes representing the sound dentin, adhesive system, and composite resin. From this main model, two models were designed to simulate dentine bonding: 1) a model with no mechanical retention, which considered flat adhesion; and 2) a model with retention, which considered four hemispherical holes on the dentine surface. Both groups were subjected to linear static analysis under tensile and shear loading of 200N. Results: At the model with retentions’ bonding interface under tensile and shear loading, a concentration of Von Mises equivalent stress was observed within the retentions, with a reduction of those stresses on the bonding boundary surface. Conclusions: Additional mechanical retention increases the tensile strength of the sound dentin-composite resin bonding interface, promoting a decrease in the magnitude of the stresses and their redistribution under tensile and shear loading


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