Query: abfraction

title: Abfraction: Etiopathogenesis, clinical aspect, and diagnostic treatment modalities: A review
abstract: Abfraction is a loss of tooth structure along the gingival margin and manifests with different clinical appearances. It has multifactorial etiology and may occur due to normal and abnormal tooth function and may also be accompanied by pathological wear, such as abrasion and erosion. The theory behind the abfraction is that the tooth flexure in the cervical area is caused due to occlusal compressive forces and tensile stresses. This results in the fractures in the hydroxyapatite (HA) crystals. It is also caused by the low packing density of the Hunter Schreger band (HSB) at the cervical area. Unfortunately, there is a lack of evidence regarding the outcome of abfraction with or without intervention. The aim of this review is to collect clinical information from the literature and discuss the etiology, pathogenesis, clinical representation, and management. Also, search databases for clinical studies that describe the role of sclerotic dentine in non carious cervical lesions (NCCLs) are becoming a clinical challenge.  The literature was searched that described the etiology, pathogenesis, clinical representation, and management of the abfraction lesions. Also, a specific question regarding the formation of sclerotic dentin in the NCCL lesion was described and searched for evidence that challenges etching, bonding, and successfully restoring NCCLs. The databases PUBMED, SCOPUS, MEDLINE, WEB of SCIENCE, and EMBASE were searched using the key terms. The inclusion criteria were the randomized controlled clinical trial, cohort studies, and cross sectional studies that aimed at determining the role of sclerotic dentine in NCCLs and its effect on etching, bonding.  One clinical study was retrieved according to the PRISMA flowchart and PICO format. The longer etching time, total etch adhesive system, and EDTA pre treatment of the sclerotic dentin of cervical wedge shaped defects could improve the bonding strength in lesions like NCCL's.  In conclusion, clinical challenges that occur due to NCCLs are better managed by a proper understanding of factors like etiopathogenesis, ultra structure of enamel, and dentine and their effect on the bonding of restorations of the tooth.

title: Abfraction Myth or Reality? Why Some Wedge shaped Cervical Lesions are not Caused by Acid Erosion?
abstract: The aims of this study is to demonstrate that not all the lost of dental structure is caused by acid neither the abrasivity of tooth brushing nor the toothpaste. Abfraction is called the wedge shaped lesion in the Cement enamel Junction (CEJ) caused by eccentric occlusal forces that lead to the tooth bending. An injury strictly of the cervical enamel that rebounds in dentine and cementum that causes the dental flexion in where periodontium plays an important role. Although the processes of lost of dental structure are due to multifactorial causes, the action of the para funcional forces is acting in one or several pieces of the same sector. During the development of the present study, different causes are mentioned and the reasons why not all the aetiology of non carious cervical lesions, are the response to the action of acids. When the harmful force that generates the loss in wedge shape is present, the structure of the enamel is open giving rise to acid elements that become risk factors to trigger a greater loss of dental structure.

title: Modified Technique of Porcelain Laminate Veneer in Premolars with Abfraction Lesions: Three Dimensional Finite Element Analysis (FEA)
abstract: The incidence of non carious cervical lesions (NCCLs) has increased as populations are aging, and teeth are increasingly retained for life. Several materials are available to treat these lesions. This study aimed to evaluate the stress distribution of maxillary premolars with NCCLs using three dimensional (3D) finite element analysis (FEA) according to different restorative techniques. A 3D FEA mathematical model simulating a sound premolar was initially modeled and replicated in 6 more models simulating a tooth with abfraction: G.1 tooth with abfraction; G.2 tooth with abfraction composite resin restoration; G.3 tooth with abfraction glass ionomer cement restoration; G.4 tooth with abfraction resin composite restoration porcelain laminate veneers; G.5 tooth with abfraction glass ionomer cement porcelain laminate veneers; and G.6 modified porcelain laminate veneers filling the lesion. All materials and structures were considered linear, elastic, homogeneous and isotropic and the results were expressed as maximum principal stress. Lower stress concentration in dentin was calculated when the tooth was restored with composite resin and glass ionomer cement. Regarding the veneer techniques, no difference was found to dentin stress among the groups, but the modified veneer concentrated less stress in the restoration than other the techniques. The control group had the highest concentration of stress in the lesion. All techniques decreased the stress concentration inside the NCCLs and the indirect veneer filling the lesion presented better biomechanical behavior than the veneer cemented above direct restorations.  Finite Element Analysis. Dental Veneers. Ceramics. Bicuspid.  A incidencia de lesoes cervicais nao cariosas (LCNC) tem aumentado, uma vez que a populacao tem envelhecido com uma menor perda de elementos dentarios. Diferentes materiais estao disponiveis para tratar dessas lesoes. Este estudo objetivou avaliar a distribuicao de tensao de pre molares superiores com LCNC por meio da analise tridimensional (3D) de elementos finitos (FEA) de acordo com diferentes tecnicas restauradoras. Um modelo matematico 3D FEA simulando um pre molar integro foi modelado e replicado em mais 6 modelos simulando um dente com abfracao: G.1 dente com abfracao; G.2 dente com abfracao resina composta; G.3 dente com abfracao cimento de ionomero de vidro; G.4 dente com abfracao resina composta faceta; G.5 dente com abfracao cimento de ionomero de vidro faceta ceramica e G.6 com faceta ceramica modificada, preenchendo a lesao. Todos os materiais e estruturas foram considerados lineares, elasticos, homogeneos e isotropicos e os resultados foram expressos como maxima tensao principal. Menor concentracao de tensao na dentina foi calculada quando o dente foi restaurado com resina composta ou cimento de ionomero de vidro. Dentre os grupos com laminados, nao houve diferenca para a dentina, entretanto a faceta modificada apresentou menor concentracao de tensao na restauracao. O grupo controle apresentou a maior concentracao de tensao na lesao. Todas as tecnicas restauradoras diminuiram a concentracao de tensao no interior das LCNCs e dentre as tecnicas com laminados a faceta modificada apresentou o melhor comportamento biomecanico.

title: Prosthetic Re Treatment Of Failed Fixed Dental Prosthesis Therapy and Its Correlation With Abfraction: A Retrospective Analysis

title: Are the bite force and electromyographic activity altered in muscle TMD patients with abfraction lesions
abstract: To verify if the maximal molar bite force (BF) and the electromyographic activity (EMG) are altered in TMD patients with abfraction lesions (AL) when compared to those without AL.  The sample was composed of 45 patients (18 60 years old) 30 diagnosed with TMD (RDC/TMD) (15 with AL and 15 without AL) and 15 controls. The BF and the EMG of the masticatory muscles (maximal voluntary contraction (MVC) and chewing gum) were measured.  TMD patients showed decreased BF (p 0.05) although there was a greater trend of muscular balance for the control group (percentage overlapping coefficient and electromyographic indexes) The TMD group without AL showed a lower number of cycles and masticatory frequency.  TMD patients with and without AL exhibited similar results in the analysis of the BF and EMG, without differences.

title: Are the bite force and electromyographic activity altered in muscle TMD patients with abfraction lesions?
abstract: To verify if the maximal molar bite force (BF) and the electromyographic activity (EMG) are altered in TMD patients with abfraction lesions (AL) when compared to those without AL.  The sample was composed of 45 patients (18 60 years old) 30 diagnosed with TMD (RDC/TMD) (15 with AL and 15 without AL) and 15 controls. The BF and the EMG of the masticatory muscles (maximal voluntary contraction (MVC) and chewing gum) were measured.  TMD patients showed decreased BF (p 0.001) without differences between patients with and without AL. The electromyographic activity during MVC was similar among all groups (p 0.05) although there was a greater trend of muscular balance for the control group (percentage overlapping coefficient and electromyographic indexes) The TMD group without AL showed a lower number of cycles and masticatory frequency.  TMD patients with and without AL exhibited similar results in the analysis of the BF and EMG, without differences.

title: Effect of laminate veneer designs on abfraction incidence using different loading conditions "finite element analysis"
abstract: Abfraction incidence is usually challenging and difficult to be identified accurately, especially, in case of existing restoration.  This study aimed to evaluate the influence of laminate veneer design on abfraction incidence in maxillary central incisor with different loading protocols using finite element analysis.  Maxillary central incisor was subjected to Computerized tomography (CT) scan to obtain 3D finite element model. Tooth without restoration (control) was subjected to a load of 100 N at 60deg and 125deg, the same load was applied with the previous directions on the tooth model with lithium disilicate laminate veneer using three preparation designs: veneer is taken up to the incisal edge level but the edge, is not reduced (Feather) (FP) design (FP) is prepared with 0.5mm incisal reduction without palatal overlapping (Butt joint. (BJP) and (POP) in which, design (FP) is prepared with 2 mm incisal reduction and 0.5 mm palatal overlap.  In feather preparation (FP) design, stress values were slightly higher than that in control model in enamel and dentin at both load directions. While, but joint preparation (BJP) design exhibited the lowest stress in both layers and direction of load.  Highest stresses were concentrated at the cement enamel junction in all loading scenarios, butt joint preparation (BJP) design in both load conditions developed lower stresses than that in other designs, and feather preparation (FP) design suggested the probability of abfraction formation.

title: Abfraction role de l'occlusion dans les LCNC
abstract: Les Lesions Cervicales Non Carieuses (LCNC) sont des pathologies, d'origine multifactorielle, de plus en plus presentes dans notre exercice quotidien. Leur prise en charge est articulee autour du concept majeur du diagnostic etiologique, qui necessite de connaitre les facteurs de risque et leurs mecanismes afin de mettre en place des mesures prophylactiques adaptees. L'introduction recente du concept d'abfraction, principalement issu de la biomecanique, suscite des controverses et demeure enigmatique. Une recherche bibliographique montre que la litterature actuelle ne permet pas d'affirmer avec certitude que l'occlusion est un facteur de risque concourant au developpement des LCNC. Toutefois, le facteur occlusal n'est pas un facteur a negliger et sera le garant de la perennite de nos therapeutiques restauratrices. De futurs essais cliniques randomises sont necessaires pour mettre en evidence plus precisement l'influence de l'occlusion sur les LCNC.

title: Clinical Study on Abfraction Lesions in Occlusal Dysfunction
abstract: The abfraction theory states that under the action of the occlusal forces non axially transmitted, the flexion of the tooth occurs in the cervical area, which initially leads to the appearance of cracks in the enamel and dentin, followed by the destruction of the dental structure. These lesions allow bacterial plaque retention, lead to dental hypersensitivity and can affect the vitality of the dental pulp. Thus, the study included 102 participants, of both sexes, 54% representing the male gender (55 subjects) and 46% the female gender (47 subjects) aged between 20 and 80, from the urban area 76% (77 subjects) and rural 24% (25 subjects) who came to the Dental Medicine office, between August 2018 and August 2019, representing 57.3% of the total number of patients treated during the aforementioned period. They have been described the acid and abrasive processes involved in the generation of these lesions,and special attention was paid to the role of mechanical stress occurring at the occlusal level, due to the transmission of forces outside the dental axis.

title: Resolution of Abfraction Associated Gingival Fenestration Utilizing Connective Tissue Grafting
abstract: Gingival fenestration (GF) is a distinct clinical entity of uncertain etiology that is seldom documented in the literature. It has been associated mainly with submucosal mechanical irritants such as calculus that subsequently create an opening in the oral soft tissue, usually at facial anterior sites. Surgical correction may be indicated to address functional and/or esthetic concerns. Case Presentation The patient, a 74 year old male, presented to the clinic with a chief complaint of "something is poking through my gum." Clinical exam revealed a gingival fenestration on the facial of tooth #11, associated with what appeared to be a pronounced noncarious cervical lesion (NCCL) Surgical treatment consisted of a connective tissue graft and odontoplasty of the sharp protruding edge of the root surface. Healing was uneventful with excellent closure of the fenestration and no evidence of recurrence after 18 months of follow up.  GF is a perforation of the mucosa typically associated with underlying sharp mechanical etiology. This report describes a fenestration that developed from a probable abfractive lesion, which later was successfully closed and exhibits long term stability.