Occlusal contact characteristics of molar teeth with food impaction: Insights from a new digital technique.

OBJECTIVES: The objective of this study was to analyze the occlusal contact characteristics of the food-impacted teeth using a new digital technique. METHODS: A 3D occlusal analysis method was developed for studying the occlusal contact characteristics of teeth affected by food impaction. In this self-controlled study, food-impacted molars from 20 participants constituted the experimental group. The corresponding healthy teeth on the opposite side served as the control group. Variables such as occlusal force (OF), occlusal contact area (OCA), and the number and distribution of occlusal contact points (OCN) in the mesio-distal directions were measured and compared between the two groups. RESULTS: There was no statistical significant difference in the values of OF, OCA and OCN between the food-impacted molars and the healthy control molars (P > 0.05). However, paired T-tests indicated significant difference in the proportion of mesial OF, OCA, and OCN in the second molars of the experimental group (0.22, 0.28 and 0.28, respectively) and the control group (0.66, 0.63, and 0.63 respectively) (P < 0.001). CONCLUSIONS: The abnormal distribution of occlusal contacts in the second molar, primarily characterized by excessive occlusal contact in the distal direction may contribute to the occurrence of food impaction. CLINICAL SIGNIFICANCE: The present study identified variations in the distribution of occlusal contacts and occlusal component force in food-impacted teeth. These findings can assist dentists in making more targeted occlusal adjustments, or applying other treatment modalities, to effectively address food impaction.

Quantitative evaluation of the proximal contact area gap change characterization under intercuspal occlusion by intraoral 3D scanning: Food impaction with tight proximal contact.

OBJECTIVE: This study aimed to present three indicators that represent the proximal contact area gap change under intercuspal occlusion and to see if and how these indicators influence food impaction with tight proximal contact. MATERIALS AND METHODS: Ninety volunteers were recruited for bite force measurement and intraoral scanning. Three-dimensional surface data and buccal bite data were obtained for 60 impacted and 60 non-impacted teeth. The scanning data were imported into the Geomagic Studio 2013 to measure three indicators, which included the gap change maximum (Δdm, µm), the buccolingual position of Δdm (P), and the gap expanded buccolingual range (S, mm). The difference between two groups of three indicators and their relationship with food impaction with tight proximal contact were analyzed by the t test, the Pearson chi-squared test, the nonparametric Mann-Whitney U test, and the binary logistic regression analysis (a = 0.05). RESULTS: All indicators (Δdm, P, and S) were statistically different (p < 0.001, p = 0.002, and p < 0.001) in the impacted and non-impacted groups. Food impaction with tight proximal contact was affected by Δdm and S (p < 0.001, p = 0.039), but not by P (p = 0.409). CONCLUSION: The excessive increase of the gap change maximum and the gap expanded buccolingual range under bite force promoted the occurrence of food impaction with tight proximal contact. CLINICAL SIGNIFICANCE: The use of intraoral scanning to measure the characteristics of the proximal contact area gap change under bite force may help to deepen our understanding of the pathogenesis of food impaction with tight proximal contact. Importantly it can provide a reference basis for individualizing and quantifying occlusal adjustment treatment.

Treatments related to temporomandibular disorders among patients with prevalent types of Ehlers-Danlos syndrome in Sweden.

The aim of this study was to assess the received TMD treatment modalities and the perceived outcome among the frequent types of EDS. A digital questionnaire was sent to the member of the National Swedish EDS Association during January-March 2022. The subsamples of hypermobile and classical EDS were constructed. Almost 90% reported TMD symptoms. Bite splint therapy, counselling, jaw training and occlusal adjustment were reported as the most common treatments with no statistically significant difference in terms of good effect between the two subsamples. Hypermobile and classical EDS might consider as an entity with regards to TMD.

Effect of artificial eccentric occlusal interferences on masticatory performance: A randomised double-blind clinical trial.

BACKGROUND: Occlusal interferences lead to changes in mandibular kinematics to compensate and improve function. However, the effects of different types of eccentric disturbance on the comminution capacity are not known. OBJECTIVE: To determine the immediate effect of eccentric occlusal interferences on masticatory performance. METHODS: This crossover clinical trial included 12 healthy dentate subjects aged 25.2 ± 3.3 years who were randomly submitted to seven types of occlusal interference: unilateral and bilateral laterotrusive and mediotrusive, protrusive, dummy and control (no interference). The interference forms were planned in a semi-adjustable articulator, fabricated with composite resin and adhered to the mandibular first molars such that subjects' maximum intercuspation was maintained. Masticatory performance and the chewing rate during 20 cycles were evaluated during subjects' comminution of silicone test food under one interference condition per test day; the multiple sieve method was applied to the comminuted particles. The interference was removed upon test completion, and a 1-week washout period was applied between tests. RESULTS: Comminuted median particle sizes were larger under unilateral (4.94 ± 0.41 mm) and bilateral (4.81 ± 0.49 mm) laterotrusive, bilateral mediotrusive (4.65 ± 0.50 mm) and protrusive (4.83 ± 0.54 mm) interferences (p < .05) than under the control (4.01 ± 0.52 mm) and dummy (4.18 ± 0.58 mm) conditions (p < .05). Only unilateral and bilateral laterotrusive interferences narrowed the comminuted particle size dispersion (p < .05). The chewing rate did not differ among conditions (p = .1944). CONCLUSION: Artificial eccentric interferences had an immediate adverse effect on masticatory performance by resulting in larger comminuted particles. CLINICAL TRIAL REGISTRATION: Brazilian Registry of Clinical Trials (RBR-8g5zfg8).

Accuracy and reproducibility of real and virtual occlusal contact points in implant-supported fixed prostheses.

AIM: To evaluate the accuracy and reproducibility of real and virtual occlusal contact points in implant-supported, fixed complete dentures. MATERIALS AND METHODS: The study included 19 participants using mandibular interim complete-arch fixed prosthesis supported by 3 or 4 implants as opposed to conventional removable complete dentures. At installation, an examiner installed the prostheses and verified the occlusal contact points through 2 methods: recording the real contact points with carbon paper (RC) followed by occlusal photography and intraoral scanning (VC) to record the virtual contact points to obtain a screen print of the software. Then, the two images were randomized to determine the order to be inserted into Microsoft PowerPoint for blind and paired evaluation. The independent variables consisted of the distribution of occlusal contacts points (qualification through pre-defined scores based on the position of the contact points on the surfaces of the teeth) and the reproducibility of the methods by verifying the number of occlusal points. For this, a descriptive analysis was used to evaluate the distribution of occlusal contacts points and the Wilcoxon test for the reproducibility of the occlusal contact points between the methods (p<0.05). RESULTS: The methods had 100% and 73.6% real and virtual occlusal contact points, respectively, which is considered clinically excellent. There was no significant difference regarding the reproducibility of the methods by the number of occlusal contact points (RC: x̅13.32; VC: x̅13.68; p=0.715). CONCLUSION: The use of the tested intraoral scanner can be an easy and fast tool for studying and mapping the occlusion, and storing data for future treatment, with the conventional method being the preferred method for performing the occlusal adjustment.

Effect of a novel rotation coordinating device on registered horizontal condylar guidance of nonarcon semi-adjustable articulators.

Background: Horizontal condylar guidance (HCG) is registered by protrusive interocclusal records but in nonarcon articulators, these records can affect the accuracy. The present study aimed to evaluate the effect of a novel rotation coordinating device (RCD) on condylar guidance setting with protrusive interocclusal records. Materials and Methods: The study was designed as a comparative in-vitro investigation. Stone maxillary and mandibular casts were mounted on a fully adjustable instrument as the patient. Duplicate casts were mounted on an arcon and a nonarcon articulator with corresponding face bow records and in maximum intercuspation relation. Five different condylar guidance inclinations for both sides (20°, 30°, 40°, 50°, and 60°) were set on the fully adjustable instrument and 16 protrusive interocclusal records were established at each setting. HCG was set for arcon, nonarcon articulators, and nonarcon articulators with RCD. Data were analyzed using one-sample t-test to compare with actual HCG and one-way analysis of variance (α =0.05). Results: Mean HCG for studied articulators was 35.40 for arcon, 30.31 for nonarcon without RCD, and 35.61 for nonarcon with RCD which were significantly different from actual HCG (P < 0.05). HCG of the nonarcon with RCD showed no significant difference with arcon articulator (P = 0.71) while both were significantly different from nonarcon without RCD (P < 0.001). Conclusion: "The RCD" compensates the condylar guidance inclination difference between arcon and nonarcon articulators. The device precisely transfers the hinge movement of the upper member of the articulator to the condylar track.

The importance of properly distributing the occlusal load for the correct biomechanics of implant-supported fixed partial dentures: stress analysis in implants, prosthetic components and infrastructures / A importância da distribuição da carga oclusal de forma adequada para a correta biomecânica de prótese parcial fixa implantosuportada: análise das tensões em implantes, componentes protéticos e infraestruturas

ABSTRACT Objective: The present study analyzed the biomechanical behavior of the generated stress on the external surface of the rehabilitation elements (implants, components and infrastructures) according to different occlusion patterns on a fixed partial denture on osseointegrated implants. Method: The experimental groups varied according to the location of the occlusal load applied to the Fixed partial denture, with a total occlusal load of 750N in all groups, opting for greater loads on the occlusal table of the molar in relation to the premolar. This evaluation was performed by the finite element method with simulations by the AnsysWorkbench 16.0 Software program. Results: The results analyzed for implants and their components showed that the more posterior the occlusal loading, the greater the stress developed (group 4), always in the connection area between the prosthetic component and the implant, as this location can induce greater screw loosening. The results analyzed for the infrastructures showed that the most distributed occlusal loading possible (group 1) is the best situation for generating less stress. However, even in group 3 which obtained the highest stresses in the critical area of the prosthetic connection, the zirconia flexural strength values generated were not worrisome. Conclusion: It can be concluded that the occlusal adjustment of Fixed partial dentures are preponderant and decisive factors for correct biomechanics and preservation of the system in the long term in order to avoid possible damage and/or failures, and exert significant and notorious differences in the behavior of all structures studied herein.

RESUMO Objetivo: O presente estudo analisou o comportamento biomecânico do estresse gerado na superfície externa dos elementos reabilitadores (implantes, componentes e infraestruturas) de acordo com diferentes padrões de oclusão em uma prótese parcial fixa sobre implantes osseointegrados. Métodos: Os grupos experimentais variaram de acordo com a localização da carga oclusal aplicada na Prótese Parcial Fixa, com carga oclusal total de 750N em todos os grupos, optando por cargas maiores na mesa oclusal do molar em relação ao pré-molar. Esta avaliação foi realizada pelo método dos elementos finitos com simulações pelo programa AnsysWorkbench 16.0 Software. Resultados: Os resultados analisados para os implantes e seus componentes mostraram que quanto mais posterior a carga oclusal, maior a tensão desenvolvida (grupo 4), sempre na área de conexão entre o componente protético e o implante, pois este local pode induzir maior soltura do parafuso. Os resultados analisados para as infraestruturas mostraram que a carga oclusal mais distribuída possível (grupo 1) é a melhor situação para gerar menos estresse. No entanto, mesmo no grupo 3 que obteve as maiores tensões na área crítica da conexão protética, os valores de resistência à flexão da zircônia gerados não foram preocupantes. Conclusões: Pode-se concluir que o ajuste oclusal das Próteses Parciais Fixas são fatores preponderantes e decisivos para correta biomecânica e preservação do sistema a longo prazo a fim de evitar possíveis danos e/ou falhas, e exercem diferenças significativas e notórias no comportamento de todas as estruturas aqui estudadas.

Correlation between occlusal contact area at various levels of interocclusal thicknesses and masticatory performance.

BACKGROUND: This study aimed to determine the correlation between occlusal contact area and masticatory performance using BiteEye® , a photo occlusal analysis device and the multiple sieve method. OBJECTIVES: To calculate the occlusal contact area at various levels of interocclusal thicknesses and to measure masticatory performance with peanuts as the test material. METHODS: Fifty-two adults (30 men and 22 women) were enrolled according to specific exclusion/inclusion criteria. The occlusal contact area was measured by obtaining the interocclusal record of the maximum intercuspal position (MIP) using silicone impression material. Occlusal contact area measurements were performed in the ranges of 0-149, 0-89, 0-59, 0-29 and 0-9 µm. Masticatory performance was measured by obtaining the median particle size (X 50 ) after converting the weight of comminuted peanuts into size using the multiple sieve method. Statistical analysis was performed at 95% significance level. RESULTS: Interocclusal thickness comparison revealed the highest correlation with X 50 in the 0-149 µm range. Stronger correlations between the occlusal contact area and X 50 were observed in cases of 20 strokes of mastication (r = -.451) than in cases of 10 strokes (r = -.383), in the posterior occlusal contact area (r = -.456) than in the full arch occlusal contact area (r = -.451) and the molar area (r = -.478) than in the premolar area (r = -.296). CONCLUSIONS: The larger the occlusal contact area, the higher the masticatory performance; this correlation was statistically significant. Regarding interocclusal thickness, the highest correlation between the occlusal contact area and masticatory performance was observed in the 0-149 µm range. CLINICAL TRIAL REGISTRATION NUMBER: GWNUDH IRB 2020-A001.

Efficacy of tooth splinting and occlusal adjustment in patients with periodontitis exhibiting masticatory dysfunction: A systematic review.

OBJECTIVE: To evaluate the efficacy of tooth splinting (TS) and occlusal adjustment (OA) compared to no TS or OA in patients with periodontitis exhibiting masticatory dysfunction. MATERIAL: The primary outcome criterion was tooth loss (TL), and the secondary outcome parameters were change in probing pocket depth (PPD), change in clinical attachment level (CAL), tooth mobility (TM), and patient-reported outcome measures (PROMs). Literature search was performed on three electronic databases (from 01/1965 to 04/2021) and focused on clinical studies with at least 12 months follow-up. RESULTS: From a total of 1515 publications, 51 articles were identified for full-text reading, of which 2 retrospective case series on TS with low risk of bias and 1 randomized and 2 prospective studies on OA with unclear risk of bias were included. For TS, synthesis of data showed that in 72 patients, 26 out of 311 teeth (weighted mean incidence of TL 8.4%) and 156 out of 1541 teeth with no TS (weighted mean incidence of TL 10.1%) were lost over 2 years following non-surgical periodontal therapy. The randomized controlled clinical trial (RCT) indicated CAL gain for teeth with OA compared to no OA. For the effect of OA on TL, PPD, and TM, heterogeneous data were retrieved from the included studies. CONCLUSIONS: Within the limitations of this review and based on a low level of evidence, it is concluded that TS does not improve survival of mobile teeth in patients with advanced periodontitis. OA on teeth with mobility and/or premature contacts may lead to improved CAL, while the effect of OA on the remaining periodontal parameters remains unclear.

[The value of an occlusal adjustment: why?, how?, and when? case report]. / El valor de un ajuste oclusal: ¿por qué?, ¿cómo? y ¿cuándo? reporte de caso.

The aim of optimal dentistry is to stabilise the stomatognathic system (teeth, periodontium, muscles and temporomandibular joint). All of these must work in harmony, as together they provide optimal care from diagnosis through planning to treatment. However, many clinicians currently give little importance to the identification of premature contacts and/or interferences prior to any dental treatment, which should be taken into account to provide improved stability in mandibular closure, correct anterior and canine guidance in mandibular movements.This clinical case describes the treatment of a patient with a diagnosis of functional occlusal disorder due to premature contact, whose treatment consisted of an occlusal adjustment by selective wear, following the technique described by the author Klineberg, with the aim of preserving the dental structure as much as possible while maintaining control during the occlusal adjustment and returning the greatest number of symmetrical and pointed contacts.

Management of bruxism associated with temporomandibular disorder: case report / Manejo do Bruxismo associado a Disfunção Temporomandibular: relato de caso

ABSTRACT Studies have found the association between episodes of bruxism and the presence of signs and symptoms of temporomandibular disorder (TMD). The aim of the present study was to report the diagnosis and palliative therapy of bruxism associated with TMD. Patient, 23 years old, male gender, presented at dental clinic, complaining of pain in the temporomandibular joint on the left side and alteration of the form of the anterior teeth. During the anamnesis it was documented that this symptom was recurrent and reported the habit of grinding teeth. The clinical examination observed discrepancy between the centric relation and the maximum habitual intercuspation, unsatisfactory protrusive guide, presence of wear facets, clicking and mandibular deviation during mouth opening. The Research Diagnostic Criteria for Temporomandibular Disorders (RDC / TMD) questionnaire was applied to diagnose TMD. By means of specific algorithms this disorder was classified as myofascial pain, disc displacement with reduction and osteoarthritis, all affecting the left side. Thus, it was proposed the assembly of the models in semi-adjustable articulator for occlusal mapping and waxing diagnosis, then the occlusal adjustment by selective wear and material addition was executed. After this procedure, the occlusal splint was installed as a palliative therapy for bruxism. This case report suggests that the dental approach by means of occlusal adjustment and occlusal splint, in a patient diagnosed with bruxism and temporomandibular disorder, reduces the signs and symptoms that affect the components of the Stomatognathic System.

RESUMO Estudos tem encontrado a associação entre os episódios de bruxismo e a presença dos sinais e sintomas de disfunção temporomandibular (DTM). O objetivo do presente trabalho foi relatar o diagnóstico e terapia paliativa do bruxismo associado à DTM. Paciente, 23 anos, gênero masculino, apresentou-se à clínica odontológica, queixando-se de dor na articulação temporomandibular do lado esquerdo e alteração da forma dos dentes anteriores. Durante a anamnese foi documentado que esse sintoma era recorrente e relatado o hábito de ranger os elementos dentais. No exame clínico observou-se discrepância entre relação cêntrica e máxima intercuspidação habitual, guia protrusiva insatisfatória, presença de facetas de desgaste, estalido e desvio mandibular durante o movimento de abertura bucal. O questionário Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) foi aplicado para diagnosticar a DTM. Por meio de algoritmos específicos essa desordem foi classificada como dor miofascial, deslocamento de disco com redução e osteoartrite, todos acometendo o lado esquerdo. Desta forma, foi proposto a montagem dos modelos em articulador semi-ajustável para mapeamento oclusal e enceramento diagnóstico. Em seguida o ajuste oclusal por desgaste seletivo e acréscimo de material foi executado. Finalizado esse procedimento, a placa estabilizadora da oclusão foi instalada como terapia paliativa para o bruxismo. Esse relato de caso sugere que a abordagem odontológica por meio do ajuste oclusal e placa oclusal, em paciente diagnosticado com bruxismo e disfunção temporomandibular, reduz os sinais e sintomas que afetam os componentes do Aparelho Estomatognático.

Intervención temprana de la mordida cruzada por la pista directa de Planas: relato de siete años de seguimiento / Early Intervention of Crossbite by Planas Direct Tracks: Follow up Report After Seven Years / Intervenção precoce da mordida cruzada pela Pistas Diretas de Planas: relato de sete anos de seguimento

Resumen Introducción: entre las maloclusiones, la mordida cruzada es la de mayor prevalencia entre los niños en edad preescolar y se considera la principal depreciadora del sistema estomatognático, con un alto riesgo de desarrollar secuelas musculoesqueléticas irreparables en la edad adulta. Por lo tanto, es fundamental elegir un tratamiento eficaz que no requiera la cooperación directa del paciente y que utilice técnicas simples de ortodoncia. El objetivo de este artículo es informar la eficacia del tratamiento de rehabilitación neuroclusal (RNO) con la técnica de las pistas directas de Planas en la corrección temprana de la mordida cruzada posterior y el seguimiento de su estabilidad oclusal durante siete años. Presentación del caso: niña de 4 años de edad, que usó biberón, diagnosticada con mordida cruzada posterior funcional unilateral izquierda y desviación de la línea media. Para el tratamiento de la RNO, se realizaron los ajustes oclusales en los dientes 63, 64 y 65, y después de la desprogramación neuromuscular, se confeccionaron las pistas directas de Planas en los dientes cruzados. Después de 29 días, se corrigió la mordida y se hicieron ajustes oclusales para proporcionar una mayor armonía oclusal. Hubo monitoreamiento cada seis meses durante siete años para verificar el equilibrio y la estabilidad del tratamiento. Conclusiones: la RNO con el uso de pista directa de Planas fue eficaz para corregir la mordida cruzada posterior con una técnica simple y de bajo costo que puede ejecutar el clínico general.

Abstract Introduction: Among malocclusions, that of cross-bite is the most prevalent among preschool children and is considered to be the main depreciator of the stomatognathic system and is further linked to a high risk of developing irreversible musculoskeletal sequelae in adulthood. Thus, it is important to choose an effective treatment early on that does not require the direct cooperation of the patient and that utilizes simple orthodontic techniques in its execution. The objective of this study was to report the efficacy of the Neuroclusal Rehabilitation (RNO) treatment, with the Planas Direct Tracks technique in a case of early treatment of posterior crossbite, and the follow up of its occlusal stability for seven years. Case presentation: a 4-year-old female patient, who was bottle-fed, was diagnosed with a left unilateral functional posterior crossbite and midline deviation. For treatment of RNO, occlusal adjustments were made on the teeth 63, 64 and 65 and after neuromuscular deprogramming, the Direct Planks were made in the crossed teeth. After 29 days, the bite was corrected, and occlusal adjustments were made in order to provide greater occlusal harmony. Monitoring and evaluation took place every six months for seven years in order to verify the balance and stability of the treatment. Conclusion: the RNO treatment with the use of Planas Direct Tracks is an effective solution for the correction of posterior crossbite using a simple, low-cost technique that can be performed by general practitioners.

Resumo Introdução: entre as más oclusões, a mordida cruzada é a de maior prevalência entre as crianças em idade pré-escolar, e se considera a principal depreciadora do sistema estomatognático, com um alto risco de desenvolver sequelas musculoesqueléticas irreparáveis na idade adulta. Portanto, é fundamental escolher um tratamento eficaz que não requeira a cooperação direta do paciente e que utilize técnicas simples de ortodontia em sua execução. O objetivo deste estudo foi informar a eficácia do tratamento de Reabilitação Neuroclusal (RNO), com a técnica das Pistas Diretas de Planas na correto precoce da mordida cruzada posterior e o seguimento de sua estabilidade oclusal durante 7 anos. Apresentação do caso: paciente de sexo feminino de 4 anos de idade, que usou mamadeira, diagnosticada com mordida cruzada posterior funcional unilateral esquerda e desvio da linha média. Para o tratamento da RNO, se realizaram os ajustes oclusais nos dentes 63, 64 e 65, depois da desprogramação neuromuscular, se confeccionaram as Pistas Diretas de Planas nos dentes cruzados. Depois de 29 dias, se corrigiu a mordida e se fizeram ajustes oclusais para proporcionar uma maior harmonia oclusal. O monitoramento se realizou cada seis meses por 7 anos para verificar o equilíbrio e a estabilidade do tratamento. Conclusões: a RNO com o uso de Pista Direta Planas foi eficaz para a correção da mordida cruzada posterior com uma técnica simples, de baixo custo que pode ser realizada pelo clínico geral.

Occlusion and Temporomandibular Disorders: A Long-Standing Controversy in Dentistry.

The relationship between temporomandibular disorders (TMDs) and occlusion remains controversial. Some authors believe that occlusion is the primary factor in the onset of TMD symptoms, whereas others feel that occlusion has no role in this at all. The majority of reasoning behind causation is based upon anecdotal rather than scientific evidence. Existing evidence in the literature supports the absence of a disease-specific association. This article describes this controversy and provides the reader with findings from contemporary literature.

Study on functional occlusal morphology by using three-dimensional printed diagnostic crown and functional generated path technology / 中华口腔医学杂志

Objective@#To establish the functional occlusal morphology of fixed prostheses by using functional generated path (FGP) technology on a three-dimensional-printed diagnostic crown in order to decrease the chance of occlusal adjustment during try-in procedure of the complete crown, and to avoid the risk of occlusal interference after cementation of prosthesis.@*Methods@#A double-blind clinical trial was performed. Ten subjects (4 males, 6 females) who needed a first molar complete crown restoration were enrolled in Department of Prosthodontics, Peking University School and Hospital of Stomatology from July 2018 to December 2018. The working models with the abutment teeth of the ten participants were scanned to obtain the digital models, then the occlusal surfaces of crown were formed by either FGP technology on a three-dimensional (3D) printed diagnostic crown and then were scanned directly for computer aided design and computer aided manufacture (CAD/CAM) crown fabrication as experiment group, or conventional technology based on database as control group. Then zirconia crowns were fabricated for two groups. During crown try-in of the two groups, preferred crowns of subjects were recorded, the occlusal contact criteria including the occlusal contact area (mm2), the heights of occlusal high spot (mm) before and after the adjustment of crowns were digitally analyzed, and the amount of adjustment (mm and mm3) were calculated on digital models by using a reverse engineering software (Giomagic Sudio & Quality). Differences of values were compared statistically with paired t-test (α=0.05).@*Results@#The amount for occlusal adjustment for crowns in the experiment group [(7.320±4.238) mm3] was statistically less than that in the control group [(20.178±9.650) mm3] (P<0.05), the occlusal contact area of experiment group [(11.430±4.102) mm2] was statistically bigger than that of the control group [(4.808±3.223) mm2] (P<0.05), the heights of occlusal high spots for crowns in the experiment group was (0.043±0.019) mm while it was (0.594±0.201) mm in the control group with statistically significant differences (P<0.05).@*Conclusions@#This method could lead to a crown with less adjustment of occlusion, less occlusal high spot and less risk of occlusal interferences.

Association between traumatic occlusal forces and periodontitis: A systematic review.

OBJECTIVE: Occlusal adjustment is commonly recommended for patients with periodontitis and traumatic occlusion. The objective of this systematic review was to analyze available evidence for the association between traumatic occlusal forces and periodontitis. METHODS: Two focused questions were proposed: What is the effect of traumatic occlusal forces on periodontal parameters in patients with and without periodontitis? And what is the effect of occlusal interventions on periodontal parameters in patients with periodontitis? A systematic review of clinical and observational studies was performed and presented in narrative form. RESULTS: After title and abstract review a total of 30 articles were retrieved and of these 14 full-text articles were retrieved for analysis. Two RCTs, 1 cohort, 4 retrospective and 7 cross-sectional studies were included. Cross-sectional studies reported a significant association between occlusal discrepancies and probing depth and clinical attachment level. However, the magnitude of the effect is negligible when groups with and without occlusal discrepancies are compared. Intervention studies reported a minimal effect on probing depth and clinical attachment level after occlusal adjustment in patients with periodontitis as compared to teeth without occlusal adjustment. CONCLUSIONS: Available human studies showed that there is limited evidence that traumatic occlusion is associated with periodontitis and to support the implementation of occlusal adjustment to significantly improve the periodontal condition in patients with periodontitis.

Integração entre cirurgia plástica periodontal e odontologia restauradora em reabilitação estética com resinas compostas (parte 3) - ajuste oclusal, acabamento, áreas de espelho, texturas e polimento / Periodontal surgery and restoring dentistry integration in aesthetic rehabilitation with composite resins (part 3) - occkusal adjustment, finishing, mirror areas, textures and polishing

Restaurações utilizando resinas compostas possibilitam desde resoluções estéticas unitárias até grandes transformações dentárias, permitindo a preservação de estrutura dental sadia. Tais materiais são eleitos devido às suas características mecânicas e ópticas semelhantes aos dentes naturais, bem como sua capacidade de adesão às estruturas dentais. Os passos clínicos que sucedem as restaurações são cruciais na prática odontológica, uma vez que são responsáveis pela sua finalização, estética e naturalidade, longevidade e manutenção da saúde dos tecidos periodontais. Procedimentos esses que promovem uma superfície lisa, reduzindo a retenção de placa bacteriana, irritação gengival, descoloração, pigmentação do corpo da restauração e manchamento marginal, colaborando para a melhoria na estética e integridade marginal das restaurações. O objetivo deste trabalho é exemplificar os passos clínicos de ajuste oclusal, acabamento, delimitação das cristas marginais e áreas de espelho,caracterização secundária e texturização da face vestibular e polimento após a finalização de procedimento de reencontro cosmético com resinas compostas em dentes anteriores em uma paciente que havia realizado, previamente, cirurgia plástica periodontal. (AU).

Restorations using composite resins enable unit aesthetic resolution as well as full tooth transformation allowing dental structure preservation. Such materials are chosen because of their optical and mechanical characteristics similar to the natural teeth, as well as for their ability to adhere to dental structures. Clinical steps after restorations are crucial in the dental practice, as they are responsible for its completion, aesthetic and naturalness, longevity and periodontal tissues health maintenance. These procedures promote a smooth surface, reducing bacxterial plaque retention, gingival irritation, discoloration, restauration body pigmentation and marginal staining, contributing to the aesthetic improvement and marginal restauration integrity. The purpose of this work is to show occlusal adjustment clinical steps, finishing, marginal ridges and mirror areasn delimitation, secondary characterization and texturing of vestibulat face and polishing cosmetic recontour procedure wuthcomposite resins in a patient who had perforned plastic periodontal surgery.

Simulated occlusal adjustments and their effects on zirconia and antagonist artificial enamel.

PURPOSE: The aim of this study was to evaluate the effect of occlusal adjustments on the surface roughness of yttria-tetragonal zirconia polycrystal (Y-TZP) and wear of opposing artificial enamel. MATERIALS AND METHODS: Twenty-five Y-TZP slabs from each brand (Lava, 3M and Bruxzir, Glidewell Laboratories) with different surface conditions (Control polished - CPZ; Polished/ground - GRZ; Polished/ground/repolished - RPZ; Glazed - GZ; Porcelain-veneered - PVZ; n=5) were abraded (500,000 cycles, 80 N) against artificial enamel (6 mm diameter steatite). Y-TZP roughness (in µm) before and after chewing simulation (CS) and antagonist steatite volume loss (in mm3) were evaluated using a contact surface profilometer. Y-TZP roughness was analyzed by three-way analysis of variance (ANOVA) and teatite wear by two-way ANOVA and Tukey Honest Difference (HSD) (P=.05). RESULTS: There was no effect of Y-TZP brand on surface roughness (P=.216) and steatite loss (P=.064). A significant interaction effect (P<.001) between surface condition and CS on Y-TZP roughness was observed. GZ specimens showed higher roughness after CS (before CS - 3.7 ± 1.8 µm; after CS - 13.54 ± 3.11 µm), with partial removal of the glaze layer. Indenters abraded against CPZ (0.09 ± 0.03 mm3) were worn more than those abraded against PVZ (0.02 ± 0.01 mm3) and GZ (0.02 ± 0.01 mm3). Higher wear caused by direct abrasion against zirconia was confirmed by SEM. CONCLUSION: Polishing with an intraoral polishing system did not reduce the roughness of zirconia. Wear of the opposing artificial enamel was affected by the material on the surface rather than the finishing technique applied, indicating that polished zirconia is more deleterious to artificial enamel than are glazed and porcelain-veneered restorations.

Quantitative clinical adjustment analysis of posterior single implant crown in a chairside digital workflow: A randomized controlled trial.

OBJECTIVES: To compare the three-dimensional changes in quantity and morphology following clinical adjustment of a posterior single implant crown between chairside digital workflow (test) and hybrid digital workflow (control). MATERIALS AND METHODS: A total of 33 participants were included for single-tooth replacement with screw-retained crowns in posterior sites of either the maxillary or mandible. A total of 17 participants were carried to a chairside digital workflow, receiving monolithic lithium disilicate (LS2)-crowns (test), while the remaining 16 participants were fitted with CAD/CAM-fabricated zirconia superstructures and hand-layered ceramic veneering crowns (control). As each crown underwent intraoral scanning (3Shape TRIOS Color, 3Shape), 3D digital models were rendered. These scans were taken both before and after try-in. Clinical adjustment dimensional changes were measured by superimposing the optical scans of models within a reverse software (Geomagic Control 2014). Adjustment counts and amounts (from vertical dimension) between two workflows were assessed and compared. Time consumption was recorded for efficiency analysis. RESULTS: All patients were successfully treated in both groups. The median maximum vertical adjustment (taking both occlusal and interproximal surfaces into consideration) was 237 µm ± 112 in the test group and 485 µm ± 195 in the control group (p < .0001), respectively. The median adjustment count was 2.00 ± 1.09 in test group and 3.00 ± 1.05 in control group (p = .001), respectively. The total active working time/ total time for two workflows was 92.3/113.7 min for the test group and 146.3/676.3 min for the control group, respectively. CONCLUSION: The test group showed fewer adjustments and apparent precision on the occlusal surface compared with the control group with only a fifth of the consumption of a hybrid workflow.

[Etiology and clinical technology of the food impaction with tight proximal contacts].

Food impaction with tight proximal contacts, also known as kinetic food impaction and food impaction without anatomical structure destruction, is mainly caused by a transient separation in contacts area during mastication. It's an intractable food impaction with high morbidity and low cure rate. There are two kinds of pathogenesis accepted: the shifting of anterior teeth incongruous with adjacent teeth or lack of anterior shifting; lack of food escape grooves. The preferred treatment is occlusal adjustment, but it's difficult to determine the area and extent of selective grinding, to quantify the occlusal adjustment, or to predict the prognosis. This review summarized the pathogenesis and treatment modality for kinetic food impaction in order to provide evidence for future researches and clinical application.

Reabilitação neuroclusal em paciente odontopediátrico com mordida cruzada posterior unilateral: relato de caso clínico / Neuro-occlusal rehabilitation in pediatric dental patient with unilateral posterior crossbite: clinical case report

Objetivo: relatar a sequência clínica de tratamento para descruzar uma mordida cruzada posterior unilateral na dentição decídua por meio da reabilitação neuroclusal. Relato de caso: o caso clínico foi realizado em um paciente do sexo masculino, com 5 anos de idade, diagnosticado com mordida cruzada posterior unilateral funcional do lado direito. Após a verificação de interferências dentais nos caninos e molares em oclusão cêntrica, realizaram-se os ajustes oclusais. Seguiu-se então o protocolo para confecção de pistas diretas de Planas, utilizando resina composta em planos inclinados na metade vestibular da face oclusal dos dentes 84 e 85 e na face vestibular dos dentes 53, 54 e 55. Logo após a confecção das pistas, observou-se a correção da mordida cruzada e a estabilidade na mudança postural da mandíbula. Considerações finais: a reabilitação neuroclusal por meio de pistas diretas de Planas apresenta grande eficácia na correção da mordida cruzada posterior, proporcionando estabilidade mandibular e estímulo para o crescimento e desenvolvimento crânio-maxilo-facial. (AU)

Objective: To report the clinical treatment sequence to uncross a unilateral posterior crossbite in deciduous dentition using neuro-occlusal rehabilitation. Case report: The clinical case was performed in a 5-year-old male patient diagnosed with a functional unilateral posterior crossbite on the right side. After verifying dental interferences with canines and molars in centric occlusion, the occlusal adjustments were performed. The protocol for producing Planas direct tracks was followed using composite resin in inclined planes in the buccal half of the occlusal surface of teeth 84 and 85 and in the buccal surface of teeth 53, 54, and 55. After the preparation of tracks, the crossbite correction and the stability in postural mandibular change were observed. Final considerations: Neuro-occlusal rehabilitation using Planas direct tracks is highly effective in correcting posterior crossbite, providing mandibular stability and stimulus for the growth and development of the maxillofacial skull. (AU)