Mandibular overdenture retained by four one-piece titanium-zirconium mini implants: A 2-year follow-up on prosthodontic outcomes.

OBJECTIVE: This 2-year prospective study reports the incidence of prosthetic complications and maintenance events after treatment with mandibular overdenture retained by four mini implants opposed to a maxillary denture. METHODS: Implant intervention included flapless or flapped surgery combined with immediate or delayed loading, as part of a randomized clinical trial. Four one-piece titanium-zirconium mini-implants (Straumann Mini Implant System) were inserted, and the retentive PEEK elements (Optiloc) were incorporated into the overdenture using chairside procedures. Prosthodontic complications and maintenance events were recorded over a 2-year follow-up, and the final outcome was defined according to standardized criteria. Data analysis included descriptive statistics, incidence and incidence density rates, and Kaplan-Meier survival. RESULTS: 73 out of 74 patients (64.9 % female), mean age of 64 (SD=8.2) years, completed the study follow-up (one withdrew after 9 months). Implant survival was 100 %. A total of 163 prosthodontic events occurred in 53 patients (72.6 %), and 20 patients had no clinical complaints or maintenance needs. The most common procedures were adjustment/repair of the overdenture base (47.0 %), replacement of retentive inserts (19.8 %), and laboratory relining (12.9 %). A high prosthodontic success rate was achieved (93.2 %), and all patients presented serviceable overdentures and continuous use after the resolution of prosthodontic complications. The incidences of matrix replacement and laboratory relines were low in the first year, while denture base adjustments were common within the first year, especially in the first 6 months. CONCLUSION: The mini implant system showed high prosthodontic success rates. Minor adjustments/repairs during the initial follow-up were common. Relines and matrix replacements tend to occur after one year of overdenture use, and matrix replacements may occur as a consequence of the need for relining.

Accuracy, adaptation and margin quality of monolithic zirconia crowns fabricated by 3D printing versus subtractive manufacturing technique: A systematic review and meta-analysis of in vitro studies.

OBJECTIVE: The purpose of this systematic review and meta-analysis was to evaluate the accuracy (trueness and precision), marginal and internal adaptation, and margin quality of zirconia crowns made by additive manufacturing compared to subtractive manufacturing technology. METHODS: The investigation adhered to the PRISMA-ScR guidelines for systematic reviews and was registered at the Prospero database (n°CRD42023452927). Four electronic databases, including PubMed, Scopus, Embase, and Web of Science and manual search was conducted to find relevant studies published until September 2023. In vitro studies that assessed the trueness and precision, marginal and internal adaptation, and margin quality of printed crowns compared to milled ones were included. Studies on crowns over implants, pontics, temporary restorations, laminates, or exclusively experimental materials were excluded. RESULTS: A total of 9 studies were included in the descriptive reporting and 7 for meta-analysis. The global meta-analysis of the trueness (P<0.74,I2=90 %) and the margin quality (P<0.61,I2=0 %) indicated no significant difference between the root mean square of printed and milled zirconia crowns. The subgroup analysis for the printing system showed a significant effect (P<0.01). The meta-analysis of the crown areas indicated no significant difference in most of the areas, except for the marginal (favoring milled crowns) and axial (favoring printed crowns) areas. For precision and adaptation, both methods showed a clinically acceptable level. CONCLUSIONS: Additive manufacturing technology produces crowns with trueness and margin quality comparable to subtractive manufacturing. Both techniques have demonstrated the ability to produce crowns with precision levels, internal discrepancy, and marginal fit within clinically acceptable limits. CLINICAL SIGNIFICANCE: 3D printing emerges as a promising and potentially applicable alternative method for manufacturing zirconia crowns, as it shows trueness and margin quality comparable to restorations produced by the subtractive method.

An in vitro study using confocal laser scanning microscopy to evaluate the marginal misfits of different implant-supported frameworks.

PURPOSE: This study aimed to develop and evaluate a simple, non-destructive method for assessing the misfit and passivity of implant-retained prostheses frameworks. MATERIALS AND METHODS: To simulate the rehabilitation of a mandible posterior partially edentulous area using 3-unit screw-retained frameworks supported by two implants were fabricated and divided into the following five groups (n = 10 in each group): OP = one-piece framework cast in Co-Cr with the conventional method (control-group); Co-Cr frameworks sectioned and welded by laser (=LAS) or tungsten inert gas (=TIG); Co-Cr CAD-CAM = milled Co-Cr framework; Zir CAD-CAM = milled zirconia framework. The horizontal |X| and vertical |Y| misfits were measured using confocal laser scanning microscopy with one or both screws tightened. Data were analyzed by a two-way ANOVA with repeated measures and Bonferroni correction (α = 0.05). RESULTS: The greatest |X| misfit was observed in the OP group with both screws tightened (290 µm) and one screw tightened (388 and 340 µm). The conventional casting groups sectioned and welded by laser or TIG had lower mean values (235.35 µm, both screws tightened; and 275 µm, one screw tightened) than the OP framework. However, these values still exceeded those of the milled Co-Cr and zirconia frameworks (190 and 216 µm with both screws tightened). Across all reading conditions, every framework subjected to testing consistently maintained vertical |Y| misfit levels below the threshold of 53 µm; however, the milled frameworks exhibited higher vertical misfits than the frameworks obtained by the conventional cast method. CONCLUSIONS: The frameworks, whether cast and sectioned with laser welding or milled from Co-Cr, exhibit improved marginal misfit and enhanced passive fit when compared to other fabrication methods. Additionally, the use of confocal laser scanning microscopy is highly effective for passivity and misfit analysis.

Occlusal Loading Effect on Stress Distribution of Endodontically Treated Teeth: Finite Element Analysis Study.

AIM: Evaluate the influence of occlusal loading on the stress distribution of endodontically treated teeth after root canal preparation with different file's sizes and tapers by means of finite element analysis. METHODOLOGY: Seven three-dimensional models of a single-rooted, single-canal lower second premolar were established, one healthy control and six endodontically treated and restored models. The shape of root canal preparations followed file configurations 30/.05, 30/.09, 35/.04, 35/.06, 40/.04, and 40/.06. Von- Mises equivalent stresses were calculated by applying 30 N, 90 N and 270 N loads to the buccal cusp tip, each one at 90º, 45º and 20º angles from the occlusal plane simulating occlusion, dental interference and laterality, respectively. RESULTS: 45º loading was more prone to formation of higher stress values. The simulation of occlusion and laterality resulted in maximum stress areas located at the inner side of the root curvature, while under occlusal interference they were on the lingual surface over the tooth's long axis. CONCLUSIONS: The angulation of occlusal loading and magnitude were determinants for stress distribution on dental structure. Both variations of size and taper were not determinants for the increase in the maximum stress areas.

Is Periodontal and Peri- Implant Disease Associated with Fixed Partial Denture Use? A 25-year Prospective Case Series.

INTRODUCTION: The association of the periodontium with the fixed prosthesis is the basis of prosthetic rehabilitation. This prospective case series aimed to evaluate periodontal health through the relation between periodontal/peri-implant disease progression and the use of fixed partial dentures (FPDs). METHODS: Probing depth (PD), clinical attachment level (CAL), gingival index (GI), and plaque index (PI) on either teeth or implants were evaluated at up to 25-year follow-up and compared with the baseline. Statistical analysis was performed using the Kaplan-Meier test (p⟨0.05). RESULTS: The prospective evaluation showed that the patients maintained adequate periodontal health. Failure (severe periodontal stages) occurred in 12.5% of patients. The survival rate for 107 teeth/implants was 80.48%. The comparisons for clinical parameters revealed no statistically significant difference (p⟩ 0.05). At T1, the measurements for anterior and posterior regions, respectively, were PD =2.7mm and 3.1mm; CAL= 3.3mm and 3.6mm; GI=0.5 (both regions); and PI=0.79 and 0.62. Periodontal/peri-implant disease progression did not relate to the use of prostheses. CONCLUSIONS: Patients with more frequent follow-up appointments and lower GI and PI showed periodontal health for longer periods. Patients with different oral hygiene levels present different periodontal disease progression. Periodic hygiene control and motivation are vital factors for extensive oral rehabilitation success.

Aesthetic Dentistry - What You Decided and What I Want: Shade Selection

ABSTRACT Objective: To assess the relationship between patients' and dentists' perceptions of shade selection and its impact on satisfaction with the prosthesis. Material and Methods: A single group pre-post study was conducted at the Prosthodontics department of a teaching hospital in India. One hundred ten participants were selected through a systematic random sampling technique with inclusion and exclusion criteria. Patients' attitudes regarding the aesthetics of their maxillary anterior teeth were recorded using a validated questionnaire. Shades for the intended prosthetic crown selected by the dentist and chosen by the patient were recorded separately, and patient satisfaction with the appearance of the final prosthesis was recorded. We used descriptive statistics followed by Pearson's Chi-square test and a binomial logistic regression model for inferential statistics. Results: 109 participant's data were available for final analysis. Patients choose lighter shades than the dentist's selection, which is statistically significant (p=0.000). 73.4% were satisfied with the final prosthesis, and the binomial logistic regression model identified using patient-selected shade for the final prosthesis was significantly associated with patients' satisfaction with the final prosthesis (OR=3.3, p=0.001). Conclusion: The patient's preference should be considered with the dentist's option when selecting a shade to create good esthetics.

Stress distribution in peri-implant bone, implants, and prostheses: 3D-FEA of marginal bone loss and prosthetic design / Distribuição de estresse no osso peri-implantar, implantes e próteses: análise 3D-FEA de perda óssea marginal e design protético

Objective: In response to the demand for dental implants, extensive research has been conducted on methods for transferring load to the surrounding bone. This study aimed to evaluate the stresses on the peripheral bone, implants, and prostheses under scenarios involving of the following variables: prosthesis designs, vertical bone heights, load angles, and restorative materials. Material and Methods: Three implants were inserted in the premolar and molar regions (5-6-7) of the two mandibular models. Model 1 represented 0 mm marginal bone loss and Model 2 simulated 3 mm bone loss. CAD/CAM-supported materials, hybrid ceramic (HC), resin-nano ceramic (RNC), lithium disilicate (LiSi), zirconia (Zr), and two prosthesis designs (splinted and non-splinted) were used for the implant-supported crowns. Forces were applied vertically (90°) to the central fossa and buccal cusps and obliquely (30°) to the buccal cusps only. The stresses were evaluated using a three-dimensional Finite Element Analysis. Results: Oblique loading resulted in the highest stress values. Of the four materials, RNC showed the low stress in the restoration, particularly in the marginal area. The use of different restorative materials did not affect stress distribution in the surrounding bone. The splinted prostheses generated lower stress magnitude on the bone, and while more stress on the implants were observed. Conclusion: In terms of the stress distribution on the peri-implant bone and implants, the use of different restorative materials is not important. Oblique loading resulted in higher stress values, and the splinted prosthesis design resulted in lower stress (AU)

Objetivo: Em resposta à demanda por implantes dentários, extensa pesquisa foi realizada sobre métodos para transferir carga ao osso circundante. Este estudo buscou avaliar os estresses no osso periférico, implantes e próteses em cenários que envolvem as seguintes variáveis: designs de próteses, alturas ósseas verticais, ângulos de carga e materiais restauradores. Material e Métodos: Três implantes foram inseridos nas regiões dos pré-molares e molares (5-6-7) de dois modelos de mandíbula. O Modelo 1 representou perda óssea marginal de 0 mm e o Modelo 2 simulou perda óssea de 3 mm. Materiais suportados por CAD/CAM, cerâmica híbrida (HC), cerâmica nano-resina (RNC), dissilicato de lítio (LiSi), zircônia (Zr) e dois designs de próteses (sintetizadas e não-sintetizadas) foram utilizados para as coroas suportadas por implantes. Forças foram aplicadas verticalmente (90°) à fossa central e cúspides bucais e obliquamente (30°) apenas às cúspides bucais. Os estresses foram avaliados usando Análise de Elementos Finitos tridimensional. Resultados: Cargas oblíquas resultaram nos valores mais altos de estresse. Entre os quatro materiais, RNC mostrou baixo estresse na restauração, especialmente na área marginal. O uso de diferentes materiais restauradores não afetou a distribuição de estresse no osso circundante. Próteses sintetizadas geraram menor magnitude de estresse no osso, enquanto mais estresse nos implantes foi observado. Conclusão: Em termos de distribuição de estresse no osso peri-implantar e implantes, o uso de diferentes materiais restauradores não é crucial. Cargas oblíquas resultaram em valores mais altos de estresse, e o design de prótese sintetizada resultou em menor estresse. (AU)

Utility of Panoramic Radiographs in the Screening of Individuals with Edentulous Arches: A Need-Analysis Study

Abstract Objective: To evaluate the utility of panoramic radiographs in pre-prosthetic screening of edentulous arches. Material and Methods: Panoramic radiographs taken for three years were retrospectively analyzed. Observations from the radiographs shall be categorized and classified into either of the two categories, namely: 'findings with minimal impact on denture fabrication' and 'findings which affect denture fabrication and require further evaluation.' Anatomic variations, jaw pathologies, and residual ridge resorption patterns were assessed. Results: This study included the initial screening of 23,020 panoramic radiographs, out of which 505 (showing either one or both edentulous arches) were included for the study purpose. The age range of the subjects was from 21 to 94 years. 52.6% of the radiographs showed positive findings. More than half of the radiographs belonged to the males (52.5%). Hyperpneumatization of the maxillary sinus, crestal position of the mental foramen, and retained root fragments were the most common entities noted in the radiographs. Changes in the mental foramen were significantly higher in males than females (p=0.002). Conclusion: Observations from this study showed that panoramic radiographs have high utility for screening edentulous arches, and they should be used in routine clinical practice before denture fabrication.

Dimensional accuracy of provisional complete crown made by the 3D printing method / Acuidade dimensional de coroas totais provisórias confeccionadas pelo método de impressão 3D

Objective: This study evaluated the dimensional accuracy of provisional complete crowns printed with photopolymerizable resin using an LCD-type 3D printer through optical metrology, varying the printing angle and the number of complete crowns printed at once on a single-build platform. Material and Methods: The complete crowns were printed with temporary crown resin, A2 temporary (Wilcos do Brasil), divided into four groups with n=12: Group A - 3 complete crowns positioned at 150° on the x-axis; Group B - 4 complete crowns positioned at 150° on the x-axis; Group C - 3 complete crowns positioned at 180° on the x-axis; and Group D - 4 complete crowns positioned at 180° on the x-axis. Dimensional accuracy was assessed by overlaying images in the Gom Inspect measurement software, where the STL of each complete crown was aligned and compared to the master model. For statistical analysis, one-way ANOVA and Shapiro-Wilk tests were used. Results: No significant statistical difference was observed between the differentangles, or the number of complete crowns printed at once. Conclusion: Based on dimensional accuracy, the printing of provisional complete crowns with an LCD-type 3D printer shows no significant statistical difference with either the 150 or 180-degree angle variations, and there is also no difference when printing 3 or 4 complete crowns at once.(AU)

Objetivo: Este estudo avaliou a acuidade dimensional de coroas totais provisórias impressas com resina fotopolimerizável por uma impressora 3D tipo LCD por meio da metrologia optica, variando angulação de impressão e número de coroas impressas por vez em uma única plataforma de construção. Material e Métodos: As coroas foram impressas com resina para coroa provisória, A2 temporário (Wilcos do Brasil), divididas em quatro grupos com n=12: Grupo A - 3 coroas posicionadas a 150° no eixo x; Grupo B - 4 coroas posicionadas a 150° no eixo x; Grupo C - 3 coroas posicionadas a 180° no eixo x e Grupo D - 4 coroas posicionadas a 180° no eixo x. A acuidade dimensional foi feita com a sobreposição de imagens no programa de aferição Gom Inspect, em que o STL de cada coroa foi alinhado e comparado ao modelo mestre. Para análise estatística, foram utilizados os testes ANOVA um fator e Shapiro-Wilk. Resultados: Não foi verificada diferença estatística significativa entre as diferentes angulações ou quantitadade de coroas impressas em uma única vez. Conclusão: Com base na acuidade dimensional, a impressão de coroas provisórias com impressora 3D tipo LCD não apresenta diferença estatística significative com nenhuma das duas variações angulação de 150 ou 180 graus e não há diferença também ao fazer a impressão de 3 ou 4 coroas de uma única vez.(AU)

Removable Partial Denture - Functional Impression Techniques: Review.

The objective of this article is to concisely review the main clinical techniques used to make the functional impression to manufacture a removable partial denture. Through this review, the dentist can develop his clinical knowledge.

A Narrative Review on Polycrystalline Ceramics for Dental Applications and Proposed Update of a Classification System.

Dental zirconias have been broadly utilized in dentistry due to their high mechanical properties and biocompatibility. Although initially introduced in dentistry as an infrastructure material, the high rate of technical complications related to veneered porcelain has led to significant efforts to improve the optical properties of dental zirconias, allowing for its monolithic indication. Modifications in the composition, processing methods/parameters, and the increase in the yttrium content and cubic phase have been presented as viable options to improve zirconias' translucency. However, concerns regarding the hydrothermal stability of partially stabilized zirconia and the trade-off observed between optical and mechanical properties resulting from the increased cubic content remain issues of concern. While the significant developments in polycrystalline ceramics have led to a wide diversity of zirconia materials with different compositions, properties, and clinical indications, the implementation of strong, esthetic, and sufficiently stable materials for long-span fixed dental prostheses has not been completely achieved. Alternatives, including advanced polycrystalline composites, functionally graded structures, and nanosized zirconia, have been proposed as promising pathways to obtain high-strength, hydrothermally stable biomaterials. Considering the evolution of zirconia ceramics in dentistry, this manuscript aims to present a critical perspective as well as an update to previous classifications of dental restorative ceramics, focusing on polycrystalline ceramics, their properties, indications, and performance.

Rehabilitación implanto protésica en paciente con injerto mandibular de larga data / Implant-prosthetic rehabilitation in a patient with a longstanding mandibular graft / Reabilitação protética com implantes em pacientes com enxerto mandibular de longa data

En la actualidad es cada vez más frecuente la consulta de pacientes que siendo sometidos en edades tempranas a cirugías de extirpación tumoral y posterior reconstrucción con injertos presentan problemas tanto funcionales como estéticos, el uso de prótesis implantosoportadas mejora la calidad de vida, pero al mismo tiempo representan un desafío por la baja disponibilidad ósea. Se presenta un caso clínico de rehabilitación protésica implantosoportada en una paciente con gran déficit óseo mandibular como consecuencia de le extirpación de una neoplasia y posterior injerto de costilla. Se colocaron 2 implantes osteointegrados en hueso remanente y rehabilitación con prótesis removible sostenida a una barra colada. Por ser un tratamiento poco invasivo y conservador fue aceptado fácilmente por la paciente y la mejora tanto en la estética como en la función fue notoria.

Nowadays, it is becoming more and more frequent to see patients who underwent surgery for tumor removal and subsequent reconstruction with grafts at an early age, presenting both functional and esthetic problems. The use of implant-supported prostheses improves the quality of life, but at the same time represents a challenge due to the low availability of bone. A clinical case of implant-supported prosthetic rehabilitation is presented in a patient with a great mandibular bone deficit as a consequence of the removal of a neoplasm and subsequent rib graft. Two osseointegrated implants were placed in the remaining bone and rehabilitation with a removable prosthesis supported by a cast bar. Being a minimally invasive and conservative treatment, it was easily accepted by the patient and the improvement in both esthetics and function was notorious.

Atualmente, são cada vez mais frequentes os pacientes submetidos à cirurgia de remoção de tumores e posterior reconstrução com enxertos em idade precoce que apresentam problemas funcionais e estéticos. O uso de próteses implanto-suportadas melhora a qualidade de vida, mas, ao mesmo tempo, representa um desafio devido à baixa disponibilidade de osso. Apresentamos um caso clínico de reabilitação protética implanto-suportada em um paciente com grande déficit ósseo mandibular em consequência da remoção de uma neoplasia e posterior enxerto de costela. Dois implantes osseointegrados foram colocados no osso remanescente e a reabilitação foi feita com uma prótese removível suportada por uma barra de gesso. Por se tratar de um tratamento minimamente invasivo e conservador, foi facilmente aceito pelo paciente e a melhora na estética e na função foi perceptível.

The effect of abutment material stiffness on the mechanical behavior of dental implant assemblies: A 3D finite element study.

PURPOSE: This study aimed to evaluate the stress distribution and microgap formation in implant assemblies with conical abutments made of different materials under an oblique load. MATERIALS AND METHODS: The mechanical behavior of an implant assembly with a titanium abutment was analyzed and compared with that of an assembly with a Y-TZP abutment using finite element analysis (FEA). A torque of 20 Ncm was first applied to the abutment screw, followed by oblique loads of 10 N-280 N applied to the prosthesis placed on the implant. The maximum stress in the abutment screw, the microgap formation process, and the critical load for bridging the internal implant space were evaluated. RESULTS: No significant difference in stress distribution between the two cases was observed, with the stresses being mainly concentrated at the top half of the screw (the predicted maximum von Mises stress was approximately 1200 MPa at 280 N). The area in contact at the implant-to-abutment interface decreased with increasing load for both abutments, with the critical load for bridging the internal implant space being roughly 140 N. The maximum gap size being was approximately 470 µm with either abutment. CONCLUSION: There was no significant difference in the stress distribution or microgap formed between implant assemblies with titanium and Y-TZP abutments having an internal conical connection.

A qualitative analysis of denture wearing experience affecting the quality of life of older adults.

OBJECTIVE: To explore how denture-related experiences affect older adults' quality of life using a qualitative assessment of the Oral Health Impact Profile for Edentulous individuals (OHIP-Edent). MATERIALS AND METHODS: Twenty elderly individuals were interviewed before and 3 months after delivering new complete dentures, using an open-ended interview guide based on the OHIP-Edent. Interviews were audio-recorded and transcribed. Data were open coded and thematically analyzed following a Grounded Theory approach. Findings were integrated and constantly compared to understand the interviewees' difficulties, beliefs, and perceptions. RESULTS: Three interconnected themes were developed: functional and psychosocial impairments, and coping strategies. Even when posed as an open-ended format, the wording of some OHIP-Edent items was confusing while others were not relevant to the respondents. New categories related to speaking, smiling, swallowing, emotional and functional coping emerged from the interviews. Interviewees adapted to chewing and swallowing difficulties through food avoidance, modification of food choice and preparation techniques, and changes in dietary behaviors. CONCLUSIONS: Denture wearing is a daily challenging experience that encompasses various functional and psychosocial aspects and sheds light on the need for addressing the coping strategies employed by patients, as the current OHIP-Edent items may not fully represent other deemed important aspects of the quality of life of individuals who wear dentures. CLINICAL RELEVANCE: Dentists must not solely rely on structured questionnaires to explore the impact of denture wearing and treatment outcomes. Clinicians can use a more holistic approach to comprehend older adults' experiences with dentures including advice about coping mechanisms, food preparation techniques, and meal planning.

Relationship between the occlusal plane and three different levels of ala-tragus line in a sample of sudanese adults / Relación entre el plano oclusal y tres niveles diferentes de la línea ala-trago en una muestra de adultos sudaneses

Aim: Correct orientation of the occlusal plane plays a vital role in achieving the perfect occlusal balance and function of complete dentures. This study aimed to evaluate the most reliable posterior reference point of the ala-tragus line (ATL) concerning occlusal plane (OP) in a sample of the dentate Sudanese population. Materials and Methods: A total of 150 subjects with healthy and well-aligned permanent teeth were randomly selected. Right lateral profile photographs were taken with subjects having a fox plane placed intra-orally, contacting the occlusal plane. Reference points corresponding to inferior, middle, and superior borders of the tragus and inferior border of the ala of the nose were marked on photographs. The angles between the lines were measured using the Auto-CAD software program, and the most parallel relationship was determined. Descriptive statistics in terms of means and standard deviations were presented. Independent t-test and one-way ANOVA tests were used to compare as appropriate. A p-value < 0.05 was considered significant. Results: The mean angle formed by the OP and ATL was 8.5±3.69º for the superior level, 4.68±3.13º for the middle line, and 2.89±2.57º for the inferior line. A significant difference was found between the means of the three angles (p< 0.001), while no significant difference (p> 0.05) was found between both genders regarding the measured angles. Conclusions: The line joining the inferior border of the ala of the nose with the inferior border of the tragus of the ear was the most reliable line in terms of parallelism to determine the occlusal plane orientation.

Antecedentes: La orientación correcta del plano oclusal juega un papel vital para lograr el equilibrio oclusal perfecto y la función de las prótesis completas. Este estudio tuvo como objetivo evaluar el punto de referencia posterior más confiable de la línea ala-trago (ATL) con respecto al plano oclusal (OP) en una muestra de la población dentada de Sudán. Materiales y Métodos: Se seleccionaron aleatoriamente un total de 150 sujetos con dientes permanentes sanos y bien alineados. Se tomaron fotografías de perfil lateral derecho de sujetos a los que se les colocó un plano de zorro intraoralmente, en contacto con el plano oclusal. En las fotografías se marcaron los puntos de referencia correspondientes a los bordes inferior, medio y superior del trago y al borde inferior del ala de la nariz. Los ángulos entre las líneas se midieron utilizando el programa de software Auto-CAD y se determinó la relación más paralela. Se presentaron estadísticas descriptivas en términos de medias y desviaciones estándar. Se utilizaron prueba-t independiente y prueba ANOVA unidireccional para las comparaciones, según correspondiera. Se consideró significativo un valor de p<0,05. Resultados: El ángulo medio formado por OP y ATL fue de 8,5±3,69º para el nivel superior, 4,68±3,13º para la línea media y 2,89±2,57º para la línea inferior. Se encontró una diferencia significativa entre las medias de los tres ángulos (p< 0,001), mientras que no se encontró diferencia significativa (p>0,05) entre ambos sexos con respecto a los ángulos medidos. Conclusión: La línea que une el borde inferior del ala de la nariz con el borde inferior del trago de la oreja fue la línea más confiable en términos de paralelismo para determinar la orientación del plano oclusal.

CAD-CAM natural restorations-Reproducing nature using a digital workflow.

OBJECTIVES: Natural restorations combine digital workflow and shell technique to create CAD/CAM restorations with the form and texture of natural teeth. This case report describes an interdisciplinary digital workflow combined with CAD/CAM natural restorations to achieve the naturalness of an anterior rehabilitation. CLINICAL CONSIDERATIONS: A 38-year-old patient attended to the office with esthetic issues. An interdisciplinary treatment plan was conducted, which included periodontal surgery to recreate the gingival contour, associated with bleaching and manufacturing CAD/CAM ceramic veneers to return an optimal teeth surface texture and shape. CONCLUSIONS: The design and manufacturing of CAD/CAM natural restorations using a digital workflow allowed a predictable result and overcame the limitations of conventional shell technique. CLINICAL SIGNIFICANCE: Conventional shell technique is used to create restorations with the form and texture of natural teeth. This article presents a combination of the conventional shell technique with a digital workflow, facilitating the design and manufacturing of CAD/CAM natural restorations.

Mechanical behavior of different machinable ceramic crowns using vertical and horizontal preparations: an in-vitro study / Comportamento mecânico de diferentes coroas cerâmicas usináveis usando preparos verticais e horizontais: um estudo in vitro

Objective: the aim of this study was to compare the mechanical behavior of different ceramics when used in thin vertical preparations versus traditional horizontal preparation. Material and Methods: two stainless-steel dies were milled to simulate a minimally invasive vertical preparation (VP) and a traditional horizontal preparation (HP) for an all-ceramic crown of a maxillary first premolar. The stainless-steel dies were duplicated using epoxy resin. Eighty monolithic crowns were milled and divided into 2 groups according to preparation design. Each design group was subdivided into 4 sub-groups according to material (n=10): IPS e.max CAD (lithium disilicate), Bruxzir shaded zirconia (full contour zirconia), CeraSmart (resin nanoceramic) and CEREC Tessera (advanced lithium disilicate). The crowns were cemented on their relevant epoxy resin dies using self-adhesive resin cement. All specimens were subjected to 15,000 thermocycles and then loaded to fracture in a universal testing machine. Data were analyzed using two-way ANOVA and Tukey pair wise comparison test. Results: the fracture resistance mean values of the VP (1344 + 118 N) was significantly lower than the HP design (1646 + 191 N). Ceramic crowns made of full contour zirconia had higher fracture resistance mean values (2842 + 380 N) than advanced lithium disilicate (1272 + 125 N) followed by lithium disilicate crowns (983 + 52 N) and resin nanoceramic (882 + 61 N). Conclusion: both vertical and horizontal preparations, regardless the different ceramic materials, showed clinically acceptable fracture resistance values. (AU)

Objetivo: o objetivo deste estudo foi comparar o comportamento mecânico de diferentes cerâmicas quando utilizadas em preparos verticais finos ou preparos horizontais tradicionais. Material e Métodos: dois modelos de aço inoxidável foram fresados para simular um preparo vertical minimamente invasivo (PV) e um preparo horizontal tradicional (PH) para uma coroa totalmente em cerâmica de um primeiro pré-molar superior. As matrizes de aço inoxidável foram duplicadas usando resina epóxi. Oitenta coroas monolíticas foram fresadas e divididas em 2 grupos de acordo com o desenho do preparo. Cada grupo foi subdividido em 4 subgrupos de acordo com o material (n=10): IPS e.max CAD (dissilicato de lítio), zircônia Bruxzir (zircônia de contorno total), CeraSmart (resina nanocerâmica) e CEREC Tessera (dissilicato de lítio avançado). As coroas foram cimentadas em suas respectivas matrizes de resina epóxi usando cimento resinoso autoadesivo. Todos os espécimes foram submetidos a 15.000 ciclos térmicos e então carregados até a fratura em uma máquina de teste universal. Os dados foram analisados usando ANOVA com dois fatores e teste de comparação por pares de Tukey. Resultados: os valores médios de resistência à fratura do PV (1344 + 118 N) foram significativamente menores do que PH (1646 + 191 N). As coroas de cerâmica feitas de zircônia de contorno total apresentaram maiores valores médios de resistência à fratura (2842 + 380 N) do que dissilicato de lítio avançado (1272 + 125 N), seguido por coroas de dissilicato de lítio (983 + 52 N) e resina nanocerâmica (882 + 61 N). Conclusão: preparos verticais e horizontais, independentemente dos diferentes materiais cerâmicos, apresentaram valores de resistência à fratura clinicamente aceitáveis. (AU)

The possible association between the types of soft palate and gag reflex: a preliminary study / A possível associação entre os tipos de palato mole e o reflexo de vômito: um estudo preliminar

Objective: whether gag reflex, a common problem encountered during dental procedures, is associated with the different types of the soft palate has not been addressed so far. This preliminary study sought to assess the potential association between the different types of soft palate and gag reflex. Material and Methods: one hundred dental patients were recruited. The type of soft palate was determined. Subjective (self-reported) gag reflex was recorded based on many questions and past experience and on a 0-6 VAS. Objective assessment of gag reflex was done using different maneuvers where the posterior part of the tongue and the soft palate were touched by dental mirror, and by taking impression for the upper arch. The association between the types of soft palate and the subjective and objective recorded gag reflex were statistically tested. Results: there were 53 (53%), 33 (33%) and 14 (14%) of the participants with class I, class II and class III soft palate, respectively. A significant association was found between the type of the soft palate and gag reflex in response to one of the subjective items (P= 0.039), more prominent among females (P= 0.009). Concerning the objective assessment, no significant associations were found among males. Meanwhile more females with class II and class III suffered gag reflex and/or actual gagging upon taking the impression (P = 0.001). Conclusion: this study illustrated an association between the type of soft palate and gag reflex, and its severity in females (more specifically soft palate types II and III) more than in males (AU)

Objetivo: o reflexo de vômito, um problema comum encontrado durante procedimentos odontológicos, está ou não associado aos diferentes tipos de palato mole, não foi ainda abordado até o momento. Este estudo preliminar procurou avaliar a possível associação entre os diferentes tipos de palato mole e o reflexo de vômito. Material e Métodos:cem pacientes odontológicos foram recrutados. O tipo de palato mole foi determinado. O reflexo de vômito subjetivo (auto-relatado) foi registrado com base em muitas perguntas e experiências anteriores e em um VAS de 0-6. A avaliação objetiva do reflexo de vômito foi feita por meio de diferentes manobras onde a parte posterior da língua e o palato mole foram tocados por espelho dental e por meio de moldagem da arcada superior. A associação entre os tipos de palato mole e o reflexo de vômito subjetivo e objetivo registrado foi testada estatisticamente. Resultados: houve 53 (53%), 33 (33%) e 14 (14%) participantes com palato mole classe I, classe II e classe III, respectivamente. Foi encontrada associação significativa entre o tipo de palato mole e o reflexo de vômito em resposta a um dos itens subjetivos (P= 0,039), mais proeminente no sexo feminino (P= 0,009). Em relação à avaliação objetiva, não foram encontradas associações significativas entre os homens. Enquanto isso, mais mulheres com classe II e classe III sofreram reflexo de vômito e/ou engasgo real ao receber a impressão (P = 0,001). Conclusão: este estudo ilustrou uma associação entre o tipo de palato mole e reflexo de vômito e sua gravidade em mulheres (mais especificamente palato mole tipos II e III) mais do que em homens. (AU)

Present and future of extraoral maxillofacial prosthodontics: Cancer rehabilitation.

Historically, facial prosthetics have successfully rehabilitated individuals with acquired or congenital anatomical deficiencies of the face. This history includes extensive efforts in research and development to explore best practices in materials, methods, and artisanal techniques. Presently, extraoral maxillofacial rehabilitation is managed by a multiprofessional team that has evolved with a broadened scope of knowledge, skills, and responsibility. This includes the mandatory integration of different professional specialists to cover the bio-psycho-social needs of the patient, systemic health and pathology surveillance, and advanced restorative techniques, which may include 3D technologies. In addition, recent digital workflows allow us to optimize this multidisciplinary integration and reduce the active time of both patients and clinicians, as well as improve the cost-efficiency of the care system, promoting its access to both patients and health systems. This paper discusses factors that affect extraoral maxillofacial rehabilitation's present and future opportunities from teamwork consolidation, techniques utilizing technology, and health systems opportunities.

Flapped versus flapless surgery and delayed versus immediate loading for a four mini implant mandibular overdenture: A RCT on post-surgical symptoms and short-term clinical outcomes.

OBJECTIVE: This factorial randomized clinical trial (RCT) tested the effects of the surgical approach (flapped-FPS vs. flapless-FLS surgery) and loading protocol (delayed-DL vs. immediate-IL) for treatment with a four mini implant mandibular overdenture. MATERIAL AND METHODS: A total of 296 one-piece titanium-zirconium mini-implants were inserted in 74 patients (IL/FLS = 17; IL/FPS = 18; DL/FLS = 20; and DL/FPS = 19). Outcomes included patient's perceived surgical burdens, clinical time, implant survival, and post-surgical symptoms and complications, assessed immediately after surgery, in the 7-day and 6-week follow-ups. RESULTS: Perceived surgical burdens were relatively low, higher for females, and no difference was found between FPS and FLS surgery. Surgical time was lower for FLS surgery. Overall symptoms were mild after 24 h, and higher for females. Less symptoms were recorded for the FLS surgery compared to the FPS for the delayed loading patients, and FLS surgery was associated with a lower risk of bleeding. No early implant failure was observed until the 6-week follow-up. Delayed was associated with discontinuous use of the prosthesis and poor function. Lower complaint rates were observed for immediate loading regardless of the surgery protocol. CONCLUSIONS: Mini implants for mandibular overdenture are a feasible option regardless of surgical access and loading protocol, with high safety and predictable survival rates, and low incidence of post-insertion complications. FLS surgery requires less clinical time and results in easier intraoral prosthetic incorporation of attachments compared to FPS surgeries. Immediate loading did not increase the risk of early implant failure when satisfactory primary stability was achieved.