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Purpose: To compare the treatment time of digital and conventional workflows for single-implant crowns, as well as prostheses made of polymer-infiltrated ceramic-network (PICN; Vita Enamic, Vita Zahnfabrik) and lithium disilicate (LS2; n!ce, Straumann). Materials and Methods: A total of 40 patients who needed a single-implant crown in posterior regions were considered and randomly divided into digital workflows (n = 20) that used an intraoral scanner (IOS; iTero Element 5D, Align Technologies) and conventional workflows (n = 20) that used polyether impressions (3M ESPE Impregum Penta). Then, each group was again distributed into two subgroups based on the crown material used: PICN (n = 10) and LS2 (n = 10). Treatment time was calculated for both digital and conventional workflows. Analysis was done at a 5% confidence interval (P < .05). An independent two-sample t test was used to compare treatment time between the groups. The Kruskal--Wallis test was used to compare clinical try-in time among subgroups. Any of the implant crowns that had to be remade in each subgroup were evaluated using the Fisher exact test. Results: The entire process of digital and conventional workflows required 104.31 ± 20.83 and 153.48 ± 16.35 minutes, respectively. Digital workflows saved 39.2% more time than the conventional protocol for the single-implant crown treatment (P < .0001). Conclusions: Both digital and conventional workflow protocols can achieve a successful outcome for single-implant monolithic crowns in posterior areas. The digital protocol yielded greater timesaving over the conventional procedure in data acquisition and laboratory steps, while the time for clinical try-in and delivery were similar. [ABSTRACT FROM AUTHOR]

Introduction: The esthetics of immediate implant dentistry can be challenging. Clinical considerations for immediate implant placement have demonstrated long‐term success rates comparable to traditional delayed implant protocols. However, it is a sensitive technique that requires proper treatment planning as well as meticulous execution to be predictable and successful in the long term. Methods: This clinical situation demands extensive knowledge of soft and hard tissue management for atraumatic tooth extraction followed by implant therapy, along with an understanding of the available materials to meet esthetic needs. This case report features a female patient with the chief complaint of needing to replace an anterior crown due to loss of retention. After a comprehensive oral assessment and cone beam computed tomography (CBCT) radiographic examination, it was determined that the crown on Tooth #9 was fractured at the subgingival level. Furthermore, gingival zenith positions displayed differences at the keratinized mucosa level in Teeth #7, #8, and #9, and the metal marginal areas of the porcelain‐fused‐to‐metal (PFM) crowns in the anterior area of Teeth #5, #7, #8, #9, and #10 were apparent. The procedure involved atraumatic extraction of Tooth #9, followed by immediate implant placement. Crowns on Teeth #5, #7, #8, and #10 were replaced, and veneers on Teeth #6 and #11 were fabricated using press lithium disilicate‐reinforced ceramic. Connective tissue graft (CTG) was contoured before final implant restorations. Results: The final implant crown was restored using a prefabricated abutment with a titanium base and lithium disilicate ceramic dental material. A well‐planned combined treatment, including atraumatic tooth extractions for immediate implants and ideal contouring of soft tissues, can significantly impact the outcome of esthetic restorations. Conclusions: Single immediate implant–supported crowns in the esthetic zone were able to fulfill the patient's esthetic expectations. [ABSTRACT FROM AUTHOR]

Background: Children with dental caries are treated with stainless steel metal crowns (SSC), but the aesthetics and precision still need to be improved. Currently, both 3D‐printed resin crowns (PRC) and computer‐aided design/computer‐aided manufacture (CAD/CAM) resin crowns (CRC) meet the clinical requirements for crown applications in terms of strength, production time, cost, and aesthetics. Aim: This study replaced SSC with customized resin crowns by 3D printing and CAD/CAM. Design: In this study, PRC, CRC, and SSC were used for incisor and molar restorations, and 60 crowns were made with 10 for each group. The fabrication efficiency, surface characteristics, marginal fit, and stability of the two different crowns were evaluated. Results: PRC and CRC show superior color and surface characteristics, though production times are longer (5.3–12.4 times and 3.3–9.1 times, respectively) than for SSC (p <.05). They, however, can be completed within 80 min. Edge gaps for PRC and CRC are significantly lower (13.0–19.2 times and 13.0–13.7 times) than for SSC (p <.05). All materials exhibit good stability. Conclusion: The 3D‐PRCs and CAD/CAM resin crowns may replace SSCs as a potential choice for clinical child caries. [ABSTRACT FROM AUTHOR]

Zirconia crowns are capping materials used in dentistry for tooth capping and are very popular due to their optical properties and natural-looking visuals. In vitro aging protocols measure zirconia's optical properties, which are vital in order for it to look natural. This study aims to conduct a systematic review to explore the effect of in vitro aging protocols on the optical properties and crystalline structure of high-translucency (HT) zirconia. A correlation matrix was obtained using Microsoft Excel, which was later transferred into SPSS for confirmatory factor analysis (CFA) and hierarchal clustering and to obtain a dendrogram in order to display the distribution of clusters for each key term relevant to the study. Further, for qualitative analysis, 17 studies were screened and reviewed. The result demonstrates that high translucency has been observed in the crystalline structure of zirconia capping. However, quantitative and qualitative results did not demonstrate the in vitro protocol; instead, neglect of the in vitro protocol's vitality in zirconia crown capping was alarming. Overall, zirconia has good optical properties when combined with catalysts such as aluminum and lithium to obtain a more sustainable crystalline structure. [ABSTRACT FROM AUTHOR]

A crown or headwear was considered one of the most important parts of clothing in the past. More than any other article of clothing, it expressed one's social position and status. As a symbol of royalty in Iran, the design of crowns evolved over different historical periods. At times, it was used as a symbol to show power and authority. At others, it was as a symbol of the tyranny of mighty kings, and sometimes a symbol of luxury and aristocratic life. The Timurid period, with all of its political and social turbulence, is considered one of the most brilliant periods of painting, where new details and subjects appeared. This article investigates the role of crowns and headdresses with a historical descriptive method based on the existing library sources. It shows how the design of the crown in the paintings of the Timurid period was mostly influenced by cultural and religious factors. Timurid artists of the Herat school did not stick to the historical facts. Instead they sought to present an ideal image of the king, following the standards of the era, displaying slight differences in each period and reign. [ABSTRACT FROM AUTHOR]

The growth peculiarities of Scots pine (Pinus sylvestris L.) have been studied by the example of an even-aged pine stand of high density. A long-term research has been conducted on a permanent sample plot. The data has been collected from the stand aged from 37 to 55 years. The characteristics of individual trees and the entire stand during the growth period in the absence of external influences (cutting, windfalls, pest damage, etc.) and after improvement cuttings have been analyzed. The influence of the amount of resource available to a tree on the formation of crowns, root systems and stem wood has been investigated. The size of the available resource has been the square of the dominance area. The root system of the pine trees of the studied stands is compact in size and, despite the high stand density, due to the high content of nutrients in the soil and the absence of moisture deficiency, it sufficiently ensures intensive tree growth corresponding to the conditions of the I quality class. It has been found that under these conditions, the average area of the root system is proportional to the average square of the dominance area. It has been shown that the stem diameter at a height of 1.3 m in the absence of external influences significantly depends on the square of the dominance area. The correlation coefficient of these indicators for the studied stand at the age of 37 is 0.89. The influence of cuttings on annual radial increment has been studied using dendrochronology methods. It has been revealed that in the year following the cutting, it has increased by 1.3–2.0 times, depending on the increase in the square of the dominance area. A method has been proposed for calculating the competition coefficient as a share of the resource required for the free growth of a tree, which is redistributed between its closest neighbours. Long-term observations have shown that with competition coefficients exceeding 0.6–0.7, the stem diameter increment rate decreases significantly, and the trees develop a sparse crown extending less than 40 % of the tree height. This, in turn, leads to growth retardation and a transition to a depressed state. This, in turn, leads to growth retardation and a transition to a depressed state.

Zirconia crowns are capping materials used in dentistry for tooth capping and are very popular due to their optical properties and natural-looking visuals. In vitro aging protocols measure zirconia’s optical properties, which are vital in order for it to look natural. This study aims to conduct a systematic review to explore the effect of in vitro aging protocols on the optical properties and crystalline structure of high-translucency (HT) zirconia. A correlation matrix was obtained using Microsoft Excel, which was later transferred into SPSS for confirmatory factor analysis (CFA) and hierarchal clustering and to obtain a dendrogram in order to display the distribution of clusters for each key term relevant to the study. Further, for qualitative analysis, 17 studies were screened and reviewed. The result demonstrates that high translucency has been observed in the crystalline structure of zirconia capping. However, quantitative and qualitative results did not demonstrate the in vitro protocol; instead, neglect of the in vitro protocol’s vitality in zirconia crown capping was alarming. Overall, zirconia has good optical properties when combined with catalysts such as aluminum and lithium to obtain a more sustainable crystalline structure.

Background and aim: To compare the marginal and internal adaptation of full veneer crowns cast from wax patterns fabricated by three-dimensional printing and conventional wax-up technique employing two different convergence angles.Material and methods: Two metal master dies, each with a convergence angle of 6 and 12-degrees, were duplicated 24 times to obtain 48 stone dies. Twelve dies from each group were randomly chosen for conventional wax-up (Group A) and the other twelve for the three-dimensional printed wax pattern (Group B) fabrication. Cobalt-chromium full veneer crowns were cemented onto the dies using glass ionomer cement. The cemented crowns and dies were sectioned in the midline buccolingually to measure the marginal and internal gaps using a stereomicroscope and digital image analysis software (Image J). Data obtained were recorded in microns, and an independent 't' test was used to compare quantitative parameters between categories.Results: Group B showed a statistically significant reduction in marginal discrepancy in crowns with a 6-degree taper (114.4 ± 37.5) compared to Group A (160.4 ±58.1). Group B did not demonstrate any significant difference when the 6-degree and 12-degree tapers were compared, but Group A showed a significant improvement in marginal and internal adaptation with the 12-degree taper.Conclusions: For the 6-degree taper, three-dimensional printing resulted in better marginal and internal fit than conventional wax patterns. Conventional and three-dimensional Printing offered similar accuracy within the acceptable range for a 12-degree taper.

Aim: This study aimed to investigate the influence of titanium base (ti‐base) abutment macro‐ and micro‐geometry on the mechanical stability of polymer‐infiltrated ceramic network (PICN) screw‐retained implant‐supported single crowns (iSCs). Materials and Methods: Twelve specimens per group were used, comprising six different implant/ti‐base abutment combinations restored with PICN iSCs: Nb‐T (gingival height [GH]: 1.5 mm, prosthetic height [PH]: 4.3 mm), CC (GH: 0.8 mm, PH: 4.3 mm), CC‐P (GH: 0.8 mm, PH: 7 mm), Nb‐V (GH: 1.5 mm, PH: 6 mm), St (GH: 1.5 mm, PH: 5.5 mm), and Th (GH: 0.5 mm, PH: 9 mm). The specimens underwent thermo‐mechanical aging, and those that survived were subsequently subjected to static loading until failure. The data were analyzed using a one‐way ANOVA test followed by Tukey post hoc test (α =.05). Results: All specimens survived thermo‐mechanical aging without complications, namely, visible cracks, debonding, or screw loosening. Th group demonstrated the highest strength values among all the groups, with significant differences compared to Nb‐T (p <.05), CC (p <.001), and St (p <.001). Additionally, CC‐P group exhibited significantly superior fracture strength results compared to CC (p <.05) and St (p <.05). Conclusion: The choice of ti‐base, particularly prosthetic height, had a significant influence on fracture resistance of PICN iSCs. Nevertheless, the height or geometrical features of the ti‐base did not exhibit a significant influence on the mechanical behavior of the iSC/ti‐base assembly under thermomechanical loading, as all specimens withstood the aging without complication or failure. [ABSTRACT FROM AUTHOR]

Objective Overview Conclusions Clinical Significance This article puts forward consensus recommendations from PROSEC North America regarding single indirect restorations made from ceramic and nonmetallic biomaterials in posterior teeth.The consensus process involved a multidisciplinary panel and three consensus workshops. A systematic literature review was conducted across five databases to gather evidence. The recommendations, informed by findings from systematic reviews and formulated based on a two‐phase e‐Delphi survey, emphasize a comprehensive treatment strategy that includes noninvasive measures alongside restorative interventions for managing dental caries and tooth wear. The recommendations advocate for selecting between direct and indirect restorations on a case‐by‐case basis, favoring inlays and onlays over crowns to align with minimally invasive dentistry principles. The recommendations highlight the critical role of selecting restorative biomaterials based on clinical performance, esthetic properties, and adherence to manufacturer guidelines. They emphasize the importance of precision in restorative procedures, including tooth preparation, impression taking, contamination control, and luting. Regular follow‐up and maintenance tailored to individual patient needs are crucial for the longevity of ceramic and nonmetallic restorations.These PROSEC recommendations provide a framework for dental practitioners to deliver high‐quality restorative care, advocating for personalized treatment planning and minimally invasive approaches to optimize oral health outcomes.The PROSEC North America recommendations highlight the importance of minimally invasive techniques in posterior tooth restorations using ceramic and non‐metallic biomaterials. These principles prioritize tooth structure conservation and personalized treatment planning, essential for enhancing clinical outcomes and long‐term oral health. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Amelogenesis imperfecta (AI) is a rare developmental anomaly characterized by poorly developed or absent tooth enamel, which complicates orthodontic treatment due to weak enamel‐bracket bond strength. This case report presents a successful management of AI using fixed orthodontic appliances and prosthodontic rehabilitation. Amelogenesis imperfecta (AI) causes enamel defects, complicating oral hygiene, reducing masticatory function and lowering self‐esteem. This case report details an 18‐year‐old female with AI who underwent fixed orthodontic treatment followed by prosthodontic rehabilitation. The multidisciplinary approach restored function and aesthetics, significantly improving her quality of life. [ABSTRACT FROM AUTHOR]

Aim: This study aims to evaluate the effect of different crown ferrule designs on fracture resistance of endodontically treated mandibular premolars restored with glass fiber post, composite core, and metal crown. Materials and Methods: A total of 150 mandibular premolar teeth underwent endodontic treatment, and based on ferrule design, the teeth were divided into five groups (n = 30 each). Group 1—2 mm circumferential ferrule; group 2—2mm buccal + lingual ferrule; Group 3—2 mm buccal ferrule; group 4—2 mm lingual ferrule; and group 5—no ferrule. Each tooth was restored using a glass fiber post, composite core, and metal crown, and then loaded at 160° on the lingual slope of the buccal cusp in a universal testing machine until fracture. Fracture values were recorded in Newtons. Data were analyzed using the Kruskal–Wallis test, and post hoc analysis was conducted with the Mann–Whitney U test (P = 0.05). Results: The highest load to fracture was seen in group 1 (1027.35 ± 164.68N), followed by group 2 (922.42 ± 49.14N), group 3 (916.06 ± 64.79N), group 4 (888.91 ± 47.36N), and group 5 (801.55 ± 52.45N), respectively. There was a statistically significant difference in fracture resistance among different groups. Conclusions: While a tooth with an incomplete ferrule was less resistant to fracture than one with a complete ferrule, it was still more resistant to fracture than one with no ferrule. Thus, increasing the number of ferrule walls improves the fracture resistance of endodontically treated teeth. [ABSTRACT FROM AUTHOR]

This paper analyzes the graphic choices in two sixteenth-century Nahua pictorials concerning the property distribution of don Miguel Damián after his death: Mexicain 34 and Ayer 1900. The uniqueness of these complementary documents has been unrecognized until now and helps us see the Central Mexican colonial testamentary tradition in a new light. The work on these documents so far has primarily focused on understanding their relationship to the Spanish will. But thinking about them also in relation to Aztec and colonial Nahua accounting documents can help us explain why testaments were so quickly and widely adopted by colonial Nahuas. The paper also shows how a careful visual analysis of these documents offers us a peek into the interstitial spaces generated by the conquest, spaces in which modes of recording, family structures, and expressive choices capture lived experiences in the process of radical cultural change between a Prehispanic past and a colonial reality. [ABSTRACT FROM AUTHOR]

In his Mann ohne Eigenschaften, Robert Musil has the character Clarisse comment on a debate between her husband, Walter, and Ulrich, the "man without qualities," about the "impossible" relation between art and life. "'Ich find das doch sehr wichtig,' sagte sie, 'daß in uns allen etwas Unmögliches ist. Es erklärt so vieles. Ich habe, wie ich zuhörte, den Eindruck gehabt, wenn man uns aufschneiden könnte, so würde unser ganzes Leben vielleicht wie ein Ring aussehen, bloß so rund um etwas.' Sie hatte schon vorher ihren Ehering abgezogen und guckte nur durch seine Öffnung gegen die belichtete Wand. 'Ich meine, in seiner Mitte ist doch nichts, und doch sieht er genau so aus, als ob es ihm nur darauf ankäme.'" The English translation is even stronger: "There is nothing inside, and yet it looks as though that were precisely what matters most." This essay interrogates this "nothing" that matters most in relation to the crown of royal authority, the "hollow crown," as Richard II calls it in Shakespeare's play. I further flesh out the matter and materiality of this bit of nothing in relation to the struggle between Creon and Antigone in Sophocles' play about the foundations of royal authority. The queen in the former play and Antigone in the latter are presented as being too much sad, as manifesting a grief that pertains to this nothing, to an indeterminate loss they both "encyst" (upon) in their subjective stances. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the effects of airborne-particle abrasion (APA) and 10-methacryloxydecyl dihydrogen phosphate (10-MDP primer) surface treatments on the fracture load of thin zirconia crowns made from 3Y-TZP and 5Y-PSZ zirconia. Eighty full-contour zirconia crowns of 0.5 mm thickness were fabricated from 3Y-TZP and 5Y-PSZ zirconia. Crowns of each material were divided into four groups based on the surface treatment applied to the fitting surface (n = 10): Group 1 (control), Group 2 (10-MDP Primer Only), Group 3 (APA Only), and Group 4 (10-MDP Primer + APA). Crowns were cemented using self-adhesive resin cement and subjected to thermocycling. Fracture load tests were performed using a universal testing machine with a hemispherical indenter. Statistical analysis was performed using one-way ANOVA, Tukey's post hoc test, and independent samples T-test (α = 0.05). The fracture load of 3Y-TZP was significantly higher than 5Y-PSZ crowns across all groups (P ≤ 0.001). Group 1 had the lowest fracture load, while Group 4 had the highest for both materials. In 3Y-TZP, the fracture load of Group 2 increased by 40% (P = 0.002) and Group 3 by 50% (P

PurposeThe aim of the in vitro study was to compare the internal merge and marginal perfection of polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) crowns under a stereomicroscope. MethodsAll-ceramic preparation is done on the maxillary first premolar which is mounted on the wax block which was scanned using 3Shape scanner and duplicated into 30 acrylic CAD/CAM dies (n = 15) for the placement of PEEK and PEKK crowns. The YENADENT milling system was used to fabricate 15 samples from Group A PEEK crowns and to fabricate 15 samples from Group B PEKK crowns. According to the manufacturer’s instructions, an equal amount of the dual-cure resin luting agent (Rely X U200 Self-Adhesive resin, 3M, Germany) was dispensed on the mixing pad before being mixed with cement and painted on the internal surfaces of the copings with the finger pressure crowns which were luted. The values were then analyzed using one-way ANOVA (post hoc) followed by Dunnett’s t-test. ResultsAmong those two groups, PEEK group materials showed the lowest mean value of (28.73.3 ± 4.01) for marginal fit and (26.72 ± 2.53) for internal gap, whereas PEKK group showed a mean value of (32.85 ± 4.63) and (33.06 ± 4.14), respectively. ConclusionAmong these two groups, comparatively less marginal fit and internal adaptation is seen in PEKK when compared to the PEEK crowns. While the marginal fit and internal adaptation of both PEEK and PEKK copings were in acceptable clinical range.

Introduction: Computer-aided design and computer-aided manufacturing (CAD/CAM) technologies have been increasingly used to fabricate provisional restorations in recent years. This study assessed how build orientation influences the fracture resistance and marginal quality of 3D-printed crowns compared with milled provisional crowns. Methods: The test group included 3D-printed crowns (Freeprint temp Shade A2, Detax, Ettlingen, Germany), which were further subdivided based on print orientation (0°, 45°, and 90°; n = 10 for each subgroup). The control group (n = 10) included milled crowns (Coratemp, White Peaks, Germany) with the same design as those of the test group. The margin quality of each crown was assessed at 60 × magnification using a digital stereomicroscope. A load-to-fracture test was performed by applying a force at a rate of 2 mm/min to assess fracture resistance. One sample from each subgroup was also subjected to scanning electron microscope (SEM) analysis. Results: The milled group exhibited the highest fracture resistance and marginal quality. Within the printed subgroups, the 0° group showed the best mean marginal quality, whereas the 90° group showed the lowest mean marginal quality (p

Aim of the Study: The aim of this study is to investigate the modifications that may occur in case of sintering temperature deviation for metal-ceramic crowns. Materials and Methods: For this in vitro study were made 15 metal-ceramic crowns for tooth 2.1 and were divided into 5 groups. The ceramic veneering comprised different sintering temperatures optimized for different properties: group 1 was sintered at 910 ºC as per the manufacturer’s recommendation, group 2 was sintered at 940ºC (+30 ºC), group 3 was sintered at 960ºC (+50 ºC), group 4 was sintered at 880ºC (-30 ºC), and group 5 was sintered at 860 ºC (-50 ºC). Using the EXOCAD scanner the maxillary cast was scanned to obtain the metal frameworks from Cr-Co alloy (SCHEFTNER CoCr – 30 microns). Ips InLine One ceramic shade A3 developed by Ivoclar Vivadent Inc is applied in two layers, each one sintered at the same temperature. After ceramic sintering, the shade of each group was registered with Vita Easy Shade spectrophotometer and Vitapan Classical shade guide. Results: Errors in sintering temperatures can change the ceramic’s density and mechanical properties but may also lead to colour shifts. This phenomenon occurs due to alterations in the ceramic material’s microstructure, which can impact its optical properties and, consequently, its perceived colour. Conclusions: In conclusion, our study highlights the crucial impact of sintering temperature variations on the quality and integrity of metal-ceramic dental restorations. Our findings point towards the need for further innovation and research in thermal management within dental ceramics processing to achieve restorations that are not only aesthetically pleasing but also functionally reliable and compatible with the natural dentition.

Dental agenesis is one of the most common developmental anomalies in humans and it is frequently associated with several other oral abnormalities. The present case describes non-familial agenesis of permanent teeth in a twenty-one-year-old boy with no apparent systemic abnormalities. The treatment included a personalized and interdisciplinary approach involving endodontics, orthodontics, implant-supported restorations and prosthetic treatments. The treatment plan was thoroughly elaborated using photographic analysis, study models, orthopantomogram, CBCT and cephalograms. Virtual smile design, diagnostic waxing and mock-ups previsualized the treatment objectives. The edentulous spaces were reconstructed by inserting dental implants and monolithic zirconia implant-supported restorations. The final results showed a highly esthetic and functional rehabilitation. Periodic check-ups have shown that the stability of the result is well maintained and that the implant-supported restorations are an optimal solution for patients with multiple anodontia. [ABSTRACT FROM AUTHOR]

This report describes the bone reduction guide which was digitally obtained to improve diagnosis, treatment outcome and follow-up. Treatment of gingival smiles due to altered passive eruption should include interdisciplinary planning and smile design to facilitate the prediction of treatment outcome. Crown lengthening surgery can be supported by digital tools to improve surgical planning and follow-up. A 30-year-old female patient was referred to a private dental clinic seeking solutions for her gingival smile. Based on the anatomical crown length, a smile design was created, and the patient was presented with a simulated smile before treatment. In the surgical phase, a full-thickness flap was raised in the upper jaw to achieve the desired outcome. Using cone-beam computed tomography to determine cementoenamel junction for smile design and treatment planning brings many benefits. Patients and clinicians can foresee treatment results. From there, appropriate changes can be made. The bone reduction guide is designed to rest on the bone to help the clinician cut the bone accurately and thoroughly follow the established plan. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the in vitro study was to compare the internal merge and marginal perfection of polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) crowns under a stereomicroscope. Methods: All-ceramic preparation is done on the maxillary first premolar which is mounted on the wax block which was scanned using 3Shape scanner and duplicated into 30 acrylic CAD/CAM dies (n = 15) for the placement of PEEK and PEKK crowns. The YENADENT milling system was used to fabricate 15 samples from Group A PEEK crowns and to fabricate 15 samples from Group B PEKK crowns. According to the manufacturer's instructions, an equal amount of the dual-cure resin luting agent (Rely X U200 Self-Adhesive resin, 3M, Germany) was dispensed on the mixing pad before being mixed with cement and painted on the internal surfaces of the copings with the finger pressure crowns which were luted. The values were then analyzed using one-way ANOVA (post hoc) followed by Dunnett's t-test. Results: Among those two groups, PEEK group materials showed the lowest mean value of (28.73.3 ± 4.01) for marginal fit and (26.72 ± 2.53) for internal gap, whereas PEKK group showed a mean value of (32.85 ± 4.63) and (33.06 ± 4.14), respectively. Conclusion: Among these two groups, comparatively less marginal fit and internal adaptation is seen in PEKK when compared to the PEEK crowns. While the marginal fit and internal adaptation of both PEEK and PEKK copings were in acceptable clinical range. [ABSTRACT FROM AUTHOR]

Computer-aided design and computer-aided manufacturing (CAD/CAM) technologies have been increasingly used to fabricate provisional restorations in recent years. This study assessed how build orientation influences the fracture resistance and marginal quality of 3D-printed crowns compared with milled provisional crowns. The test group included 3D-printed crowns (Freeprint temp Shade A2, Detax, Ettlingen, Germany), which were further subdivided based on print orientation (0°, 45°, and 90°; n = 10 for each subgroup). The control group (n = 10) included milled crowns (Coratemp, White Peaks, Germany) with the same design as those of the test group. The margin quality of each crown was assessed at 60 × magnification using a digital stereomicroscope. A load-to-fracture test was performed by applying a force at a rate of 2 mm/min to assess fracture resistance. One sample from each subgroup was also subjected to scanning electron microscope (SEM) analysis. The milled group exhibited the highest fracture resistance and marginal quality. Within the printed subgroups, the 0° group showed the best mean marginal quality, whereas the 90° group showed the lowest mean marginal quality (p < 0.05). Within the test groups, the 90° group had the highest mean fracture resistance (p < 0.05). In the SEM analysis, the milled group exhibited the most homogenous boundaries, whereas among the 3D-printed subgroups, the samples printed at 0° had the best margin quality. The manufacturing method significantly influences the marginal quality and fracture resistance. Milled crowns demonstrated superior marginal quality and fracture resistance compared to those of 3D printed crowns. Furthermore, the print orientation of 0° led to the best marginal quality, whereas printing at 90° led to the highest fracture resistance. [ABSTRACT FROM AUTHOR]

The materials used in dentistry for the fabrication of all-ceramic restorations have undergone great and rapid developments over the last two decades. Among the most common ceramic materials in dentistry are those based on zirconium and lithium disilicate. Due to the properties of these materials, they are in great demand in the field of dental restoration production. Thus, dental restorations that will use those materials are commonly machined in CAD/CAM systems, which offer the possibility of manufacturing all-ceramic dental restorations in a very short period of time. This article reviews the modern materials in the field of all-ceramic dental restorations, their manufacturing processes, as well as what determines which ceramic materials are used for the production of CAD/CAM blanks and their production technology. [ABSTRACT FROM AUTHOR]

Background: Achieving optimal marginal fit is essential for the success of Virgilite Based Lithium Disilicate Ceramic crowns. Materials and Methods: In this in-vitro study, we compared the marginal fit of Virgilite Based Lithium Disilicate Ceramic crowns using two different CAD/CAM scanners, powder free (System A, Omnicam) and powder based (System B, Blue cam). Results: The mean marginal gap for System A was found to be 63.5 μm (standard deviation ± 10.2 μm), while for System B, it was 57.8 μm (standard deviation ± 9.8 μm). System B demonstrated a slightly superior marginal fit compared to System A, with a difference of 5.7 μm. Conclusion: Within the limitations of this study, it can be concluded that both Omnicam and Blue cam produced clinically acceptable marginal fit of Virgilite Based Lithium Disilicate Ceramic crowns. However, Blue cam exhibited a slightly better marginal fit compared to Omnicam. Further clinical studies are warranted to validate these findings.

Key Clinical Message Amelogenesis imperfecta (AI) is a rare developmental anomaly characterized by poorly developed or absent tooth enamel, which complicates orthodontic treatment due to weak enamel‐bracket bond strength. This case report presents a successful management of AI using fixed orthodontic appliances and prosthodontic rehabilitation. Abstract Amelogenesis imperfecta (AI) causes enamel defects, complicating oral hygiene, reducing masticatory function and lowering self‐esteem. This case report details an 18‐year‐old female with AI who underwent fixed orthodontic treatment followed by prosthodontic rehabilitation. The multidisciplinary approach restored function and aesthetics, significantly improving her quality of life.

Objectives: The aim of this randomized controlled trial was to see if the minimally invasive approach (reduced restoration thickness) would result in good clinical success of monolithic ceramic crowns compared to conventional layered all-ceramic crowns, and thus be an alternative to conventional tooth preparation. Materials and methods: The ceramic that was investigated was IPS e.max lithium-disilicate ceramic produced using two different processing methods. A comparison was made between monolithic crowns with reduced thickness and standard layered crowns. Fifty-two patients, who had undergone endodontic treatment on either a premolar or molar, were randomly assigned into two groups. The teeth intended for layered crowns underwent to a 2 mm occlusal reduction with a 1 mm rounded shoulder, whereas the teeth intended for monolithic crowns underwent to a 1 mm reduction in the occlusal area with a 0.6 mm rounded shoulder. The clinical success was evaluated in eight categories using modified United States Public Health Service (USPHS) criteria. The observation period was 36 months, with control appointments every 6 months. Results: There was no significant difference in clinical success between monolithic and conventional layered crowns after 3 years. One monolithic crown fractured while all other crowns were intact and the survival rate was 96%. All layered crowns were intact and the survival rate was 100%. Conclusion: The results of this study indicate that the minimally invasive approach can be a good alternative to conventional tooth preparation. IPS e.max lithium-disilicate ceramic demonstrated an exceptional three-year survival rate independently of the thickness of the material.

Let G be a finite group. In order to determine the smallest cardinality d (G) of a generating set of G and a generating set with this cardinality, one should repeat 'many times' the test whether a subset of G of 'small' cardinality generates G. We prove that if a chief series of G is known, then the numbers of these 'generating tests' can be drastically reduced. At most | G | 13 / 5 subsets must be tested. This implies that the minimum generating set problem for a finite group G can be solved in polynomial time. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Clinical Dentistry & Research is the property of Dental Press International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim: This systematic review assessed the shear bond strength of orthodontic brackets bonded to temporary crowns. The study followed PRISMA guidelines and the Cochrane Guidelines for Systematic Reviews, with a registered protocol (PROSPERO: CRD42023447478). Materials and Methods: in vitro studies were included, while animal studies, case reports, and abstracts were excluded. A comprehensive search strategy was implemented in multiple databases and supplemented with manual searches. Two independent reviewers screened studies, and data were extracted using a standardized form. Risk of bias was assessed using the RoBDEMAT tool. Meta-analysis was performed using random-effects models. Results: Out of 514 identified records, 21 studies were included. Various surface conditioning methods, adhesives, and brackets were used. Shear bond strength ranged from 0.03 to 22.54 MPa. Most studies had a risk of bias due to inadequate reporting. Significant heterogeneity was observed and outliers were removed. Conclusions: This review highlights the importance of combining chemical and mechanical surface treatments for bonding orthodontic brackets to provisional crowns. However, further research with rigorous methodology is required to establish more conclusive findings. [ABSTRACT FROM AUTHOR]

This article from the Romanian Journal of Oral Rehabilitation explores the impact of sintering temperatures on the assessment of dental ceramics. The study reveals that deviations in sintering temperatures can lead to changes in the density, mechanical properties, and color of the ceramic. The article also discusses the use of IPS Dentcisal powders and a spectrophotometer for shade matching and ceramic layering in dental restorations. However, the study found that despite these tools, the registered shades did not always align with the expected shade or shade guide. The findings highlight the importance of precise control over sintering temperatures and a comprehensive understanding of their effects on dental ceramics. [Extracted from the article]

Background: Self‐adhesive resin cement has been used extensively with zirconia crowns. Several in vitro studies showed that adhesive resin cementation may increase zirconia crowns' retention and their fatigue resistance. Objectives: This retrospective study aimed to evaluate the clinical performance, survival and success rates and complications encountered with zirconia crowns cemented with two different self‐adhesive resin cements. Methods: A total of 112 patients who received 176 monolithic zirconia crowns were evaluated. Crowns were cemented with RelyX Unicem 2 (n = 74) and Panavia SA (n = 102) self‐adhesive resin cements. Clinical assessments of the crowns and supporting periodontal structures were performed following the modified California Dental Association (CDA) criteria. Intraoral photographs and periapical and bitewing radiographs were obtained for further assessment by two evaluators. Descriptive statistics, McNemar, t‐test, log rank (Mantel‐Cox) tests and Kaplan–Meier survival analyses were performed (a =.05). Results: The 5‐year survival and success rates were 100% and 96.4%, respectively. The complications encountered were recurrent caries (2.2%) and the need for endodontic treatment (0.5%). No technical complications, such as fracture or loss of retention, were observed. The type of cement and patient‐related factors did not influence the survival and success rates of the crowns. Conclusions: Survival rate of zirconia crowns cemented with two different self‐adhesive resin cements was 100% after 5 years. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of four retention systems for implant-supported posterior crowns under compressive loading using three-dimensional finite element analysis. A morse-taper dental implant (4.1 × 10 mm) was designed with Computer Aided Design software based on non-uniform rational B-spline surfaces. According to International Organization for Standardization 14,801:2016, the implant was positioned at 3 mm above the crestal level. Then four models were designed with different crown retention systems: screw-retained (A), cement-retained (B), lateral-screw-retained (C), and modified lateral-screw-retained (D). The models were imported to the analysis software and mesh was generated based on the coincident nodes between the juxtaposed lines. For the boundary conditions, two loads (600 N) were applied (axial to the implant fixture and oblique at 30°) totaling 8 conditions according to retention design and loading. The von-Mises stress analysis showed that different retention systems modify the stress magnitude in the implant-supported posterior crown. There is a similar stress pattern in the implant threads. However, models C and D presented higher stress concentrations in the crown margin in comparison with A and B. The oblique loading highly increased the stress magnitude for all models. In the simulated conditions, part of the stress was concentrated at the lateral screw under axial loading for model C and oblique loading for model D. The results indicate a possible new failure origin for crown retained using lateral screws in comparison to conventional cement-retained or screw-retained systems.

Objectives: This study aimed to evaluate the periapical status (PAS) of restored non–root-filled (RNRF) teeth amongst a group of patients attending dental teaching clinics at Jordan University of Science & Technology. It also aimed to assess the association of type and quality of coronal restorations and periapical disease. Methods: This was a cross-sectional study. To be included, participants needed to have at least 1 non–root-filled tooth restored with either direct or indirect restoration. A sample of 491 participants was examined. Clinical examination and digital periapical radiographs were used to record material used and assess the quality of the restorations. Chi-square test and logistic regression analysis were used to analyse the association between PAS and gender, age, restoration material/type, and quality. Results: Overall, 26.3% of the participants were diagnosed with apical periodontitis (AP) on 1 or more of the examined teeth. No significant differences in the prevalence of AP were observed when comparing amalgam to composite or indirect restorations (P = .386). Furthermore, no association was reported between AP and gender or age, while a significant association was observed with the restoration's quality (P < .001). Conclusions: The high prevalence of AP in the examined sample is of clinical concern and suggests that more attention should be directed towards dental health awareness in Jordan. Teeth restored with inadequate restorations were twice as likely to have AP.

Objectives: To evaluate the influence of polyether ether ketone coping crown on the adaptation of implant abutment. Method: The vitro study was conducted at the Department of Prosthodontics, Hainan Stomatological Hospital, China, from October 2021 to March 2022, and comprised patients undergoing implant surgery on first molar. Patients were divided into two group, with group A patients receiving polyether ether ketone coping crowns, and group B receiving zirconia crowns. Replica technique was used to replicate the gap between the crowns and the abutments. The thickness of the silicone film was measured under the stereomicroscope, and the gap between the groups was compared. Data was analysed using SPSS 22. Results: In group A, mean marginal gap was 82.43±25.00um, and mean overall gap was 85.45±33.75um. In group B, the corresponding values were 65.09 11.69um and 78.04±26.67um. There was a significant difference in the adaptation between the groups at the marginal and overall measurement points (p lessthan 0.05). Conclusion: Marginal and internal adaptations of polyether ether ketone coping crown for abutment could be considered clinically acceptable. Key Words: Crowns, Dental abutment, Dental implants, Dental marginal adaptation, Polyetheretherketone.

Objective: The purpose of this study was to evaluate the use of magnifying loupes (×2.5) on the quality of tooth preparation for complete coverage crowns; performed by predoctoral students using an objective and quantitative digital method. Materials and Methods: Forty‐two predoctoral students were randomly assigned into 2 groups to perform tooth preparation for a complete coverage crown on a mandibular first molar in a manikin, with and without the use of magnifying loupes. All preparations were digitally evaluated by PrepCheck 3.0 (Dentsply Sirona). Parameters including tooth reduction, total occlusal convergence (TOC), undercut, margin quality and surface quality were assessed. Continuous data were analysed using Paired t‐tests or Wilcoxon Signed Ranks tests. Ordinal data were analysed by McNemer's tests. To further detect the majority pattern (> 50%) in each group (with and without loupes), one‐sample t‐test or one‐sample Wilcoxon Signed Rank test was performed. The level of significance was set at p =.001 after Bonferroni adjustments for multiple testing. Results: No significant differences in the measured outcomes were found between the groups with or without the use of magnifying loupes (p >.002). The majority (>50%) of both groups had no undercuts (99.3% and 99.4% both p <.001) and the preparation type was within tolerance (81.6% and 85.3%, both p <.001) with acceptable margin (86.4% and 86.3%, both p <.001) and acceptable surface quality (99.0% and 99.1%, both p <.001). However, the majority of both groups underprepared occlusally (96.0% and 95.4%, both p <.001) and axially (65.3% and 67%, both p <.001). Only 30.0%–42.1% of the participants achieved the TOC within 0–20°. Conclusions: Within the limitations of this study, the use of magnification loupes does not appear to significantly improve the quality of tooth preparation for complete coverage crown. The TOC was also found to be overprepared and occlusally underprepared. [ABSTRACT FROM AUTHOR]

Some resin polymers available for three-dimensional (3D) printing are slightly elastic, which may be advantageous when used for full crown coverage of the primary teeth. This study was performed to evaluate the mechanical properties of two types of 3D-printed resin crowns in terms of strength and surface characteristics. Polymer resins used for temporary crowns (TCs) and temporary flexible dentures (TFDs) were tested. Digitally designed crowns with different thicknesses (0.4 and 0.6 mm) were 3D-printed. Milled zirconia crowns were used as the control. The static and dynamic fracture loads of the crowns were measured. The crown surface was evaluated using scanning electron microscopy. The average strength did not differ between the types of crowns. The differences between the dynamic and static fracture loads were insignificant. In the TC group, thicker crowns showed lower strength both under static and dynamic loads. After thermomechanical loading, microcracks and dropouts of macrofillers were detected on the surface of all types of resin crowns. The deposition of abraded debris occurred more in the TFD group. The 3D-printed resin crowns were thought to endure biting forces in children. However, some limitations of the material itself should be improved for consideration as a new treatment option in pediatric dentistry. [ABSTRACT FROM AUTHOR]

The use of dental ceramics on anterior teeth is associated with predictable and long-lasting esthetic results. However, treatment on darkened substrates is challenging. Various conservative options, including ceramic veneers, are available to change the shape and color of anterior teeth. The aim of this case report is to describe the esthetic rehabilitation of a darkened central incisor in a maxillary anterior region that had irregular gingival contours, multiple composite resin restorations, and unsatisfactory tooth shapes. Harmony was restored through periodontal recontouring surgery, placement of a lithium disilicate crown (consisting of a veneer cemented to a coping) on the darkened central incisor, and placement of lithium disilicate veneers on the other maxillary anterior teeth. [ABSTRACT FROM AUTHOR]

This survey paper wants to highlight the mathematical impact of the celebrated paper by Gaschütz in which the concepts of prefrattini subgroups and crowns were introduced. [ABSTRACT FROM AUTHOR]

ABSTRACT Introduction: Structural defects in teeth significantly impact oral health, leading to broader implications for an individual’s overall well-being. Porcelain-fused-to-metal (PFM) crowns and bridges are the preferred forms of fixed dental prostheses (FDP) for restoring lost form, function, and aesthetics of the missing or damaged tooth/teeth. This study aimed to investigate the distribution pattern and proportions of FDP across genders, age groups, types of teeth, and jaw locations. Methods: This was a retrospective analysis of records of dental prostheses availed at the National Referral Hospital from July 2016 to June 2021. Specific data on FDP were extracted and utilized for the analysis. Results: The median age of patients was 33 (23 - 41) years for females and 37 (26 - 50) years for males. Female patients accounted for the majority of FDP recipients, consisting of 56.7% of the total cases. Posterior crowns (80.7%) and, anterior bridges (48.7%) are the most prevalent FDP types. In the upper jaw, a significant proportion of FDP consisted of posterior crowns (70.5%) and, anterior bridges (55.9%). In contrast, the lower jaw predominantly received more crowns (96.0%) and bridges (49.3%) in the posterior region. Conclusions: FDP are prevalent among female patients with a lower median age. Anterior bridges restoring aesthetics are more prevalent in the upper jaw, whereas the bridges and crowns for posterior teeth are more in the lower jaw. Dental practitioners can tailor treatment approaches to meet patient expectations, whether to focus on aesthetics or functionality.

Background: It is common for dental technicians to adjust the proximal surface of adjacent teeth on casts when fabricating single crowns. However, whether the accuracy of the proximal contact is affected if this step is eliminated is unclear. Objective: To evaluate the accuracy of the proximal contact of single crowns for mandibular first molars fabricated from four different restorative materials, without adjustment of the proximal surface of the adjacent teeth by the laboratory/dental technician. Methods: This study was in vitro; all the clinical procedures were conducted on a dentoform. The mandibular first molar tooth on the dentoform was prepared using diamond burs and a high speed handpiece. Twenty single crowns were fabricated, five for each group (monolithic zirconia, lithium disilicate, metal ceramic, and cast gold). No proximal surface adjacent to the definitive crowns was adjusted for tight contact in the dental laboratory. Both the qualitative analyses, using dental floss and shimstock, and the quantitative analyses, using a stereo microscope, were performed to evaluate the accuracy of the proximal contact of the restoration with the adjacent teeth. In the quantitative analysis, one-way analysis of variance was used to compare mean values at a significance level of 0.05. Results: In quantitative analysis, the differences between the proximal contact tightness of the four groups was not statistically significant (P = 0.802 for mesial contacts, P = 0.354 for distal contacts). In qualitative analysis, in most crowns, dental floss passed through the contact with tight resistance and only one film of shimstock could be inserted between the adjacent teeth and the restoration. However, one specimen from the cast gold crown had open contact. Conclusions: Even without proximal surface adjustment of the adjacent teeth during the crown fabrication process, adequate proximal contact tightness between the restoration and adjacent teeth could be achieved.

Introduction: The purpose of this in vitro study was to test the influence of the margin design of implant supported monolithic zirconia crowns and test if monolithic zirconia crowns with extra fine finish line thickness cemented on zirconia implant abutments can bare the maximum masticatory forces on molars and hence be used in the posterior region. Methods: Fourteen identical monolithic zirconia crowns cemented on zirconia implant abutments mounted on titanium bases and fixed on implant replicas embedded in PMMA resin were divided into two groups: group I designed with a 0.5 mm CFL (CFL) and group II with a feather-edge finish line (FEFL) of 0.3 mm. All specimens underwent static load until fracture in order to determine the break force. Break forces in N were recorded for each group. Results: The CFL group exhibited slightly higher fracture resistance (1879.14 ± 322.28 N) compared to the feather-edge finish line group (1685.00 ± 362.18 N). However, statistical analysis revealed that the observed difference between the two groups (194.14 ± 183.24; p = 0.310) was not significant. Conclusions: Within the limitations of this study, both monolithic zirconia crowns with 0.5 mm chamfer and 0.3 mm feather edge margins cemented on zirconia implant abutments can be used in the posterior region as their resistance to fracture is similar and surpasses the maximum masticatory force applied on molars. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Mexicana de Odontología Pediátrica (2594-1798) is the property of Academia Mexicana de Odontologia Pediatrica, A. C. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An innovative 2D-material, graphocrown, was designed and studied. Our graphocrown computations revealed a higher stability compared to previous materials studied with the same generalized C2O formula. The energetic benefit of the graphocrown formation from benzenehexol was also evaluated. The structure and properties of graphocrowns with various layer arrangements were analysed and compared. In addition, the formation of potassium complexes with the new material was studied. It was found that graphocrown binds potassium better than 18-crown-6, and the intercalation of graphocrown with potassium is more favourable, compared to graphite. Finally, the band structure, as well as the mobility of the charge carriers in the graphocrown, were investigated. [ABSTRACT FROM AUTHOR]

The current focus of minimally invasive dentistry is to treat the lesions using less invasive treatment options. This review describes a conservative, non-invasive approach of treating carious deciduous molar using Stainless steel Crown, termed the "Hall technique". It interferes with the interplay between the three primary factors of the Keyes triad. It emphasises carious lesion management can be done by biofilm alteration to cease further carious progression and preservation of the affected dental hard tissue. This review provides in-depth detail about the rationale, indications, advantages, concerns and aids in evidence-based decisions regarding Hall's technique for Stainless Steel Crowns. [ABSTRACT FROM AUTHOR]