Temporary Cement Research Articles

The effect of different pretreatments and cleaning methods prior to adhesive cementation of lithium disilicate restorations. In vitro study

AimThis study aimed to evaluate the bond strength of adhesively cemented lithium disilicate restorations to dentin by applying different pretreatments and cleaning methods. Material and MethodsTwenty-five human posterior teeth were mounted in an acrylic mold, flattened to expose mid-coronal dentin, and divided into five groups based on different pretreatments and cleaning methods prior to adhesive cementation. After cementation, the teeth were sectioned to obtain 1 mm2 specimens, yielding 15 specimens in each group that were subjected to aging and thermocycling process, followed by a microtensile bond test and failure mode assessment. ResultsThe highest bond strength values were in the control group and in the group that was treated with fluoride and where the temporary cement was removed using pumice, whereas the lowest values were in groups that were cleaned by excavator irrespective of whether they were treated with fluoride or not. However, all groups showed mainly cohesive failure without any statistically significant differences. ConclusionsTo eliminate any possible negative impact of eugenol on adhesion to dentin, surface cleaning by rotational brush and pumice is recommended prior to cementing lithium disilicate restorations.

Influence of Different Cements on Bonding Efficiency Between Implant Abutment and Standard Restoration.

This study aimed to investigate the efficiency of different cements for luting implant restorations. Standard restorations were bonded with different cements, including a zincoxide-based temporary cement (ZOE), a resin-modified glass ionomer cement (GIC) and a resin-based, eugenol-free cement (RBEFC). The restorations were stored under moist conditions and were subsequently subjected to thermal cycling and mechanical loading (TCML). Retention forces were determined with an axial tensile test and removabilty of the restorations was analyzed with a pneumatic crown remover. GIC provided significantly higher retention forces than RBEFC, which provided significantly higher values than ZOE. After storage, retention forces were significantly higher than after TCML. With regard to removability, no significant differences were identified between ZOE and RBEFC, but a significantly higher number of applications was required to remove restorations luted with RBEFC. All cements provided sufficient retention forces, yet removal of restoration might be more demanding if luted with RBEFC.

Influence of the Composition of Provisional Luting Materials on the Bond Strength of Temporary Single-Tooth Crowns on Titanium Abutments.

In addition to zinc oxide-based cements, resin-based materials are also available for temporary cementation. The aim of this in vitro study was to determine the influence of the different material compositions on temporary bonds. In nine test series (n = 30), temporary bis-acrylate single-tooth crowns were bonded onto prefabricated titanium abutments with nine different temporary luting materials. After simulating an initial (24 h, distilled water, 37 °C), a short-term (7 days, distilled water, 37 °C) and a long-term provisional restoration period (12h, distilled water, 37 °C; thermocycling: 5000 cycles) in subgroups (n = 10), the bond strength was examined using a combined tensile-shear test. Statistical analysis was performed by univariate analysis of variance or a non-parametric Kruskal-Wallis test, followed by post hoc tests. Of the three resin-based materials, two showed significantly higher bond strength values compared to all other materials (p < 0.001), regardless of the storage procedure. The resin-based materials were followed by eugenol-free and eugenol-containing zinc oxide materials. Significant intragroup differences were observed between the composite-based materials after all storage periods. This was only observed for some of the zinc oxide-based materials. The results show that under in vitro conditions, not only the composition of the temporary luting materials but also the different storage conditions have a significant influence on temporary bonds.

Biological interaction, esthetics, handling, and loss rate of temporary luting cements — a clinical single-blind randomized controlled trial

ObjectivesTo evaluate three temporary luting cements in terms of their restoration loss rates, biological interactions, esthetic properties, and handling characteristics.Materials and methods75 adults requiring fixed prosthodontics voluntarily participated in a single-blind, randomized controlled trial. After preparation, temporary restorations were luted with a randomly selected temporary luting cement (either Provicol QM Plus (PQP), Bifix Temp (BT), or Provicol QM Aesthetic (PQA)). Clinical examinations were performed one to two weeks after cementation. The following criteria were evaluated: tooth vitality, percussion, hypersensitivity, gingival bleeding, odor formation, esthetics, cement handling, removability, cleanability, and retention loss. Antagonistic teeth served as controls. Statistical analysis was performed using the paired t-test, one-way ANOVA, Pearson’s chi-square and Fisher’s exact test, where appropriate.ResultsThe overall loss rate of temporary restorations was 16.0%, showing no cement-specific differences. Postoperative hypersensitivity occurred in 8% of cases regardless of cement type. Esthetic impairment was reported by 31% of the PQP-fixed restorations, compared with 4.0% and 4.2% of the BT and PQA-bonded restorations. Cement application was reported to be easy in 100% of cases, excess removal in 88–96%, depending on the cement used.ConclusionsThe choice of luting material affects the esthetic appearance of a temporary restoration and should be considered, particularly in restorations in esthetically demanding areas. No significant differences between the cements were identified regarding biocompatibility, handling, and loss rate.Clinical relevanceTranslucent cements can help to reduce color interferences, resulting in a more appealing appearance of the temporary restoration.

Contemporary Concepts of Adhesive Cementation of Glass-Fiber Posts: A Narrative Review.

(1) Background: Cementation of glass fiber posts to root canals has been associated with various failures, especially debonding. This narrative review aims to present the contemporary concepts concerning the adhesive cementation of glass fiber post and to discuss the optimal management of these factors. (2) Methods: Electronic search was performed in MEDLINE/Pub Med and Google Scholar using selected keywords examining the parameters post length, surface treatment of glass fiber posts, post space preparation and dentin pretreatment, resin cement selection, adhesive systems and hybrid layer formation, and clinical techniques. (3) Results: The search led to the selection of 44 articles. Epoxy resin-based endodontic sealers are recommended and the use of temporary cement in the root canal should be avoided. The minimum length of a glass fiber post adhesively cemented to a root canal is 5 mm. Irrigating the root canals with chlorhexidine, MTAD, or EDTA (alone or in combination with NaOCl) after post space preparation seems to enhance the bond strength. Silane application on the surface of the post seems to be beneficial. Concerning resin cements and adhesive systems, the results were rather inconclusive. Finally, resin cement should be applied inside the root canal with an elongation tip and photoactivation should be delayed. (4) Conclusions: Contemporary concepts of adhesive cementation of glass fiber posts can indeed improve the bond between glass fiber posts, resin cement, and root canal dentin, however, evidence coming from long-term randomized prospective clinical trials is needed in order to obtain safer conclusions.

A comparative evaluation of the effect of eugenol exposure time on the bond strength of an etch-and-rinse and a self-etch adhesive to dentin: An in vitro study.

The study aimed to comparatively evaluate the effect of eugenol exposure time on the micro-shear bond strength (μ-SBS) of etch-and-rinse and a self-etch adhesive to dentin. One hundred and twelve teeth samples were prepared from bisectioning 56 freshly extracted human mandibular molars and were randomly divided into 14 subgroups of 8 samples each (n = 8). Three subgroups containing eugenol and a noneugenol-based restorative material were placed on the dentin surface and left for 24 h, 7 days, and 14 days, respectively, and were compared to a control. Two bonding systems were evaluated: one being etch-and-rinse and the other self-etch adhesive. The μ-SBS were calculated and expressed in MPa. The data were analyzed using mixed model analysis of variance. The level of statistical significance was set at 5%. There was a statistically significant reduction in the μ-SBS values when the self-etch adhesive was used, after the removal of eugenol-containing cement placed for 24 h. However, the reduction in the μ-SBS values after 7 days or 14 days was not significant. Exposure to eugenol containing temporary cement for 24 h significantly reduces the μ-SBS of self-etching adhesives to dentin. However, exposure for 1 week or more has minimal effects.

Fracture resistance of CAD/CAM milled versus direct hand-made interim laminate veneers

BackgroundComparative studies of interim veneer restorations crafted using subtractive computer-aided manufacturing (s-CAM) milling technology and traditional direct hand-made approaches are needed. PurposeThis comparative in vitro study evaluated the fracture resistance of two types of provisional veneer restorations for maxillary central incisors: milled (s-CAM) and traditional direct hand-made bis-acryl veneers. Materials and methodsFifty maxillary right central incisor veneers (25 specimens per group) were fabricated and divided according to the fabrication method: (1) s-CAM milled (Structure CAD, VOCO Dental); and (2) hand-made (Protemp Plus, 3M). The restorations were cemented onto 3D-printed resin dies using temporary cement and subjected to 1000 cycles of thermal cycling between 5° and 55 °C. These restorations subsequently were subjected to compressive loading until fracture occurred. Images of the fractured samples were captured using a scanning electron microscope (SEM). Statistical analysis was performed using the one-way ANOVA test and the Mann-Whitney U test. ResultsSignificant differences (p < 0.001) in the fracture resistance were observed between the two groups. s-CAM milled interim veneers displayed higher fracture resistance values (439.60 ± 26 N) compared to the traditional method (149.15 ± 10 N). ConclusionThe manufacturing method significantly influences the fracture resistance of interim veneer restorations. s-CAM interim laminate veneer restorations for maxillary central incisors exhibit a fracture resistance superior to that of the traditional method using bis-acryl.Clinical relevanceClinicians should consider CAD/CAM milled veneers for scenarios demanding long-term interim restoration and the withstanding of high occlusal forces.

Biochar from cashew residue enhances silicon adsorption and reduces cohesion and mechanical resistance at meso- and micro-structural scales of soil with cohesive character

Horizons with cohesive character impose physical restraints on plant development, particularly when it occurs near the soil surface. Howbeit, the genesis of cohesive character in soils is associated with temporary and reversible cementation by amorphous silica. Thus, we hypothesized that the biochar obtained from residues from cashew processing would improve soil porosity and promotes silicon adsorption, consequently reducing cohesion and mechanical resistance while improving the physical quality of soils with cohesive character. We collected soil samples with deformed structure from the Bt1 horizon of a Typic Haplustult with cohesive character in northeast Brazil. These samples were used to prepare test substrates by combining air-dried and sieved soil samples and biochar at application rates of 0, 5, 10, 20, and 40 Mg ha−1. All the samples in each treatment underwent ten cycles of wetting and drying (one cycle per week) to allow the manifestation of the cohesive character. Subsequently, we assessed silicon adsorption capacity, soil bulk density, porosity, soil penetration resistance, tensile strength, and rheometric properties. In the 5 and 10 Mg ha−1 doses, the physical quality remained like the control treatment (0 Mg ha−1). The 20 and 40 Mg ha−1 doses resulted in increased soil silicon adsorption capacity (+7.6 and +15.3%, respectively), total porosity (+2.0 and +1.9%, respectively), and macroporosity (+14.6 and +15.3%, respectively), compared to the treatment without biochar. Conversely, these doses led to a reduction in soil bulk density (-0.1 and −0.8%, respectively), penetration resistance (-16.2 and −16.1%, respectively), tensile strength (-24.2 and −36.5%, respectively), deformation at the end of the linear viscoelastic range (-6.3 and −10.5%, respectively), shear stress at the end of the linear viscoelastic range (-16.4 and −26.9%, respectively), and maximum shear stress (-13.7 and −22.3%, respectively). In conclusion, the application of biochar improved soil porosity and promoted silicon adsorption, thus reducing the bulk density, cohesion, and mechanical resistance, enhancing the physical quality of soils with cohesive character, especially for doses of 20 and 40 Mg ha−1.

Utilizing an antibiotic-eluting articulated cemented spacer in the two-stage management of infected total hip arthroplasty: a technical note.

Two-stage revision is generally preferred to eradicate chronic periprosthetic infections after total hip arthroplasty (THA) because of its good infection control and promising results. During two-stage revision, a temporary antibiotic-impregnated cement spacer was initially used for the local delivery of antibiotics, thereby reducing the risk of infection recurrence. Many researchers have reported various techniques for fabricating cemented spacers; however, there is no established standard technique. We share our cost-effective and easily reproducible technique for creating an articulated cemented spacer for managing infected THA.

Antimicrobial Efficacy of Simvastatin and Double Antibiotic Paste as Intracanal Medicaments: A Randomised Clinical Study

Abstract Introduction: Root canal debridement, irrigation and a microorganism-free environment are key factors in the success of root canal treatment. Intracanal medicaments are used to enhance root canal disinfection. Simvastatin is derived from lovastatin and is a semisynthetic medication. This study compares and evaluates the effect of simvastatin and double antibiotic paste (DAP) as an intracanal medicament in single-rooted teeth with apical periodontitis using colony-forming units (CFUs)/ml. Materials and Methods: Twenty-eight patients with single-rooted teeth diagnosed with apical periodontitis were selected. Under aseptic conditions, patency was gained, sterile saline solution was deposited in the canal and the first sample (S1) was collected. Cleaning and shaping were then carried out following an appropriate technique depending on the configuration of the canal. After irrigation and biomechanical preparation, teeth were randomly assigned to two different groups, and the test intracanal medicament was applied to the root canals. Coronal openings were sealed with temporary restorative cement. The second sample (S2) was collected after 7 days. The samples obtained were checked for a reduction in the bacterial load. They were incubated aerobically for 48 h, and the CFUs were calculated. The Mann–Whitney U and Wilcoxon’s signed-rank tests were used to analyse the results statistically. Results: A significant reduction in bacterial count was present after administration of the intracanal medicament. On intergroup comparison, there was no statistically significant difference in bacterial decrease between the two groups. Comparatively, the mean reduction in the bacterial count was higher in the DAP group. Conclusion: It can be concluded that DAP and simvastatin were effective in the reduction of the bacterial count in single-rooted teeth diagnosed with apical periodontitis. However, DAP demonstrated a better performance in the reduction of bacterial counts.

Endodontic treatment in the management of cracked tooth

In many cases, endodontic treatment is unnecessarily performed while managing cracked tooth. However, there are many cases where it is unclear whether endodontic treatment should be performed or not during thetreatment of cracked tooth. One good way is to attach the final prosthesis with a temporary cement and then have a lot of conversations with the patient about their condition. Through this process, the timing of final ce-mentation or endodontic treatment can be determined. Of course, even if we do so, endodontic treatment may be performed in some cases, so the management of cracked tooth is inevitably called endodontic treatment originated treatment.

Особливості змін електроодонтодіагностичних показників пульпи інтактних зубів та зубів з некаріозними ураженнями у віковому аспекті

Actuality. When planning the application of medical and prosthetic measures, choosing the method of protection of the prepared tooth surfaces, the method of manufacturing temporary and permanent structures and cement for fixation, both the degree of destruction of the tooth crown and the state of the pulp are important. It is known that the degree of mineralization of enamel and dentin changes with age, obliteration of root canals occurs, which should be taken into account when choosing methods of prosthetic restoration of tooth crowns. Each orthopedic construction has certain clinical requirements regarding the volume of preparation of hard tissues of the teeth, and when planning methods and materials for the protection of the surface of the prepared teeth, age characteristics should be taken into account, which formed the basis for our research. Aim. Electroodontometric examination of the state of the pulp of affected vital teeth, compared to the norm in the age aspect for the prevention of complications of orthopedic treatment. Materials and methods. We observed 68 people aged 18 to 59, who were divided into two groups. The first group (control) consisted of 30 people whose teeth were examined without clinically diagnosed signs of hard tissue lesions and who did not have orthopedic structures in the oral cavity. The second clinical group included 38 patients with non-carious lesions of tooth crowns and clinical indications for permanent prosthetics. The specified contingent of persons was also divided into three age groups: 18–29, 30–44, and 45–59 years. In all patients, the state of the dental pulp was assessed by the method of electroodontometry (EOD), using the Endoest-3D device. Before the beginning of the measurement, professional hygiene of the oral cavity was performed. To prevent the loss of electric current, the teeth under study were isolated from saliva and the surface of the tooth was dried. The tip of the probe of the device was lubricated with conductive gel and sensitive points were touched with minimal current. The results. When analyzing the obtained results, it was established that there is a strong correlation between the patient’s age and EOD indicators at the corresponding measurement points: in the areas of the cutting edge (r = 0.74), in the cervical areas, vestibular (r = 0.79) in the points of the vestibular surface in the area of the equator (r = 0.70), with (р &lt; 0.05) with a general tendency to a significant decrease in the indicators of electrical excitability of the pulp of the vital teeth in the age aspect. Orthopedic treatment of patients of the second group with lesions of the hard tissues of the teeth of various genesis was carried out using both modern technologies and traditional aesthetic designs. Veneers, vestibular half-crowns, metal-ceramic and metal-free crowns with the use of desensitizers and temporary structures were made for the patients of these groups. Clinical results confirm the absence of complaints about postoperative sensitivity, which indicates the effectiveness of means of preventing complications. Conclusions. Electrodental diagnostics of the vital teeth should be carried out before orthopedic treatment to assess the state of the pulp and prevent prosthetic complications. Indicators of electrical excitability of the pulp of vital teeth tend to decrease significantly with age. Reliable differences of EOD indicators in the cervical area of the vestibular surface of the affected teeth were established in relation to the indicators of the vestibular surface at the level of the equator and measurement points of the cutting edge or the top of the buccal tubercle. There are significant differences between the EOD indicators of intact and affected teeth, which proves the need for the use of medical and prosthetic measures to prevent complications from the pulp. Keywords: electroodontology, teeth, dental pulp, non-carious lesions of teeth, orthopedic structures.

Effect of cement type, luting protocol, and ceramic abutment material on the shade of cemented titanium-based lithium disilicate crowns and surrounding peri-implant soft tissue: a spectrophotometric analysis.

The objective of the study was to analyze the impact of cement, bonding pretreatment, and ceramic abutment material on the overall color results of CAD-CAM ceramic crowns bonded to titanium-based hybrid abutments. For single implant restoration of a maxillary lateral incisor a total of 51 CAD-CAM-fabricated monolithic lithium disilicate crowns were fabricated and subsequently bonded onto 24 lithium disilicate Ti-base abutments, 24 zirconia Ti-base abutments and 3 resin abutment replicas as a control group. The 48 copings were cemented with three definitive and one provisional cement on both grit-blasted and non-blasted Ti-bases. The color of each restoration and surrounding artificial gingiva was measured spectrophotometrically at predefined measuring points and the CIELAB (ΔEab) color scale values were recorded. The color outcome of ceramic crowns bonded to hybrid abutments and soft tissues was affected differently by cements of different brands. Grit-blasting of Ti-bases prior to cementing CAD-CAM copings affected the color results of all-ceramic crowns. There was a significant difference (P = .038) for the median ΔE value between blasted and non-blasted reconstructions at the cervical aspect of the crown. Full-ceramic crowns on zirconia Ti-base abutments exhibited significantly lower ΔE values below the threshold of visibility (ΔE 1.8). In all subcategories tested, the use of a highly opaque temporary cement demonstrated the lowest median ΔE for both the crown and the artificial gingiva. Various cements, core ceramic materials and airborne particle abrasion prior to bonding can adversely affect the color of Ti-base supported ceramic crowns and peri-implant soft tissue. However, zirconia CAD-CAM copings and an opaque cement can effectively mask this darkening.

Investigation of the Effect of Mouthwash on Bonding Temporary Crown Materials with Various Temporary Cements

Objectives: This study was conducted with the aim of investigating the effects of surface treatments and mouthwash on the bond strength of different temporary restorative materials with provisional cements. &#x0D; Methods: A total of 252 samples 10 mm in diameter and 2 mm in thickness were prepared from three different provisional restorative materials. Each temporary crown material was randomly divided into three separate groups, and surface treatments were applied. (no surface treatment, air abrasion, or hydrofluoric acid etching). Two types of temporary cements were bonded to the surface. Half of them were treated with mouthwash; the other half were kept in distilled water as a control group. &#x0D; Results: As the result of the analysis of variance; the interaction of the material used, the type of cement and the material*cement*retained medium was statistically very significant (p

Magnesium Oxychloride and Magnesium Oxysulfate Cements as Temporary Plugging Agents in Geothermal Drilling.

The development and utilization of geothermal resources are effective ways to alleviate the current haze situation, adjust the energy structure, and achieve energy conservation and emission reduction. Geothermal formations typically contain extensive fracture networks, with fracture openings. These fracture networks can result in substantial losses of the drilling fluid and increased costs for geothermal drilling. Temporary plugging cements are used to solve the problem of lost circulation due to their high strength and high acid solubility. In this paper, two types of temporary plugging materials, magnesium oxysulfate (MOS) cement and magnesium oxychloride (MOC) cement, were prepared. The influence of the plugging agent on the flow field and the force exerted on the solid under the action of the fluid was analyzed using fluid-solid coupling software. The simulation results show that when subjected to a flow rate of 10 m/s, the edge of the cement experiences a significant force, while the stress is not widely transmitted to the middle and rear of the cement. This indicates that the cement has a strong resistance to the fluid flow. The fundamental characteristics of MOC cement and MOS cement, such as compressive strength and setting time, were investigated. The test results show that adjusting the molar ratio of the two types of cements can shorten the setting time by 60% and increase the compressive strength to up to 23 MPa. In addition, the acid solubility of the cement with different ratios of raw materials is above 95%. The plugging performance of these two cements as loss circulation materials was evaluated by using a physical simulation device. The pressure bearing capacity of the MOC cement with different MgO/MgCl2·6H2O/H2O molar ratios ranged between 13.4 and 23.6 MPa. The maximum bearing capacity of the MOS cement can reach up to 18.6 MPa. The results showed that both cements possess excellent plugging and pressure bearing capacity.

Antibiotic-loaded spacer arthroplasty in a terrible triad injury with unreconstructable radial head fracture: a case report

BackgroundRadial head arthroplasty is a viable option in cases with terrible triad injuries of elbow, wherein the radial head sustains significant comminution that precludes reconstruction. Nevertheless, this alternative is not recommended for individuals with poor elbow skin conditions, accompanied neuropsychiatric disorders, or low patient compliance. This case report presents a patient with bilateral terrible triad injury, along with the aforementioned conditions. The report outlines the treatment challenges of such a case and proposes potential solutions.Case presentationA 37-year-old Persian male patient presenting with a bilateral terrible triad fracture–dislocation and a history of psychoactive substance abuse, was admitted to our emergency department. The patient underwent radial head replacement using a cement spacer containing antibiotics, due to the comminuted radial head in the presence of a contaminated wound on the left elbow. The fracture of the right side was successfully fixed. Subsequent to discharge, the patient did not attend any follow-up appointments. After a period of 6 months, he was admitted to the psychiatric ward and orthopedic consultation was requested to evaluate the patient.ConclusionIn acute terrible triad injuries with unreconstructable radial head fractures where arthroplasty with metallic prostheses may not be suitable due to contaminated wounds, unstable psychiatric condition, and low patient cooperation, temporary orthopedic cement spacers can maintain elbow biomechanics, stability, and sterility.

Long-term follow-up of equine incisor endodontic treatments using an orthograde technique.

This retrospective clinical study was performed to determine the suitability and success rate of endodontic treatment of equine incisors presenting with apical and periapical disease. All horses presented to a referral equine dental clinic between March 2013 and December 2019 specifically selected as candidates suitable for endodontic treatment were included in this study. Initial clinical and radiographic presentation of incisor disorder cases suitable for endodontic treatment were recorded (88 incisors) and follow-up examination for long-term viability (8 months to 5 years) was performed in cases involving 32 incisors in total. A total of 68 horses with 88 incisors were included in this study for endodontic restorative treatment. Different dental materials were used, with a temporary 3-layered technique using calcium hydroxide apically and temporary cement and resin composite occlusally most commonly used at the first treatment. Complete obturation with resin composite was performed in 48% of the cases requiring second treatments (50 incisors). Follow-up examination involving 32 incisors showed that successful endodontic treatment was achieved in 75% of the teeth treated. Endodontic treatment of diseased incisors is a viable option in equid patients with a success rate comparable to humans in practice. The use of flowable resin composite as an obturation material has been shown to be successful at either the second treatment or in carefully selected patients at the first treatment.

Evaluation of radiopacity of cements used in implant-supported prosthesis by indirect digital radiography: an in-vitro study.

In order to help dentists in choosing the right type of cement for implant-based prostheses, the radiopacity of commonly used cements available in the market was investigated by digital radiography with PSP sensor. In the present study, temporary cements of TempBond (Kerr, Germany), TempBond clear (Kerr, Germany), Dycal (Dentsply, USA) and permanent cements of Multilink N (Ivoclar, Brazil), Panavia F 2.0 (Kurrary, Japan), Fuji plus (GC, Japan), RelyX (3M, USA), Durelon (3M, USA) were used. Four pill-like samples with 0.5 mm and 1 mm thickness and 5 mm in diameter inside the silicon index as recommended by the manufacturer were prepared for each cement. Aluminum step wedge (99% aluminum alloy) was used as control. Using digital radiography, cement and aluminum step wedge samples were radiographed. The images of cement tablets were measured by digital radiography using DFW software to check their radiopacity values. Bonferroni test and Mann-Whitney U test were used for comparison of cements. The highest radiopacity between the group of 1 and 0.5 mm thickness was related to Glass ionomer Fujiplus GC (2407±45.99) and TempBond (137.21±22.46) cement, respectively. Whereas, the lowest radiopacity among the groups was related to Clear cement. The difference between the mean radiopacities among the studied groups was statistically significant (p<0.001). Based on the results, among the available cements, Glass ionomer Fujiplus GC and TempBond cement are the most efficient for 1 and 0.5 mm thickness, respectively, and Clear cement is the least efficient cement in both groups in terms of radiopacity.

Effect of Temporary Cement on the Color of Temporary Crowns Made by Conventional Pressing Methods and Substractive CAM/CAD Technologies

The color stability of temporary restoration is crucial, especially in sensitive areas in terms of aesthetics. This research aimed to determine the effect of temporary cement on the color of temporary crowns made by conventional pressing methods (indirect) and CAM/CAD technologies using milling machines and 3D printers. This study was carried out in a laboratory, utilizing A2 color in all manufacturing methods. The color of the restorations was measured by a spectrophotometer after cementation with semi-permanent resin cement. Subsequently, color changes of the samples (ranging from 0 to 100) were calculated using the Commission International de l'Eclairage (CIE) Lab system. Data analysis was based on descriptive statistics methods and statistical tests, including one-way analysis of variance (ANOVA) and Tukey's post hoc test. According to the results of ANOVA, there was a significant difference between the three groups in terms of the 'a' and 'b' indexes (P&lt;0.001). However, regarding the 'l' index, no significant difference was observed among the three groups (P=0.250). Also, based on Tukey's post hoc test, a significant relationship was seen between the first and second pairs in the 3D printer group, and between the first and third pairs in the milling group (P&lt;0.001). However, no significant difference was observed in the conventional pressing group. The results showed that the 3D printing method exhibited the highest amount of color change among the three methods, while the milling method demonstrated the lowest amount of change.

Comparison of marginal leakage and retentive strength of implant-supported milled zirconia and cobalt-chromium copings cemented with different temporary cements

ABSTRACT Background: Few studies assessed the effect of coping material (particularly milled metal copings) on the retentive strength of cements and reported contradictory results. Thus, this study aims to assess the marginal leakage and retentive strength of implant-supported milled zirconia and cobalt-chromium (Co-Cr) copings cemented with different temporary cements. Materials and Methods: In this in vitro study, Zirconia and Co-Cr copings were fabricated on 100 straight titanium abutments. Each group of copings was divided into five subgroups (n = 10) for the use of different cements: permanent zinc-phosphate (ZP) cement, temporary zinc oxide eugenol cement (temp bond [TB]), calcium hydroxide-based temporary cement (Dycal [DC]), polymer-based eugenol-free acrylic-urethane temporary cement (Dentotemp [DT]), and methacrylate-based temporary cement (Implantlink [IL]). The retentive strength and marginal leakage of restorations were assessed. Data were analyzed by one-way ANOVA, Tukey, and Fisher’s exact tests (α = 0.05). Results: In the Co-Cr group, the retentive strength values (in Newtons) were as follows: ZP (411.40 ± 5.19) &gt;DC (248.80 ± 5.01) &gt;IL (200.10 ± 5.06) &gt;DT (157.90 ± 5.19) &gt;TB (98.50 ± 6.88). This order was as follows in the zirconia group: ZP (388.70 ± 5.35) &gt;DC (226.60 ± 5.08) &gt;IL (179.00 ± 3.71) &gt;DT (136.00 ± 4.88) &gt;TB (78.60 ± 3.50). All pairwise comparisons were statistically significant (P &lt; 0.001). The difference in marginal leakage was not significant among the groups (P = 0.480). Conclusion: The type of coping material and cement type significantly affected retentive strength, but not marginal leakage, of implant restorations. Milled Co-Cr copings showed higher retentive strength than zirconia copings, and ZP cement followed by DC yielded the highest retention.