Cement Group Research Articles

Evaluation of Sealing Potential of Different Repair Materials in Furcation Perforations Using Dye Penetration: An In Vitro Study

The present study aimed to assess the sealing ability of various repair materials in furcation perforations using dye penetration. A total of 80 human first molars from mandible with unbroken enamel surfaces, which were extracted completely for periodontal reasons, were chosen. All extracted teeth were kept in a sterile solution up until further use. Endo-access bur was used to prepare endodontic access cavity, and a high-speed long shank round bur was used to create a planned perforation on the floor of pulp. All the specimens were randomly grouped (20 teeth in each group): Group I: control; group II: Pro-Root MTA; group III: resin-modified glass-ionomer cement (RM GIC); and group IV: Biodentin. After placement of repair materials in perforated furcation, the chamber of each tooth was accessed with 2% methylene blue dye. Later, a diamond disk was used to split the teeth buccolingually. A stereomicroscope (10×) was used to visualize the highest dye penetration. The least penetration was seen in teeth repaired by Biodentin group (0.88 ± 0.02), next by Pro-Root MTA group (1.24 ± 0.13) and resin-modified glass ionomer cement group (3.62 ± 0.46). A statistically significant difference was seen among different perforation repair materials by analysis of variance. A statistically significant difference (p value < 0.05) was found between each group, excluding group II v/s group IV. This study concluded that reduced dye penetration in perforation repair along the furcations and improved sealing ability are shown by biodentine group in comparison to Pro-Root MTA and resin-modified glass-ionomer cement group. Root perforations along the furcation that develop due to the endodontic procedures have a remarkable damaging effect on prognosis and frequently result in loss of secondary periodontal attachment, thus resulting in early loss of the involved tooth. Therefore, the selection of biocompatible repair material aids to enhance the treatment prognosis.

Biomechanical study of polymethyl methacrylate bone cement and allogeneic bone for strengthening sheep vertebrae

To investigate the feasibility and mechanical properties of polymethyl methacrylate (PMMA) bone cement and allogeneic bone mixture to strengthen sheep vertebrae with osteoporotic compression fracture. A total of 75 lumbar vertebrae (L 1-L 5) of adult goats was harvested to prepare the osteoporotic vertebral body model by decalcification. The volume of vertebral body and the weight and bone density before and after decalcification were measured. And the failure strength, failure displacement, and stiffness were tested by using a mechanical tester. Then the vertebral compression fracture models were prepared and divided into 3 groups ( n=25). The vertebral bodies were injected with allogeneic bone in group A, PMMA bone cement in group B, and mixture of allogeneic bone and PMMA bone cement in a ratio of 1∶1 in group C. After CT observation of the implant distribution in the vertebral body, the failure strength, failure displacement, and stiffness of the vertebral body were measured again. There was no significant difference in weight, bone density, and volume of vertebral bodies before decalcification between groups ( P>0.05). After decalcification, there was no significant difference in bone density, decreasing rate, and weight between groups ( P>0.05). There were significant differences in vertebral body weight and bone mineral density between pre- and post-decalcification in 3 groups ( P<0.05). CT showed that the implants in each group were evenly distributed in the vertebral body with no leakage. Before fracture, the differences in vertebral body failure strength, failure displacement, and stiffness between groups were not significant ( P>0.05). After augmentation, the failure displacement of group A was significantly greater than that of groups B and C, and the failure strength and stiffness were less than those of groups B and C, the failure displacement of group C was greater than that of group B, and the failure strength and stiffness were less than those of group B, the differences between groups were significant ( P<0.05). Except for the failure strength of group A ( P>0.05), the differences in the failure strength, failure displacement, and stiffness before fracture and after augmentation in the other groups were significant ( P<0.05). The mixture of allogeneic bone and PMMA bone cement in a ratio of 1∶1 can improve the strength of the vertebral body of sheep osteoporotic compression fractures and restore the initial stiffness of the vertebral body. It has good mechanical properties and can be used as one of the filling materials in percutaneous vertebroplasty.

Hyaluronic acid facilitates bone repair effects of calcium phosphate cement by accelerating osteogenic expression

Calcium phosphate cements (CPC) are widely anticipated to be an optimum bone repair substitute due to its satisfied biocompatibility and degradability, suitable to be used in minimally invasive treatment of bone defects. However the clinical application of CPC is still not satisfied by its poor cohesiveness and mechanical properties, in particular its osteoinductivity. Hyaluronic acid reinforced calcium phosphate cements (HA/CPC) showed extroadinary potential not only enhancing the compressive strength of the cements but also significantly increasing its osteoinductivity. In our study, the compressive strength of HA/CPC increased significantly when the cement was added 1% hyaluronic acid (denoted as 1-HA/CPC). In the meantime, hyaluronic acid obviously promoted ALP activity, osteogenic related protein and mRNA expression of hBMSCs (human bone marrow mesenchymal stem cells) in vitro, cement group of HA/CPC with 4% hyaluronic acid adding (denoted as 4-HA/CPC) showed optimal enhancement in hBMSCs differentiation. After being implanted in rat tibial defects, 4-HA/CPC group exhibited better bone repair ability and bone growth promoting factors, comparing to pure CPC and 1-HA/CPC groups. The underlying biological mechanism of this stimulation for HA/CPC may be on account of higher osteogenic promoting factors secretion and osteogenic genes expression with hyaluronic acid incorporation. These results indicate that hyaluronic acid is a highly anticipated additive to improve physicochemical properties and osteoinductivity performance of CPCs for minimally invasive healing of bone defects.

Evaluating the Antimicrobial Properties of Glass Ionomer, Zinc Phosphate, and Polycarboxylate Cement

Background and Aim: There exists increased demineralization risk of enamel adjacent to fixed orthodontic attachments by cariogenic bacterias (e.g., Streptpcoccus mutans, Streptpcoccus sobrinus) and inadequate data about commonly used orthodontic cements. Thus, we evaluated the antibacterial effects of three common domestic and foreign orthodontic cements (Glass ionomer, Zinc phosphate, &amp; polycarboxylate) on two cariogenic pathogens (S. mutans &amp; S. sobrinus). Methods &amp; Materials: In this laboratory study, after culturing two standard strains of Streptococcus mutans and Subrinus bacteria and concentrating and diluting them, a direct contact test was used to evaluate the antibacterial properties of types of cement. The study groups (n=5) included the following: three types of glass ionomer resilience cement, Hoffman’s zinc phosphate and Hoffman’s polycarboxylate, and three glass ionomer cement, zinc phosphate, and carboxylate from Aria Dent factory in Iran. The acquired data were analyzed using SPSS v. 17. Ethical Considerations: The present study was approved by Babol University of Medical Sciences (Code: MUBABOL.REC.1391.7).Results: In both types of culture media, containing Streptococcus mutans and Streptococcus subrinus bacteria, there was a significant difference between culture media containing 3 groups of cements respecting bacterial growth inhibition zone (P&lt;0.001). In general, The mean diameter of the inhibition zone was greater in Iranian polycarboxylate, compared to its foreign counterpart (P&lt;0.001). Results: Regarding to zone of inhibition, there was statistically significant difference between three tested cements in both S.mutans and S.sobrinus culturing media (P&lt;0.001). The mean diameter of inhibition zone was greater for Iranian polycarboxylate compared to its foreign counterpart (P&lt;0.001). Conclusion: Glass ionomer cement demonstrated better antibacterial effect compared to zinc phosphate and polycarboxylate cements. There was also greater antibacterial effect of three tested cements on S.sobrinus than S.mutans. Iranian polycarboxylate showed stronger inhibition on both mentioned bacterias compared to the foreign one.

Prospective study of short term functional outcome in elderly patients treated with cemented vs uncemented bipolar hemiarthroplasty for transcervical neck of femur fractures

Objective: Transcervical femur neck fractures are common occurrences in elderly age group leading to significant impact in the health care setup. Bipolar hemiarthroplasty is the commonly performed surgery in this age group. There has been an ongoing debate based on outcome of cemented vs uncemented hemiarthroplasty. The purpose of the study is to evaluate the functional outcome with individual techniques assessed by the Harris Hip Score. Materials and Methods: It was a single centre prospective study with the total sample size of 50. Randomisation was done into 2 groups, one to be treated with uncemented bipolar hemiarthroplasty and the other one with cemented hemiarthroplasty. The comparison was done based on the demographic data, intraoperative parameters, post-operative complications and functions. The patients were followed up till one year and functional outcome was evaluated using the Harris Hip Score. Results: The average age of the patients in the study is 75.02 years, with most patients between 70 -80 years and females (54%) being more than males (46%). Surgical time and blood loss was greater for the cemented (94.4min and 234.8ml) cohort than the uncemented (60.80 min surgical time and 183.20 ml blood loss) (p value < 0.001). However the functional outcome at the end of one year was the similar in both the study groups. Mean Harris Hip Score at 1 year for cemented group was 94.1 and uncemented group was 94.43 with p value = 0.862 (not significant). Conclusion: Based on our results the advantages of using an uncemented hemiarthroplasty are less intraoperative bleeding, shorter duration of surgery which was statistically significant. Both cemented and uncemented hemiarthroplasty are accepted modality of treatment in transcervical femur neck fractures in elderly, as there is no statistical difference in the functional outcome at the end of one year.

Humeral osteolysis after reverse shoulder arthroplasty using cemented or cementless stems comparative retrospective study with a mean follow-up of 9 years

IntroductionThe cause of proximal humeral osteolysis after reverse shoulder arthroplasty (RSA) remains controversial. The primary objective of our study was to compare the radiographic outcomes of Grammont-type RSA when a cemented stem is used versus when a cementless stem is used. The secondary objective was to identify the cause of these radiographic changes, especially for the cementless stems. HypothesisMore proximal humerus bone loss occurs when a cementless humeral stem is used. MethodsWith a minimum follow-up of 5 years, two paired cohorts were compared retrospectively: 70 RSA with cemented stem and 70 RSA with cementless stem. Using the radiographs made at the final follow-up visit, we looked for tuberosity resorption, signs of stress shielding, the presence of periprosthetic radiolucent lines and scapular notching. ResultsAt a mean follow-up of 9 years (5.0–20.6), the RSA revision rate was 1.8% in the cemented group and 3.6% in the cementless group (p=1). Tuberosity resorption was twice as common in the cementless group: 59% versus 30% (p<0.001). Signs of stress shielding such as osteopenia were only present in the cementless group. In both groups, tuberosity resorption was often associated with scapular notching. In the shoulders with tuberosity resorption, stage≥3 scapular notching was more common in the cementless group (p=0.001). DiscussionFor the cementless stems, proximal humeral osteolysis can in part be attributed to stress shielding. The relationship between notching and tuberosity resorption in the two groups also suggests a secondary biological cause. Level of evidenceIII; Comparative retrospective study.

Short-term Effect of Four Root Filling Materials on the Flexural Strength of Human Root Dentin

Background: This study aimed to assess the effects of calcium hydroxide, Biodentine, calcium-enriched mixture (CEM) cement, and mineral trioxide aggregate (MTA) on root dentin flexural strength after a 30-day exposure period. Methods: This in vitro experimental study evaluated 25 freshly extracted sound human incisors with no caries or restorations. The apical 5 mm and the coronal two-thirds of the crowns were cut such that all samples had 10 mm length. Dentin samples (n=20 in each group) were then exposed to 2 mm thickness of calcium hydroxide, Biodentine, CEM cement, MTA, or saline (control) in petri dishes for 30 days. Finally, dentin samples were subjected to a three-point bending test after the intervention, and the flexural strength data were analyzed using one-way ANOVA, Tukey’s test, and t test. Results: Thirty-day exposure to all four biomaterials decreased the flexural strength of root dentin (P&lt;0.05). The four groups were significantly different in terms of the flexural strength of root dentin (P=0.001). The flexural strength of root dentin was significantly lower following exposure to calcium hydroxide (P=0.003), Biodentine (P=0.011), CEM cement (P=0.001), and MTA (P=0.007) compared to saline. The reduction in strength following exposure to calcium hydroxide was higher than that in Biodentine, CEM cement, and MTA groups (P&lt;0.05) while the latter three were not significantly different in this respect (P&gt;0.05). Conclusions: In general, all four tested biomaterials decrease the dentin strength although this reduction is more prominent by calcium hydroxide.

Surgical treatment of distal radius giant cell tumors

We aimed to evaluate the effectiveness of surgical methods commonly used for the clinical treatment of giant cell tumors (GCT) of the distal radius. From 2010 to 2018, 32 patients with GCT of the distal radius who underwent surgical treatment were eligible for the study. Among them, 21 patients with available pathological results, complete imaging data and at least 18 months of follow-up were enrolled in the study. Eleven of the patients underwent en bloc resection and non-vascularized autologous fibula reconstruction (Group A), while 10 patients underwent microwave ablation, lesion curettage, and internal fixation with bone cement (Group B). Imaging was carried out to understand the effect of the surgical treatment and postoperative complications. Variables of interested included operation time and blood loss, preoperative and postoperative wrist joint mobility, and postoperative complications during follow-up. The operation time and intraoperative blood loss in group A were higher than in group B, and the difference between groups was statistically significant. The wrist range of motion before and after surgery was statistically significant both in Group A and Group B (p < 0.05). The scale deviation and MSTS scores of group A were better than group B (p > 0.05), flexion, extension, radial deviation index in group B was better than group A (p < 0.05). By evaluating the postoperative functional outcomes of the operated wrist in the two groups, we found that both surgical methods are reliable for treating GCT of the distal radius, with satisfactory postoperative functional recovery and a low incidence of postoperative recurrence (only 1 of 10 patients in group B). The two surgical methods have their own advantages and disadvantages and provide surgeons with one more choice in the clinical context.

Compressive strength of lithium disilicate inlay cementation on three different composite resins

Background/purposeCeramic restorations have been increasingly applied over recent years. But the performance of cement is still unknown after cementation. This study was aimed to compare the compressive strength and the performances of three different types of composite resin after lithium disilicate inlay cementation. Materials and methodsTwenty-four human maxillary premolars were embedded in resin blocks, finished a MOD inlay preparation and scanned with an extraoral scanner. Lithium disilicate ceramic inlays (IPS e.max, Ivoclar Vivadent, Liechtenstein) were fabricated according to the scanner's model. All the specimens were then etched, bonded, and cemented with three different composite resins. Right after 5000 thermal cyclings, the specimens were accepted compressive tests to evaluate the compressive strength and failure types. Moreover, the fracture fragments of the specimens were examined using scanning electron microscopy (SEM) to verify the fracture type. ResultsDual-cured resin cement (Rely X Ultimate) showed the highest compressive strength (1002 ± 508 N), followed by the light-cured flowable resin (Z350 XT) (971 ± 209 N) and light-cured bulkfill (Filtek Bulkfill) resin (581 ± 191 N). Type IV (root fracture) failures in the dual-cured resin cement group was 25%, and light-cured flowable resin was 37.5%. But none of type IV fracture was found in the light-cured bulkfill flowable group. ConclusionDual-cured resin cement demonstrates the highest compressive strength after ceramic inlay cementation. Light-cured bulkfill resin shows the lowest compressive strength, but catastrophic failure is absent in this group.

Comparison of Volumetric Dimensional Changes of Calcium Aluminate, Resin Modified Glass Ionomers and Resin Luting Cements Among Different Storage Conditions

Objective: The aim was to evaluate the volumetric dimensional changes of calcium aluminate glass-ionomer luting agent to resin modified-Glass ionomer cement (RM-GIC), self-etch and conventional resin based cement (RBC) among different storage conditions. Methods: Twenty cylindrical specimens (7 mm × 2 mm) for four cements [Calcium aluminate (Ceramir-CM), RM-GIC (Fuji Plus-FP), RBC (Rely X Ultimate-RA) and RBC-self-etch (Rely X Unicem-RU)] were fabricated and polished. Five specimens from each material were randomly assigned to the four test conditions. These conditions were silicone oil at 22 °C and 37 °C and distilled water at 22 °C and 37 °C respectively. A resolution balance was used to measure the weight of each specimen at 1, 2, 3 and 4 weeks. Archimedes’ principle equations were used to measure volumetric dimensional changes. Ion release analysis for Ca+ and OH- of the storage medium solution of calcium aluminate cement was performed using atomic absorption spectroscopy and pH measurement respectively at 1, 2, 3 and 7 weeks. Data was analyzed using ANOVA and Tukey post hoc test. Results: A significant difference in volumetric changes (ρ &lt; 0.05) was observed for different cements. Calcium aluminate (CM) showed maximum volumetric changes followed by FP. However, resin cements (RA and RU) showed significantly lower volumetric changes. Oil immersion exhibited shrinkage and water immersion showed volumetric expansion in all materials. Increase in duration of immersion, increased the dimensional changes (shrinkage or expansion) among all cement groups (ρ &lt; 0.05). Both temperature and duration showed significant influence on Ca+ ion release. Conclusions: Calcium aluminate cement had the highest level of dimensional changes (17.28% and 20.52%) while both resin luting agents show least expansion without a significant difference between them. Ceramir luting agent expands significantly in water and continues to release Ca2+ ions with time and higher temperature. The clinical use of calcium aluminate cements based on the high dimensional changes observed in the study is debatable.

Influence of basalt fiber on mechanical properties of permeable cement stabilized macadam base

Different groups of permeable cement stabilized macadam specimens material test, which used different basalt fiber content were carried out, studying the influence of basalt fiber content on compressive strength and splitting strength of materials. The results showed that basalt fiber can improve the long term compressive strength and splitting strength of permeable cement stabilized macadam. When the basalt fiber content is 0.7 ‰ and the fiber length is 12 cm, the compressive strength and splitting strength of the specimen are improved best.

Effects of tourniquet use on clinical outcomes and cement penetration in TKA when tranexamic acid administrated: a randomized controlled trial

BackgroundThe role of a tourniquet is still controversial for patients undergoing total knee arthroplasty (TKA). Our current study was performed to determine whether the nonuse of the tourniquet combine with tranexamic acid (TXA) application in TKA patients with end-stage osteoarthritis would accelerate the perioperative recovery rate and provide enough cement mantle thickness for implant fixation.MethodsIn this prospective, randomized controlled trial, 150 end-stage knee osteoarthritis patients receiving TKA were divided into three groups: group A (tourniquet group), group B (non-tourniquet group), and group C (tourniquet in cementation group). All enrolled patients received 3 g of intravenous TXA and 1 g topical TXA. The primary outcomes included blood loss variables and transfusion values. The secondary outcomes included VAS pain score, inflammatory factors level, range of motion, HSS score, postoperative hospital stay, and complication. Furthermore, by using a digital linear tomosynthesis technique, tibial baseplate bone cement mantle thickness was measured in four zones based on the knee society scoring system.ResultsNo significant difference was found among the three groups with regards to total blood loss, transfusion, and complication. However, patients in group B showed lower inflammatory factors levels, shorter length of hospital stay, better range of motion, and lower postoperative pain. No significant difference was found among the three groups in four zones in terms of bone cement mantle thickness.ConclusionsFor end-stage knee osteoarthritis patients, the absence of tourniquet did not appear to affect blood loss and cement penetration in TKA patients. Furthermore, less inflammation reaction and better knee function can be achieved without a tourniquet. We recommend no longer use a tourniquet in primary TKA for patients with end-stage osteoarthritis when TXA is administrated.Trial registrationChiCTR-INR-16009026.Level of evidenceTherapeutic Level I.

The physical properties and anticariogenic effect of experimental resin cement containing ursolic acid.

The aim was to evaluate the physical properties and anti-bacterial activity of resin cement containing ursolic acid (UA) and determine the optimal concentration of UA. Five types of experimental resin cement were prepared according to UA concentration (0, 0.1, 0.5, 1.0, and 2.0 wt%). Flexural strength, film thickness and in vitro cytotoxicity were measured to confirm whether the resin was appropriate under International Organization for Standardization (ISO) criteria. Fifty extracted human molars were prepared, and indirect resin inlays were cemented with experimental resins. Acid-resistant nail varnish was applied, except for the 2-mm area around the restoration. Artificial caries were induced for 6 days through Streptococcus (S.) mutans (ATCC25175). Quantitative light-induced fluorescence (QLF) was used to evaluate the caries progression. One-way analysis of variance (ANOVA) followed by the Dunnett correction were used to statistically analyze the data. In all groups, the physical property of flexural strength, film thickness, and cytotoxicity were satisfied for ISO criteria (p > 0.05). On ∆F (-%) and ∆Q (-%⋅Px) values as QLF parameters, there was a tendency of being lower in groups of resin cement containing higher concentration of UA. Resin cement containing UA of greater than or equal to 0.5% significantly inhibited caries in the area around restoration (p < 0.05). There was no difference between the groups containing UA of greater than or equal to 0.5%. Resin cement containing 0.5% or more UA showed anti-carious effect in the limited range of 2% and satisfied the ISO criteria for flexural strength, film thickness and cytotoxicity.

Lower early revision rates after uncemented Oxford Unicompartmental Knee Arthroplasty (UKA) than cemented Oxford UKA: A meta-analysis

BackgroundUKA has been proved to offer good results in treating patients with unicompartmental knee osteoarthritis (OA). However, there is still a controversy about the better fixation mode in UKA procedure between cemented and uncemented prosthesis. Therefore, this meta-analysis was conducted to compare clinical and radiological outcomes of cemented versus uncemented Oxford UKA. HypothesisThe study surmised that uncemented Oxford UKA was associated with shorter operation time, higher function scores, lower revision rate and less radiolucency than cemented Oxford UKA. MethodsA meta-analysis to compare postoperative outcomes between cemented and uncemented Oxford UKA wsa conducted. The primary outcomes included Oxford knee score (OKS), revision rate, and incidence of radiolucency. The secondary outcomes included operation time, knee society score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), range of motion (ROM). PubMed, Embase, Web of Science, the Cochrane Library and China national knowledge infrastructure were searched until April, 2020 to identify studies for including. Relevant data were analyzed using RevMan v5.3. ResultsWe identified nine studies involving 901 patients meeting our inclusion criteria. No significant difference of OKS was found in both groups. Compared with cemented group, uncemented Oxford UKA group was associated with lower revision rate (95% CI: 0.90 to 3.73; OR=1.83) and less radiolucent lines (95% CI: 0.79 to 9.52; OR=2.75) after following up for at least 2years. The operation time was significantly shorter by 10.12minutes (95% CI: p<0.00001) in the uncemented group when compared against the cemented group. The KSS, WOMAC, ROM were not significantly different between two groups. ConclusionsUncemented Oxford UKA had lower revision rate, shorter operation time and less radiolucent lines than cemented Oxford UKA did. There is still need for more long follow-up clinical trials with high evidence level to determine which method of fixation is of preferable for Oxford UKA in the future. Level of evidenceI.

Effect of aging on color stability of amine-free resin cement through the ceramic laminate veneer.

Background:This study aimed to assess the color change of two amine-free dual-cure resin cements following aging in comparison with a light-cure resin cement.Materials and Methods:This in vitro, experimental study evaluated 6 groups (n = 10), including three groups of cements bonded to feldspathic porcelain and three groups of resin cements alone. Panavia V5 (Kuraray) and G-CEM LinkForce (GC) dual-cure resin cements and Choice 2 (Bisco) light-cure resin cements were bonded to porcelain according to the manufacturers’ instructions. The color parameters of the groups were measured before and after 5000 thermal cycles by spectrophotometry. Data were analyzed using two-way ANOVA and Tukey's post hoc test (α =0.05).Results:The color change (ΔE) of the cement groups alone was significantly greater than that of porcelain-bonded cements. The ΔE of G-CEM LinkForce cement group was significantly higher than that of Panavia V5 group (P = 0.020), and the ΔE of the latter group was significantly higher than that of Choice 2 cement group (P = 0.021).Conclusion:Considering the color change of cements evaluated in this study, Choice 2 and Panavia V5 cements bonded to porcelain showed acceptable color change, which indicates that they are suitable for cementation of esthetic dental restorations. Ceramic laminates have become an ideal esthetic treatment for anterior restorations. The resin cement discoloration can affect final appearance of these restorations. Besides that, exposed resin cement line can lead to the esthetic problem over time.

Lateral versus posterolateral approach of hemiarthroplasty for fracture neck of femur using bipolar prosthesis

Introduction: The purpose of the study is to compare functional outcome, early surgical complications and component alignment between lateral and posterolateral approach of hemiarthroplasty using bipolar prosthesis in fracture neck of femur. Method: Data was collected from 60 patients, who had fracture neck of femur and aged 55 years and above, between the period April 2018 to October 2019, with minimal sample size of 30 in each group. It is a prospective observational study. Aim of the study is to compare the lateral and posterolateral approaches for hemiarthroplasty. Results: In a total pool of 60 patients, the mean age of patients in posterolateral group was 70.97 years while that in the lateral group was 73.03 years. Out of the 60 participants, 25 were male patients while 35 female patients. The mean duration of surgery in posterolateral approach in the cemented group (13 patients) was 73.85 minutes, while in uncemented group (17 patients) was 64.65 minutes. In the lateral approach mean duration of surgery in cemented group (25 patients) was 73.92 minutes while in uncemented (5 patients) was 65.80 minutes. Average blood loss in posterolateral approach group was 254.67 ml and that in the lateral approach group was 263.00 ml. There was no complication of post-operative infection found in either study groups. In our study, leg length discrepancy of >10mm found in 16.7% (n=5) of posterolateral group and 13.3% (n=4) in lateral group and was statistically insignificant. Femoral stem positioning was neutral within both posterolateral and lateral surgical approach groups. There was no posterior dislocation in either approach groups. The mean Harris hip score (HHS) at 6 months in posterolateral group was 71.9 with the lowest score of 38.4 and the highest score of 96.2. The mean HHS at 6 months in the lateral group was 66.75 with the lowest score of 47.6 and the highest of 85. Comparison of the HHS at 6 months between the two groups shows that HHS at 6 months is higher in posterolateral approach group. Conclusion: There is no significant difference between the lateral and posterolateral approaches in the outcomes of duration of surgery, amount of blood loss, early surgical complications, post-operative prosthesis alignment and the functional outcome. In our study it is concluded that the approach used for HA (hip arthroplasty) depends on the preference and training of the surgeon and results of both the approaches are comparable.

Effect of Er:YAG laser radiation on pull-out fracture load of esthetic posts luted to root canal dentin with various resin cements

This study investigated the influence of erbium-doped: yttrium aluminum garnet (Er:YAG) laser on the pull-out fracture load of fiber-reinforced composite (FRC) posts luted to dentin with different resin cements. In this in vitro experimental study, 90 premolars were endodontically treated. The post spaces were prepared, and the teeth were divided into three groups dependent on the cement applied for luting FRC posts: Group 1: An etch-and-rinse system, Group 2: A self-etch cement, and Group 3: A self-adhesive cement. After 6 months' storage and thermocycling, each group was divided into three subgroups (n = 10) according to the treatment applied for removing the posts; subgroup 1: Control, subgroup 2: Treatment with Er:YAG laser at 250 mJ, 20 Hz, and subgroup 3: Treatment by Er:YAG laser at 300 mJ, 10 Hz. The pull-out load was recorded in Newton. The data were analyzed by two-way ANOVA at P < 0.05. The fracture load was significantly affected by the cementation group (P = 0.005) and treatment subgroup (P = 0.008). The pull-out load of self-etch cement was significantly greater than that of the self-adhesive and etch-and-rinse systems (P < 0.05). Treatment with Er:YAG laser caused a significant reduction in pull-out load of FRC posts (P < 0.05). The fracture load of fiber posts is influenced by the type of cement and treatment applied. Post removal would be less challenging when using a self-adhesive or conventional etch-and-rinse cement or using Er:YAG laser at the FRC-resin interface.

Effect of cementation techniques on fracture load of monolithic zirconia crowns

Aim The aim of this study was to evaluate the effect of cement on the fracture load of monolithic zirconia crowns with different yttria content (3 and 5 mol%). Methods A total of 62 monolithic zirconia crowns, 40 3Y-zirconia crowns (Prettau® Zirconia, Zirkonzahn) and 22 5Y-zirconia crowns (Prettau® 4 Anterior®, Zirkonzahn) were produced to a shallow chamfer molar preparation. The 3Y-crowns were divided into four groups and attached to composite abutment duplicates (SDR® flow+, Dentsply DeTrey GmbH) using the following four cementation techniques; (1) Self-adhesive resin-based cement, (2) Pre-treatment with air-abrasion and self-adhesive resin-based cement, (3) Zinc phosphate cement, (4) Glass-ionomer cement. The 5Y-crowns were divided into two groups and attached to the duplicates with; (1) Self-adhesive resin-based cement, or (2) Air-abrasion pre-treatment and self-adhesive resin-based cement. All crowns were loaded axially (0.5 mm/min) on the occlusal surface until fracture occurred. Results Among the 3Y-zirconia groups, the zinc phosphate cement group fractured at lower loads compared to the resin-based cement groups, with and without air-abrasion, (p < .012). Among the 5Y-groups the air-abraded crowns fractured at statistically significant lower loads compared to the untreated crowns (p < .028). Load at fracture values were significantly different between the two zirconia materials (p < .001), with fracture loads ranging from 3873 to 7500 N in the 3Y-groups, and 2100 to 4948 N in the 5Y-groups. Conclusions Resin-based cementation increased the fracture load compared to non-adhesive cementation. The 3Y-crowns fractured at almost twice the loads of the 5Y-crowns. Pre-treatment with air abrasion reduced the strength of the 5Y-crowns only, showing the importance of differentiating the treatment of the two materials.

Effect of Preheating Cycles on Microshear Bond Strength of Nanohybrid Resin Composite Luted to CAD/CAM Ceramic

Objective: This study aimed to investigate the microshear bond strength of adhesive resin cement to Leucite-reinforced CAD/CAM ceramic and compare it with that of prewarmed nanohybrid resin composite. Materials and methods: Sixty Empress CAD ceramic plates were prepared. Each ceramic plate received five Tygon tube micro-cylinders filled with bonding agents creating 5 resinous micro-cylinders on each ceramic plate. In the first group (GpA), they were filled with resin cement, nanohybrid resin composite as a bonding agent was applied in the second group (GpB), after warming at 50℃, in the third group (GpC), two prewarming cycles were performed. Light-curing for 20seconds was applied. Micro-shear bond strength testing (μSBS) was performed using universal testing machine with a crosshead speed of 1 mm/min until failure occurred. The μSBS was calculated in MPa by dividing the load (Newton) over the respective surface area (mm 2 ).Data were tabulated and analyzed and showed normal distribution when checked using Kolmogorov–Smirnov test. One-way ANOVA used to compare between the tested groups for μSBS data followed by Tukey HSD post-hoc test for pairwise comparisons. Significant level was set at 5% (α=0.05). Results: One- way ANOVA showed a significant difference between tested groups (p < 0.001). Where heated composite (two prewarming cycle) showed the highest mSBS compared to other groups (p < 0.05). Nevertheless, heated composite (one prewarming cycle) showed an improved μSBS compared to resin cement group, but the increase was insignificant (p=0.081). Conclusion: pre-heated nanohybrid resin composites seem to be a potential alternative to resin cement to lute ceramic restorations.

Pulp liner materials in selective caries removal: study protocol for a randomised controlled trial

IntroductionThe literature shows that selective carious tissue removal (SCTR) decreases the number and diversity of bacteria, stops the caries process and reduces the risk of pulp exposure. However, no consensus...