Cementation Technique Research Articles

A Systematic Review of Cementation Techniques to Minimize Cement Excess in Cement-Retained Implant Restorations.

Background: The most used types of retention of implant-supported prostheses are screw-retained or cement-retained restorations. The advantages and disadvantages of both have been identified by various authors over the years. However, cement-retained implant crowns and fixed partial dentures are among the most used types of restorations in implant prostheses, due to their aesthetic and clinical advantages. When cemented prostheses are made on implants, the problem of cement residues is important and often associated with biological implant pathologies. The objective of this research was to establish to what extent the techniques to reduce excess cement really affect the volume of cement residues. Materials and Methods: This review was written following the PRISMA statement; a detailed search was carried out in three different electronic databases—PubMed, Scopus, and Cochrane Library. The inclusion criteria were prospective clinical studies, with at least 10 participants per group, and with at least 6 months of the follow-up period. Results: There have been many proposals for techniques supposed to reduce the amount of excess cement in the peri-implant sulcus and on the prosthetic components, but of these, which are exceptional in their in vitro capabilities, very few have been clinically validated, and this represents the real limitation and a great lack of knowledge regarding this topic. Three articles met the inclusion criteria, which were analyzed and compared, to obtain the information necessary for the purposes of the systematic review. Discussion: Extraoral cementation can reduce the excess cement, which, after a normal excess removal procedure, is, nevertheless, of such size that it does not affect the possibility of peri-implant pathologies developing. All these studies concluded that a small amount of cement residue is found in the gingival sulcus, and using eugenol-free oxide cements, the residues were only deposited on the metal surfaces, with a better peri-implant tissues health. Conclusion: Despite the limitations of this study, it was possible to carefully analyze these characteristics and obtain valuable suggestions for daily clinical practice. Resinous cements are considered, due to the free monomers present in them, toxic for the soft tissues. The provisional zinc-oxide cements, also eugenol-free, represent the ideal choice. The different grades of retentive forces provided by these cements do not seem to have clinical effects on the decementation of restorations.

A Kinetic Study on Enhanced Cementation of Gold Ions by Galvanic Interactions between Aluminum (Al) as an Electron Donor and Activated Carbon (AC) as an Electron Mediator in Ammonium Thiosulfate System

The enhanced cementation technique by galvanic interaction of aluminum (Al; electron donor) and activated carbon (AC; electron mediator) to recover gold (Au) ions from the ammonium thiosulfate solution is a promising technique to eliminate the challenges of poor recovery in the system. This study presents the kinetics of Au ion cementation in an ammonium thiosulfate lixiviant as functions of initial Au concentration, size/amount of Al and AC, temperature, and shaking speed. The recovery results basically followed first order kinetics and showed that the cementation rate increased with a higher initial concentration of Au, smaller electron donor size, greater both electron donor and mediator quantity, decrease in temperature, and higher shaking speed in the system, while size of electron mediator did not significantly affect Au recovery.

Prosthetic Complications of Screw-Retained Restoration Using Multiunit Abutments Versus Intraoral Luting on Titanium Base in Implant-Supported Complete Overdentures Randomized Clinical Trial

BACKGROUND: This trial aims to study the difference between prostheses screwmented on full-arch implants using the intraoral luting cement technique on titanium bases versus transmucosal abutments in terms of prosthetic complications. MATERIALS AND METHODS: Twenty patients were recruited in this trial, there were mainly two groups. A screw-retained full-arch implant-supported prosthesis was constructed over four dental implants on upper or lower jaws. For the control group, multiunit abutments were used to construct a screw-retained prosthesis. As for the experimental group, Ti-base abutments were used over the dental implants to construct a screw-retained prosthesis. In both groups, the prosthetic framework was made using polyether ether ketone (PEEK) material and luted intraorally over the titanium sleeve using resin cement. A binary outcome of prosthetic complication was taken in 6 and 12 months. Abutment screw loosening, prosthetic screw loosening, prosthetic screw fracture, abutment screw fracture, veneer fracture, framework fracture, Ti-base decementation, and overall prosthetic loosening were the prosthetic complications included in the trial. RESULTS: At the end of the study, a total of 19 patients adhered to the trial. Throughout the exposure process of implants, two implants failed in one patient from the Ti-base group. This patient was excluded from the study on his request. There was no statistically significant difference present between Ti-base and multiunit abutment groups in terms of abutment and prosthetic screw loosening, abutment and prosthetic screw fracture, veneer and framework fracture, Ti-base decementation, and overall prosthesis loosening for 6 and 12 months. Data were explored for normality using Kolmogorov–Smirnov and Shapiro–Wilk tests, data showed non-parametric (not-normal) distribution. Qualitative data were presented as frequencies and percentages. Wilcoxon and Mann–Whitney tests were used to compare the qualitative outcomes in this study. CONCLUSION: Both multiunit and Ti-base are considered a viable line of treatment to construct a screw-retained full arch implant-supported prosthesis.

Ten years' follow-up for cemented hip arthroplasty in patients <60 years of age with standardization of cementing technique: A multicentric study

Introduction: Total hip arthroplasty (THA) is the preferred treatment for persistent disability due to hip pathologies and restoration of normal functions. Although there is a general consensus of using un-cemented implants for adults and elderly with good bone quality and cemented for senior citizen population, implant choice for middle aged group of 40 years to 60 years is still a subject of debate, especially in financial constrained situations. In our study, we have determined the implant survivorship and functional outcomes of cemented THA in patients between 40 and 60 years of age, at the minimum follow-up of 10 years with emphasis on standardization of cementing technique. Materials and Methods: This is a retrospective study including 25 patients who had undergone cemented hip arthroplasty. Data were collected from five different surgical centres, whose orthopedic surgeons had common surgical training and were following a common cementing technique. Results: Mean Harris Hip Score of 25 hips at final follow-up was 90 and Visual Analog Scale 1.88. The functional outcome was good to excellent at final follow-up in 89% hips. There was a significant improvement in pain and activity level after surgery (P < 0.001) and maintained at the final follow-up. Conclusion: Our series provides evidence for utility of cemented hip implants in low functional demand patients along with emphasizing the importance of a good cementing technique for the long-term survival of cemented hip arthroplasty in the age group of 40–60 years.

Cemented Polished Tapered Stems Have Lower Revision Rates Than Commonly Used Cementless Implant up to 17 Years of Follow-Up: An Analysis of 201,889 Total Hip Replacements From the Australian Orthopedic Association National Joint Replacement Registry.

Data assessing femoral stems may be influenced by grouping together matt and polished stems, despite their differing reported survivorship. The aim of this study is to assess the difference in revision rates between commonly used cemented and cementless stems when polished tapered stems are assessed independently of matt stems. Australian Orthopaedic Association National Joint Replacement Registry data from 1999 to 2019 were used to assess difference in revision rates between the 5 most commonly implanted femoral cemented and cementless stems for osteoarthritis. Cemented matt femoral stems, stems using line-to-line cementing techniques and procedures using non-cross-linked polyethylene, large head (>32 mm) metal-on-metal bearing surfaces or exchangeable necks were excluded. Cumulative percent revision was used to help compare survivorship between stems. There were 201,889 total hip replacements meeting the inclusion criteria, of which 50.0% were cemented and 50.0% cementless. Cemented stems had a lower rate of revision at all time points compared to cementless stems. This was most significant during the first 2 weeks (hazard ratio 0.48, 95% confidence interval 0.40-0.58, P < .001) compared to 2 weeks postoperatively and onwards (hazard ratio 0.85, 95% confidence interval 0.81-0.90, P < .001). A subanalysis of head size, bearing type, and surgeon volume further supported the use of a cemented stem. Commonly used cemented polished tapered stems have a lower revision rate when compared to commonly used cementless prostheses, and are recommended in all age groups for both low-volume and high-volume surgeons especially when head size 32 mm or smaller is used.

TOTAL HIP ARTHROPLASTY IN THE PUBLIC HEALTH SYSTEM OF SÃO PAULO: COMPARING TYPES OF FIXATION.

(i) to describe the demographic profile of patients who underwent THA in the public health system of the municipality of São Paulo during the last 12 years and (ii) to compare fixation methods regarding costs, hospital stay length, and death rates. This is an ecological study conducted with data available on TabNet, a platform belonging to DATASUS. Public data (from the government health system) on THA procedures performed in São Paulo from 2008 to 2019 were extracted. Gender, age, city region, THA fixation method, number of surgeries, costs, hospital stay length, and death rates were analyzed. We analyzed 7,673 THA, of which 6220 (81%) were performed via cementless/hybrid fixation and 1453 (19%), via the cemented technique. Cementless/hybrid fixation had a higher cost (US$ 495.27) than the cemented one (p < 0.001). Nevertheless, hospital stay length was 0.87 days longer for cemented fixation than the cementless/hybrid one. We found no significant difference in death rates between THA fixation methods. THA cementless/hybrid fixation is prevalent in the municipality of São Paulo, which had higher total costs and shorter hospitalizations than cemented fixation. We found no difference between THA fixation methods and death rates. Level of Evidence IV, Case Series.

Effect of intraradicular reinforcement strategies on the fracture strength of endodontically treated anterior teeth with overflared canals.

BackgroundThis study is done to evaluate the effect of different reinforcement techniques of overflared root canals with fiber posts on the fracture resistance of endodontically treated anterior teeth. It also introduces a new technique for simultaneous reinforcement and cementation of fiber posts using dual-cured core build-up composite resin. Material and MethodsThe crowns of 48 single-rooted maxillary anterior teeth were cut and randomly divided into 4 groups (n=12) based on root reinforcement techniques after root canal treatment and post space preparation: Group 1: self-adhesive resin cement (SARC), Group2: dual-cure composite resin (DCC), Group3: Composite resin reinforcement (CRR), Group 4: Direct anatomical post (DAP). Then a core was made for the roots. The periodontal ligament was simulated using a thin layer of PVC impression material. A universal testing machine applied a compressive force to the lingual surface at an angle of 135 ° and 1 mm/min speed. Data were analyzed using One-Way ANOVA and a post-hoc Tukey test. Fracture patterns were analyzed using the Chi-square test (p<0.05). ResultsThe difference between the control and DAP group was statistically significant (p=0.01), but there were no significant differences between other groups (p>0.05). Regarding fracture patterns, there were no significant differences between groups. ConclusionsAll reinforcement techniques increased the fracture strength compared to the control group. However, DAP was the only group that had a statistically significant difference. CRR and DCC presented intermediate values without significant differences. Key words:Fiber post, endodontically treated teeth, root canals, reinforcement, fracture strength.

Is the French Paradox cementing philosophy superior to the standard cementing? A randomized controlled radiostereometric trial and comparative analysis.

AimsHighly polished stems with force-closed design have shown satisfactory clinical results despite being related to relatively high early migration. It has been suggested that the minimal thickness of cement mantles surrounding the femoral stem should be 2 mm to 4 mm to avoid aseptic loosening. The line-to-line cementing technique of the femoral stem, designed to achieve stem press-fit, challenges this opinion. We compared the migration of a highly polished stem with force-closed design by standard and line-to-line cementing to investigate whether differences in early migration of the stems occur in a clinical study.MethodsIn this single-blind, randomized controlled, clinical radiostereometric analysis (RSA) study, the migration pattern of the cemented Corail hip stem was compared between line-to-line and standard cementing in 48 arthroplasties. The primary outcome measure was femoral stem migration in terms of rotation and translation around and along with the X-, Y-, and Z- axes measured using model-based RSA at three, 12, and 24 months. A linear mixed-effects model was used for statistical analysis.ResultsResults from mixed model analyses revealed a lower mean retroversion for line-to-line (0.72° (95% confidence interval (CI) 0.38° to 1.07°; p < 0.001), but no significant differences in subsidence between the techniques (-0.15 mm (95% CI -0.53 to 0.227; p = 0.429) at 24 months. Radiolucent lines measuring < 2 mm wide were found in three and five arthroplasties cemented by the standard and line-to-line method, respectively.ConclusionThe cemented Corail stem with a force-closed design seems to settle earlier and better with the line-to-line cementing method, although for subsidence the difference was not significant. However, the lower rate of migration into retroversion may reduce the wear and cement deformation, contributing to good long-term fixation and implant survival.Cite this article: Bone Joint J 2022;104-B(1):19–26.

A comprehensive review on bonding between monolithic ceramics and tooth structure with different adhesive agents.

Reliable bonding between the prepared tooth and monolithic ceramics can be achieved by various luting agents available on the market. The selection of luting agent and cementation technique plays an important role in the success of the restoration. With the advent of resin-based adhesive systems as luting agents, clinicians' perspectives have changed to a more conservative approach. Recent systems, chemically adhere athe crowns to the prepared tooth structure showing higher bond strength. To reach the aesthetic demands of the patients, all-ceramic restorations were considered over metal-ceramic crowns. Few all-ceramic crowns are brittle, the strength is dependent on the chemical structure and method of fabrication. While some all-ceramic restorations gain strength after cementation. Thus, the choice of luting agent used in cementing all-ceramic crowns is crucial. Even though many luting agents are being introduced no single luting agent fulfilled all the requirements. Among them, adhesive cements showed greater bond strength and enhanced the retention of minimal preparation, which are less retentive. Traditional non-adhesive agents can be used in retentive preparations that bond through mechanical means rather than the chemical bond seen in newer adhesive cements. Also, surface treatments of zirconia showed greater bond strengths irrespective of the luting agent being used. These include air abrasion, acid etching, applying silane couplers, and primers that increase the surface area for adhesion. The use of all-ceramic restorations, the need for surface treatments, types of surface treatments, adhesion and adhesive agents, and evidence from current in vitroresearch on monolithic ceramics and tooth adhesion were all discussed in this review.

Varus Collapse in Total Knee Arthroplasty: Does Fixation or Bone Fail First?

Aseptic tibial loosening is now considered the most common reason that total knee arthroplasties (TKA) fail long term. There are unique subsets of patients that fail into varus alignment of the tibial tray with collapse of the medial proximal tibia. It is currently unknown if the implant fixation fails first or if the proximal medial tibia collapses first. We performed a retrospective analysis of 88 patients that were revised at our institution secondary to aseptic varus collapse of the proximal tibia. Two fellowship-trained arthroplasty surgeons performed a retrospective analysis on sequential precollapse radiographs in each patient to determine which failed first: the implant fixation (implant-cement or cement-bone interface) or the medial proximal tibia. 36/88 (40.9%) patients had a series of precollapse radiographs that could be reviewed. Failure at the implant-cement interface before varus collapse in 23 vs 22 patients, failure at the implant-cement and cement-bone interface before varus collapse in two patients, and contemporaneous failure at the implant-cement interface and varus collapse in 11 vs 12 patients were identified by reviewers one and two, respectively. The most frequent mechanism of failure identified was failure of the implant-cement interface followed by subsequent medial tibial varus collapse. Improving implant fixation may decrease the incidence of this unique failure mechanism. We advocate the use of supplemental stem fixation in high-risk patients and optimal cement techniques for all patients as methods of potentially avoiding tibial varus collapse, one of the most frequent modes of long-term failure.

Pulsatile Lavage Systems with High Impact Pressure and High Flow Produce Cleaner Cancellous Bone Prior to Cementation in Cemented Arthroplasty.

In cemented joint arthroplasty, state-of-the-art cementing techniques include high-pressure pulsatile saline lavage prior to cementation. Even with its outstanding importance in cementation, there are surprisingly few studies regarding the physical parameters that define pulsatile lavage systems. To investigate the parameters of impact pressure, flow rate, frequency and the cleaning effect in cancellous bone, we established a standardized laboratory model. Standardized fat-filled carbon foam specimens representing human cancellous bone were cleaned with three different high-pressure pulsatile lavage systems. Via CT scans before and after cleaning, the cleaning effect was evaluated. All systems showed a cleaning depth of at least 3.0 mm and therefore can be generally recommended to clean cancellous bone in cemented joint arthroplasty. When comparing the three lavage systems, the study showed significant differences regarding cleaning depths and volume, with one system being superior to its peer systems. Regarding the physical parameters, high impact pressure in combination with high flow rate and longer distance to the flushed object seems to be the best combination to improve the cleaning of cancellous bone and therefore increase the chances of a deeper cement penetration that is required in cemented joint arthroplasty. In summary, this study provides the first standardized comparison of different lavage systems and thus gives initial guidance on how to optimally prepare cancellous bone for cemented joint arthroplasty.

Application of Semipermanent Cements and Conventional Cement with Modified Cementing Technique in Dental Implantology.

ObjectivesThe aim of this study was to evaluate the influence of artificial ageing on the retention force of original semipermanent cements, as well as the possibility of using conventional cements for semipermanent cementation with adequate modification of the cementing protocol.Materials and methodsForty CoCrMo alloy crowns were divided in four groups (each group n=10) and fixed with two semipermanent cements (resin-based and glass ionomer-based cements) and one conventional (zinc phosphate), using conventional and modified cementation techniques on titanium abutments. The samples were stored in humid conditions for 24 hours at 37°C and subjected to thermocycling (500 cycles) and mechanical cyclic loading (7 days, 3, 6, 9 and 12 months function simulation). The cast crowns were removed and the retention force was recorded.ResultsThe highest initial retention force measured was for zinc-phosphate cement - conventional cementing (198,00±61,90 N), followed in descending order by zinc-phosphate cement - modified cementing technique (152,00±45,42 N), long term temporary cement – GC Fuji Temp LT (57,70±20,40 N), and semipermanent cement - Telio CS Cem Implant (56,10±18,68 N). After 12 months, the highest retention force measured was for zinc-phosphate cement - conventional cementing (88, 90±14, 45 N), followed by zinc-phosphate cement – modified cementing (48, 15±14,41N), semipermanent cement GC Fuji Temp LT (16,55±3,88 N) and Telio CS Cem Implant (15,55±5,52 N).ConclusionsZinc-phosphate cement - modified cementing technique and original semipermanent cements can be recommended for conditional permanent cementing of implant supported crowns.Clinical relevanceThe use of semipermanenet cements and zinc-phosphate cement - modified cementing technique provides a predictable retrievability of implant-supported crowns.

Luting indirect restorations with resin cements versus composite resins: Effects of preheating and ultrasound energy on film thickness.

This study aims to evaluate and compare the film thickness obtained with a resin cement and two composite resins, preheated and/or ultrasonically vibrated, as luting agents. One hundred and twenty-six (126) pairs of resin discs were randomly assigned to six experimental groups (n= 21) according to luting agent (Variolink Esthetic LC, IPS Empress Direct or Estelite Omega) and cementation technique (preheating at 68°C and/or ultrasonic vibration). Specimens were luted by applying a controlled force. Following sectioning and film thickness measurement through field emission gun scanning electron microscopy, statistical analysis was carried out considering a 5% significance level. Statistically significant lower film thickness was observed in Variolink Esthetic LC group when compared to all composite resin groups (p< 0.001), except IPS Empress Direct preheated and ultrasonically vibrated group (p = 0.073). IPS Empress Direct with ultrasonic vibration yielded statistically lower film thickness values than Estelite Omega groups, regardless of luting technique (p< 0.05). Ultrasonically vibrated Estelite Omega groups showed statistically lower film thickness values than solely preheated groups (p< 0.05). Both Variolink Esthetic LC and IPS Empress Direct preheated and ultrasonically vibrated provided the lowest film thickness. The addition of ultrasonic vibration during cementation proved to be effective in reducing film thickness of both tested composite resins. The cementation technique will have variable results depending on the luting material. Adhesive cementation protocols with composite resins should mainly consider ultrasonic vibration, but also preheating, as strategies for reducing film thickness. The tested resin cement, alongside with IPS Empress Direct composite resin preheated and ultrasonically vibrated, provided the lowest film thickness among the tested materials and techniques.

A Review and Description of Acetabular Impaction Bone Grafting: Updating the Traditional Technique

Restoring acetabular bone loss in revision hip arthroplasty is a major challenge for the orthopaedic surgeon. This paper discusses the traditional cemented technique of impaction bone grafting as applied to the acetabulum, as well as the evolution of the technique to employ uncemented implants. Some of the recent published literature regarding these techniques is reviewed and the personal experiences of the senior author with these techniques are also reported.

Cementation of a dual mobility cup in a well-fixed acetabular component- a reliable option in revision total hip arthroplasty?

BackgroundThe “cup-in-cup” technique allows for revision of failed total hip arthroplasty (THA) when the cementless cup is well fixed. Furthermore, it can be used for liner wear or mechanical failure where liner replacement may be impossible or impractical. Recently, the “cup-in-cup” technique in combination with dual mobility cups (DMC) has drawn increased attention. Our aim was to report on the clinical and radiographic outcomes following this surgery.MethodsFrom 2015 to 2020, 33 patients treated with the DMC- “cup in cup” technique were retrospectively reviewed. Fourteen patients had died while 19 were available for the final follow-up (FU), of which 15 underwent both a radiograph and a FU visit, 2 underwent a radiograph only and 2 underwent a telephone interview only. Patient-related outcome measures included the HHS and the WOMAC. Radiographs were assessed for implant loosening and positioning. Primary endpoint was revision of any cause and secondary endpoint was loosening of the DMC at the latest FU. The survival analysis was conducted using the Kaplan-Meier method.ResultsThe mean age at surgery was 78.6 ± 7.1 (63–93) years and the mean surgery duration was 124.4 ± 52.0 (60–245) minutes. Recurrent dislocation (42.4%), periprosthetic fracture (39.4%) and polyethylene wear (6.1%) were the most frequent reasons for surgery. The mean FU duration (n = 19) was 28.5 ± 17.3 (3–64) months. The mean HHS score at FU was 59.4 ± 22.2 (29–91) and the mean WOMAC score was 59.7 ± 25.6 (15.6–93.8).Two cups were revised due to instability and one revision was performed due to periprosthetic joint infection, accounting for an overall cup survival rate of 86.8% after a mean FU of 22.9 ± 18.0 (1.5–64.6) months. The survival rate free of loosening was 90.9% after a mean FU of 22.3 ± 18.5 (1.5–64.7) months.ConclusionsWe found that the cementation of a DMC in a well-fixed cup is a promising short- to mid-term treatment addressing THA instability especially in elderly and frail patients, who benefit from a reduced operation time. Proper cementation technique, adequate cup positioning as well as selection of a sufficiently large DMC are crucial for treatment success. Longer FUs will be needed in the future in order to further prove the benefit of this technique.

Does Additive Pressurized Carbon Dioxide Lavage Improve Cement Penetration and Bond Strength in Cemented Arthroplasty?

The modern cementing technique in cemented arthroplasty is a highly standardized and, therefore, safe procedure. Nevertheless, aseptic loosening is still the main reason for revision after cemented total knee or cemented total hip arthroplasty. To investigate whether an additional carbon dioxide lavage after a high-pressure pulsatile saline lavage has a positive effect on the bone–cement interface or cement penetration, we set up a standardized laboratory experiment with 28 human femoral heads. After a standardized cleaning procedure, the test implants were cemented onto the cancellous bone. Subsequently, the maximum failure load of the bone–cement interface was determined using a material testing machine to pull off the implant, and the cement penetration was determined using computed tomography. Neither the maximum failure load nor cement penetration into the cancellous bone revealed significant differences between the groups. In conclusion, according to our experiments, the additive use of the carbon dioxide lavage after the high-pressure pulsatile lavage has no additional benefit for the cleaning of the cancellous bone and, therefore, cannot be recommended without restrictions.

Polymethyl methacrylate cure time in simulated in vivo total knee arthroplasty versus in vitro conditions

BackgroundThe present means of confirming the cure of intra-operative polymethyl methacrylate (PMMA) cement are to wait for the remainder cement to harden. To our knowledge, there is no available technique to determine the precise moment of cure for in-vivo cement beneath the tibial tray. This study uses a novel means to determine cement curing time in two environments. One environment represents the operating theater, and the other environment attempts to model cement conditions under the tibial tray during surgery.Materials and methodsWe determined the temperature-versus-time plot of cement curing using the following two temperature sensors: one in a simulated implanted tibial tray and another in the remainder cement. We performed 55 tests using dental methyl methacrylate cement mixed in the same ratio as the orthopedic cement. To simulate in vivo conditions, a simulated stainless-steel tibial tray was implanted on a cancellous bone substitute (Sawbones, Vashon Island, WA, USA) using standard cement technique and subsequently placed in a 90°F (32.2 °C) circulating water bath. We positioned a temperature sensor in the cement mantel and positioned a second sensor in a portion of the remaining cement. The temperature from both sensors was measured simultaneously, beginning at 5 min after mixing and continuing for 20 min. The first derivative of the temperature provided the precise curing time for each condition. We analyzed the results of 55 repeated experiments with an independent samples t-test.ResultsWith the described technique, we were able to accurately determine the moment of cure of the cement beneath the simulated tray. There was a mean difference between cure time of 5 min and 26 s (p value < 0.001) between the two conditions.ConclusionsWe validated that our technique was successful in determining the precise time to cure in two different environments.Level of evidenceThis was not a clinical trial and did not involve patients as such the level of evidence was Grade A: Consistent 1 and 2.

Hydroxyapatite cement cranioplasty for reconstruction of translabyrinthine approach: aesthetic results, long-term satisfaction, quality of life, and complications.

Translabyrinthine approaches (TLAs) for resection of skull base neoplasms are complex with variable reconstruction techniques. Fat grafts in conjunction with hydroxyapatite bone cement techniques have seldom been described in terms of possible superiority to other skull base reconstruction techniques. We sought to determine the impact of this skull base reconstruction technique on clinical outcomes and patient's satisfaction. We performed a retrospective analysis of all patients who underwent translabyrinthine approaches for resection of CPA lesions over a 5-year period. Both post-op objective and subjective markers of reconstruction, as well as postoperative complications, were collected and analyzed. Sixty-nine patients were included, 34 underwent reconstruction with hydroxyapatite and fat (rHAC) and 35 with fat alone (rF). rHAC was associated with fewer cranial wound superficial infection/dehiscence (0% vs 14.3%; p = 0.029) and shorter length of stay (mean ± standard deviation) (6.9 ± 7.4 vs 4.4 ± 3.7days, p = 0.008). Postoperative subjective characterization of rHAC demonstrated improved satisfaction scores (1.38 ± 0.5 vs 1.83 ± 1; p = 0.049) and fewer reports of post-operative irregularities (11.5% vs 37.5%; p = 0.017). The use of hydroxyapatite for cranial reconstruction after translabyrinthine approaches has improved patient satisfaction and decreased cranial defects in our small series. Postoperative complications are consistent with other described methods, but with shorter hospital stay, decreased risk of superficial wound dehiscence/infection, and a perceived superiority in preventing percutaneous post-op CSF leaks.

Fracture Resistance and Strain Analysis of Zirconia Copings With Vertical Knife Edge and Three Horizontal Finish Line Designs; Chamfer, Deep Chamfer and Shoulder With Two Cementation Techniques

Objective: The purpose of this in vitro study is to evaluate the effect of four finish line configurations and two cement types on the fracture resistance of zirconia copings. Material and Methods: Forty yttrium tetragonal zirconia polycrystals copings were manufactured on epoxy resin dies with four preparation designs: knife edge, chamfer, deep chamfer 0.5, 1 mm and shoulder 1 mm. The copings were cemented with two cement types (glass ionomer and resin cement); (n = 5). Two strain gauges were attached on each coping before they were vertically loaded till fracture with a universal testing machine. Data were analyzed by 2-way analysis of variance ANOVA (p &lt; .05). Fractured specimens were examined for mode of failure with digital microscope. Results: Knife edge showed the highest mean fracture resistance (987.04 ± 94.18) followed by Chamfer (883.28 ± 205.42) followed by Shoulder (828.64 ± 227.79) and finally Deep chamfer finish line (767.66 ± 207.09) with no statistically significant difference. Resin cemented copings had higher mean Fracture resistance (911.76 ± 167.95) than glass ionomer cemented copings (821.55 ± 224.24) with no statistically significant difference. Knife edge had the highest strain mean values on the buccal (374.04 ± 195.43) and lingual (235.80 ± 103.46) surface. Shoulder finish line showed the lowest mean strain values on the buccal (127.47 ± 40.32) and lingual (68.35 ± 80.68) with no statistically significant difference. Resin cemented copings had higher buccal (295.05 ± 167.92) and lingual (197.38 ± 99.85) mean strain values than glass ionomer copings (149.14 ± 60.94) and (90.27 ± 55.62) with no statistically significant difference. Conclusion: Vertical knife edge finish line is a promising alternative and either adhesive or conventional cementation can be used with zirconia copings. KEYWORDS Cementation; Flexural strength; Prosthodontics; Tooth preparation; Zirconium.

CORR Insights®: Does the Risk of Death Within 48 Hours of Hip Hemiarthroplasty Differ Between Patients Treated with Cemented and Cementless Implants? A Meta-analysis of Large, National Registries.

CORR Insights®: Does the Risk of Death Within 48 Hours of Hip Hemiarthroplasty Differ Between Patients Treated with Cemented and Cementless Implants? A Meta-analysis of Large, National Registries.