[Cement in revision arthroplasty-what about the "glacier effect"? : Case studies viewed from different perspectives]. / Zement in der Revisionsendoprothetik ­ Was ist mit dem "Gletschereffekt"? : Fallbeispiele aus unterschiedlichen Perspektiven betrachtet.

BACKGROUND: The number of operations concerning revision arthroplasty has been increasing continuously in recent years, and it can be assumed that they will continue to increase in the future. If an arthroplasty implant becomes loose, it must be changed. The question often arises as to how the new implant should be fixed in the bone. ADVANTAGES: Revision implants can be inserted into the bone without cement. In the subsequent period, a secondary osseointegration of the implant takes place. Another possibility is to anchor the implant by using bone cement. The advantage of cemented anchorage is that the implant is firmly fixed in the bone, in principle, immediately, and it is possible to fully load the implant directly. Direct postoperative full weight bearing is helpful, especially for older and multimorbid patients, in order to achieve rapid mobilization. PREREQUISITES AND CHALLENGES: When using cement in revision cases, however, there are a few prerequisites and challenges that the surgeon should definitely take into account. In the case of revision, the bone in the former implant bed is often deficient and appears thinned and sclerosed. It is, therefore, important to analyze the bone quality preoperatively on radiographic images and to include it in the planning of the anchoring strategy. In addition, the individual bone quality of the patient must also be taken into account intraoperatively. In any case, it must be clarified whether the basic prerequisites for the sufficient bond strength of the cement with the bone to be formed can still be met. Furthermore, the principles of cementing technique must be strictly observed, and the goal of a perfect cement mantle must be aimed for. If the indication for this is overstated, early loosening of the cemented revision arthroplasty is very likely.

Formulations of NaOCl-based in liquid, gel form or with surfactants on dentin deproteinization before fiber post cementation.

The objective of the study was to evaluate the effects of dentin deproteinization protocols for post space using different formulations containing sodium hypochlorite before fiber post cementation with self-adhesive resinous cement. The groups were divided according to the irrigation protocol (DWC, SHS, SHT and SHG). The residue cleanliness, bond strength, adhesive failure pattern, and tag formation at the adhesive interface between the self-adhesive cement and the dentin were evaluated. For this, analysis in scanning electron microscope, push-out test and confocal laser scanning microscopy were performed. The SHT protocol showed the highest residue cleanliness on the dentin surface of the post space (p<0.05). In addition, SHT protocol showed highest bond strength and tag formation in the cervical and middle thirds (p<0.05). Dentin deproteinization with sodium hypochlorite with surfactant provided the best dentin cleaning of residues, bond strength and tag formation after cementation of the fiber post with self-adhesive cement.

Influence of cement type, excess removal, and polishing on the cement joint.

OBJECTIVES: To compare marginal gap width and depth with different cementation systems, excess removal, and after polishing. METHOD AND MATERIALS: In total, 80 composite crowns were milled, divided into ten groups, and cemented on identical artificial teeth. Eight crowns per group were fixed with (i) zinc phosphate cement (ZnOPh), (ii) glass-ionomer cement (GIC), (iii) resin-reinforced glass-ionomer cement (GIC mod), (iv) dual-curing adhesive composite (Comp dual), or (v) dual-curing self-adhesive composite (Comp SE dual). Excess removal was performed with a scaler after brief light-cure (tack-cure), final light-cure, during rubber or gel phase or by wiping with foam pellet. Curing was completed in chemical, dark cure, or light-curing modus. The specimens were polished and stored in water (37°C). The margins were digitized using a 3D laser-scanning microscope (VK-X100 series, Keyence). The width and the depth of the marginal gap were measured at 10 points between the crown margin and the preparation margin. RESULTS: The width after excess removal varied between 65.1 ± 15.7 µm (Comp dual, wipe, with polishing) and 208.6 ± 266.7 µm (Comp SE dual, dark cure, without polishing). The depth varied between 29.8 ± 22.2 µm (Comp dual, wipe, with polishing) and 89.5 ± 45.2 µm (Comp SE dual, dark cure, without polishing). The impact on gap width and depth was detected for fixation material, excess removal, and polishing. CONCLUSION: The gap depth and width depend on the luting material and the mode of access removal. Polishing can improve the gap quality, especially for GIC and resin-based systems.

Ablación tumoral y cementación en el tratamiento de las metástasis vertebrales. Estudio multicéntrico / Tumor ablation and vertebral augmentation in the treatment of vertebral metastases: A multicenter study

Introducción: El tratamiento de las fracturas vertebrales metastásicas sin compresión neural se realiza con técnicas percutáneas de cementación. El aumento de presión intratumoral por estas técnicas puede enviar células tumorales al torrente sanguíneo. Para evitar esa diseminación y mejorar el tratamiento del dolor se han introducido las técnicas de ablación que permitirían crear una cavidad en el tumor previo a la cementación o directamente necrosar la metástasis cuando el tamaño es pequeño. Material: Presentamos la experiencia con la ablación de dos hospitales y dos técnicas de ablación distintas. El primer grupo usó la ablación por radiofrecuencia (ARF) en 14 pacientes (26 vértebras) de los cuales en cuatro se asoció una artrodesis vertebral. El segundo grupo usó la ablación por microondas (AMO); 93 pacientes (129 lesiones) sin asociar instrumentación vertebral. Resultados: En el grupo de ARF la mejoría del dolor en la escala visual analógica (EVA) fue de 7,7 a 2,6 a las seis semanas. No hubo complicaciones derivadas de la ablación. En la mayoría de los casos se asoció la cementación. En el grupo de AMO la mejoría del dolor en EVA pasó de 6,8 a 1,7 a las seis semanas. En todos los casos se asoció la cementación. No hubo complicaciones derivadas de la ablación. Conclusiones: La asociación de las técnicas de ablación a la cementación vertebral es una técnica segura, que permite mejorar notablemente el dolor del paciente y puede ayudar al control de la enfermedad.(AU)

Introduction: Treatment of metastatic vertebral fractures without neural compression is performed with percutaneous cementation techniques. The increase in intratumoral pressure by these techniques can send tumor cells into the bloodstream. To prevent this dissemination and improve pain treatment, ablation techniques have been introduced that would allow the creation of a cavity in the tumor prior to cementation or directly necrosing the metastasis when its size is small. Material: We present the experience with ablation of two hospitals and two different ablation techniques. The first group used radiofrequency ablation (A) in 14 patients (26 vertebrae), 4 of whom underwent vertebral arthrodesis. The second group used microwave ablation (B) in 93 patients (129 lesions) without associated vertebral instrumentation. Results: In group A pain improvement in VAS was 7.7–2.6 at 6 weeks. There were no complications derived from the ablation. In most cases cementation was associated. In the group B pain improvement in VAS went from 6.8–1.7 at 6 weeks. Cementation was associated in all cases. There were no complications derived from the ablation. Conclusion: The association of ablation techniques with vertebral cementation is a safe technique that significantly improves the patient's pain and can help control the disease.(AU)

[Translated article] Tumor ablation and vertebral augmentation in the treatment of vertebral metastases: A multicenter study / Ablación tumoral y cementación en el tratamiento de las metástasis vertebrales. Estudio multicéntrico

Introducción: El tratamiento de las fracturas vertebrales metastásicas sin compresión neural se realiza con técnicas percutáneas de cementación. El aumento de presión intratumoral por estas técnicas puede enviar células tumorales al torrente sanguíneo. Para evitar esa diseminación y mejorar el tratamiento del dolor se han introducido las técnicas de ablación que permitirían crear una cavidad en el tumor previo a la cementación o directamente necrosar la metástasis cuando el tamaño es pequeño. Material: Presentamos la experiencia con la ablación de dos hospitales y dos técnicas de ablación distintas. El primer grupo usó la ablación por radiofrecuencia (ARF) en 14 pacientes (26 vértebras) de los cuales en cuatro se asoció una artrodesis vertebral. El segundo grupo usó la ablación por microondas (AMO); 93 pacientes (129 lesiones) sin asociar instrumentación vertebral. Resultados: En el grupo de ARF la mejoría del dolor en la escala visual analógica (EVA) fue de 7,7 a 2,6 a las seis semanas. No hubo complicaciones derivadas de la ablación. En la mayoría de los casos se asoció la cementación. En el grupo de AMO la mejoría del dolor en EVA pasó de 6,8 a 1,7 a las seis semanas. En todos los casos se asoció la cementación. No hubo complicaciones derivadas de la ablación. Conclusiones: La asociación de las técnicas de ablación a la cementación vertebral es una técnica segura, que permite mejorar notablemente el dolor del paciente y puede ayudar al control de la enfermedad.(AU)

Introduction: Treatment of metastatic vertebral fractures without neural compression is performed with percutaneous cementation techniques. The increase in intratumoral pressure by these techniques can send tumor cells into the bloodstream. To prevent this dissemination and improve pain treatment, ablation techniques have been introduced that would allow the creation of a cavity in the tumor prior to cementation or directly necrosing the metastasis when its size is small. Material: We present the experience with ablation of two hospitals and two different ablation techniques. The first group used radiofrequency ablation (A) in 14 patients (26 vertebrae), 4 of whom underwent vertebral arthrodesis. The second group used microwave ablation (B) in 93 patients (129 lesions) without associated vertebral instrumentation. Results: In group A pain improvement in VAS was 7.7–2.6 at 6 weeks. There were no complications derived from the ablation. In most cases cementation was associated. In the group B pain improvement in VAS went from 6.8–1.7 at 6 weeks. Cementation was associated in all cases. There were no complications derived from the ablation. Conclusion: The association of ablation techniques with vertebral cementation is a safe technique that significantly improves the patient's pain and can help control the disease.(AU)

The load capacity of maxillary central incisor with simulated flared root canal restored with different fiber-reinforced composite post and cementation protocols.

Background: This study aimed to evaluate the load capacity of maxillary central incisors with simulated flared root canal restored with different fiber-reinforced composite (FRC) post cemented with either self-adhesive or self-etch resin cement and its mode of fracture. Methods: Sixty-five extracted maxillary incisors were decoronated, its canal was artificially flared and randomly categorized into group tFRC (tapered FRC post) (n = 22), mFRC (multi-FRC post) (n = 21), and DIS-FRC (direct individually shaped-FRC (DIS-FRC) post) (n = 22), which were further subdivided based on cementation resin. The posts were cemented and a standardized resin core was constructed. After thermocycling, the samples were loaded statically and the maximum load was recorded. Results: The load capacity of the maxillary central incisor was influenced by the different FRC post system and not the resin cement (p = 0.289), and no significant interaction was found between them. Group mFRC (522.9N) yielded a significantly higher load capacity compared to DIS-FRC (421.1N). Overall, a 55% favorable fracture pattern was observed, and this was not statistically significant. Conclusion: Within the limitation of the study, it can be concluded that prefabricated FRC posts outperform DIS-FRC posts in terms of the load capacity of a maxillary central incisor with a simulated flared root canal. The cementation methods whether a self-adhesive or self-etch resin cement, was not demonstrated to influence the load capacity of a maxillary central incisor with a flared root canal. There were no significant differences between the favorable and non-favorable fracture when FRC post systems were used to restored a maxillary central incisor with a flared root canal.

[The third-generation modern cementing technique in hip and knee arthroplasty]. / Moderne Zementiertechnik der dritten Generation in der Knie- und Hüftendoprothetik.

BACKGROUND: Implant loosening is the most common reason for revision surgery. OBJECTIVES: Contribution of modern cementing technique to the long-term stability of an implant. METHODS: Evaluation of the available evidence on modern cementing technique. RESULTS: Modern cementing technique in hip arthroplasty is considered established and leads to better cementing results. In knee arthroplasty, there are also specific recommendations, including intensive cleaning of the bone bed, mixing of bone cement under vacuum and application of bone cement to the implant and the bone. CONCLUSIONS: The use of modern cementing technique in hip and knee arthroplasty facilitates cementing, increases safety, and minimizes the risk of mechanical loosening.

Effect of sodium hypochlorite-based formulations on the adhesion interface after fiber post cementation.

The study evaluated the persistence of residues, bond strength and tags formation of a cementation system after post-space irrigation with different sodium hypochlorite-based irrigants. The groups were divided according to the irrigation protocol (DW: distilled water; SHS: sodium hypochlorite solution; SHG: sodium hypochlorite gel; and, SHT: sodium hypochlorite with surfactant). Forty roots (n=10) were used to evaluate the persistence of residues by scanning electron microscopy. Other forty roots were used to the push-out bond strength test, failure mode and tag formation analyses. Non-parametric data were submitted to Kruskal Wallis and Dunn tests, while parametric data were evaluated by one-way ANOVA. No difference was observed in the persistence of residues. DW showed the highest bond strength and tag formation. Type 2 failure mode was the most frequent in the experimental groups. Compared to control, SHT showed the best performance, since less negative effects on adhesive interface was observed.

Efeito de diferentes irrigantes finais na resistência união de um cimento de silicato de cálcio: estudo in vitro / Effect of different final irrigants on the bond strength of a calcium silicate cement : in vitro study

Objetivo: Este estudo teve como objetivo avaliar a resistência de união do cimento Biodentine® à dentina radicular após a utilização de diferentes irrigantes finais. Método: Vinte dentes humanos extraídos tiveram seu terço médio radicular cortado em fatias que foram submersas em hipoclorito de sódio 2,5% e posteriormente divididas aleatoriamente em 4 grupos experimentais (n=15) conforme o irrigante final utilizado (1) água destilada (controle), (2) QMixTM, (3) ácido cítrico 10%, (4) EDTA 17%. Após a imersão na substância teste as amostras foram preenchidas com o cimento Biodentine e imersas em solução salina tamponada com fosfato (PBS) por um período de 7 dias. O teste de push out foi realizado e os valores de resistência de união em Mpa foram obtidos. Os dados foram analisados pelos testes de Kruskal Wallis e Studend- Newman-Keuls. Resultados: Os piores valores de união foram obtidos após a utilização do EDTA enquanto a água destilada, o QMix e o ácido cítrico apresentaram resultados estatisticamente semelhantes entre si. Conclusão: A remoção da smear layer não resultou em melhora nos resultados de união do cimento Biodentine.(AU)

Objective: This study aimed to evaluate the bond strength of Biodentine® cement to root dentin after the use of different final irrigants. Method: Twenty extracted human teeth had their middle root third cut into slices that were submerged in 2.5% sodium hypochlorite and then randomly divided into 4 experimental groups (n=15) according to the final irrigant used (1) distilled water (control), (2) QMixTM, (3) 10% citric acid, (4) 17% EDTA. After immersion in the test substance the samples were filled with Biodentine cement and immersed in phosphate buffered saline (PBS) for a period of 7 days. The push out test was performed and the bond strength values in MPa were obtained. The data were analyzed by Kruskal Wallis and Studend- Newman-Keuls tests. Results: The worst bond values were obtained after using EDTA while distilled water, QMix and citric acid showed statistically similar results to each other. Conclusion: Removal of the smear layer did not result in improved bonding results of Biodentine cement.(AU)

Root filling quality and bond strength of endodontic sealers to human and bovine dentin / Qualidade da obturação e resistência de união de cimentos endodônticos à dentina humana e bovina

Objetivo: Este estudo teve como objetivo comparar a qualidade da obturação e a resistência de união de dois cimentos endodônticos, AH Plus e Bio-C Sealer, em dentes humanos e bovinos. Métodos: Os canais radiculares de 60 dentes unirradiculares [30 humanos (H) e 30 bovinos (B)] foram preparados e obturados por condensação lateral da guta-percha e AH Plus (grupos AP-H e AP-B) ou Bio-C Sealer (grupos BC-H e BC-B). Seis fatias de 1,5 mm de espessura foram obtidas de cada raiz. Os espécimes foram observados em estereomicroscópio para avaliar a qualidade da obturação, considerando possíveis espaços vazios no material obturador. Posteriormente, as fatias radiculares foram avaliadas em termos de resistência de união por push-out e modo de falha. Os dados foram analisados pelos testes de Mann-Whitney e coeficientes de correlação de Spearman (α=5%). Resultados: A qualidade de obturação fornecida por AP e BC foi semelhante em ambos os substratos de dentina. No entanto, ao comparar dentes humanos e bovinos, os escores de espaços vazios foram maiores nas amostras bovinas, para ambos os cimentos. AP teve maior resistência de união à dentina humana e bovina do que BC. No entanto, não houve diferença significativa na resistência de união entre os substratos dentinários, para ambos os cimentos testados. Além disso, houve uma correlação positiva e moderada entre os valores de resistência de união de dentes humanos e bovinos. O modo de falha misto foi o mais prevalente. Conclusão: AP e BC fornecem qualidade de obturação semelhante, mas o primeiro apresenta maiores valores de resistência de união à dentina humana e bovina. A utilização de dentes bovinos como substitutos de amostras humanas parece ser adequada em estudos relacionados à resistência de união, mas não naqueles que testam a qualidade da obturação endodôntica.(AU)

Objective: This study aimed to compare the filling quality and bond strength of two endodontic sealers, AH Plus and Bio-C Sealer, in human and bovine teeth. Methods: The root canals of 60 [30 human (H) and 30 bovine (B)] single-rooted teeth were prepared and filled by lateral condensation of gutta-percha and AH Plus (groups AP-H and AP-B) or Bio-C Sealer (groups BC-H and BC-B). Six 1.5-mm-thick slices were obtained from each root. The specimens were observed under a stereomicroscope to assess filling quality, considering possible voids within the filling material. Subsequently, root slices were evaluated in terms of push-out bond strength and failure mode. Data were analyzed by Mann-Whitney tests and Spearman correlation coefficients (α=5%). Results: The filling quality provided by AP and BC was similar in both dentin substrates. However, when comparing human and bovine teeth, void scores were greater in the bovine samples, for both sealers. AP had higher bond strength to human and bovine dentin than BC. However, there was no significant difference in bond strength between dentin substrates, for both sealers tested. Also, there was a positive and moderate correlation between the bond strength values of human and bovine teeth. The mixed failure mode was the most prevalent. Conclusion: AP and BC provide similar filling quality, but the first presents higher bond strength values to human and bovine dentin. The use of bovine teeth as substitutes for human samples seems adequate in studies related to bond strength, but not in those testing root canal filling quality.(AU)

Analysis of the adhesive interface of dentine treated with carbodiimide and chitosan before cementation of fiberglass posts with different resin cements.

The objective of this study is to evaluate the effect of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and chitosan (CHI) on the adhesive interface of resin cements to root dentine. Forty-five upper canines were sectioned, endodontically treated, prepared and divided into three groups according to dentine treatment (distilled water-DW, CHI 0.2% and EDC 0.5) and in three subgroups according to resin cement: RelyX ARC, Panavia F 2.0 or RelyX U200. Slices were obtained, with five slices of each third submitted to the analysis of the adaptation of the adhesive interface through scores and the perimeter with gaps in confocal laser scanning microscopy and one slice of each third later evaluated qualitatively in scanning electron microscopy. The results were analyzed using with Kruskal-Wallis and Spearman correlation tests. There was no difference in adaptation for the different resin cements (p = .438). EDC presented better adaptation when compared to the groups treated with DW and CHI (p < .001), while the CHI and DW presented similar adaptation values (p = .365). No difference was observed in the perimeter referring to the gap areas for the different resin cements (p = .510). EDC showed a lower percentage of perimeters with gaps when compared to CHI (p < .001), with the percentage of perimeter with gaps of teeth treated with CHI being lower than DW (p < .001). A positive correlation coefficient equal to 0.763 was obtained between the perimeter with gaps and the adaptation data of the adhesive interface (p < .001). EDC resulted in better adaptation of the adhesive interface and a lower percentage of perimeters with gaps compared to chitosan.

[Three-dimensional finite element analysis of cement flow in abutment margin-crown platform switching].

OBJECTIVE: To analyze the cement flow in the abutment margin-crown platform switching structure by using the three-dimensional finite element analysis, in order to prove that whether the abutment margin-crown platform switching structure can reduce the inflow depth of cement in the implantation adhesive retention. METHODS: By using ANSYS 19.0 software, two models were created, including the one with regular margin and crown (Model one, the traditional group), and the other one with abutment margin-crown platform switching structure (Model two, the platform switching group). Both abutments of the two models were wrapped by gingiva, and the depth of the abutment margins was 1.5 mm submucosal. Two-way fluid structure coupling calculations were produced in two models by using ANSYS 19.0 software. In the two models, the same amount of cement were put between the inner side of the crowns and the abutments. The process of cementing the crown to the abutment was simulated when the crown was 0.6 mm above the abutment. The crown was falling at a constant speed in the whole process spending 0.1 s. Then we observed the cement flow outside the crowns at the time of 0.025 s, 0.05 s, 0.075 s, 0.1 s, and measured the depth of cement over the margins at the time of 0.1 s. RESULTS: At the time of 0 s, 0.025 s, 0.05 s, the cements in the two models were all above the abutment margins. At the time of 0.075 s, in Model one, the gingiva was squeezed by the cement and became deformed, and then a gap was formed between the gingiva and the abutment into which the cement started to flow. In Model two, because of the narrow neck of the crown, the cement flowed out from the gingival as it was pressed by the upward counterforce from the gingival and the abutment margin. At the time of 0.1 s, in Model one, the cement continued to flow deep inside with the gravity force and pressure, and the depth of the cement over the margin was 1 mm. In Model two, the cement continued to flow out from the gingival at the time of 0.075 s, and the depth of the cement over the margin was 0 mm. CONCLUSION: When the abutment was wrapped by the gingiva, the inflow depth of cement in the implantation adhesive retention can be reduced in the abutment margin-crown platform switching structure.

How can excess residual cement be reduced in implant-supported restorations?: An in vitro study.

OBJECTIVE: The aim of this study was to investigate the effect of different cements and cementation techniques used in implant-supported restorations and the application of various vent modifications and extraoral replica techniques on the amount of overflowing cement in cemented systems. MATERIALS AND METHODS: In this study, three different abutment designs were used as fully closed, occlusal vented, and occlusal + proximal vented. An extraoral replica was produced by milling the CAD/CAM ceramic block. The number of groups with and without replicas was determined as six (n = 10). For the cementation procedures, three different cements were tested: dual-cure resin, eugenol-free zinc oxide, and polycarboxylate cements. Cobalt-chromium superstructures to be cemented to the implant analog-abutment complex were produced by direct metal laser sintering method. Twenty-four hours after the cementation process, residual cement were measered with Micro-CT. In comparisons between groups, ANOVA test was used for normally distributed variables and Kruskall-Wallis H test was used for non-normally distributed variables at a significance level of p < 0.05. RESULTS: The difference in residual cement volumes between the groups in terms of both cementation techniques (whether or not to use an extraoral replica and different vent desings) and cement types was found to be statistically significant (p < 0.05). There was significantly less residual cement in all groups that used extraoral replicas than those that did not. As for the cement types, the most residual cement occurred in the resin cement. CONCLUSION: The use of extraoral replicas and vent designs on the abutment significantly reduces the amount of residual cement. Regardless of the cementation technique, the type of cement used affects the amount of excess cement. CLINICAL RELEVANCE: To reduce residual cement, both the type of cement and the cementation technique used must be considered.

Pre-cementation treatment of glass-ceramics with vacuum impregnated resin coatings.

OBJECTIVE: The study aimed to investigate the effectiveness of a vacuum impregnation process to eliminate the porosity at the ceramic-resin interface to optimize the reinforcement of a glass-ceramic by resin cementation. METHODS: 100 leucite glass-ceramic disks (1.0 ± 0.1 mm thickness) were air-abraded, etched with 9.6 % HF acid, and silanated. Specimens were randomly allocated to 5 groups (n = 20). Group A received no further treatment (uncoated control). Groups B and D were resin-coated under atmospheric pressure, whereas groups C and E were resin-coated using vacuum impregnation. The polymerized resin-coating surfaces of specimens in groups B and C were polished to achieve a resin thickness of 100 ± 10 µm, while in groups D and E no resin-coating modification was performed prior to bi-axial flexure strength (BFS) determination. Optical microscopy was undertaken on the fracture fragments to identify the failure mode and origin. Comparisons of BFS group means were made by a one-way analysis of variance (ANOVA) and post-hoc Tukey test at α = 0.05. RESULTS: All resin-coated sample groups (B-E) showed a statistically significant increase in mean BFS compared with the uncoated control (p < 0.01). There was a significant difference in BFS between the ambient and vacuum impregnated unpolished groups (D and E) (p < 0.01), with the greatest strengthening achieved using a vacuum impregnation technique. SIGNIFICANCE: Results highlight the opportunity to further develop processes to apply thin conformal resin coatings, applied as a pre-cementation step to strengthen dental glass-ceramics.

Selective adhesive luting: A novel technique for improving adhesion achieved by universal resin cements.

OBJECTIVE: We aimed to introduce the concept of "Selective adhesive luting-SAL" which is explained through clinical steps and supported by preliminary laboratory evidence. CLINICAL CONSIDERATIONS: Cementation with rubber dam is difficult to perform in case of short abutment teeth and/or subgingival crown margins. By means of universal resin cements/universal adhesive systems, which can be employed in self-adhesive as well as adhesive luting procedures, this paper presents a novel technique allowing clinicians to perform reliable cementation where rubber dam isolation is difficult. The SAL technique entails the application of a universal adhesive system only on easily accessible abutment surfaces, enabling simultaneous adhesive and self-adhesive luting in different portions of the abutment. The SAL clinical workflow is explained through prosthodontic rehabilitation of maxillary right central incisor affected by microdontia and restored with a lithium-disilicate crown. Furthermore, our laboratory microshear bond strength study supports the rationale behind SAL application demonstrating higher bond strength even when the adhesive resin is placed only on one portion of the cementation substrate. CLINICAL SIGNIFICANCE: This article advocates the application of SAL technique in clinical situations where effective adhesive luting is uncertain, since it can improve the adhesion between the tooth and universal resin cements.

Survival rate and treatment success of glass fiber posts cemented with two adhesive cementation strategies after up to 106 months: a randomized clinical trial.

OBJECTIVES: The objective of this study is to evaluate the longevity of two fiber post cementation strategies in a prospective, multicenter, non-inferiority, double-blind randomized controlled trial. METHODS: A total of 152 teeth, with adequate endodontic treatment and loss of coronal structure and bilateral simultaneous posterior occlusal contacts, were randomly allocated to receive glass fiber posts cemented with a conventional cementation strategy (CRC group: adhesive system + resin cement) (Adper Single Bond + RelyX ARC; 3 M-ESPE) or a self-adhesive cementation strategy (SRC group: self-adhesive resin cement; RelyX U100/U200; 3 M-ESPE). The patients were recalled annually for clinical and radiographical evaluation with a 93% recall rate (142 teeth, with 74 at CR groups and 68 at SRC group). The primary outcome was survival rate, considering the fiber post debonding (loss of retention). The secondary outcome included the success rate of the prosthetic treatment with crown debonding, post fracture, and tooth loss (not related to post failure). Both outcomes were evaluated annually. The Kaplan-Meier method and Cox regression with 95% confidence interval were used for the statistical analysis. RESULTS: For the primary outcome (failures directly related to fiber posts cementation strategy), there were 4 fiber post debondings (2 per group), 8 root fractures (3 for SRC group and 5 for CRC group), and one mixed failure (debonding combined with root fracture for CRC), with both strategies presenting similar survival rates (p = 0.331), with 88.9% for the CRC group and 90.9% for the SRC group. For the secondary outcome (failures not related to fiber post cementation strategies), there were 8 crown debondings, 3 post fractures, and 3 tooth losses, with no statistically difference between groups (p = 0.701), with 77% for SRC and 82% for CRC. CONCLUSION: Fiber post cementation strategies with conventional or self-adhesive resin cement presents similar tooth survival and success rates. TRIAL REGISTRATION: NCT01461239 CLINICAL RELEVANCE: Both adhesive cementation strategies led to high survival and success rates and are indicated for fiber post cementation, even after a long follow-up period (up to 106 months).

Dental Luting Cements: An Updated Comprehensive Review.

The cementation of indirect restoration is one of the most important steps in prosthetic and restorative dentistry. Cementation aims to bond the prosthetic restoration to the prepared enamel or enamel and dentine. Successful cementation protocols prevent biofilm formation at the margin between tooth and restoration and minimize mechanical and biological complications. With the advancements in dental cements, they have been modified to be versatile in terms of handling, curing, and bond strengths. This review presents updates on dental cements, focusing on the composition, properties, advantages, limitations, and indications of the various cements available. Currently, dental restorations are made from various biomaterials, and depending on each clinical case, an appropriate luting material will be selected. There is no luting material that can be universally used. Therefore, it is important to distinguish the physical, mechanical, and biological properties of luting materials in order to identify the best options for each case. Nowadays, the most commonly used dental cements are glass-ionomer and resin cement. The type, shade, thickness of resin cement and the shade of the ceramic, all together, have a tangible influence on the final restoration color. Surface treatments of the restoration increase the microtensile bond strength. Hence, the proper surface treatment protocol of both the substrate and restoration surfaces is needed before cementation. Additionally, the manufacturer's instructions for the thin cement-layer thickness are important for the long-term success of the restoration.

Trends in Total Knee Arthroplasty Cementing Technique Among Arthroplasty Surgeons-A Survey of the American Association of Hip and Knee Surgeons Members.

BACKGROUND: Aseptic loosening persists as one of the leading causes of failure following cemented primary total knee arthroplasty (TKA). Cement technique may impact implant fixation. We hypothesized that there is variability in TKA cement technique among arthroplasty surgeons. METHODS: A 28-question survey regarding variables in surgeons' preferred TKA cementation technique was distributed to 2,791 current American Association of Hip and Knee Surgeons (AAHKS) members with a response rate of 30.8% (903 respondents). Patterns of responses were analyzed by grouping respondents by their answers to certain questions including cementing technique, tibial cement location, and femoral cement location. RESULTS: A total of 73.5% reported performing at least 7 of 8 of the highest consensus techniques, including vacuum mixing (79.9%), using two bags (76.1%), tibial implant first (95.2%), single-stage cementing (96.9%), compression of the implants in extension (91.7%), and use of a tourniquet (84.3%). Medium and high viscosity cement was most commonly used (37.9 and 37.8%, respectively). Finger pressurization was most common (76.1%) compared to a gun (29.8%). There were 26.5% of respondents performing 6 or fewer of the most common majority techniques and seemed to perform other less common techniques (eg, use of a single bag of cement, trialing or closure prior to cement curing, and heating to accelerate cement curing). Cement was most commonly applied to the entire bone and implant surface on both the tibia (46.4%) and femur (47.7%), leaving much variation in the remaining cement application location responses. DISCUSSION: There appears to be variability in cemented TKA technique among arthroplasty surgeons. There were 26.5% of respondents performing less of the majority techniques and also performed other additional low-response rate techniques. Further studies that look at the impacts of variation in techniques on outcomes may be warranted. Our study demonstrates the need for defining best practices for cement technique given the substantial variability identified.

Biomechanical performance of three fiberglass post cementation techniques: Imaging, in vitro, and in silico analysis.

PURPOSE: The structural integrity of the resin cement layer, the bond strength, and the biomechanical behavior of different fiberglass post cementation techniques were evaluated. METHODS: Thirty-three bovine incisors were divided into three groups (n = 11): conventional fiberglass post (CFP), conventional fiberglass post in flared root canals (CFL), and relined fiberglass post (RFP). Six specimens from each group were submitted for high-resolution microcomputed tomography (µCT) to evaluate the integrity and presence/volume of voids at the resin cement layer. Finite element analysis (FEA) of two three-dimensional (3D) models of each group were conducted, one considered ideal (without interface defects) and another containing the conditions identified in the µCT analysis. Push-out bond strength tests were conducted for all specimens. RESULTS: The CFL group had the greatest mean values of void (Thirds cervical: 73.67; middle: 95.67; apical: 47.33) and gap concentration (Thirds cervical: 14.67; middle: 15.83; apical: 8.33) compared with CFP and RFP. A significant difference in bond strength was observed between the cervical (1.33 MPa) and middle thirds (1.85 MPa) compared with the apical third (4.85 MPa) of the CFL. A significant difference was observed in the bond strength in the CFL (1.33 MPa) and RFP (3.29 MPa) in the cervical third, which were statistically similar to the bond strength of the CFP. The tensile stress distributions were similar in most structures, localized in the cervical region on the lingual surface. CONCLUSIONS: Structural defects in the interface layer might influence the bond strength and biomechanical behavior under the different fiberglass post cementations.

Pulsatile Lavage Improves Tibial Cement Penetration and Implant Stability in Medial Unicompartmental Arthroplasty: A Cadaveric Study.

Cemented unicompartmental knee arthroplasty (UKA) shows good survivorship and function. However, implant failure, causing the need for revision, can occur. Aseptic loosening is still among the most common reasons for revision. The purpose of this study was to assess the influence of preimplantation lavage technique on tibial cement penetration depth, tibial cement volume, and load to fracture in the tibial component of mobile-bearing UKA. In 10 pairs of fresh frozen human tibiae, cemented UKA was implanted by an experienced surgeon. Tibial components were then implanted, left and right tibiae were randomly allocated to group A or B. Prior to implantation, irrigation was performed with either syringe lavage or pulsatile jet lavage in a standardized manner. Cement surface was 4170.2 mm2 (3271.6-5497.8 mm2) in the syringe lavage group, whereas the jet lavage group showed 4499.3 mm2 (3354.3-5809.1 mm2); cement volume was significantly higher as well (4143.4 mm3 (2956.6-6198.6 mm3) compared with 5936.9 mm3 (3077.5-8183.1 mm3)). Cement penetration depth was 2.5 mm (1.7-3.2 mm) for the jet lavage, and 1.8 mm (1.2-2.4 mm) for the syringe lavage. The mean fracture load was 4680 N in the jet lavage group and 3800 N in the syringe lavage group (p = 0.001). Subsidence was significantly higher for syringe lavage. This study suggests a correlation of cement penetration depth and cement volume to implant failure in the tibial component of a UKA using a cadaveric model. The type of bone lavage most likely influences these two key parameters.