Histopathological Effects of Bone Cement on Cartilage Tissue.

INTRODUCTION: Glass ionomer bone cement is frequently applied with cartilage grafts in otology, even as a single unit. OBJECTIVE: This experimental study was performed to investigate the histopathological effects of bone cement on cartilage tissue. METHODS: The study was conducted between January 2018 and April 2018 and used 12 New Zealand White rabbits. The right ears of the rabbits constituted the study group, while the left ears were the controls. Ketac Cem Radiopaque (3 M Germany) was used as glass ionomer cement. Tissue samples from the rabbits were subjected to histopathological analysis to compare acute and chronic inflammation, foreign body reaction, angiogenesis, collagenesis, fibrosis, necrosis, cartilage fracture, osseous metaplasia, and loss of chondrocyte nuclei between the groups. RESULTS: The rates of cartilage fracture (P = 0.044), foreign body reaction (P < 0.001), acute inflammation (P = 0.009), chronic inflammation (P = 0.002), and angiogenesis (P = 0.003) were significantly higher in the study group compared with the controls. The study group showed some degree of necrosis; no necrosis was observed in the control group, but the difference was not statistically significant (P = 0.101). There were no significant differences in fibrosis, collagenesis, osseous metaplasia, or loss of chondrocyte nuclei between the groups. CONCLUSIONS: This study showed that application of bone cement can cause acute and chronic inflammation, foreign body reactions, angiogenesis, and cartilage fractures. Further studies are needed to determine the long-term effects of bone cement on cartilage.

Potencial bioativo de cimento à base de silicato de cálcio e ácido poliacrílico em lesões de cárie dentinárias formadas por um modelo de biofilme de microcosmo / Potential bioactive cement based on calcium silicate and polyacrylic acid in dentinal caries lesions formed by a biofilm model of microcosm

O objetivo deste estudo foi avaliar a capacidade de cimentos à base de ácido poliacrílico e silicato de cálcio em aumentar a densidade mineral da dentina desmineralizada por um modelo de biofilme de microcosmo. Além disso, a técnica de dupla energia em micro-CT foi proposta para quantificar a formação de biofilme e a densidade mineral da dentina nas amostras. Quarenta e cinco cavidades em dentina foram preparadas em 9 terceiros molares humanos sadios, sendo 5 em cada dente. As amostras receberam o inóculo bacteriano e foram incubadas em BHI (Brain Heart Infusion) adicionado com 5% de sacarose durante 96h para formação do biofilme. Em seguida, foram realizados dois escaneamentos consecutivos de cada amostra (40kv e 70kv) no micro-CT e cada cavidade foi preenchida com diferentes cimentos experimentais: policarboxilato de zinco (Poly Zinc™), ionômero de vidro convencional (Ketac Molar™) e dois materiais à base de silicato de cálcio (MTA e Biodentine™) enquanto que a cavidade central foi mantida como controle e preenchida com cera utilidade. As amostras foram mantidas durante 45 dias sob simulação da pressão intrapulpar utilizando-se SBF (Simulated Body Fluid) e após o período experimental foram novamente escaneadas. A reconstrução e aquisição foram realizadas utilizando parâmetros padronizados. Os resultados foram testados quanto à normalidade utilizando o teste de Shapiro-Wilk, seguido por métodos não paramétricos. O uso da dupla energia no micro-CT revelou formação de biofilme em todas as cavidades e uma correlação positiva entre o volume da cavidade e o volume do biofilme formado (0,77; p <0,01) foi encontrada. A perda mineral na dentina foi alta (± 90%) para todas as cavidades e mostraram valores de densidade mineral inferior a um limiar definido para a cárie dentinária (1,2g/cm3 ). O aumento da densidade mineral foi maior com MTA ou Poly Zinc™ (43,56% e 41,64%), os quais foram estatisticamente semelhantes, seguido pelo Biodentine™ (36,40%) e Ketac Molar™ (32,54%). Concluiu-se que o modelo de microcosmo bacteriano humano foi capaz de produzir lesões cariosas in vitro e que a técnica de micro-CT por dupla energia provou ser um método eficaz para quantificar a formação de biofilme e a densidade mineral da dentina cariada. Todos os cimentos utilizados apresentaram potencial de aumentar a densidade mineral da dentina desmineralizada, ressaltando o elevado potencial bioativo do cimento policarboxilato de zinco. (AU)

The aim of this study was to evaluate the effect of polyacrylic acid-based and calcium silicates cements in increasing mineral density of demineralized dentin produced by a microcosm model for caries formation. Moreover, a dual energy micro-CT technique was used to quantify biofilm formation and mineral density. Forty-five dentin cavities were prepared in 9 sound human third molars, 5 in each tooth. Samples received the bacterial inoculum and were incubated in BHI (Brain Heart Infusion) added with 5% of sucrose for 96h to allow biofilm formation. After that, two consecutive micro-CT scans were acquired from each specimen (low energy - 40kv and high energy - 70kv) and then, each cavity was filled with different experimental cements, namely: a zinc polycarboxilate (Poly Zinc™), a conventional glass ionomer (Ketac Molar™) and two calcium silicate based materials (MTA and Biodentine™) while the central cavity was kept as control and filled with dental wax. Specimens were kept for 45 days under simulated pulp pressure using SBF (Simulated Body Fluid) and after the experimental period they were again scanned. Reconstruction and acquisition were accomplished using standardized parameters. Data was tested for normality using the Shapiro-Wilk test, followed by non-parametric methods. Dual-energy micro-CT technique disclosed biofilm formation in all cavities and a positive correlation between cavity volume and volume of formed biofilm was obtained (0.77, p<0.01). The mineral decrease obtained in dentin was high (± 90%) for all cavities and all demineralized areas showed mineral density values lower than a defined threshold for dentin caries (1.2g/cm3 ). Increase in mineral density of dentin was best achieved using MTA or Poly Zinc™ (43.56% and 41.64% remineralization), where both were not statistically different. These were followed by Biodentine™ (36.40%) and Ketac Molar™ (32.54%). It is possible to conclude that a microcosm human bacterial biofilm model was able to produce carious lesions in vitro and a dual energy micro-CT technique proved to be an effective method to quantify biofilm formation and mineral density of carious dentin. All cements showed potential to increase mineral density, especially zinc policarboxylate cement.(AU)

Effect of 3 cements on white spot lesion formation after full-coverage rapid maxillary expander: A comparative in-vivo study.

INTRODUCTION: The aim of this study was to assess the effects of 3 luting agents (glass ionomer cement, compomer, and polycarboxylate cement) on white spot lesion formation in patients with full-coverage bonded acrylic splint expanders. White spot lesion formation was assessed with quantitative light-induced fluorescence. METHODS: Full-coverage rapid maxillary expanders were cemented with glass ionomer cement, compomer, and polycarboxylate cement in groups 1, 2, and 3, respectively. A control group comprised patients who never had orthodontic treatment. Quantitative light-induced fluorescence images taken before and after rapid maxillary expansion treatment were analyzed for these parameters: the percentages of fluorescence loss with respect to the fluorescence of sound tooth tissue (ΔF) and maximum loss of fluorescence intensity in the whole lesion; lesion area with ΔF equal to less than a -5% threshold; and the percentage of fluorescence loss with respect to the fluorescence of sound tissue times the area that indicated lesion volume. RESULTS: All 3 groups showed statistically significantly greater demineralization than the control group. The 3 experimental groups differed from each other in half of the parameters calculated. Teeth in the polycarboxylate group developed the most white spot lesions. CONCLUSIONS: With the highest rate of white spot lesion formation, polycarboxylate cements should not be used for full-coverage bonded acrylic splint expanders. Compomers may be preferred over glass ionomer cements, based on the findings of this study.

Heterotopic ossification following hip arthroplasty: a comparative radiographic study about its development with the use of three different kinds of implants.

BACKGROUND: Our purpose was to record the incidence of heterotopic ossification (HO) following hip replacement by different variables to identify patient groups that are likely to develop HO in the absence of a prophylactic protocol. METHODS: Radiographically, we studied 651 patients having undergone hip joint replacement, evaluating three kinds of implants: ceramic-ceramic-coupled total hip replacement (THR), TriboFit® with polycarbonate urethane-ceramic coupling and endoprosthesis. Each patient was analysed for HO development by age, gender, diagnosis, presence of previous ossifications, surgical approach and kind of implant. Within the population that developed HO, data were assessed for correlation with severity of ossification graded according to Brooker classification. RESULTS: The overall incidence of HOs was 59.91 %. The factors increasing their incidence in the univariate analysis were as follows: lower age of the patients with HO (mean 77.6 years, p = 0.0018) than those subjects who did not develop HO (mean 80.2 years); male gender (64.4 %, p = 0.1011); diagnosis of coxarthrosis (72.7 %, p = 0.0001) compared to femur neck fracture (55.9 %, p = 0.0001); presence of previous HO (76.2 %, p = 0.0260); lateral approach (65.5 %) as opposed to anterior-lateral approach (55.6 %, p = 0.0163); and ceramic-ceramic THR (68.1 %) and TriboFit® (67.0 %) compared to endoprosthesis (51.3 %, p = 0.0001). During multivariate analysis, the presence of HO after previous hip surgery (p = 0.0324) and the kind of implant (p = 0.0004) showed to be independent risk factors for the development of HO. Analysing the population that developed HO, we found that the severity of ossification by Brooker classification was influenced by gender (p = 0.0478) and kind of implant (p = 0.0093). CONCLUSIONS: In agreement with the literature, our radiographic study confirms the following risk factors of HO development in absence of any prophylactic treatment: male gender, diagnosis of coxarthrosis compared to femur neck fracture, previous HO, surgical approach and kind of implant. In particular, Hardinge-Bauer and Watson-Jones surgical approaches, characterized by a wide exposure of the coxofemoral joint, and ceramic-ceramic THR and TriboFit® implants significantly increase the development of HO.

Cytocompatibility testing of cell culture modules fabricated from specific candidate biomaterials using injection molding.

Most polymers used in clinical applications today are materials that have been developed originally for application areas other than biomedicine. Testing the cell- and tissue-compatibility of novel materials in vitro and in vivo is of key importance for the approval of medical devices and is regulated according to the Council Directive 93/42/EEC of the European communities concerning medical devices. In the standardized testing methods the testing sample is placed in commercially available cell culture plates, which are often made from polystyrene. Thus not only the testing sample itself influences cell behavior but also the culture vessel material. In order to exclude this influence, a new system for cell testing will be presented allowing a more precise and systematic investigation by preparing tailored inserts which are made of the testing material. Inserts prepared from polystyrene, polycarbonate and poly(ether imide) were tested for their cytotoxity and cell adherence. Furthermore a proof of principle concerning the preparation of inserts with a membrane-like surface structure and its surface modification was established. Physicochemical investigations revealed a similar morphology and showed to be very similar to the findings to analogous preparations and modifications of flat-sheet membranes.

pH-Sensitive degradable polymersomes for triggered release of anticancer drugs: a comparative study with micelles.

pH-Sensitive degradable polymersomes and micelles were prepared based on diblock copolymer of poly(ethylene glycol) (PEG) and an acid-labile polycarbonate, poly(2,4,6-trimethoxybenzylidenepentaerythritol carbonate) (PTMBPEC). Polymersomes of PEG(1.9k)-PTMBPEC(6k) revealed average sizes of 100-200 nm. The acetals of polymersomes, similar to those of PEG(5k)-PTMBPEC(5.8k) micelles, though stable at pH 7.4 were prone to fast hydrolysis at mildly acidic pH of 4.0 and 5.0, with half lives of 0.5 and 3d, respectively. The acetal hydrolysis resulted in significant size increase of polymersomes, to over 1000 nm in 24h at pH 4.0. Drug encapsulation studies revealed that polymersomes were able to simultaneously load paclitaxel (PTX, hydrophobic) and doxorubicin hydrochloride (DOX.HCl, hydrophilic), whereas micelles loaded PTX only. Notably, polymersomes showed lower drug loading efficiencies for PTX than micelles (30.0-37.7% versus 61.4-65.2%). The in vitro release studies demonstrated that release of PTX and DOX.HCl from polymersomes was highly pH-dependent, i.e. significantly faster drug release at mildly acidic pH of 4.0 and 5.0 compared to physiological pH. Furthermore, much higher release rates were observed for PTX release from the polymersomes compared to that from the micelles under otherwise the same conditions. These pH-sensitive nano-sized degradable polymersomes hold great promise for combination therapy for cancers.

The positive relationship between excess cement and peri-implant disease: a prospective clinical endoscopic study.

BACKGROUND: Cement-retained restorations are commonly used on dental implants. Residual excess cement after placement of fixed partial dentures has been associated with clinical and radiographic signs of peri-implant disease. The purpose of this study was to explore the relationship between excess dental cement and peri-implant disease using the dental endoscope. METHODS: Thirty-nine consecutive patients with implants exhibiting clinical and/or radiographic signs of peri-implant disease were studied. Patients were enrolled in the study during a 5-year period in a private periodontal practice. Twelve of these patients had similar implants without signs of inflammation; these implants served as controls. There were 20 controls and 42 test implants. All were evaluated using a dental endoscope initially, and all but one implant was evaluated at a 30-day follow-up. Results from both groups were assessed by two trained operators and recorded. RESULTS: None of the controls and all 42 of the test implants had clinical signs of peri-implant disease at initial treatment. Excess cement was found in none of the controls and 34 of the test sites. Thirty days after cement removal, 25 of 33 test sites from which the cement was removed had no clinical or endoscopic signs of inflammation. CONCLUSIONS: Excess dental cement was associated with signs of peri-implant disease in the majority (81%) of the cases. Clinical and endoscopic signs of peri-implant disease were absent in 74% of the test implants after the removal of excess cement.

Complications of pegged and non-pegged hydroxyapatite orbital implants.

PURPOSE: The purpose of this study is twofold: to assess the incidence and implications of complications unique to placing a freestanding polycarbonate peg in patients with hydroxyapatite implants and to compare the incidence of complications in these patients with the incidence in patients with non-pegged hydroxyapatite implants. METHODS: This is a retrospective clinical case series of 103 patients who underwent hydroxyapatite implant insertion at our institution. The incidence of postoperative complications in patients who underwent freestanding polycarbonate pegging procedures (n = 21) and those who had not (n = 82) were compared. RESULTS: One postoperative complication - infection - occurred in a significantly higher percentage of patients in the pegged group (42.9%, 9/21) compared with the non-pegged group (19.5%, 16/82), (p = 0.037). Fifteen of the 21 patients (71.4%) in the pegged group experienced complications unique to freestanding polycarbonate pegging. Overall, 95.2% (20/21) of patients in the pegged group experienced a complication compared with 58.5% (48/82) of patients in the non-pegged group, (p = 0.001). In addition, there was an average of 3.1 (66/21) complications per patient in the pegged group compared with an average of 1.9 (106/82) complications per patient in the non-pegged group (p = 0.010). CONCLUSIONS: Patients who received a freestanding polycarbonate pegged implant had a high risk of experiencing complications unique to pegging, and therefore a significantly higher rate of complications overall when compared with patients whose implant was not pegged. In addition, patients who received a pegged implant had a higher incidence of infection. However, most patients retained their pegs despite complications.

Complications of hydroxyapatite pegging: comparison between polycarbonate and titanium peg system.

PURPOSE: Polycarbonate peg has been customarily used for pegging of hydroxyapatite for years. For better movement, tissue tolerance, and to decrease the complications of pegging, titanium peg system has been used. This study compares the two systems. METHODS: Complications associated with pegging (polycarbonate: Bio-Eye or titanium: Dr-Perry new P-K) were retrospectively reviewed from the charts of 153 patients admitted to the Labbafinejad Medical Center, Tehran, Iran, for over 5 years from 1997 to 2003. RESULTS: A total of 153 cases were studied. Ninety-six (62.3%) were male and 57 (37.7%) were female, and the mean age was 27.7 years (6-59 years). In 88 cases pegs were poly-carbonate and sleeve system and in 65 cases pegs were titanium. Forty-one (46%) of cases with polycarbonate and 18 (27%) of cases with titanium had at least one or more complications (p=0.018). The most common complications were granulation tissue, discharge, overgrowth of conjunctiva, and peg falling out in 25%, 23%, 13%, and 8% in polycarbonate peg and 15%, 5%, 1.5%, and 0% in titanium peg group. The prevalence of the last three complications was statistically lower in titanium peg compared with polycarbonate. Twenty-five cases (35%) with polycarbonate peg and 5 cases (7.5%) with titanium peg had two or more complications (p=0.03). Peg removal was done in 11 cases of polycarbonate but only two cases of titanium peg in order to treat the complication. CONCLUSIONS: Both pegging systems had some complications, although these were less severe and prevalent in titanium peg. More studies on complications due to titanium pegs are recommended.

Clinical comparison of postoperative sensitivity for an adhesive resin cement containing 4-META and a conventional glass-lonomer cement.

PURPOSE: The aim of this clinical 2-year follow-up study was to compare the postoperative sensitivity of abutment teeth restored with full coverage restorations retained with either conventional glass-ionomer cement or a new adhesive resin cement containing 4-methacrylolyloxyethyl trimellitate anhydride (4-META). MATERIALS AND METHODS: Sixty patients received 120 full-coverage restorations on vital abutment teeth, cemented with either a glass-ionomer cement (Ketac-Cem) or a new adhesive resin cement (Chemiace II). A randomized split-mouth design and a patient double-blind data acquisition protocol were used. The teeth were examined before cementation, after 1 week, and after 6, 12, and 24 months. RESULTS: With regard to postcementation sensitivity, a low incidence was observed for both groups. With the adhesive resin cement, little postoperative hypersensitivity was observed after 1 week (13.3%), 6 months (5.9%), 12 months (2.1%), and 24 months (none); results were similar with the conventional glass-ionomer cement Ketac-Cem after 1 week (5.9%), 6 months (5.9%), 12 months (6.4%), and 24 months (none). After 6 months, 2 teeth of the Chemiace II group showed no sensitivity. Endodontic treatment was carried out for these 2 abutment teeth. After 24 months, no cases of postoperative hypersensitivity were recorded for either group. CONCLUSION: In this study, the incidence of postoperative hypersensitivity after cementation of full-crown restorations with a conventional glass-ionomer cement and a new adhesive resin cement was similar.

Surface analysis of an encapsulation membrane after its implantation in mini-pigs.

The biocompatibility of membranes aiming at being a part of a bioartificial pancreas has been tested. For that purpose, we have studied a polycarbonate membrane surface after its implantation in mini-pigs. The membranes were made hydrophilic by an argon plasma surface treatment followed by a dipping in a hydrophilic polymer solution. Two polymers were tested: polyvinylpyrrolidone (PVP) and hydroxypropylmethylcellulose (HPMC). To test their biocompatibility, an encapsulation device for pig Langerhans islets, with external membranes treated as described above, was implanted in different mini-pigs. The pigs received no further treatment. The devices were explanted after in vivo exposure and the membranes were analysed by XPS (x-ray photoelectron spectroscopy) and ToF-SIMS (time-of-flight secondary ion mass spectrometry). After this time, the substrate with the PVP or HPMC treatment was still detected on the different samples. The surface treatment signal, however, was attenuated. This is explained by the detection of other components partly covering the surface. XPS and ToF-SIMS analyses revealed the presence of biological molecules on the two faces of the membrane: the outside face in contact with the biological environment and the inside face in contact with the device. ToF-SIMS images show the inhomogeneity of the biological molecules on the membrane surface. In conclusion, biological molecules adhered to the encapsulation membrane surface after implantation but the surface treatments remained unaltered.

Chronic inflammation from polycarbonate motility peg inhibits osteogenesis in a human hydroxyapatite orbital implant.

The histologic findings of a pegged hydroxyapatite orbital implant removed due to chronic inflammation and pain are described. A 44-year-old woman underwent explantation of a hydroxyapatite sphere and polycarbonate motility peg due to chronic redness, swelling, discharge, and pain. Histology revealed complete fibrovascularization of the implant, with approximately 90% ossification. No bone marrow was identified. Histologic sections revealed fibrous connective tissue at the periphery of a sclerotic bony mass with a granulomatous inflammatory infiltrate at the motility peg aperture. There were no bacterial, mycobacterial, or fungal organisms identified histologically or by culture. Consistent with previous reports, hydroxyapatite orbital implants are amenable to fibrovascular ingrowth and bony transformation. The presence of a granulomatous inflammatory reaction around the polycarbonate motility peg in this case may have prevented complete osseous transformation of the hydroxyapatite implant.

Influence of temporary cement remnant and surface cleaning method on bond strength to dentin of a composite luting system.

The aim of the current study was to evaluate the influence of polycarboxylate temporary cement remaining on the dentin surface on the bond strength of a composite luting system. An acrylic resin plate was luted to bovine dentin with a polycarboxylate temporary cement (HY-Bond Temporary Cement Hard, HYB). The temporary cement was not used for the control groups. After removing the temporary cement with an excavator, dentin specimens were divided into five groups; 1) no subsequent treatment, 2) cleaning with a rotational brush (RTB), 3) cleaning with a rotational brush and non-fluoridated flour of pumice, 4) sweeping with an air scaler, and 5) treated with a sonic toothbrush. A silane-treated ceramic disk (IPS Empress) was bonded to each dentin specimen with a composite luting system (Panavia F). Shear testing results showed that the RTB groups exhibited the highest bond strength regardless of the use of temporary cement (P < 0.05). The use of a rotational brush with water coolant is recommended to achieve ideal bond strength between the Panavia F luting system and dentin to which HYB temporary cement was primarily applied.

Use of a light-polymerized composite removable partial denture base for a patient hypersensitive to poly(methyl methacrylate), polysulfone, and polycarbonate: a clinical report.

This article describes a light-polymerized composite denture base used for a patient with hypersensitivity to poly(methyl methacrylate) (PMMA), polysulfone (PSF), and polycarbonate (PC). A urethane-dimethacrylate (UDMA) composite was used as an alternative to fabricate both the denture base and the custom artificial teeth. Immediately after placing the new prosthesis, allergic symptoms disappeared from the patient's mucous membrane. The denture has functioned satisfactorily for more than 2.5 years without recurrence of the hypersensitivity.

Decalcification in relation to brackets bonded with glass ionomer cement or a resin adhesive.

Forty randomly selected patients had brackets bonded on one side of the of the maxillary labial segment with glass ionomer cement. Teeth on the opposite side were bonded with a resin adhesive. Teeth were assessed for decalcification pretreatment, at debond, and at review using a standardized photographic technique and a modified DDE index. The mean number of teeth affected by decalcification and the mean extent of decalcification per tooth increased during the treatment period, but from debond to review both of these measurements decreased for teeth bonded with either material (p)<0.01, t-test). Decalcification appears to become less severe posttreatment, but does not appear to be significantly affected during 12 to 18 months of orthodontic treatment by bonding with glass ionomer cement. Dietary and other environmental factors, including fluoride preparations, may be of greater importance in the prevention of decalcification during fixed appliance therapy.

Clinical comparison of postoperative sensitivity for a glass ionomer and a zinc phosphate luting cement.

In 60 patients, 120 partial and full-coverage restorations were cemented on vital abutment teeth with either a glass ionomer or a zinc phosphate luting cement. A split-mouth design and a patient blind data acquisition protocol were used. During an average observation period of 17.3 months there were no differences between the two types of luting cements in regard to subjective and clinical parameters. A high incidence of postoperative hypersensitivity, which is often said to accompany the use of glass ionomer luting cements, was not observed. With the cementation method used in this study, the glass ionomer cement Ketac-Cem Maxicap was an acceptable alternative to conventional zinc phosphate cement. Capsule systems make the clinical handling of glass ionomer luting cements safe and easy and should be used routinely in dental practice.

Coroas de aço inoxidável em odontopediatria / The stainless steel crown in pedodontics

Devido à importância das coroas de aço em odontopediatria, muitas técnicas operatórias têm sido apresentadas com o objetivo de aumentar sua resistência e adaptaçäo. Uma revisäo de literatura a este respeito será apresentrada

Guided tissue regeneration using calcium phosphate implants together with 4 different membranes. A study on furcations in dogs.

Four different membranes were used in conjunction with porous calcium phosphate granules to treat grade II furcations in lower molars of 6 dogs. Six months later block sections were used to measure the amount of regeneration and inflammation. The 4 membranes (polycarbonate, silicone rubber, polytetrafluoroethylene, and polycaprolactone) all gave similar improvements in bone fill ranging from 1.74 +/- 0.44 mm to 2.02 +/- 0.38 mm while control areas had only 0.34 +/- 0.12 mm. The amount of new attachment ranged from 2.32 +/- 0.62 mm to 2.58 +/- 0.62 mm for the membranes and was 0.26 +/- 0.11 mm for controls. There were increased numbers of chronic inflammatory cells seen with the polycarbonate and polycaprolactone group compared to controls and the other 2 membranes.

[Intrapulpal temperature change during the setting reactions of various dental cements]. / Simanlarin sertlesme reaksiyonlari esnasinda pulpada olusturduklari isi degisimleri.

Mixing of certain types of dental materials may produce pulpal injury due to a series of chemical reactions giving way to an exothermic reaction. Three different dental cements; zinc phosphate, polycarboxilate and glass ionomer cements which may increase the intrapulpal temperature were investigated in the present study. The cements were mixed according to the manufacturers' instructions in one group, the liquid and powder ratios were increased by one portion in the other two groups. The intrapulpal temperature changed between 1.32-4.54 degrees C among the three test groups. The intrapulpal temperature rise was markedly influenced when the amount of powder and liquid ratios were changed.