JPH0574542B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a calcium phosphate hydraulic cement composition. <Prior art> Calcium phosphate hydraulic cement compositions are useful as tooth and bone repair materials because they are converted into compounds that resemble the main components of teeth and bones in living organisms through setting and hardening, and are also useful as materials for restoring teeth and bones. It is useful as an adsorbent for harmful organic substances or inorganic ions in macromolecules and living organisms. Conventionally, such calcium phosphate hydraulic cement compositions have been prepared by using a combination of salts and dilute acids as a curing liquid (for example, as disclosed in Japanese Patent Application Laid-open No. 59-1989).
88351), or an acidic solution containing an unsaturated carboxylic acid polymer (for example, JP-A-60-253454). However, in such conventional calcium phosphate hydraulic cement compositions, until the hardness of the cement is finished,
The curing liquid was highly acidic and caused considerable irritation to living organisms. Furthermore, even after the cement has hardened, the pH decreases due to the elution of unreacted acids, resulting in the problem of irritation to living organisms. To solve this problem, calcium phosphate hydraulic cement compositions that harden with water have been developed (for example, FC REPORT, vol. 6 (1988),
p.475-480 “Hydraulic apatite as bioceramics”). To date, several types of calcium phosphate hydraulic cement compositions that harden with water have been developed. Showa 64-
No. 37445) is known. The pH of this calcium phosphate hydraulic cement composition is approximately neutral, and it is less irritating to living organisms, thus solving the problems of conventionally known calcium phosphate hydraulic cement compositions. However, its disadvantages include that it takes on a so-called wet sand-like appearance when mixed with water and has poor operability. That is, if there is too little water, the mud will be unkempt, and if there is too much water, the mud will fall while being transported to the desired location, making it difficult to use. Furthermore, the fluidity of the mixed mud is poor, making it difficult to fill narrow spaces or places with complex shapes. <Problems to be Solved by the Invention> Accordingly, the main object of the present invention is to provide a calcium phosphate hydraulic cement composition that provides appropriate consistency and good operability during kneading. Another object of the present invention is to regularly use a calcium phosphate hydraulic cement composition that exhibits sufficient fluidity and wettability to enable reliable and tight filling even in narrow spaces and places with complex shapes. That's true. Yet another object of the present invention is to provide a calcium phosphate hydraulic cement composition in which the degree of extension of the curing time can be arbitrarily selected as required. <Means for Solving the Problems> According to the present invention, there is provided a hydraulic cement composition containing a calcium phosphate compound as a main component, wherein the hydraulic cement composition contains water and a polymeric surfactant. Calcium phosphate hydraulic cement compositions are provided. The present invention will be explained in more detail below. In the present invention, it is an essential condition that the calcium phosphate hydraulic cement composition contains water and a polymeric surfactant. By incorporating it into cement powder and water,
It has been found that the desired objective can be achieved. Examples of polymeric surfactants that can be preferably used in the present invention include synthetic polymers such as polyethylene glycol and polyvinyl alcohol, biopolymers such as methylcellulose, carboxymethylcellulose, and hydroxypropylmethylcellulose, and derivatives of these compounds. However, any compound or derivative thereof can be used as long as it is not toxic to living organisms. These compounds and their derivatives may be used alone or in a mixture of two or more. In the present invention, polyethylene glycol is particularly preferred because it has almost no toxicity to living organisms and there is no risk of rancidity or mold growth. These polymer compounds may be commercially available. In this case, preferred molecular weight and viscosity are polyethylene glycol with a molecular weight of 4000 to 50000, polyvinyl alcohol with a degree of polymerization of 1000 to 3000, and methylcellulose, carboxymethylcellulose, and hydroxypropyl cellulose with a viscosity of 2% by weight aqueous solution of 2000 to 3000.
Preferably in the 10000cps range. Since the above-mentioned polymeric surfactant is water-soluble, in the calcium phosphate hydraulic cement composition according to the present invention, it is preferable to include it in advance in water, which is usually a hardening liquid, or to cement it in powder form. It may also be included in powder. Furthermore, it is also possible to contain it in both powder and liquid. In the present invention, the concentration of the polymeric surfactant in the cured aqueous solution varies depending on the type, molecular weight, viscosity, etc. of the polymeric surfactant used, as well as the type of calcium phosphate compound used, but in general, A range of about 1-50% by weight is preferred. If it is less than 1% by weight, sufficient operability will not be obtained;
If it exceeds 50% by weight, the viscosity during kneading will be too high and it will be difficult to use, which is not preferable. For example, as a cement powder, a mixture of α-type tribasic calcium phosphate and dibasic calcium phosphate dihydrate (Ca/P
When using polyethylene glycol with a molecular weight of 6,000 to 20,000 as the polymeric surfactant, the concentration of polyethylene glycol in the curing aqueous solution is preferably 5 to 50% by weight. In the calcium phosphate hydraulic cement composition according to the invention, the curing aqueous solution used contains:
Furthermore, lubricant is added in an amount of 1 to 20% by weight based on the curing aqueous solution.
It is preferable to add it from the viewpoint of operability during kneading. Preferred lubricants include, for example, glycerin. As calcium phosphate compounds that can be preferably used in the calcium phosphate hydraulic cement composition of the present invention, for example, α-type tertiary calcium phosphate, quaternary calcium phosphate, dibasic calcium phosphate dihydrate, etc. are used alone or as a mixture of two or more. can. It is also preferable to add β-type tertiary calcium phosphate, hydroxyapatite, fluoroapatite, calcium pyrophosphate, etc., if necessary. In the present invention, in particular, α-type tribasic calcium phosphate and dibasic calcium phosphate dihydrate are used.
A mixture having a Ca/P molar ratio of 1.20 to 1.47 is preferred. This is because the curing time is short and the strength of the cured product is sufficiently high. In addition to the above-mentioned components, the calcium phosphate hydraulic cement composition of the present invention may optionally contain an X-ray contrast agent, an antibacterial agent, etc., if necessary. For example, preferred X-ray contrast agents include barium sulfate, bismuth subcarbonate, iodoform, and the like, and preferred antibacterial agents include iodoform and chlorhexidine. <Examples> The present invention will be explained in more detail below with reference to Examples, but these Examples are not intended to limit the present invention in any way. Example 1 As calcium phosphate compounds, α-type tertiary calcium phosphate and dibasic calcium phosphate dihydrate were used.
Powder materials mixed at a Ca/P molar ratio of 1.33 and α-type tribasic calcium phosphate and quaternary calcium phosphate were mixed.
Powder materials mixed at a Ca/P molar ratio of 1.67 were used. On the other hand, as a polymeric surfactant, the molecular weight
6000 polyethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.)
30% aqueous solution of polyvinyl alcohol with a degree of polymerization of 1750 (manufactured by Tokyo Kasei Co., Ltd.), 2% aqueous solution of methyl cellulose with a viscosity of 4000 (manufactured by Shin-Etsu Chemical Co., Ltd.), carboxymethyl cellulose (standard product, Wako Pure Chemical Industries, Ltd.) KK)
The above calcium phosphate compound powder was hardened using a 2% aqueous solution of hydroxymethyl cellulose (manufactured by Shin-Etsu Chemical Co., Ltd.) with a viscosity of 4000. In all combinations, the operability during kneading was significantly improved, and the fluidity and wettability during kneading were also improved. Example 2 As calcium phosphate compounds, α-type tertiary calcium phosphate and dibasic calcium phosphate dihydrate were used at Ca/P molar ratios of 1.20, 1.25, 1.33, 1.45 and
Powders containing barium sulfate and bismuth subcarbonate as X-ray contrast agents at 15% each based on the weight of the cement powder were used in a powder material mixed at a ratio of 1.47. This powder was cured with an aqueous solution containing 10% by weight of polyethylene glycol (manufactured by Yoneyama Pharmaceutical Co., Ltd.) with a molecular weight of 20,000 as a polymeric surfactant and 10% by weight of glycerin, and the curing time and compressive strength were measured. The compressive strength was measured after leaving the cured product (7 mmφ, 14 mm L) in water at 37° C. for 24 hours, and then taking it out while still wet. For the measurement, a model 1125 universal testing machine manufactured by Instron Co., Ltd. was used, and the loading rate was 0.5 mm/min. The results are shown in Table 1. Comparative Example The curing time and compressive strength were measured in the same manner as in Example 2, except that only water was used instead of the polymeric surfactant. Table 1 shows the results.
Shown below. As is clear from the results shown in Table 1, the curing time is much longer when the polymeric surfactant according to the present invention of Example 2 is used; This is a preferred length of curing time when used as a filler. On the other hand, when only water in the comparative example was used, the curing time was too short to be used as a tooth root canal filling material. Furthermore, as is clear from Table 1, the compressive strength in Example 2 using the polymeric surfactant of the present invention was equal to or higher than that in Comparative Example.

[Table] Example 3 Molecular weight 300000-500000 as a polymeric surfactant
2 of polyethylene glycol (manufactured by Meisei Chemical Co., Ltd.)
Ca/P of α-type tribasic calcium phosphate and dibasic calcium phosphate dihydrate using a wt% aqueous solution.
A cured product was produced in the same manner as in Example 2, except that the molar ratio was 1.33, and the curing time was measured in the same manner. The curing time in this case was 12 minutes. As shown in Table 1 above, in Example 2, the polymer surfactants were cured using a 30% by weight aqueous solution of polyethylene glycol (manufactured by Yoneyama Pharmaceutical Co., Ltd.) with a molecular weight of 20,000 and an aqueous solution containing 10% by weight of glycerin. In the case of Example 2, it is 80 minutes,
Furthermore, the curing time was only slightly extended compared to the comparative example in which the curing liquid was 9 minutes, which was only water. In this case as well, the consistency and operability during kneading were maintained well. In this way, by appropriately selecting the type, molecular weight, addition ratio, etc. of the polymer compound used as the surfactant, it is possible to arbitrarily select the degree of extension of the curing time. <Effects of the Invention> As described above, the present invention provides a calcium phosphate hydraulic cement composition that has appropriate consistency and good operability during kneading. This calcium phosphate hydraulic cement composition has sufficient fluidity and wettability to enable it to be tightly and reliably filled into every corner, even in narrow spaces and places with complex shapes, and its curing time is also required. The degree of extension can be set arbitrarily depending on the situation.

Claims (1)

[Scope of Claims] 1. A hydraulic cement composition containing a calcium phosphate compound as a main component, wherein the hydraulic cement composition contains water and a polymeric surfactant. 2. The calcium phosphate water according to claim 1, wherein the calcium phosphate compound is a mixture of α-type tertiary calcium phosphate and dibasic calcium phosphate dihydrate at a Ca/P molar ratio of 1.20 to 1.47. Hard cement composition.