JP3927293B2 - Method for polymerizing dental photopolymerizable composition and dental light irradiator used therefor - Google Patents

Description

この結果は、光重合性コンポジットレジンは光に近い部分から徐々に硬化していくこと、光重合性コンポジットレジン中の光はその指向性、方向性が無くなるほど多く散乱されていることを示している。
【００３４】
【実施例２】
ヒト大臼歯新鮮抜去歯の咬合面に直径５ｍｍ、深さ４ｍｍの１級窩洞Ｈを形成し、実施例１で用いた光重合性コンポジットレジンをシステムに付属のボンディング材を用いて僅かに少ない目に充填し、図５（ａ）に示すように、実施例１に記載した光照射器のＥＳＣＡファイバー５を窩底にまで挿入し、２０秒間光を照射した。その後、（ｂ）のように、ＥＳＣＡファイバー５を修復物表面で切断し、（ｃ）のようにその上に上記の光重合性コンポジットレジンＭを盛り足して歯冠形態を回復し、上記光照射器からのレーザ光を盛り足した光重合性コンポジットレジンＭＡ上部より照射して充填修復操作を終えた。この修復歯に対し、４℃〜６０℃、各１分ずつのサーマルサイクル試験を１０００回加えたが、修復物の脱落は認められなかった。この試験後、試験に供した歯を、０．１％塩基性フクシン水溶液に３７℃にて１日間浸漬し、歯を切断して断面を観察したところ、窩壁への色素の侵入は認められず、窩底のギャップも観察されなかった。
【００３５】
〔比較例〕
ヒト大臼歯咬合面に実施例２と同じ方法にて同じ大きさの窩洞を形成し、実施例２と同じ接着剤と光重合性コンポジットレジンを用いて充填を行った。次に、この光重合性コンポジットレジンに対し、市販の光照射器「スペクトラム」（デンツプライ社，光強度７００ｍＷ／ｃｍ² ）の光を上方３ｍｍの距離より２０秒間照射したところ、窩洞周縁に同心円状に白い線が発生し、この試料を０．１％塩基性フクシン溶液に１日間浸漬したところ、上記の白い線に沿って赤い色素が浸透しているのが観察された。
【００３６】
【実施例３】
図３に示すように、実施例１と同じレーザ光源１を用い、それから発生するレーザ光を直径０．５ｍｍ，長さ２０ｍのポリウレタン系被覆付きアクリル系光ファイバー２（三菱レイヨン社製、ＥＳＣＡ）に直接導き、該光ファイバー先端部２ａを、内部に光ファイバーを長手方向に導通可能にした金属製把持部（ハンドピース）３の中を通しハンドピース３の先端より６ｍｍ突出させたものを光照射器として使用した。光ファイバー２は、光照射器の光源１Ａの上部に設けたリール手段１５にコンパクトに巻き付け、必要な長さをリール手段１５から引き出して使用する。
患者の大臼歯の咬合面に直径４ｍｍ，深さ３ｍｍの１級窩洞を形成し、そこに、実施例２で用いたボンディング剤及びコンポジットレジンを適用し、充填した。次に、上記光照射器の光ファイバー２の先端部２ａを窩底部近傍に挿入し、レーザ光を２０秒間照射し、コンポジットレジンを硬化させ、光ファイバーを窩洞内より抜き去り、これにより、窩洞内に形成された孔部とその上部に前述のコンポジットレジンを追加し、望ましい歯冠形態を形成した。次に、同じ光照射器を用いて今度は光ファイバーを窩洞上方３ｍｍに位置させ、２０秒間レーザ光を照射し、追加したコンポジットレジンを硬化させて歯冠形態を固定した。
その後、患者の体液に汚染された可能性のある光ファイバー２の先端部２ａを切断して廃棄し、ハンドピース３，先端ガイド１３およびカバー１４を滅菌して、窩洞の填塞操作を終えた。
【００３７】
【発明の効果】
本発明の歯科用光照射器を使用した本発明の方法によれば、以下の利点を得ることができる。
１．光重合性コンポジットレジンが窩洞または歯科用模型の底面から表面部に向かうように重合硬化するので、底部に未硬化部分が残るおそれがなく、光重合性コンポジットレジン全体が完全に硬化する。
２．光重合性コンポジットレジンと歯質との接着界面に、光重合性コンポジットレジンの重合収縮応力を負荷して接着層を破壊する危険性が少なく、光重合性コンポジットレジンと歯質との強力な接着を実現することができ、光重合性コンポジットレジンの脱落が少なくなる。
３．光重合性コンポジットレジンと歯質との間の間隙が無くなり、齲蝕原因菌の繁殖場所が無くなり、齲蝕の再発が防止できる。
４．患部が非常に深い場合にも、窩底に接する部分の光重合性コンポジットレジンが未重合のまま残されているという可能性は無くなり、光重合性コンポジットレジン成分の歯髄への浸透の可能性が大幅に低減される。
５．窩洞に導入した光ファイバーから光を照射するため、光が口腔外に放射されることがなく、歯科医が強力な光照射にさらされて、目に障害を受ける恐れがない。
６．光照射器先端の光放射部を患者ごとに滅菌可能とし、患者の体液で汚染された部分の光ファイバーを切断して捨て、さらに、汚染される可能性のある部分をカバーにて被覆し、そのカバーを患者ごとに使い捨てとすることにより、患者間の交差感染が防止できる。
【図面の簡単な説明】
【図１】（ａ）は本発明の第１実施形態に係る歯科用光照射器を示す構成図、（ｂ）は光照射器の光ファイバーが窩洞に挿入された状態を示す図である。
【図２】第２実施形態に係る歯科用光照射器を示す構成図である。
【図３】第３実施形態に係る歯科用光照射器を示す構成図である。
【図４】本発明の実施例に係る歯科用光照射器を示す構成図である。
【図５】充填修復操作を示す図である。
【符号の説明】
１…光源、２…導光手段、５，２ａ…先端部（光放射部）、Ｈ…窩洞、Ｍ…光重合組成物。[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a method for polymerizing a dental photopolymerizable composition used for performing caries filling and repair treatment, and a light irradiator for irradiating the photopolymerizable composition.
[0002]
[Prior art]
In recent years, a dental polymerizable composition (composite resin) composed of a polymerizable monomer, a polymerization initiator, and an inorganic filler has been improved in strength and wear resistance, and easily reproduced in color tone and tooth form. Progress in this area has been recognized, and it has been used in many other applications such as caries filling restoration, crown materials, and so on. In particular, a photopolymerizable composite resin that initiates polymerization upon irradiation with visible light has dramatically expanded the market because of its convenience, and is now a standard product.
[0003]
However, such polymerizable composite resins also have drawbacks. That is, shrinkage occurs when polymerizing, and particularly, when a photopolymerizable composite resin is polymerized, a very large shrinkage stress is generated, and a gap is generated between the cavity and the composite resin. This contraction stress is also related to pain during treatment of the patient, and since the gap can cause the filling to fall off and can also be a breeding space for caries-causing bacteria, methods for avoiding the creation of gaps have been intensively studied. However, there is still no technology to solve this problem essentially.
[0004]
The dental light irradiator used for polymerizing the polymerizable composite resin will be described below. The most commonly used one is a light source using a halogen-tungsten lamp and an on / off state of the light source. It consists of control means consisting of switches and timers for setting off and irradiation time, cooling means consisting of cooling fans, and light guiding means that bundles optical fibers in a thickness of about 6 mm to 16 mm, and more Light illuminators aiming at irradiating a thick light beam with a large amount of light from above the photopolymerizable composite resin filled in the cavity are dominant. The method of polymerizing a photopolymerizable composite resin using such an irradiator further expands the problems of gaps and cracks based on the polymerization shrinkage.
[0005]
For example, when light is irradiated from above the photopolymerizable composite resin filled in the cylindrical cavity, the photopolymerizable composite resin on the cavity surface is polymerized and hardened in the first few seconds, and the cavity surface is covered. In the next few seconds to several tens of seconds, the remaining deeper photopolymerizable composite resin is polymerized, but due to the shrinkage accompanying the polymerization, the occurrence of gaps and cracks is inevitable. In addition, the higher the intensity of light, the faster the photopolymerization occurs, but the faster the polymerization, the faster the polymerizable composite resin shrinks, and gaps and cracks are likely to occur.
Furthermore, in the method of irradiating light from above the cavity of the photopolymerizable composite resin, it is impossible to confirm that the photopolymerizable composite resin at the bottom of the fossa is really polymerized and cured, and an unpolymerized composite resin is not formed at the bottom of the cavity. The risk of the monomer component penetrating into the dental pulp at a high concentration could not be excluded.
[0006]
Based on this problem awareness, Japanese Patent Application Laid-Open No. 64-15037 proposed a shrinkage correction type differential photopolymerization method. In this proposal, two types of photopolymerizable composite resins that are sensitive to different wavelengths are prepared. First, a first photopolymerizable composite resin is applied to the fossa wall, and then a second photopolymerizable composite resin is applied thereon. It is proposed to fill, then photopolymerize the second photopolymerizable composite resin, and finally to photopolymerize the first photopolymerizable composite resin, and dentine due to polymerization shrinkage occurring in the cavity Teaches how to minimize adverse effects on
[0007]
This proposal does not cure a relatively small amount of the first photopolymerizable composite resin corresponding to the protective material of the fossa wall, and the second photopolymerizable composite resin, which is the main filler, is polymerized first. The polymerization shrinkage of the photopolymerizable composite resin is compensated by the flow (deformation) of the first photopolymerizable composite resin, so that the shrinkage of the second composite resin can be completed without damaging the tooth, Even if a relatively small amount of the first photopolymerizable composite resin is polymerized thereafter, if the amount of the first photopolymerizable composite resin is small, the contraction has little effect on the tooth. The point is considered to be.
[0008]
[Problems to be solved by the invention]
However, the above proposal does not have a specific description regarding the material used for this purpose, the operation method is complicated, and the effect is technically questionable. That is, the dental polymerizable composite resin is a slurry or paste-like material, and even if the fossa wall is protected with the first photopolymerizable composite, the second polymerization is performed in a small hole like a carious cavity. It is very difficult to fill the polymerizable composite resin that protects the cavity wall without flowing or deforming, and as a result, the cavity edge (the entrance to the cavity) is the second. It will be covered with a photopolymerizable composite resin. That is, when the second photopolymerizable composite resin is polymerized and cured, it is difficult to avoid the phenomenon that the composite clogs the cavity surface and polymerization shrinkage stress is generated inside the cavity.
[0009]
Also, for example, even if the first photopolymerizable composite resin and the second photopolymerizable composite resin start polymerization at different wavelengths, generally the photopolymerization initiator is only a certain single wavelength. It does not respond selectively, but it absorbs light in a fairly wide wavelength range and responds. Further, a light irradiator using a halogen lamp that is generally used at present also includes light in a wide wavelength range. Therefore, when photopolymerizing the second photopolymerizable composite resin, it is difficult to completely prevent the polymerization of the first photopolymerizable composite resin from being induced. This phenomenon cannot be avoided. For these reasons, there are many unreasonable points in this proposal, and problems remain.
[0010]
On the other hand, the present inventors conducted an experiment in which a light-dispersible rod (manufactured by Harwey, Lucy Wedge) was inserted into a composite resin lump and irradiated with laser light at the light entrance of the rod. Was dispersed mainly from the peripheral surface of the rod, but the intensity of the dispersed light was stronger as it was closer to the light entrance, and when the composite resin polymerized by the light dispersed from the rod was examined, the composite resin It was found that the head hardened well, but the tip of the rod hardly hardened.
[0011]
Even when a transparent plastic rod or tube is inserted in place of the light-dispersible rod and the same experiment is performed, the composite resin is hardened in the vicinity of the light entrance and the end of the rod is hardened. Part of the composite resin hardly cured. This is presumably due to the fact that in the above light guiding means, a lot of laser light is dispersed in the vicinity of the light entrance and there is little laser light irradiated from the tip of a rod or the like. Therefore, in the conventional technique of introducing laser light into the composite resin, the surface of the cavity close to the light source is cured first, and the bottom is not sufficiently cured. Absent.
[0012]
An object of the present invention is to provide a method for solving the occurrence of polymerization shrinkage stress in the cavity wall by carrying out polymerization from the bottom of the composite resin filled in the cavity and a light irradiator used therefor. Furthermore, the present invention relates to a method for preventing the infection of a doctor or other patients by making the tip of the dental light irradiator disposable, which is contaminated with blood, saliva, etc. of the patient during dental treatment. It is to provide a light irradiator.
[0013]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that when thin light is incident on the dental photopolymerizable composition (composite resin), the light is caused by the filler constituting the photopolymerizable composite resin. In response to severe scattering, the inventors have found that light spreads in a spherical shape in the photopolymerizable composite resin, that is, spreads in a direction almost opposite to the incident direction. In addition, the dentin of the teeth scatters light as well as the photopolymerizable composite resin, and a considerable part of the light incident on the bottom of the carious cavity composed of dentin is reflected toward the photopolymerizable composite resin. I found out that it would be. Based on this finding, the present invention has been completed. That is, the method for polymerizing a dental photopolymerizable composition of the present invention comprises a light irradiator comprising a light source of laser light and a light guide means having at least a light emitting portion at the tip formed of an optical fiber and connected to the light source. A method for polymerizing a used dental photopolymerizable composition, wherein the cavity of a dental mold is filled with the photopolymerizable composition, and the light emitting part of the light guide means is near the bottom of the photopolymerizable composition. The photopolymerizable composition is polymerized and cured from the bottom to the surface by emitting laser light having a wavelength of 350 to 500 nm at 10 to 100 mW from the tip of the light emitting part. After the polymerization and curing of the photopolymerizable composition, the light emitting part formed of an optical fiber can be cut at the surface of the cured composition, and the optical fiber can be placed in the cured composition. In contrast to this, an optical fiber having a non-affinity surface to the photopolymerizable composition is used as the optical fiber, and after the polymerization and curing of the photopolymerizable composition, the optical fiber is extracted from the cured composition and thereby formed. The voids can be further filled with a photopolymerizable composition, and the composition can be polymerized and cured. The dental light irradiator of the present invention includes a light source that emits a laser beam having a wavelength of 350 to 500 nm at 10 to 100 mW, and at least a light emitting portion at the tip is formed of an optical fiber, and the light emitting portion is a cavity of a dental mold. Or introduced near the bottom of the photopolymerizable composition filled in the cavity Have a length Laser from the tip only Rays Radiation The composition is photopolymerized from the portion near the bottom of the cavity toward the surface. With light guiding means The light emitting part has a surface having affinity for the photopolymerizable composition. . The light radiating unit may be integrated with or separate from the light guide means. In the case of a separate body, the dental light irradiator is provided with a detachable mechanism for connecting or detaching the light radiating part to or from the light guide means. Can be provided. In addition, when the light emitting unit is integrated with the optical fiber forming the light guide means, the light guide means can be provided with a cutting mechanism for cutting the optical fiber. . Good Preferably, a cover for preventing contamination covering the light guide means is provided.
[0014]
To repair the cavity using the method of the present invention, the dentist applies the special adhesive attached to the dental photopolymerizable composite resin product to the cavity created by removing the caries-infected tooth. Thereafter, the photopolymerizable composite resin, which is a photopolymerizable composition, is filled in the cavity with a slight amount. Thereafter, the light guide means of the light irradiator of the present invention is inserted into the oral cavity, the light emitting portion at the tip of the light guide means is inserted into the cavity, and the tip of the optical fiber forming the light emitting portion contacts the fossa bottom. Alternatively, after reaching the portion determined to be immediately before, light is irradiated for a time required for polymerization of the photopolymerizable composite resin. Thereafter, the optical fiber is pulled out from the cavity, or the optical fiber is cut at an appropriate portion while leaving the optical fiber in the cavity, and the light guide means is removed from the oral cavity.
The irradiator used in the present invention is composed of a light source, a light source control means, a light guide means, and a light radiating unit integral with or separate from the light source means.
When the optical fiber is left in the cavity, the optical fiber protruding from the filling surface is cut at the filling surface. Next, an amount of photopolymerizable composite resin sufficient to restore normal crown shape is added on the cured composite resin, and light is irradiated from above to polymerize the added photopolymerizable composite resin. The repair is completed by fine adjustment and polishing.
In addition, preparation of a dental prosthesis using a dental mold can be performed according to the above-described method. In that case, the photopolymerizable composition is filled in the cavity of the mold, and this is polymerized and cured by the light irradiator of the present invention.
[0015]
The optical fiber used in the present invention may be made of either acrylic plastic or quartz. Since it is inexpensive and the photopolymerizable composite resin is an acrylic compound, an acrylic resin is preferable in consideration of the adhesiveness between the optical fiber and the photopolymerizable composite resin.
When leaving the optical fiber in the cured composition, it is desirable to use an optical fiber having a surface having an affinity for the polymerizable composition, and to firmly bond the cured composition and the optical fiber. If the adhesion between the optical fiber and the cured composition is insufficient, fine voids may be formed there, which may cause secondary caries.
When the optical fiber is an acrylic plastic, the compatible surface may be the optical fiber itself. When the optical fiber is a quartz optical fiber, the surface of the optical fiber is coated with a known silane coupling agent to form the compatible surface. Can be made.
[0016]
When pulling out the optical fiber from the cured composition, it is desirable to use an optical fiber having a non-affinity surface for the polymerizable composition to facilitate the extraction from the cured composition. The non-affinity surface can be formed by coating the surface of an optical fiber with a nonpolar polyolefin, a synthetic rubber or a fluorine-containing polymer.
When there is a space from which the optical fiber is drawn, it is necessary to sufficiently fill the space with the photopolymerizable composite resin.
[0017]
The light source used in the dental light irradiator of the present invention is a laser having a wavelength of 350 to 500 nm, specifically Nd: YAG (Nd: Y _Three Al _Five O ₁₂ ), The laser oscillation wavelength of 946 nm is oscillated, and KN (KNbO) which is a nonlinear optical crystal is oscillated in this resonator. _Three ) Is inserted to oscillate the second harmonic (473 nm). As another light source, a semiconductor laser that oscillates at a wavelength of 350 to 500 nm, or a lamp light source such as a halogen-tungsten lamp or a metal halide lamp can be used. It is important that the lamp light does not heat the irradiated part through the infrared cut filter.
It is also possible to use an array of LEDs instead of the laser light to collect light.
The reason why the wavelength of light is set to 350 to 500 nm is that if it is less than 350 nm, the human body is adversely affected by ultraviolet rays, and if it exceeds 500 nm, photopolymerization is not excited, and with respect to light intensity, a laser light source is used. The light intensity in the case of 10 mW to 100 mW is necessary, and the light intensity in the case of the lamp light source needs to be 10 mW to 200 mW. Since the laser beam has a single wavelength, the curing performance of the composition is excellent, so that the polymerization can be performed with less light intensity than the lamp light. If it is less than the lower limit of the above light intensity, photopolymerization does not act, and if it exceeds the upper limit, the human body is thermally adversely affected.
[0018]
The control means used in the dental light irradiator of the present invention comprises a timer and a switch for turning on / off the light source, blocking / releasing the optical path from the light source to the light guide fiber, and setting the irradiation time.
[0019]
The light guide means used in the dental light irradiator of the present invention can use an optical fiber, and the light from the light source is guided to the optical fiber by, for example, a condensing optical system, and the light is inserted into the cavity. It leads efficiently to the radiation part. This optical fiber may be a monofilament or a multifilament, and there may be a connection point in the middle from the light source to the tip portion inserted into the cavity.
[0020]
In the present invention, it is important that the light emitting part introduced into the photopolymerizable composition is an optical fiber. An attempt was made to insert the spectroscopic rod proposed in the aforementioned Japanese Patent Application Laid-Open No. 64-15037 or a transparent light-guiding rod having no spectroscopic property into a cavity filled with a photopolymerizable composite resin. The directional rod transmits incident light in all directions, and polymerization cannot be started from the cavity floor alone, and even a transparent rod has a sufficient effect because a large amount of light leaks to the cavity surface. There wasn't. On the other hand, since light is not emitted from the side surface of the optical fiber but light is emitted only from the tip, the light can be emitted from the cavity or the bottom of the mold very well. Further, since the diameter of the optical fiber is extremely thin, it is superior to a spectroscopic rod or the like in any of insertion, placement, and removal from the photopolymerizable composite resin.
[0021]
The tip of the optical fiber to be inserted into the cavity according to the present invention should be detachable so that it can be easily removed in order to simplify the treatment after the photopolymerizable composite resin in the cavity is cured. To make it easy to cut. This optical fiber is preferably disposable.
[0022]
The light irradiator of the present invention can be constituted by a light guide means comprising a light source and one continuous optical fiber. In this light irradiator, it is preferable to provide a cutting mechanism for cutting the optical fiber near the tip of the light guide means. After introducing and treating the distal end of the optical fiber into the cavity, it is desirable to cut and discard the distal end of the optical fiber that may be contaminated by the patient's blood saliva or the like. For each individual patient, it is desired to always perform dental treatment with a clean optical fiber.
The optical fiber may be cut with a scissors or a knife, but from the viewpoint of convenience of operation, it is preferable that the cutting mechanism is incorporated in a handpiece that holds the optical fiber. For example, a button can be provided on the handpiece, and the optical fiber can be cut directly by the force of pressing the button, or the force can be transmitted to a rod and the optical fiber can be cut at an arbitrary position by a cutter at the end of the rod. it can.
Further, if an optical fiber attaching / detaching mechanism is provided between the light guide means, light is attenuated at the portion, and the amount of light applied to the cavity is reduced. Since the continuous optical fiber has no attachment / detachment mechanism, the light utilization rate is excellent.
The attachment / detachment mechanism is preferably provided with adjuster / adapter means for making both optical axes coincide with each other and making attachment / detachment easy.
[0023]
It is important that the thickness of the optical fiber is not excessively removed by the insertion of the photopolymerizable composite resin filled in the cavity, and the diameter is 1.5 mm or less, preferably 1 mm or less, more preferably 0.8 mm or less. Is used. The optical fiber used in the present invention may be a monofilament or a multifilament as long as the above thickness is satisfied, but a monofilament is more preferable because it has less light loss.
[0024]
Although the length of the tip of the optical fiber is related to the design of the light guide means, it cannot be specified unconditionally. However, when the light guide means is a hand piece type that is brought close to the affected area by the hand piece, the optical fiber is 5 mm from the tip of the hand piece. It is desirable to protrude above. In the case where a continuous optical fiber is used as the light guide means, and the tip is held by a handpiece or tweezers and inserted into the cavity, the optical fiber has a length of several meters. However, when the length of the optical fiber is further increased, it is preferable to use reel means for winding up excess fiber.
[0025]
The shape of the optical fiber is related to the length of the optical fiber, but it may be straight when the length protruding from the tip of the handpiece is about 5 mm, but it may be straight, but with a tweezers etc. When gripped and used, it may have a curvature of 10 mm to 50 mm in diameter.
[0026]
It is desirable for the light irradiator of the present invention to prevent contamination by blood saliva of the patient. Since the light guide means close to the light emitting portion has a high possibility of contamination, it should be covered, and the above-described handpiece can also serve as a cover. Further, in order to prevent contamination, a protective pipe may be provided on the light source side of the handpiece, and an additional cover may be provided by passing the light guide means.
Also, an auxiliary cover that covers the dentist's hand and the base part excluding the light emitting part at the tip of the light guide means can be used together. According to this auxiliary cover, it is possible to prevent the device and the dentist from being contaminated by the body fluid of the patient. This cover can insert the light guide means into a bag-like material made of a resin sheet and put the hand into the plastic bag to hold the light guide means. These additional covers or auxiliary covers are replaced and disposable for each patient.
[0027]
The photopolymerizable composite resin used in the dental light irradiator of the present invention is composed of a polymerizable monomer, a polymerization initiator, an inorganic filler, and other additives, and is used for the polymerization. Monomers are alkyl (meth) acrylate (alkyl group having 1 to 10 carbon atoms), polyalkylene glycol di (meth) acrylate (2 to 20 carbon atoms), ethylene glycol oligomer di (meth) acrylate (2 to 10 amount) ), Bisphenol A di (meth) acrylate, 2.2-bis [p- (γ-methacryloxy-β-hydroxypropoxy) phenyl] propane, 2,2-di (4-methacryloxypolyethoxyphenyl) propane (1 2-10 ethoxy groups in the molecule), trimethylolpropane tri (meth) acrylate, pentaerythrito Monofunctional and / or polyfunctional (meth) acrylic acid esters such as rutetra (meth) acrylate, and urethane (reaction product of 2 moles of (meth) acrylate having a hydroxyl group and 1 mole of diisocyanate) Preferred are (meth) acrylic acid esters, specifically monomers as disclosed in JP-B-55-33687 and JP-A-56-152408. These monomers may be used alone, but it is preferable to use a mixture of two or more monomers. The monomer is used in the composition in a proportion of 10 to 50% by weight.
[0028]
Further, the above polymerization initiator is a photopolymerization initiator comprising an α-diketone and a tertiary amine described in JP-A-48-49875 and JP-A-60-26002, JP-A-57. Examples thereof include conventionally known initiators such as α-diketones and peroxides described in JP-203077 and JP-A-60-149603. These catalysts are used in the range of 0.1 to 5% by weight based on the polymerizable monomer.
As the filler, various inorganic, organic, or inorganic / organic composite fillers conventionally used can be used. Specific examples thereof include silicon dioxide (quartz, quartz glass, silica gel), and alumina, but various glasses and ceramics containing silicon and boron and / or aluminum together with various heavy metals. Clay minerals such as diatomaceous earth, kaolin and montmorillonite, activated clay, synthetic zeolite, mica, calcium fluoride, calcium phosphate, barium sulfate, zirconium dioxide, titanium dioxide and the like can also be used.
For the surface treatment of the filler, a commonly used silane coupling agent, for example, ω-methacryloxyalkyltrimethoxysilane (carbon number between methacryloxy group and silicon atom: 3 to 12), ω-methacryloxyalkyltrimethyl. Organosilicon compounds such as ethoxysilane (carbon number between methacryloxy group and silicon atom: 3 to 12), vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltriacetoxysilane are used.
Furthermore, the photopolymerizable composite resin used in the present invention may contain a stabilizer or a general additive such as a pigment, if necessary.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1A shows a light irradiator according to the first embodiment of the present invention. The light irradiator includes a laser light source 1, a light guide means 2 such as an optical fiber, a hand piece 3 for gripping with a hand, and a light emitting portion 5 which is a tip portion of the light guide means 2. As described above, the optical fiber 5 for resin insertion is inserted in the dental photopolymerizable composite resin M filled in the cavity H near the bottom surface and polymerized and cured from the cavity bottom HI toward the surface H2. The light guide means of the present invention comprises the optical fiber 2 that forms the main body and the optical fiber 5 for resin insertion that forms the tip. The handpiece 3 is covered with an auxiliary cover 10 made of a polyethylene bag to expose the optical fiber tip 5. A hand is put inside the cover 10 to hold the handpiece 3. Thereby, the cover 10 covers the handpiece 3 and the hand to prevent the handpiece 3 and the hand from being contaminated by the oral cavity of the patient.
[0030]
FIG. 2 shows a second embodiment, and unlike the first embodiment, the light emitting portion 5A is separate from the light guide means 2. FIG. Further, a light collecting means 6 such as a lens is supported on the handpiece 3 via a frame body 8. For example, an adapter 9 (detachment mechanism) such as a 90 ° rotation connector is detachably connected to the frame 8, and the light emitting portion 5 </ b> A is held by the adapter 9. The light emitting portion 5A is optically connected to the light guide means 2 via the light collecting means 6. The light guiding means 2 may be formed of a transparent plastic rod or tube in addition to the optical fiber.
[0031]
FIG. 3 shows a third embodiment. This light irradiator is provided near the tip of the laser light source 1, the light guide 2 composed of a single continuous optical fiber, the handpiece 3 attached in the vicinity of the tip 2 a of the light guide 2, and the handpiece 3. An optical fiber cutting button 12, which is a cutting mechanism, a tip guide 13 made of a metal tube, an additional plastic cover 14 for preventing the optical fiber 2 from being contaminated by touching the patient's oral cavity, and an upper portion of the laser light source 1. And an optical fiber reel 15 around which the optical fiber is wound. One optical fiber 2 drawn out from the optical fiber reel 15 in the distal direction has an insertion hole in the distal end guide 13 with the distal end portion 2a forming the light emitting portion projecting through the cover 14 and the handpiece 3. Retained. When the optical fiber cutting button 12 is pressed, a cutter (not shown) advances to cut the optical fiber 2, and when the pressing force is released, the button 12 is automatically returned by a spring. The tip 2 a of the used optical fiber 2 is discarded, and a new optical fiber 2 is pulled out from the optical fiber reel 15.
[0032]
[Example 1]
In the following embodiment, as shown in FIG. 4, a semiconductor laser-excited solid-state laser light source 1 that oscillates light having a wavelength of 473 nm as a second harmonic is used as a light source. A light irradiator was used in which an acrylic optical fiber 5B, which is a detachable tip portion, was attached to the handpiece 3 with the optical axis aligned with the optical axis.
A commercially available photopolymerizable dental composite resin “Clearfill AP-X (A2 color)” is filled in a transparent glass tube having a diameter of 10 mm and a depth of 10 mm instead of a cavity, and a diameter of 0.5 mm is provided at the center. Optical fiber (manufactured by Mitsubishi Rayon Co., Ltd., ESCA) was inserted, and 36 mW of light was irradiated for the time shown in Table 1. After that, the photopolymerizable composite resin that adheres to the ESCA fiber and is cured is removed from the glass tube, and the unpolymerized photopolymerizable composite resin that adheres to the outer periphery of the cured resin resin is wiped with chilli paper impregnated with alcohol. left. The cured product was substantially spherical, and the diameter of the cured product was measured using a caliper. The results are shown in Table 1.
[0033]

This result shows that the photopolymerizable composite resin is gradually cured from the part close to the light, and that the light in the photopolymerizable composite resin is scattered so much that its directivity and directionality are lost. Yes.
[0034]
[Example 2]
A first-order cavity H having a diameter of 5 mm and a depth of 4 mm is formed on the occlusal surface of a freshly extracted human molar, and the photopolymerizable composite resin used in Example 1 is slightly fewer using the bonding material attached to the system. As shown in FIG. 5A, the ESCA fiber 5 of the light irradiator described in Example 1 was inserted into the fossa and irradiated with light for 20 seconds. Thereafter, as shown in (b), the ESCA fiber 5 is cut on the restoration surface, and the photopolymerizable composite resin M is added on the ESCA fiber 5 as shown in (c) to restore the crown shape. The filling and repairing operation was completed by irradiating from the upper part of the photopolymerizable composite resin MA with the laser beam from the irradiator. Although 1000 times of thermal cycle tests of 1 minute each at 4 ° C. to 60 ° C. were applied to this restored tooth, no dropout of the restoration was observed. After this test, the teeth subjected to the test were immersed in a 0.1% basic fuchsin aqueous solution at 37 ° C. for 1 day, the teeth were cut and the cross-section was observed, and pigment penetration into the fossa wall was observed. Neither foveal gap was observed.
[0035]
[Comparative Example]
A cavity of the same size was formed on the occlusal surface of the human molar by the same method as in Example 2, and filling was performed using the same adhesive and photopolymerizable composite resin as in Example 2. Next, for this photopolymerizable composite resin, a commercially available light irradiator “Spectrum” (Denzply, light intensity 700 mW / cm ² ) For 20 seconds from a distance of 3 mm above, a concentric white line was generated around the cavity, and when this sample was immersed in a 0.1% basic fuchsin solution for 1 day, A red pigment penetrated along the surface.
[0036]
[Example 3]
As shown in FIG. 3, the same laser light source 1 as in Example 1 was used, and the laser light generated therefrom was applied to an acrylic optical fiber 2 with a polyurethane coating having a diameter of 0.5 mm and a length of 20 m (manufactured by Mitsubishi Rayon Co., ESCA). Directly guided through the metal gripping part (handpiece) 3 through which the optical fiber can be conducted in the longitudinal direction is projected 6 mm from the tip of the handpiece 3 as a light irradiator. used. The optical fiber 2 is compactly wound around the reel means 15 provided on the upper part of the light source 1A of the light irradiator, and a necessary length is drawn from the reel means 15 for use.
A first-order cavity having a diameter of 4 mm and a depth of 3 mm was formed on the occlusal surface of the patient's molar teeth, and the bonding agent and composite resin used in Example 2 were applied and filled therein. Next, the tip 2a of the optical fiber 2 of the light irradiator is inserted in the vicinity of the bottom of the cavity, irradiated with laser light for 20 seconds, the composite resin is cured, and the optical fiber is removed from the cavity. The above-mentioned composite resin was added to the formed hole and the upper part thereof to form a desired crown shape. Next, using the same light irradiator, the optical fiber was positioned 3 mm above the cavity, irradiated with laser light for 20 seconds, and the added composite resin was cured to fix the crown shape.
Thereafter, the distal end portion 2a of the optical fiber 2 possibly contaminated with the body fluid of the patient was cut and discarded, and the handpiece 3, the distal end guide 13 and the cover 14 were sterilized, and the cavity filling operation was completed.
[0037]
【The invention's effect】
According to the method of the present invention using the dental light irradiator of the present invention, the following advantages can be obtained.
1. Since the photopolymerizable composite resin is polymerized and cured so as to go from the bottom surface of the cavity or dental model to the surface portion, there is no possibility that an uncured portion remains on the bottom portion, and the entire photopolymerizable composite resin is completely cured.
2. Strong adhesion between the photopolymerizable composite resin and the tooth with little risk of damaging the adhesive layer by applying the polymerization shrinkage stress of the photopolymerizable composite resin to the adhesive interface between the photopolymerizable composite resin and the tooth The photopolymerizable composite resin is less dropped off.
3. There is no gap between the photopolymerizable composite resin and the tooth, no breeding place for caries-causing bacteria, and caries can be prevented from recurring.
4). Even when the affected area is very deep, there is no possibility that the photopolymerizable composite resin in the part in contact with the fossa remains unpolymerized, and there is a possibility of penetration of the photopolymerizable composite resin component into the dental pulp. It is greatly reduced.
5. Since light is emitted from the optical fiber introduced into the cavity, the light is not emitted outside the oral cavity, and the dentist is exposed to the intense light irradiation so that there is no risk of damage to the eyes.
6). The light emitting part at the tip of the light irradiator can be sterilized for each patient, the optical fiber of the part contaminated with the patient's body fluid is cut and discarded, and the part that may be contaminated is covered with a cover. By making the cover disposable for each patient, cross-infection between patients can be prevented.
[Brief description of the drawings]
FIG. 1A is a configuration diagram illustrating a dental light irradiator according to a first embodiment of the present invention, and FIG. 1B is a diagram illustrating a state where an optical fiber of the light irradiator is inserted into a cavity.
FIG. 2 is a configuration diagram showing a dental light irradiator according to a second embodiment.
FIG. 3 is a configuration diagram showing a dental light irradiator according to a third embodiment.
FIG. 4 is a configuration diagram illustrating a dental light irradiator according to an embodiment of the present invention.
FIG. 5 is a diagram showing a filling repair operation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Light source, 2 ... Light guide means 5, 2a ... Tip part (light emission part), H ... Cavity, M ... Photopolymerization composition.

Claims (7)

  A method for polymerizing a dental photopolymerizable composition using a light irradiator having a light source of laser light and a light guide means having at least a light emitting portion at the tip formed of an optical fiber and connected to the light source, The mold cavity is filled with a photopolymerizable composition, the light emitting part of the light guiding means is introduced near the bottom of the photopolymerizable composition, and the light emitting part is 350 to 100 mW from 10 to 100 mW from the tip. A method for polymerizing a dental photopolymerizable composition, comprising emitting a laser beam having a wavelength of 500 nm to polymerize and cure the photopolymerizable composition from the bottom to the surface.   2. The dental photopolymerizable composition according to claim 1, further comprising: after the polymerization and curing of the photopolymerizable composition, cutting the introduced light emitting portion at the surface of the cured composition, and placing an optical fiber in the cured composition. A method for polymerizing the composition.   The optical fiber according to claim 1, wherein an optical fiber having a non-affinity surface for the photopolymerizable composition is used as the optical fiber, and after the polymerization and curing of the photopolymerizable composition, the optical fiber is extracted from the cured composition, thereby A method for polymerizing a dental photopolymerizable composition, wherein the resulting void is further filled with a photopolymerizable composition and the composition is polymerized and cured. A light source that emits a laser beam having a wavelength of 350 to 500 nm at 10 to 100 mW;
At least a light emitting portion of the tip is formed by an optical fiber, having said light emitting unit length that is introduced into near the bottom of the photopolymerizable composition filled in a dental mold cavity or cavities, tip only A light guide means for emitting the laser beam to photopolymerize the composition from a portion near the bottom of the cavity toward the surface ;
A dental light irradiator in which the light emitting part has a surface having affinity for a photopolymerizable composition .   5. The dental light irradiator according to claim 4, further comprising an attaching / detaching mechanism for connecting or detaching the light emitting portion to / from the light guiding means.   5. The dental light irradiator according to claim 4, further comprising a cutting mechanism for cutting the light emitting portion of the light guiding means. The dental light irradiator according to any one of claims 4 to 6 , further comprising a cover for preventing contamination of the light guide means.

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