The Attractive Glass Abutment System () HANDOUT! " " # $ % $ # & ' ( ) FAQs New Solutions Pharmaceuticals Tel.: +971 6 7460661 Fax : +971 6 7460771 P.O.Box. 18161 Ajman - UAE e-mail : info@newsolutionsdl.com www.newsolutionsdl.com
Introduction The concept of using vacuum and adhesion to fix the bridge on the alveolar mucosa is relatively old. Dentists started the experiments using this principle in the beginning of the last century. Many unfortunate attempts have been tried to make this idea a practical reality because finding the right material was always the main obstacle. All the materials used like metal, plastics and ceramics caused irritation and inflammation for the underlying tissues. Eventually, all these problems have been solved as the System has been invented. It is a neutral, chemical resistance material that has no reaction with any substances in the oral cavity. It is very flexible at the melting temperature (1560-1600 C). It has the ability to take the shape of any structure at that temperature with the smallest details. Indications The attractive glass abutment system () can be used in many situations to restore the missing teeth. The ideal indications are to solve free-end saddle cases (distal extension), whether it is unilateral, bilateral, supporting long span bridges and also can be used in combination with implants, as shown in the figure below:-
The situations explained in the figure, are to be considered to have the best prognosis. However, the glass abutment can be used in other cases where less number of natural teeth abutments is present but they are classified to be extreme cases with good stability. So, deciding to apply this system in such cases is dependant on the patients' chief complaint. The glass abutment system can also be used in association with implants with caution. As a scientific fact, implants are rigid inside the bone which gives no range of movement during the mastication. Natural teeth and the glass abutment have micro movement in response to mastication forces due to the soft tissue pad (resiliency of the mucosa). So, Glass abutment/implant supported FPDs could be critical since there is a discrepancy in the forces absorption mechanism. However, many cases have succeeded. Case selection & basic principles To fully understand the applications of the glass abutment system () and to have the ability to make a good case selections and speculate its prognosis, it's essential to follow these basic principles: 1- Alveolar ridge condition: as the Glass abutment will be seated on the alveolar mucosa and subsequently on the ridge. It is important to have relatively acceptable boney structure with stable soft tissue covering since it takes the support from that apparatus. In cases of a very narrow alveolar ridge or extensively moving flabby tissues, it is not advisable to use the glass abutment unless some simple surgical corrections for the alveolar ridge to be made first (alveoplasty etc.).
2- Status of the existing dentition: since we are dealing with fixed prosthetic dentures, we should look carefully at the natural teeth abutments. As a basic rule in cases of the glass abutments supported FPDs, the number of missing teeth should equal the number of natural teeth abutments (preparations), for example: if the first and second molars are missing, first and second premolars should be prepared as natural teeth abutments and the glass abutment is always placed under the last posterior tooth. The glass abutment can also be used in the anterior region and can be totally covered with ceramic for an acceptable esthetic appearance. The glass abutment should not be placed in close contact to the adjacent natural teeth since that may cause irritation of the interdental papilla and losing the bone regeneration feature. For instance, if the plan was to make a three-unit bridge whereas the second premolar and the second molar are present to replace the missing first molar. In such cases, do not us the glass abutment under the pontic area i.e. the first molar area. The minimum number of prosthetic units to be used with the glass abutment system is four. (2 units over the natural teeth abutment, one ponitc and the glass abutment will be placed under the last posterior tooth) 3- Antagonism: moreover the importance of the adjacent teeth, the presence of an antagonist dentition (opposing teeth) is significant in order to activate many special features in the Attractive Glass Abutment System (): a- Even distribution of forces b- Bone stimulation and osteoblastic activity c- Gingival cells reservation d- Self-cleansing mechanism Note: * A partial antagonism is acceptable. ** The antagonist could be a natural tooth, FPD, RD, or another Glass Abutment supported FPD.
Contraindications: 1- Narrow alveolar bone crest 2- Severely resorped boney structure 3- Unstable alveolar mucosa with lateral movement exceeding (5-8mm) 4- Fresh socket / not healed extraction site 5- Oral pathologies 6- Supra-eruption position of the opposing dentition. Dentist's part Basically, the clinical procedure that is needed to be done on the dental chair includes: 1- Case selection : the case selection depends on understanding the system's principles. 2- Preparation : natural abutment teeth preparation in compliance with the type of chosen pillar construction. 3- Final impression : good final impression clearly showing the finish line and the adjacent alveolar bone where the glass abutment will be placed. The Glass Abutment System can be used with most bridges construction materials available in the market (Precious materials, non-precious, PFM, Zirconia etc ) The dentist should discuss with the () certified technician about the position of the glass abutment as the dentist can examine the condition of the alveolar ridge and the adjacent teeth clinically better than to be understood from the gypsum model. Bite registration is required either with wax or other materials. If there are no support zones preserved, record interalveolar relation with wax rim
Laboratory procedure The policy of our company is to maintain the good quality and make sure that every case comes out of the laboratory is absolutely correct. So, (8) laboratories have been chosen covering areas of Abu Dhabi, Dubai, Al-Ain, Sharjah and Ajman to provide the best service to the dentists. When the impression is received, it will be poured, trimmed and becomes ready for starting the laboratory procedure, which is generally includes: 1- Marking the place of the glass abutment on the model. 2- The glass abutments are provided to the laboratories inside plastic capsules, and they are in two different sizes; large and small depending on the of dimensions of the ridge. 3- The glass abutment will carried by a handle especially designed for this purpose, with different head sizes goes with the size of the glass abutment. 4- The glass abutment will be heated to a high temperature (1550-1600 C) On this degree, the glass abutment will be a soft ball ready to be pressed on its marked place on the model (ridge). 5- Pressing the soft glass abutment on the model. In this stage, the glassy material will take exactly the shape and the details of the alveolar ridge and that will be transferred to the patient mouth.
6- With () special burs, the glass abutment will be prepared to the desired shape and to create specific retention features. 7- Preparing the bridge units 8- Provide it to the dental clinic Why the glass? The glass was the material of choice for the following reasons : 1- Melting ability 2- Workability 3- Rigidity 4- Chemical resistance The attractive glass abutment () is made of special type of glass that has special features : Melting Temperature : 1550 1600 C Pressure Strength : (120 150) Mpa/Kp/mm 2 Elastic coefficient ranges from (500-800) MPa Poor thermal and electrical conductivity Withstand great pressure and shearing power Delivery instructions After the laboratory procedure is finished, the glass abutment and the FPD will be delivered to the dentist. So, what to do next?
1- Removal of the temporary crowns 2- Removal of any remnant of the temporary cement 3- Moisten the glass abutment and its place in the FPD with water and put them together (temporarily). Do not use cement 4- Try-in the FPD with temporarily applied glass abutment to find out their precision. 5- With a sharp excavator, check the quality of the peripheral seal between the mucosa and the glass abutment How to Examine the fitting of the Glass Abutment supported FPD? Stability Test : Place the glass abutment on the burning sign that s marked on the gypsum model, with the identification groove directed buccally, press the glass abutment by directing a vertical force with your index finger toward the model, if any movement was noticed, you need to contact your technician. Blanching Test : During the try-in stage, the patient should be asked to close on the glass abutment supported FPD. Blanching of the mucosa underneath the glass abutment should be observed. The blanching should not be present on opening; otherwise, a continuous pressure will be directed on the alveolar bone which will end up in bone resorption. This sign may vary in intensity and in time needed to be apparent as sometimes it is a gradual process. So, careful examination is required. Saliva Adhesion Sign During the blanching test, ask the patient to open and close. Escaping of a small amount of saliva from underneath the glass abutment on biting is considered to be a positive sign.
6- Having successful tests guarantees the accurate placing of the glass abutment in the patient mouth subsequently we can start cementation of the glass abutment. In this stage, the glass abutment should be cemented inside the FPD using (Zinc Phosphate) or (Zinc Polycarboxylate) cements but Not Glass Inomer cement due to some unfavorable reactions between the cement and the component of the glass abutment.(gic can be used to cement the FPD to the natural teeth abutments only). Remove all the excess and make sure that the fitting smooth surface of the glass abutment is free of cement. The fitting surface can be cleaned with a moistened cotton pallet and a tweezer, keep outside the patient mouth until it is set. 7- Dryness of the natural teeth abutments and prepare them for either permanent or temporary cementation. 8- Cementation of the glass abutment supported FPD in the patient mouth with the desired permanent cement. 9- Adjustment of the occlusion (if needed) with the articulating paper. Usually the patient will not feel any pressure, pain or presence of a forgiven body. But the clinical studies showed that, some of the patients may have a slight discomfort for (3-5) days in the area of the glass abutment due to the adaptation process of the alveolar mucosa. The patient should be aware of this possibility, reassurance and periodical check-ups should be carried out.
Periodical check-ups are recommended to be after one week, three months and every six months. Oral Hygiene instructions (Brushing, flossing etc)
WHAT MAKES THE GLASS ABUTMENT SYSTEM () SO UNIQUE? A- Providing patients with a fixed prosthesis instead of removable and a prognosis similar to the conventional FPDs and even more. B- There is absolutely no need for any surgical intervention or healing period and that is a great advantage for the medically compromised patients who can't undergo a surgical treatment. C- Forces distribution : one of the most important advantage of the attractive glass abutment system () is the distribution scheme of the mastication forces. This system is a revolutionary solution for the distal extension cases since it distributes the loads all over the alveolar ridge and the units of the bridge not only on the natural teeth abutments. The forces take an arch-shape spread all over the bridge area. D- Bone reservation / regeneration under the glass abutment i.e. stimulation of the osteoblastic activity and increase of the bone calcium (Ca) content. This feature is of a great significance as there will be no bone resorption associated with the attractive glass abutment system (). The glass abutment moves almost 3000 movement/day in the axial direction, this movement will have like a massaging effect that enhances the blood circulation in the area. Moreover, the fitting surface area of the glass abutment is similar to the overlying crown. This similarity will guarantee an optimum magnitude of forces to be directed toward the underlying tissues. these forces are ideal to stimulate the bone cells. E- Gingival tissues reservation / regeneration. F- Self-cleansing mechanism: because of the optimum homogeneity of () material.
Every time the patient releases the bite, enough amount of saliva will be under the glass abutment, on biting, and due to the presence of the opposing tooth, the saliva will be pushed out. So, the fitting surface will be absolutely clean with no soft tissues irritation or inflammation. G- Cost and time efficient as the charges are comparatively much less, and it will be delivered to be readily used within a week time.
Frequently Asked Questions 1- Does the vacuum created by the glass abutment system cause ischemia? No, Due to the micro-movement of the glass abutment which will massage the mucosa and enhances the blood circulation, moreover, it is not very powerful vacuuming system, it is just enough to ensure the stability of the bridge. 2- Will the glass abutment cause bone resorption? No, on the contrary, the glass abutment causes bone regeneration by the stimulation of the osteoblastic activity as long as increasing the calcium content of the bone. 3- Will the glass abutment cause soft tissue irritation? No, the glass abutment is a homogenous, smooth material that causes no mechanical irritation of the underlying tissues in addition to that is the selfcleansing mechanism. 4- How to maintain the hygiene under the glass abutment (food impaction, cleaning etc)? First of all, due to the tight contact between the glass abutment and the underlying mucosa, no food impaction can take place. However, accumulation of plaque is also not favorable because of the self-cleansing mechanism, homogeneity and smoothness of the material. 5- How many pontics the glass abutment can tolerate? There is no specific figure, but it depends on the system's main principle which says ; the number of missing teeth should equal the number of natural teeth abutments (preparations), for example: if the first and second molars are missing, first and second premolars should be prepared as natural teeth abutments and the glass abutment is always placed under the last posterior tooth. 6- What is the prognosis of the glass abutment supported FPDs.? It depends on accuracy of case selection and the quality of the natural teeth abutments. According to the studies, the glass abutment supported bridges lasted for 12-15 years. But generally, the prognosis is same as any conventional FPD. 7- What is the difference between the conventional cantilever bridge and glass abutment supported bridge? The significant difference is the forces distribution. It distributes the loads all over the alveolar ridge and the units of the bridge not only on the natural teeth abutments. The forces take an arch-shape spread all over the bridge area. While the open end cantilever have all the forces concentrated on the natural teeth abutments only. Moreover many features come with the massaging effect of the glass abutment system that is not present in conventional cantilever like bone regeneration and self-cleansing mechanisms. 8- Is it possible to use this system in the anterior region? Yes, with a very good esthetic as it can be covered with ceramic.
9- Is it possible to replace a single tooth only depending of the system's vacuum concept without preparing the adjacent natural teeth? No, the vacuum system is designed for stabilizing and hygiene purposes only. 10- Is it possible to be used in the replacement of a single tooth by preparing one adjacent tooth only to construct a two-unit bridge? No. Because of the approximation to the interdental papilla that may end up in irritation and resorption. Moreover, the minimum number of prosthetic units to be used with the glass abutment system is four to ensure good stability. 11- Is it possible to be place mesial to the edentulous area? No, it should be always the last posterior to have a good stability and to be away from the interdental papilla. But the only exception is in the cases of supporting long span bridges. 12- Is it possible to put two glass abutments in the same bridge? No, because the distribution of loads is optimum to activate the bone regeneration mechanism over one glass abutment only. Otherwise the forces will be distributed over a bigger surface area and end up in bone resorption. 13- Is there any special impression material or special impression technique? No, the normal balanced impression techniques and materials. 14- Could it be applied to diabetic patients? Yes, as it causes no periodontal problems and needed no surgical intervention. 15- What is the cost of this system? Comparatively cheap 16- Is it possible to place two glass abutment supported FPDs opposite to each other. Yes 17- Is it possible for the opposing dentition to be removable dentures or conventional FPDs? Yes 18- What is the glass abutment () made of? Thermo-glass plastic material (borosilicate), neutral, chemical resistance material and withstand pressure and shearing power. 19- How to fix the glass abutment inside the bridge? By either zinc phosphate or zinc polycaroxylate but not the GIC as it has some unfavorable reactions with the glass material. 20- What type of bridge construction materials should be used with the glass abutment system? Almost all : PFM, precious material, ceramics and zirconia.
21- Can be used with implants? The glass abutment system can also be used in association with implants with caution. As a scientific fact, the implants are rigid inside the bone which gives no range of movement during the mastication. Natural teeth and the glass abutment have micro movement in response to mastication forces due to the soft tissue pad. So, Glass abutment/implant supported FPDs could be critical since there is a discrepancy in the forces absorption mechanism. However many cases have succeeded.