Lecture 6 (Tissue Management) PDF

Lecture 7 Asst. Prof. Dr. Manhal Abdul-Rahman FLUID CONTROL & SOFT TISSUE MANAGEMENT Moisture control FLUID SOURCES OF THE ORAL CAVITY Ø Saliva (pair of paro,d &submandibular and sublingual glands). Saliva...

Lecture 7 Asst. Prof. Dr. Manhal Abdul-Rahman FLUID CONTROL & SOFT TISSUE MANAGEMENT Moisture control FLUID SOURCES OF THE ORAL CAVITY Ø Saliva (pair of paro,d &submandibular and sublingual glands). Saliva flow rate 0.26 +/- 0.16 ml/min and that of saliva while chewing different foods was 3.6 +/- 0.8 ml/min. Ø Inflamed gingival ,ssues/ Iatrogenic soH ,ssue damage (Gingival bleeding during tooth prepara,on) Ø Water / dental materials (Rotary instruments, triplex syringe, etchants, irrigant solu,ons). Average a high speed rotatory cuPng instrument is 30 mL per minute. Ø Gingival crevicular fluid (sulcular fluid). Gingival crevicular fluid 0.05 to 0.20 µL per minute. WHY SHOULD ISOLATE THE OPERATIVE SITE? Ø To obtain a dry clean opera,ng field Ø For easy access and visibility Ø To improve the proper,es of dental materials Ø To protect the pa,ent and the operator Ø To improve the opera,ng efficiency How is moisture control important? 1. PaDent related factors Ø Provides comfort. Ø Protects from swallowing or aspira,ng foreign bodies. 2. Task/technique being performed Ø Dental materials are moisture sensi,ve, success of adhesion and physical proper,es relies on a dry field. 3. Operator related factors Ø Infec,on control to minimize aerosol produc,on Ø Increased accessibility to opera,ve site Ø Improves visibility of the working field Ø Less fogging of the dental mirror. Ø Prevents contamina,on. Depending on the locaDon of the preparaDons in the dental arch, a number of techniques can create fluid control & the necessary dry field of operaDon. 1) Mechanical method a) Rubber dam When all margins are supra-gingival, moisture control with a rubber dam is probably the most effec,ve method. In most instances, however, a rubber dam cannot be used, so a Mul,ple Isola,on Techniques should be performed to achieve op,mal saliva control. Advantages of rubber dam are Isola,on of 1 or more teeth, eliminates saliva from the opera,ng field and retracts the soH ,ssues. b) CoUon roll Absorbent co^on rolls must be placed at the source of the saliva, the muco-buccal fold or in the sublingual area, In the maxillary arch, placing a single co^on roll in the ves,bule immediately buccal. If a maxillary roll does not stay in posi,on but slips down, it can be retained with a finger or the mouth mirror. When a mandibular impression is made, placement of addi,onal co^on rolls to block off the sublingual and submandibular salivary ducts is usually necessary. A horseshoe shape co^on in the maxillary and mandibular muco-buccal folds may be also effec,ve. c) CoUon roll holder Holds co^on rolls in place, have two advantages over co^on roll alone, Cheek and tongue are slightly retracted and Enhances visibility. d) Absorbing cards Another method for controlling saliva flow. These cards are pressed-paper wafers that may be covered with a reflec,ve foil on one side. The paper side is placed against the dried buccal ,ssue and adheres to it. In addi,on, two co^on rolls should be placed in the maxillary and mandibular ves,bules to control saliva and displace the cheek laterally. The tongue can cause problems when work is being done in the mandibular arch. Saliva evacuators may help eliminate excess flow. e) Saliva evacuators If lingually placed co^on rolls repeatedly become dislodged (or in conjunc,on with a conven,onal saliva evacuator, fail to control moisture adequately), a flange-type evacuator (e.g., the Svedopter [E. C. Moore Company] or the Speejector [Pulpdent Corpora,on]) should be considered. To avoid the risk of soH ,ssue trauma, this device must be placed carefully. A co^on roll placed between the blade and the mylohyoid ridge of the alveolar process minimizes intraoral discomfort for the pa,ent and avoids  poten,al injury of the soH ,ssues A disposable saliva ejector designed to displace the tongue may also be effec,ve 2) Chemical method a) Local anesthesia In addi,on to the pain control normally needed during ,ssue displacement, local anesthesia may help considerably with saliva control during impression making. Nerve impulses from the periodontal ligament form part of the mechanism that regulates saliva flow; when these are blocked by the anesthe,c, saliva produc,on is considerably reduced. b) MedicaDons When saliva control is difficult a medica,on with an,-sialagogic ac,on (drugs that inhibit parasympathe,c innerva,on, this will inhibit ac,on of myo-epithelial cells of salivary gland thereby reduce secre,ons) may be considered. Dry mouth is a side effect of certain an,cholinergics. This group of drugs includes atropine1 tablet of 0.4mg per day, Methantheline bromide (banthine):50 mg 1 hour before procedure dicyclomine, and Propantheline bromide (pro-banthine): 15 mg 1 hour before procedure. An,cholinergics should be prescribed with cauDon in older adults and should not be administered to any pa,ent with heart disease. They are also contraindicated in individuals with glaucoma because they can cause permanent blindness Clonidine hydrochloride: 0.2 mg 1 hour before procedure, an anDhypertensive drug, has successfully reduced salivary output. It is considered safer than anDcholinergics and has no specified contraindica,ons. However, it should be used cau,ously in hypertensive pa,ents. Clonidine hydrochloride (an,hypertensive) Gingival Retrac.on A procedure by which the finishing line is temporarily exposed by enlarging the gingival sulcus to create a space both laterally and ver9cally between the gingival margin and the gingival termina9on so that the prin9ng material penetrates in sufficient quan9ty to obtain good impression which involves the details of the end margin of the prepara9on that is located subgingivally (the exact copy of the prepara9on). Gingival Sulcus (Crevice) A shallow groove around the tooth bounded on one side by the surface of the tooth and on the other by the epithelial lining of the free margin of the gingiva. It is “V” shaped with its base at the most coronal level of the epithelial aDachment to the tooth root. Biological Width Biologic width is defined as the dimension of the so, -ssue, which is a3ached to the por-on of the tooth coronal to the crest of alveolar bone. There is a definite propor9on between the sulcus depth, the epithelial aDachment, the connec9ve 9ssue aDachment and the alveolar crest. The total width of junc-onal epithelium (range between 0.71 to 1.35mm, mean 0.97mm) and supraalveolar connec-ve -ssue a3achment (rang 1.06 - 1.08mm, mean 1.07mm) forms the biologic width is 0.97 + 1.07 = 2.04 mm. They established the mean sulcular depth as 0.69. What is its funcDon? (Its importance in restoraDve denDstry) The significance of biologic width is that, it acts as a barrier and prevents penetra-on of microorganisms into the periodon-um. Maintenance of biologic width is essen9al to preserve the periodontal health and to remove any irrita9on that may damage the periodon9um. It is said that a minimum of 3mm space between the restora9on margin and the alveolar bone is required to permit adequate healing and to maintain a healthy periodon9um. This 3 mm consists of 1mm of supraalveolar connec9ve 9ssue, 1mm of junc9onal epithelium and 1mm of sulcular depth. This allows for adequate biologic width (2.04mm) even when the margins are placed 0.5mm within the sulcus. How to preserve? The loca9on, fit and finish of restora9ve margins are cri9cal factors in the maintenance of periodontal health. So, a huge considera9on and care should have performed during isola9on and retrac9on (even with digital impression techniques) besides tooth prepara9on to the biological width to ensure the healthy standards and maintenance the normal values of the periodon9um. ObjecDves of gingival retracDon 1. Create an access for the impression material to the area of the prepara9on that is located subgingivally. 2. To provide enough thickness of the impression material at the area of the finishing line to prevent distor9on of the impression. 3. Providing the best possible condi9on for the impression material, fluid control. 4. Reduce fluid a mount in the sulcus that might cause void in the impression. Gingival retracDon techniques 111))) Mechanical (plain retrac9on cord, retrac9on crown, copper band or tube , anatomic compression caps, Matrices and wedges, Rubber dam ) 222))) Chemo mechanical (combina9on of mechanical and chemical) aaa))) Impregnated retrac9on cord, with one of the following: Ø aluminum sulfate Ø epinephrine Ø ferric sulfate Ø zinc chloride Ø aluminum chloride bbb))) Displacement polymer & paste (cordless technique) 333))) Radical or surgical means or technique (electro surgery, Laser). 1) Mechanical It might be done by either of the followings: Ø Retrac9on cord Ø Retrac9on Crown Ø Copper band or tube Ø Anatomic compression caps Ø Matrices and wedges Ø Rubber dam Generally, in this technique, we apply pressure on the gingiva through gingival sulcus. This mechanical pressure, aaer certain period of 9me, physically push the gingiva away from the finishing line. It might be done by the construc9on of temporary crown with slightly long margin leaving it for 24 hours, or by using rubber clamp, or by using plan retrac9on cord( free of medicament )….etc. The most common way by using retrac-on cord. Retrac-on cord is a special cord made of coDon comes either with or without medicament (vasoconstrictor). Cord without a vasoconstrictor is used to obtain a mechanical gingival retrac9on.it comes in different sizes. Classifica@on of retrac@on cords 1. According to chemical treatment Ø Plain cord without any medicament.  Ø Impregnated cord (impregnated with hemosta,c agent). 2. According to configuraDon Ø Twisted Ø Kni^ed Ø Braided Twisted and braided cords can’t offer ease of packability and ,ssue displacement like kni^ed ones. Advantages of kniUed cord over other types 1) Afford greater inter-thread space than braided cord. 2) Form an interlocking chain of thousands of ,ny loops, making it Ø Easy to pack below the gingival margin Ø Stays put when packed into place. 3) Compresses upon packing, then expands for ,ssue displacement. 3. According to thickness (diameter) According to its size, we have different thickness of retrac9on cord (color-coded thickness): Ø Black - 000 Ø Yellow – 00 Both are recommended for anterior teeth with minimal crevicular space. Also can be used as a primary cord for the double cord technique. Ø Purple - 0 Ø Blue – 1  Both are recommended for bicuspids. Also #0 is used as the primary cord for the double cord technique, while #1 cord is recommended to be used as the secondary cord Ø Green - 2 Ø Red – 3 Both sizes are used for molars where 9ssue friability permits. Some textbook divide retrac-on cord into three main size: Ø SMALL- involve (#000 &# 00) to be used in anterior teeth, where thin firmly 9ssue is present Ø MEDIUM- involve (#0, #1 & #2) to be used where greater bulk is encountered e.g. posterior teeth Ø LARGE- involve size (#3) should be used with cau9on as can produce soa 9ssue trauma. Cord packing instruments Cord packers are dental instruments used to pack gingival retrac,on cord into the sulcus. Most cord packing instruments have a slightly rounded ,p with serra,on to hold the cord while it is posi,oned intra-sulcularly. Fischer packer is a cord packing instrument. Furthermore, plas,c instrument (Ash No. 6) can be used for cord packing. The cord packers with round, non-serrated working ends are used for atrauma,c cord placement; serrated cord packers should only be used with braided cord. Fischer packing instrument These specially designed packers ease the packing of Ultrapak® kniDed cord. Their thin edges and fine serra9ons sink into the cord, preven9ng it from slipping off and reducing the risk of cuhng the gingival aDachment. It available in two form Ø 45° to handle: with heads at 45° to the handle with three packing sides. Circular packing of the prep can be completed without the need to flip the instrument end to end. Use the small packer on lower anterior and upper lateral incisors. Ø 90° and parallel to handle: Same size and three-sided heads as the 45º to handle packer, except one of the heads is in line with the shank and the other is at a right angle to the shank. 2) Chemo mechanical Usually in this technique, we use retrac9on cord that contain a vasoconstrictor (adrenaline or AL.sulfat). Cords are soaked in the Hemosta9c solu9on before placement or Some cords are already impregnated with hemosta9c solu9on elimina9ng this step (adrenaline 8%, aluminium sulfate, or Aluminium chloride 5-10%). Whether plain or impregnated cord, the cord pack into the gingival sulcus between the tooth and the gingival 9ssue, using a plas9c instrument (fischer packing instrument or Ash no.6) , the cord will physically push the gingiva away from the finishing line and the combina9on of the chemical ac9on and pressure packing will cause transit gingival ischemia, this will lead to shrinkage of gingival 9ssue and control fluid seepage from gingival sulcus, we put the retrac9on cord inside the gingival sulcus all around the tooth for 10 minutes , the area of our work should be kept dry during this period ,then, the cord can be removed leaving the gingival 9ssue in an expanding state and this, will provide space to inject the impression material around the tooth at the area of finishing line by the use of impression syringe. Step-by-Step Procedure 1- Isolate the prepared teeth with coDon rolls, place saliva evacuators and any other aids as required, and dry the field with air. Do not excessively desiccate the tooth because this may lead to postopera9ve sensi9vity. 2- Cut a length of cord sufficient to encircle the tooth.  3- Dip the cord in astringent solu9on and squeeze out the excess with a gauze square. An impregnated cord can be placed dry but should be slightly moistened in situ immediately before removal from the sulcus, to prevent the thin sulcular epithelium from s9cking to it and tearing when it is removed. A convenient way to limit the amount of moisture added is to apply water held between the 9ps of a dental forceps by opening it. 4- Twist non-braided cords 9ghtly for easier placement. 5- Loop the cord around the tooth, and gently push it into the sulcus with a suitable instrument. These notes should be considered during cord placement procedure 1- Star9ng point: It is easiest to start inter-proximally, because more sulcular depth available than facial or lingual. 2- Instrument angula9on: The instrument should be angled slightly toward the tooth so that the cord is pushed directly into the sulcus, also be angled slightly toward any cord previously packed; otherwise, it might be displaced. A second instrument holding the cord may aid in subsequent placement. 3- Placement and pressure: Gentle and Firm Pressure applied to the cord, it should place apical to the margins of prepara9on. 4- Over packing and repeated use of displacement cord should be Avoided it could cause tearing of the gingival aDachment, which leads to irreversible recession. Double (dual) Cord Technique With a deeper subgingival prepara9on, aaer removing the cord, the sulcus ‘closes’ not allowing the ingress of the impression material in the subgingival area, so in such a case you might need to use 2 or double cords. When 2 cords are need, it requires that about 1 mm of intact tooth structure remains between the top of the ini9al cord and the prepara9on margin. The first cord is thin, lea during impression taking, while the second cord is thick. In this technique, a thin cord is placed without overlap at the boDom of the gingival crevice. A second cord is placed on top to achieve lateral 9ssue displacement. The laDer is removed immediately before impression making, whereas the ini9al cord is lea in place to help minimize seepage during Impression, be careful not to exert excessive pressure on the 9ssues, which can damage the epithelial aDachment (Biological Width). This technique is indicated when we have: 1. Impression of mul9ple prepared teeth 2. Impression for compromised 9ssue health 3. Excess gingival fluid exudates. Advantages 1) The first cord remains in place within the sulcus thus reducing the tendency of the gingival cuff to recoil and displace par9ally set impression material. 2) Helps to control gingival hemorrhage and exudate. 3) Overcomes the problem of the impression tearing because of inadequate bulk, an especially important considera9on with hydrocolloids, which have low tear strength. Remember: Never pack a dry cord Ø Dry cord adheres to the cervicular epithelium and may tear the epithelium upon its removal and may elicit a wound healing reac9on. Ø Dry cord is harder to pack into the sulcus, leads to more bleeding upon cord removal and an unacceptable impression, and makes it more likely that a less than ideal gingival response will follow. Gingival retracDon pastes (Cordless technique) In most cases, gingival retrac9on cord is the most effec9ve method for retrac9ng 9ssue to the depth of the sulcus. Unfortunately, gingival retrac9on cord may injure the gingival sulcular epithelium and the gingival bleeding is difficult to control when packing a cord into the sulcus making impression difficult or impossible. Using a retrac9on cord requires proper 9ssue manipula9on and is technique sensi9ve. For this reason, a new class of gingival retrac9on materials has been introduced in the form of retrac9on paste like Expasyl (Aluminum chloride 15%) and Magic Foam Cord (Polyvinylsiloxane, addi9on type silicone elastomer). Expasyl retrac-on paste It is an AlCl3-containing paste (Aluminum chloride 15%) is injected into the dried sulcus with a special delivery gun. Advantages of this system include good hemostasis with less discomfort than with tradi9onal cord. However, less 9ssue displacement is achieved than with cord. Improved displacement may be achieved if the paste is directed into the sulcus by applying pressure with a hollow coDon roll.  Magic Foam Cord (Coltène/Whaledent) Magic foam is a polydimethylsiloxane with a 9n catalyst. The resul9ng release of gas resulted in a fourfold(x4) volumetric expansion. When the paste was applied into the sulcus, reac9on between base and catalyst take place with gas release that resulted in volumetric expansion of the material that cause an apically directed flow that enlarged the gingival sulcus and allowed impression making, a hollow coDon roll is used to apply pressure to the expanding foam to directed expansion apically. Other cordless retrac9on materials, e.g., Racegel (Septodont) Traxodent (Premier); GingiTrac (Centrix) provide for excellent hemostasis and some gingival retrac9on. Whatever is the material, aaer isola9on of the area, the material is injected inside the gingival sulcus star9ng from the deepest area at interproximal area, leave the material for 5 to 10 minutes then clean the area and inspect the result. The advantage of cordless retrac-on technique is providing a non-trauma9c, non-invasive 9ssue management and excellent hemostasis in the gingival sulcus for fixed prosthodon9c impressions. 3) Surgical technique (radical or surgical means) Some methods that use the surgical approaches to improve the visualiza9on of the prepara9on margins of the tooth are not true retrac9on techniques. This is because they actually remove some part or all of the overlying gingival 9ssue in order to expose the finish line of the prepara9on and/or control hemorrhage. These techniques are more invasive and should only be used in cases where there is adequate amounts of aDached gingiva. These methods include the following: u ROTARY GINGIVAL CURETTAGE (GINGETTAGE) It is a toughing technique involves prepara9on of the tooth sub-gingivally while simultaneously curehng the inner lining of the gingival sulcus (a por9on of the epithelium within the sulcus is removed to expose the finish line). It should be done only on the healthy gingival 9ssue CRIETERIA TO BE FULLFILLED FOR GINGETTAGE Ø There should be no bleeding on probing Ø The depth of the sulcus should be minimum of 3 mm DISADVANTAGES OF GINGETTAGE Ø Instrument has poor tac9le sense so this technique is very sensi9ve Ø It can poten9ally damage the periodon9um TECHNIQUE OF GINGETTAGE Ø It is usually done simultaneously along with finish line prepara9on. Ø Por9on of sulcular epithelium is removed using a torpedo diamond bur. Ø To improve tac9le sense hand piece is run very slowly. Ø Abundant water should be sprayed during the procedure. Ø A retrac9on cord is impregnated with AlCl3 can be used to control bleeding u Electro-surgical method In this technique, an electro-surgical unit could be used to remove the gingival 9ssue from the area of the finishing line with the advantage of controlling the post-surgical hemorrhage. However, electrosurgery is contraindicated when there is gingival inflamma9on or periodontal disease. In this case, gingivectomy could be performed. There is the poten9al for gingival 9ssue recession aaer treatment. Indica-ons: q For minor 9ssue removal before taking impression, toughing the inner epithelium lining of gingival sulcus, improving access for the subgingival margin. q Control post-surgical hemorrhage. Contra-indica-ons: o Thin aDached gingivae (lower anterior, upper canines) o Electronic medical devices Cardiac Piece Makers o Metallic restora9on & Instruments u SoG issue Laser Soa 9ssue lasers have been introduced into den9stry and can provide an excellent adjunct for 9ssue management before impression making for gingival retrac9on, Nd- YAG lasers are used. Advantages of Laser: 1. Certain laser den9stry procedures do not require anesthesia. 2. Laser procedures minimize bleeding because the high-energy light beam aids in the clohng (coagula9on) of exposed blood vessels, thus inhibi9ng blood loss. 3. Precise recontouring of gingiva. 4. No gingival recession and no discomfort to the pa9ent. 5. Bacterial infec9ons are minimized because the high-energy beam sterilizes the area being worked on. 6. Damage to surrounding 9ssue is minimized. 7. Wounds heal faster and 9ssues can be regenerated.