Efficiency in tooth restoration Let s Grow Tooth Bioactive/regenerative materials to increase comfort and decrease failure

Transcription

1 Efficiency in tooth restoration Let s Grow Tooth Bioactive/regenerative materials to increase comfort and decrease failure Jack D Griffin, Jr DMD Diplomat American Board of Aesthetic Dentistry Accredited American Academy of Cosmetic Dentistry Master Academy of General Dentistry Thank you for choosing to spend your time with us. We know that there are many choices in continuing education and we sincerely want this to be one of the best experiences in dental CE today. Our goal is to help you gain greater understanding, confidence, and skill that will allow you to take your restorative practice to the next level in dentistry making your practice more efficient. Please let us know if there is anything we can do to help you as we take a journey down the road of long term restoration success together. If you don t know where you are going, any road will take you there. All materials in this manual are protected please don t copy without permission

2 Let s grow some tooth Bioactivity Regenerative bioactive [bi o-ak tiv] having an effect on or eliciting a response from living tissue. Obviously we aren t growing tooth from scratch. Perhaps a better term for what we are describing is regenerative in that we are creating an environment to promote secondary dentin formation and bacterial inhibition. With regenerative materials we are trying to stimulate dentin repair, healing, and formation using materials that are bio-friendly. Course outline: 1. Liners and bases that insulate, protect, and seal 2. Giomers: the class of restorative materials that inhibit bacteria but perform like composite 3. Cements that are biofriendly, easy to clean up, and sensitivity free 4. Universal bonding agents the new GOTTA HAVE materials 5. Bulk fill materials for posterior restorations more predictable, more efficient 6. Putting it all together with direct and indirect restorations Some regenerative materials: TheraCal LC (Bisco) a liner Biodentine (Septodont) a base Ceramir (Doxa) a cement Giomers (Shofu) a class of restorative materials 2

3 TheraCal LC (Bisco) a liner that promotes dentin regeneration What it is A Resin Modified Calcium Silicate (RMCS) Stimulates apatite formation and dentin repair MTA (Mineral Trioxide Aggregate) chemistry Early high alkalinity (high ph = 11) Neutralizes over weeks Self-sealing minor bond to dentin Anti-microbial Comparisons Dycal is alkaline but not stable Washes out May interfere with DBA Biodentine similar dentin/pulp response Cumbersome to mix Easy to place Dentin replacement base Need 2nd appt to restore over Clinical use Liner to protect pulp Place on moist dentin prior to DBA Keep 1mm deep or less Opacity prevents deep cure Direct pulp cap possible Keep 1mm from enamel May show through less opaque composite How does it work? A source of reparative ions Alkaline environment required for dentin healing Stimulant of hydroxy-apaptite Bacteriostatic Dentin tubule protectant/sealant Thermal insulation Notes: Giomers (Shofu) a class of restorative materials that inhibits bacterial growth while stimulating dentin repair. Probably has clinical characteristics similar to any material you currently use within in the same restorative category WITH the benefit of fluoride release, recharge, and re-release. A restorative material with the following: Surface Pre-Reacted Glass (S-PRG) Unique release of 6 bioactive, regeneration inducing ions High ability for acid neutralization Inhibition of plaque formation Great clinical characteristics 3

4 Giomer ion release by S-PRG: + NA BO Al 3+ SiO Sr F Sodium: - Borate: water soluble, induces function of the other 5 ions bacteriocidal, promotes dentin formation, decrease bacteria adhesion, anti-plaque - Aluminum: blocks dentin tubules, decreases hypersensitivity - Silicate: Calcification of dentin - Strontium: Buffer, acid resistance, stimulate dentin regeneration - Fluoride: Formation of fluoroapatite, anti-caries, anti-bacterial, remineralization of decalcified lesions A glass ionomer type core, protected from the negative effects of moisture, in a resin matrix. The result is glass ionomer benefits with physical properties of composite. Notes: Giomer restoratives Flowable Universal hybrid Packable posterior Bulk fill flowable Sealant All with same giomer benefits. Distinguishing characteristics. 4

5 Does your etch matter? Texture Rinse-ability Color Long term antimicrobial? Phosphoric acid kills NOW Bezalkonium Chloride kills LATER Does killing bugs matter? Matrix metalloproteinases = MMP s enzymes that may break down the hybrid layer between dentin and resin 2% Chlorhexidine has been shown to decrease the MMP deterioration of our bonding to collagen. Notes: Isolation is critical Dam Isolite DentaPop/DriTip Cotton rolls Gauze Notes: 5

6 Posterior Composites Stuff we gonna need Curing light Instruments Bonding agent Composite Flowable Matrix Polishers Indirect Restorations CERAMIR (Doxa) Regenerative cement GI plus calcium aluminate Bioactive cement apatite formation Easiest clean up ever Least sensitivity of any cement tested NO RESIN Alkaline ph Hydrophilic No silane, no primer, no bonding agents Awesome for metal, zirconia, lithium disilicate No bad taste! 6

7 BeautiCem SA (Shofu) Giomer, bonds highly to almost everything. High fluoride release, re-chargable, great properties. Similar to all others in Self Adhesive category with the benefits of the giomer. Restoration cementation adhesive or non-adhesive Cementing is either adhesive or non-adhesive. A major clinical advantage of zirconia and lithium disilicate is that they can be cemented or bonded in place depending upon the resistance of the preparation and preference of the dentist. In those cases where preparation design is retentive in nature, cementation is a viable option with the amount of surface area and degree of divergence of the prepared walls can provide sufficient micromechanical retention. Resin reinforced glass ionomer cements like RelyX Luting (3M ESPE) or GC Fuji Plus (GC America) and newer bioactive cements like Ceramir (Doxa) have been popular choices because of lower reported sensitivity, ease of use, and long term clinical success on retentive preparations. These cements are often more opaque and less esthetic than the resins and so the more translucent the e.max the more this matters. The 2 critical junctions during definitive placement of any restoration is first the bond of the luting material to the internal surface of the restoration and secondly to the tooth. When preparations are short, overly tapered, or occlusal forces heavy, resin bonding is indicated and would provide maximum restoration retention, microleakage prevention, and increased fracture/fatigue resistance of the restorative material itself. Failure most often occurs at the cement/restoration interface and not at the cement/dentin interface. Important points: UNIVERSAL BONDING AGENTS: (i.e. All Bond Universal, Bisco; Scotchbond Universal, 3M) have changed our bonding protocol simpler and better. These are giving us the best all around bond strengths ever to a variety of surfaces whether dry or wet, etched or not etched, metal or porcelain. So Universal Bond Agents simplify things no more total and self-etch bond agents, no zirconia or metal primers, no worry about too wet or too dry. CLEAN after try in: on pre-etched porcelain of any kind (and for zirconia) maximum bond strengths can only be achieved after removing salivary contaminants. Ivoclean (Ivoclar) does this better than anything and conditions the surface for better bonding (particularly 7

8 zirconia). Must reapply silane Ivoclean use. If there is little or no enamel, we don t etch. The universal bonding agents are terrific non-etch adhesives on dentin or prepped enamel both Bisco and 3M have dual cure universal DBA s to insure set under opaque restorations. If lots of enamel, selectively etch it first. Research is showing less long term breakdown of dentin bonds by protease/enzymes if we use something to kill bacterial like chlorhexiding or benzalkonium chloride (BAC) prior to bonding. We use an etch (Etch 37 with BAC, Bisco) when we etch. Certainly an antimicrobial scrub (Concepsis, Ultradent: Cavity Cleanser, Bisco) makes sense as well. Self-adhesive dual-cure resin cements Like RelyX Unicem (3M), SpeedCem (Ivoclar), SmartCem (Dentsply) show very good retention, little sensitivity, and ease of use as long as the retention of the prep is good. While these cements are popular, the retention and microleakage is not nearly as good as a separate bonding agent applied to the tooth and restoration followed by a dual cure resin cement like All Bond Universal+DuoLink Universal (Bisco) or Scotchbond Universal+RelyX Ultimate (3M). Adhesive protocol for maximum lithium disilicate dependability (crowns, veneers, etc): 1. Limit layering porcelain where not needed for esthetics 2. Retentive preps 4-8 degree taper, minimum 3-4mm walls, strong core 3. e.max press make sure the lab has etched and silanated 4. e.max CAD in office 20 second 5% HF etch, rinse well, silane, resin depending on system used for luting 5. Try in. Rinse. Clean with Ivoclean 20 seconds. Rinse well. 6. Universal bonding agent applied to restoration. Air thinned. NO CURE. 7. Isolate tooth. Clean dentin alcohol on microbrush or aluminum chloride scrub or chlorhexidine, or pumice 8. Universal bonding agent applied to tooth. Air thinned. NO CURE. 9. Luting material dual cure resin for crowns or opaque anteriors, light cure only resin for thin veneers or translucent anteriors (to avoid shade shifting) Try in, clean.universal DBA on porcelain and tooth...air thin both.place resin cement Esthetics of LiDi is at the limit of the ceramist. With proper cut back and addition of layered porcelain, esthetics can be as good as any material out there. Again, lab selection is the determining factor. Blocking dark color is not quite as dependable as more opaque materials like metal and zirconia. Remember, a monolithic piece of LiDi has much less chance of failure than one with layering porcelain, but for highly esthetic cases we use this material for almost all of them. The 8

9 combination of strength and esthetics with e.max is unsurpassed in esthetic dentistry today. The case above is e.max press, moderate translucency, cut back and customized. Important points of interest: 1. Always show lab the color of the tooth so they can use the correct opacity. There are 5 different opacities of e.max press ingots. 2. Sand blasting with AlO3 may cause tiny fractures which may grow and IS NOT RECOMMENDED by Ivoclar If you do with e.max CAD, use light pressure, far distance, glass beads, only to remove investment 3. Cementation is allowed for retentive preps, but bonding improves retention and may strengthen porcelain by reducing crack propagation from inside and other iatrogenic problems 4. Don t over etch slightly frosty, not chalky only 20 seconds with 5% HFl, rinse well, silanate 5. Not strong enough for posterior or high stress anterior bridges 6. Adjustments should be done with high speed finish diamonds, water, light pressure. Polish done with a porcelain polish system. Polish paste on chamy or felt wheel optional. 7. For veneers a minimal prep is supported by Ivoclar as little as 0.3mm Zirconia The quest for stronger, longer lasting esthetic restorations has continued since the practice of dentistry began. Today our goal is to combine ease in prep and placement, accepted esthetics, and predictable clinical longevity all at an in a manner that increases practice efficiency in a troubled economy. As we balance the functional performance of a material with the heightened esthetic standards of today, we sometimes have to think about taking a cosmetic step backward to gain more strength and durability. Along with these philosophical dilemmas there is often conflicting information on how best to use and handle newer materials and techniques: etch or no etch, sand blast or not, light or chemical cure, cement or bond? Advances with indirect esthetic materials the last few years have brought the profession higher levels of strength and esthetics than ever before with materials like lithium dislocate and zirconium oxide. Yttriastabilized tetragonal zirconia polycrystal, Y-Tzp, has become very widely used the last few years because of its fracture resisting flexural strength over 1000MPa, non-metalic color, kind wear patterns on opposing teeth, easy intraoral polishability, tooth preparation similar to other all porcelain crowns, and excellent long term clinical success. Layering porcelain can be added to a zirconium coping to heighten esthetics but the weak adherence of the stacked or pressed layer has been a common area of clinical failure if the layering material is in function. Zirconia is a very strong monolithic restoration and an excellent substructure but the bond between layering porcelain and the zirconia is very clinically significant. Fracture or chipping of the veneering porcelain has been seen in a high percentage of cases and it s use has been challenged by several researchers there is less failure. It is certainly less opaque and better looking than it has been in years past. Esthetic limitations for monolithic zirconia are overcome these days by using some of the less ugly newer zirconia formulations 9

10 plus the external staining of the lab. With flexural strengths exceeding 1000MPa, the ability to withstand mastication forces is extremely good with proper prep and impression techniques. The newer less opaque zirconias have made the PFM obsolete in many practices. For molars and teeth being restored to less than the highest cosmetic standards, monolithic zirconia must be considered. The fit is fantastic and the longevity is unsurpassed by anything but gold. Tooth preparation: Great bonding cannot compensate for poor tooth preparation. Just like we said with lithium disilicate, the prep is critical to long term retention. The preparation of the tooth must fit the characteristics of the restorative material and designed to aid in restoration resistance to dis-lodging and fracture. Zirconia bonding may not compensate for preps designed with walls of excessive taper, the tee-pee prep, or those with very short axial walls, less than 3mm, and the practitioner may experience more restoration de-bonding. For full monolithic crowns 1.0mm in all directions is acceptable with a rounded shoulder or shamfer, no sharp internal line angles, identifiable margins. The more layering porcelain you need, the more reduction that is needed. Cementation Cementing is either adhesive or non-adhesive. A major clinical advantage of zirconia is that it can be cemented or bonded in place depending upon the resistance of the preparation and preference of the dentist. In those cases where preparation design is retentive in nature, cementation is a viable option with the amount of surface area and degree of divergence of the prepared walls can provide sufficient micromechanical retention. Resin reinforced glass ionomer cements like RelyX Luting (3M ESPE) or GC Fuji Plus (GC America) and newer bioactive cements like Ceramir (Doxa) have been popular choices because of lower reported sensitivity, ease of use, and long term clinical success on retentive preparations. These cements are often more opaque and less esthetic than the resins and so as zirconia gets less opaque, this may become a factor when higher esthetics is warranted. The 2 critical junctions during definitive placement of any restoration is first the bond of the luting material to the internal surface of the restoration and secondly to the tooth. When preparations are short, overly tapered, or occlusal forces heavy, resin bonding is indicated and would provide maximum restoration retention, microleakage prevention, and increased fracture/fatigue resistance of the restorative material itself. Failure most often occurs at the cement/restoration interface and not at the cement/dentin interface. Non-adhesive cementation without bonding is much easier to clean up less hygienists screaming at doctors. The reality is that bonding is stronger despite being more technique sensitive. We have to bond when retention is poor or the material is weak. Don t be afraid of adhesive cementation, work on your protocol and be rock solid in your decision making. That said, non-adhesive cementation feels good to us: easy clean up, fast, dependable, little sensitivity. Remember that even when using Adhesive cementation gives us the most dependable bond at both cement interfaces. Dual cure resin cements that are bonded both to the zirconia and the tooth are warranted in cases with excessively tapered preps, short preps or small teeth, or questionable occlusal forces. In these cases it is prudent to maximize bonding. A primer (z- Prime Plus, Bisco) should be used with dual cure resin cements if not 10

11 light curing and a Universal Bonding Agent (All Bond U, Bisco; Scotchbond U, 3M) if light curing for maximum strengths. Bio-regenerative cementation is a newer method where the cement actually stimulates the formation of hydroxyapatite resulting in very little leakage and great retention. Ceramir (Doxa) is such a cement and the bond strength increases and microleakage decreases with time. It is a unique cement combining glass inonomer and calcium aluminate resulting in a bioactive formulation. No primer, silane, or bonding agent is neeed. This cement may be the easiest to clean up on the market. Bonding to dentin: Quality adhesive boning to dentin is critical for restoration retention, reduction in sensitivity, and microleakage control. The strongest long term dentin bond is still total phosphoric acid, rinsing, and then application of a dentin bonding agent (DBA). Many practitioners have reservations about completely removing the smear layer because of experience with postoperative sensitivity. To that regard, self-etch self-priming systems with the UNIVERSAL BONDING AGENTS (All Bond Universal Bisco, Scotchbond Universal 3M) have shown to give superior bond strengths to dentin, porcelain, zirconia and etched enamel without the nervousness not removing the smear layer by a total etch technique. After blowing thin their low film thickness (~10 microns) will not interfere with restoration seating. Bonding to zirconia: Zirconia (ZrO2) is a silica-free, acid resistant, polycrystalline ceramic making glass etching treatments such as hydrofluoric acid (HFl) followed by silane USELESS. Great bonding depends upon micromechanical interlocking to a roughened surface from sand blasting followed by chemical bonding from a primer followed by a quality dual cure resin-based cement. Dual cure resin cements are preferred in adhesive cementation because of because of the ability to self-cure through opaque zirconia, control of set time is in staff hands, and margins can be light cured to insure setting at this critical junction. Adhesive protocol for maximum monolithic zirconia dependability: 1. Limit layering porcelain where not needed for esthetics 2. Retentive preps 4-8 degree taper, minimum 3-4mm walls, strong core 3. Light sandblasting of zirconia 4. Clean zirconia after try in with Ivoclean primes surface for bonding 5. Universal dual cure DBA applied to zirconia, air thinned 6. Isolate tooth, clean dentin 7. Universal dual cure DBA, air thin, no cure 8. Use dual cure resin cement always light cure the margin for highest conversion rate Important points of interest: 1. Cement whenever the retention is good 3-4mm wall height in all directions 2. When doing adhesive cementation same protocol to tooth and restoration with universal bonding agent 3. Don t etch tooth unless significant enamel remains 4. Practice distance and cure time with your light to get easy clean up initial set down in your office don t cure contacts at all until flossing done 5. Floss after clean-up of buccal and lingual 6. When cleaning up or flossing, make sure pressure is maintained to prevent movement 7. Isolate well when bonding microleakage is often a direct result of contamination with blood or saliva 11

12 Direct restorations: For many of us who don t live full time in the Beverly Hills front teeth only world, direct restorations is where we spend much of our clinical time. The key is to be efficient to be profitable while doing work that doesn t have to be re-done or adjusted later. We will briefly touch on a few procedures that can make or break our office efficiency. Post and cores/build ups The foundation is the key. Often little thought goes into the strengthening of the tooth core and root system. Of course we were taught in school that the post and core does nothing to strengthen the tooth but merely to aid in restoration retention. Of course, that was before adhesive dentistry. We must by as diligent and meticulous with our pre-crown foundation as we are when we place veneers. Important points of interest: 1. The strongest post is a sand blasted metal post bonded in place with a resin cement 2. We seldom do them anymore because of esthetics and potential root fracture 3. Use a post system with tapered drills and posts for easier seating and removal of less dentin 4. When using etch down a canal, rinse thoroughly and change angles with the water to make sure of complete removal 5. Only blot dry the canal or paper point, keep moist so the dual cure DBA goes into canal easier 6. Air thin, do not cure 7. A dual cure DBA followed by resin cement/build up from an automix gun (i.e. Core Flo BISCO, Build-It Pentron) and inject filling the canal only. An option is to cement the post with a selfadhesive dual cure resin cement without etching and DBA (ie SpeedCem, SmartCem 2, Rely X Unicem) 8. Place DBA coated post into canal, cure this will prevent movement of the post while shaping core 9. Complete the core with the buildup material, shape, cure Direct composites We will spend most of our time on 2 things, bulk filling and contacts. Everyone has their own favorite composite and much of the marketing is spent on delivery these days. Again, pay attention to details when placing them and be meticulous in your steps. Important points of interest: 1. Isolation is key rubber dam, Isolite, DentaPop-DryTips. 2. Use new #330 bur on EVERY patient, light pressure, good water. 3. Bond strength to decay is ZERO. Check with caries indicator and verify how good you really are (Sable Seek, Ultradent). 4. For deep restorations or pulp capping there is a terrific new liner that stimulates apetite formation called TheraCal (Bisco). A game changer! Biodentine (Septodont) works just as well to 12

13 stop sensitivity and heal dentin but is much harder to use. For TheraCal place on deepest part of prep over pulp, place on slightly moist dentin, 2mm or more from margins, 1mm deep at most, light cure well. Etch and DBA after curing well. Restore as normal. 5. Use a versatile sectional and ring system it s a no brainer (ComposiTight 3dXR Garrison, V3 Triodent). Pre-wedging is a great way to protect gingiva and aid in sectional placement. 6. Tools like ReelMatrix or PinchMatrix (Garrison) are awesome for large restorations and Perform Contact instruments are great for those tough cases. 7. When doing total etch, phosphoric acid with antibacterial only seconds, rinse thoroughly, blow only to remove standing water or use suction only to remove excess water 8. Newer UNIVERSAL DBA s (All Bond Universal, Bisco and Scotchbond Universal, 3M ESPE) are very promising. Etch or no etch, dry or wet, direct or indirect, zirconia or porcelain or composite. 9. At this point in 2013, the best long term bonds to dentin and enamel are with total etch and separate DBA. SELECTIVE etching makes the most sense at this point. That is, etching the enamel only for 10 seconds, thorough rinse, suction dry, followed by a universal DBA on both enamel and dentin. 10. Air thin the solvent well the ethanol or acetone can cause sensitivity and lessen bond strengths so air thinning us a MUST. 11. If more than 1mm between prep margins on back-to-back restorations, it is more predictable to do one at a time. 12. At this point, the wedge should only hold the matrix against the tooth, the matrix provides shape to the restoration, and the ring is what provides separation to compensate for the matrix 13. Bulk fill dentin replacements (i.e. Venus Bulk Fill Heraeus, Sure fill Dentsply, SonicFill Kerr) are terrific cover or they ll be grey. 14. Don t underestimate trans-enamel curing cure from 30 seconds occlusal, then facial, then lingual for a more complete cure. Always have the assistant re-cure after final shaping 15. Consider strongly a newer class of flowable restorative giomer materials (Beautifil Flow Plus, Shofu) as a great all round flowable with the ability to withstand occlusal forces. Terrific for many situations even class II. This stuff is pretty amazing awesome flow, strength, and beauty for a flowabe and studies have even shown a great ability to hold up in occlusal and Class II situations. Plus, it has a high fluoride release that is RECHARGEABLE. Home fluoride treatments work extremely well with this material for root decay patients, rampant decay, and those patients with less than ideal home care. Success is where preparation meets opportunity. Jack D Griffin, Jr DMD MAGD AACD ABAD HUEsmilecenter@aol.comU NOTES: 13

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