Robert A. Lowe, DDS

 have been used successfully in restorative dentistry for decades, these materials still pose some clinical problems. Microleakage continues to be an issue, particularly at the interface between dentin and the composite resin. Chemical adhesion between glass ionomer cement and dentin has been shown to promote a better “seal” to dentin than that of adhesive resins alone.1-3 This fact led to the development of the so-called sandwich technique, in which glass ionomer cement is used as a lining under composite resin restorations, particularly where the cavosurface margin is in contact with dentin.4 The weak link has always been the composite portion of the “sandwich” restoration.

The biological assault on composite materials can vary due to the individual’s oral environment (pH), quality and quantity of saliva, and acidic challenge to natural tooth structures and restorative materials, as well as the patient’s ability to keep tooth surfaces plaque-free. However, some of today’s resin-based restorative materials actively release and recharge mineral ions, a significant improvement over traditional passive materials that merely fill the prepared cavity after caries removal. This case report will demonstrate the use of bioactive and other mineral-enriched materials that may be an improvement over the use of glass ionomer materials as dentin replacements capped with a conventional passive composite resin.

Bioactivity is only possible in the presence of water. According to McCabe et al, “the potential for dynamic behavior exists with materials that are partly water-based, transport water, or have phases or zones with significant water content, and for which the water within the material can react to changes in the ambient conditions. Such materials have the potential for ‘smart’ behavior.”5 The availability of calcium, phosphate, and fluoride ions can facilitate conditions that stimulate mineralization and the formation of chemical bonds that help seal the tooth and prevent microleakage at the cavosurface margins of a restoration.

A universal, stackable, light cure composite that is strong, durable, wear and fracture-resistant, releases and recharges calcium, phosphate and fluoride, and is indicated for all classes of cavities

The white dental filling material is said to mimic the properties of natural teeth

The material is esthetic, high-strength, and contains no Bis-GMA, Bisphenol A, or BPA derivatives

Its chemistry is designed to penetrate and integrate with tooth structure for margin-free adaptation

800-343-4342 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 

Activa BioActive-Restorative from Pulpdent Corporation is a moisture-friendly bioactive material that supports natural remineralization by releasing calcium, phosphate, and fluoride and contains a rubberized resin component that acts as a shock absorber, much like natural dentin. Activa Presto is the first light cure, mineral-enriched composite that mimics the properties of natural tooth structure. This material also has the esthetic quality to match nano and microhybrid composite materials and can be used for all anterior and posterior applications.

The following case demonstrates the sandwich technique using Activa BioActive-Restorative as a dentin replacement and Activa Presto as an enamel replacement.

In the following case, a patient who is unable to afford a crown receives a direct restoration using bioactive materials. 

 is a preoperative occlusal view of tooth No. 3 showing marginal failure in the area of the existing restoration near the mesial marginal ridge. A portion of the mesial margin has been compromised due to fracture, and recurrent decay was diagnosed using quantitative laser fluorescence and verified clinically.

Caries detection with SoproCare from Acteon shows active caries lesion around a defective restorative margin on tooth No. 3 (

). Decay is visible upon removal of the defective restoration (

), and a Smart Burs II from SS White Dental is used to remove infected dentin only. Affected dentin (ie, demineralized dentin) can be restored with the calcium and phosphate made available by using Activa BioActive-Restorative as the dentin replacement.

Once infected dentin removal is complete, the preparation is etched with Etch-Rite 38% phosphoric acid from Pulpdent Corporation for 15 seconds and rinsed well. Excess moisture is removed using high-volume suction so the etched dentin is not overdried and desiccated.

At a Glance

An adhesive resin is applied to the dentin surface, air thinned, and light cured. It is important to note that the presence of an adhesive resin does not affect the ability of ions to diffuse from Activa BioActive-Restorative to the demineralized tooth (dentin) surface. Studies by Sauro et al6 and others show that calcium, phosphate, and fluoride ions pass through the bonding agent and deposit apatite crystals, which help prevent the degradation of the adhesive bond.

Next, Activa BioActive-Restorative is placed in the cavity and light cured, leaving approximately 1 to 1.5 mm for the final layer of restorative material (

). Activa Presto was chosen for the enamel replacement because it is a mineral-enriched universal composite material with a stackable viscosity that holds its shape. Its calcium-and-phosphate component and shock-absorbing ability mimic the properties of natural teeth.

The moisture-friendly resin facilitates the release and recharge of these essential tooth-building ions and creates nucleation sites and an environment favorable for both apatite formation and marginal seal. After light curing, Activa Presto is highly polishable and maintains its luster. 

 is an occlusal view of the completed restoration on the occlusal surface of tooth No. 3.

An updated version of the sandwich technique has been demonstrated using materials that can help support the natural rebuilding process of diseased tooth structure. Although they provide fluoride to convert heathy apatite to fluorapatite, glass ionomers do not have calcium and phosphate availability to restore affected dentin back to a healthy, remineralized condition.

1. McLean JW, Wilson AD. Fissure sealing and filling with an adhesive glass-ionomer cement. 

. 1974;136(7):269-276. doi:10.1038/sj.bdj.4803174

2. McLean JW. Evolution of glass-ionomer cements: a personal view. J Esthet Dent. 1994;6(5):195-206. doi:10.1111/j.1708-8240.1994.tb00860.x

3. Ngo HG, Mount GJ, Peters MC. A study of glass-ionomer cement and its interface with enamel and dentin using a low-temperature, high-resolution scanning electron microscopic technique. 

4. Mount GJ. Clinical requirements for successful “sandwich”—dentine to glass ionomer cement to composites resin. Aust Dent J. 1989;34(3):259-265. doi:10.1111/j.1834-7819.1989.tb00680.x

5. McCabe JF, Yan Z, AI Naimi OT, Mahmoud G, Rolland SL. Smart materials in dentistry. 

. 2011;56(suppl 1):3-10. Doi:10.1111/j.1834-7819.2010.01291.x

6. Sauro S, Makeeva I, Faus-Matoses V, et al. Effects of ions-releasing restorative materials on the dentine bonding longevity of modern universal adhesives after load-cycle and prolonged artificial saliva aging. 

Articles

A demonstration of how using Pulpdent’s Activa Presto presents a new paradigm for the “Sandwich Technique” in restorative dentistry.

How To Use Bioactivity With Exceptional Esthetics

Technique in 2 Minutes: How To Use The Universal Bond System For A Perfect, Predictable Fit

A view of the mandibular ceramic restorations on the master model before cementation. The restorations are fabricated from IPS e.max from Ivoclar Vivadent.

First, each restoration is etched with 9% hydrofluoric acid Porcelain Etchant from BISCO for 30 seconds.

Next, the hydrofluoric acid etchant is rinsed thoroughly from the inside of the restorations, then air-dried.

In the next step, a phosphoric acid etch such as Ultra-Etch from Ultradent, is placed on the preparations and after 15 seconds is rinsed off with water for at least another 15 seconds. Next, the preparations are thoroughly air-dried.

Now Consepsis 2% chlorhexidine solution from Ultradent, is used to disinfect the preparation,

Before the excess chlorhexidine is removed using a high volume suction so the tooth structure remains hydrated.

With the preps etched, rinsed, and cleaned, Tokuyama Universal Bond is then applied to the preparations.

The bonding agent is air thinned, which is done to evaporate the solvent.

After placing a coat of Tokuyama Universal Bond on the inside of the restorations, they are then loaded with EsteCem II resin cement from Tokuyama Dental America.

The mandibular incisor restorations are being held in place and positive pressure is applied to express excess cement around the periphery of the margins.

A No. 2 Keystone flat brush from Patterson Dental is bent at a 45-degree angle using a hemostat. It is then used to remove excess cement from the marginal areas of the seated restoration.

Next, the restorations are tacked to place with a curing light so the remaining excess cement can be cleaned away without dislodging the restorations.

Dental tape is now used to remove cement excess from the interproximal areas.

Once cement removal is complete, the restorations are light-cured according to the manufacturer’s instructions.

Here is a facial retracted view of the cemented mandibular ceramic restorations.

Here, a protrusive excursion shows separation of all posterior teeth.

A right lateral working excursion displays separation of all posterior teeth on the patient’s right side.

A left lateral excursion shows separation of all posterior teeth on the patient’s left side. Note that because of the post orthodontic positions of the teeth, the cuspids do not line up. Anterior coupling of the remaining anterior teeth protects the posterior teeth during the functional movement.

The case finished, here is a retracted full arch view of the completed cementation in centric occlusion.

In conclusion here is a retracted full arch view of the completed cementation in centric occlusion at a 1-year postoperative visit.

Videos

A quick visual technique guide for using Tokuyama Dental's Universal Bond System to place multiple crowns in the same seating appointment. The dentistry in this case is performed by Robert A. Lowe, DDS, FAGD, FICD, FADI, FACD.

Technique in 2 Minutes: How to Use The Universal Bond System For A Perfect, Predictable Fit

The creation of an ideally prepared tooth and its detail being “captured” in a master impression are critical steps in the indirect dental restorative process. All can be for naught if a meticulous delivery technique is not followed. Most indirect definitive restorations are crafted with precision on carefully trimmed dies machined with pin placement to align the cast’s preparations in the exact position relative to one another as they appear in the patient’s oral cavity. The final test of accuracy, however, is in the patient’s mouth. Often, ceramic restorations may appear to have perfect fit contact on the master dies relative to one another yet requires adjustment when tried on a patient. Required adjustments are to be expected from time to time when dealing with an indirect fabrication method.

Self-etch: compatible with total-etch and selective-etch techniques

Fully compatible with light-cured, self-cured, and dual-cured composites

High bond strength to polymerizable materials

It is also true that multiple adjacent restorations may appear to have proximal contact upon try-on, only to have a slightly altered fit after cementation. Alterations may require a remake if the restoration is placed in an improper position, and it cannot be recovered before the set of the cement. Some clinicians espouse a “multiple cementation technique,” placing 8 to 10 restorations at one time. This can often lead to a disastrous result if even one restoration is placed in a slightly altered position affecting the correct seating of the remaining units.

Dental Cements—A Historical Perspective

By definition, dental cements are “luting agents” meant to fill the microscopic gap between restorative materials and tooth structure. There are multiple types of cement agents.

While universally used for many years, zinc phosphate cements are soluble in oral fluids and can “wash out” when restorative materials are not engineered to fit precisely. Polycarboxylate cements have a slight advantage in that they “chelate” to dentin. Still, the film thickness is greater than that of zinc phosphate cements, which can sometimes be problematic with a fully restored seating. Glass ionomer cements offer some distinct advantages over both zinc phosphates and polycarboxylates. The film is extremely thin, and the material has a fluoride release that has shown to be anticariogenic. The downside? Glass ionomers are still quite soluble in oral fluids.

The next generation in cement evolution moved on to modified resin ionomers. These cements have the advantages of glass ionomers but are even less soluble in the oral environment. In fact, some manufacturers report “zero” solubility with resin ionomers.

A common thread with all of these types of cements is they do not bond to restorative materials. However, the resin cement family evolved out of total-etch and dentin adhesive technologies. Resin cements require pretreatment of the tooth surface with 37% phosphoric acid and the application of a dentin bonding agent prior to application. Resin cements form a micromechanical bond to both tooth structure on one side and restorative material on the other side. Also, they are insoluble in oral fluids.

The latest advance in resin cements is “universal” self-etching cements that may be used with or without a dentin adhesive. They appear to have many advantages of total-etch resin cement systems, yet have the ease of using more traditional types of cements. It is important to emphasize, in some cases, bond strengths of universal self-etching resin cements are not as high when used in “self-etch mode” as those for resin cements using the “total-etch technique” in conjunction with a dentin adhesive. Ideally, it would be beneficial to have a universal adhesive that does not require acid etching to reach optimal bond strengths in enamel and not require light curing prior to cementation, affecting the final marginal fit of the restoration.

It is important to remember that the purpose of any cement is to fill the microgap between tooth structure and restorative material to aid in retaining that restoration. Proper resistance and retention form of preparation is still critical for the successful retention of any restorative material.

Using a Truly Universal Bonding System With Indirect Restorations

Choosing to bond ceramic restorations using a resin cement and dentin adhesive offers one of the higher, if not the highest, bond strength to affix a ceramic restoration to tooth structure. In some clinical situations where maximum bond strength is required, such as for partial coverage ceramic restorations, like porcelain veneers, or for full coverage with less than ideal preparations as far as retentive qualities, it is the method of choice for most clinicians. Still, as with any indirect bonding procedure, there is a degree of technique sensitivity due to the number of steps required to achieve ideal bonding in an environment that can be difficult to isolate from moisture.

Universal bonding systems have simplified the bonding of indirect ceramic restorations. For instance, Tokuyama Universal Bond by Tokuyama Dental America has been introduced with unique features such as no longer needing to light cure the adhesive after application. Also, Tokuyama Universal Bond is a self-curing bonding agent, so it will cure on its own when light cannot reach the material, for example, when bonding zirconium restorations. Another feature of Tokuyama Universal Bond is that there is no need to agitate for 20 seconds to ensure the bonding agent’s penetration into the tooth substrate. Just place, air thin, and cement. Finally, Tokuyama Universal Bond contains primers in both of its components. These included primers mean a separate silane primer is not necessary when bonding glass-ceramics. Even when cementing a zirconium restoration, a separate metallic zirconium primer is also not needed.

Using a Truly Universal Bonding System—A Case Report

For any multiple-unit cases involving the anterior region, the central and lateral incisors are the most important both esthetically and functionally in guiding the mandible into a protrusive posterior disclusion when the patient’s jaw moves forward during the chewing stroke. The cuspids are also critical as they guide the mandible to separate the posterior teeth during lateral excursions.

Together, these teeth perform a function called “anterior coupling,” allowing all posterior teeth to separate immediately from the centric relation/occlusion position. First, all restorations were tried on individually and evaluated for marginal integrity and fit. Next, proximal contacts were evaluated with dental floss while the dental assistant stabilized adjacent restorations. At this point, proximal contacts should be adjusted with porcelain polishing wheels as needed.

Next, we evaluated the “collective fit” by placing all restorations on their respective preparations and assessing whether the restorations fit passively. Any minor displacement of individual restorations or resistance to complete seating is indicative of a contact that is too tight and needs an adjustment. To make this process easier, we replaced the restoration on the master die in the appropriate position on the master model.

We placed a piece of articulation paper between the restorations to mark the contact area, then “erased” the spot with the porcelain adjuster and reevaluated the fit. This process may need to be repeated a few times before the fit is passive, yet the contact is maintained as “lightly resistant” to dental floss. It is important to note this alone does not mean the restorations will fit passively in the mouth. Remember, teeth don’t move, but dies can move a bit on the master model even when they are pinned.

A facebow transfer and centric occlusion records were taken at the master impression appointment between the maxillary and mandibular preparations. The maxillary provisional restorations and mandibular preparations permit the laboratory technician to “cross mount” the provisional casts and the master casts during the fabrication process. Cross mounting allows for a very accurate approximation in centric relation/occlusion of the definitive maxillary restorations to the mandibular provisional restorations.

Because of this, after the maxillary restorations are adjusted for proximal contact and a passive, collective fit is achieved, an entire maxillary case can now be cemented. Mandibular restorations are adjusted to fit the cemented maxillary restorations then polished as may be required prior to cementation.

In the case illustrated, the maxillary restorations have been placed prior to the mandibular restorations. The first step was to place the central and lateral incisors in position and verify the seat again visually and then radiographically. Digital x-rays allowed for the immediate verification of complete seating on the operatory monitor. For this case, total-etch protocol and resin cement were utilized to maximize bond strength because of occlusal considerations and the patient’s history of clenching.

A properly adjusted occlusal guard was fabricated at the end of treatment to help minimize functional stress on the restorations. In this case, a 37% phosphoric acid etch, Ultra-Etch by Ultradent, was placed on the preparations for 15 seconds 

, thoroughly rinsed off, then dried with air. The dried preparations were disinfected and rewet with Consepsis 2% chlorhexidine gluconate, also from Ultradent 

. Consepsis has been shown to inhibit the release of matrix metalloproteinase, which can break down the dentin bond over time.

Next, the excess Consepsis was removed with high-volume suction, so the dentin surface was not desiccated 

. Because the 4 mandibular incisors will be placed simultaneously, 4 drops of Tokuyama Universal Bond’s A-bond and 4 drops of B-bond were placed in a mixing well, mixed with a micro applicator, then applied to the preparations 

. The adhesive was air thinned for 5 seconds with low air and, after that, 5 seconds of air thinning with stronger air to evaporate the solvent 

A coat of Tokuyama Universal Bond was placed inside the ceramic restorations, air thinned for 10 more seconds, then filled with EsteCem II, Tokuyama Dental America’s resin cement 

. Tokuyama Universal Bond is an excellent companion product to EsteCem II because it exhibits enhanced bond strengths to all substrates without the necessity of extra activators or primers. This helps simplify the cementation process since the same protocol can be used regardless of the choice of restorative material.

Once both central and lateral incisors are completely seated with positive pressure expressing excess around the periphery of the margins 

, a No. 2 Keystone brush from Patterson Dental was used to wipe away all excess material 

. A tacking tip is used to spot cure the restorations in the center to stabilize 

 while continuing cement clean up with the sable brush, and then dental tape was applied 

The final cure of all restorations was completed according to the manufacturer’s instructions 

. There is now a retracted facial view of the central and lateral incisors after placement 

. This process was completed respectively for the cuspids and first premolars, leaving only the first molars to cement next to the natural remaining second molars.

Invariably at this point, even though there may have been a passive fit before, these restorations may now be tight and not go to full seat. Proximal contacts should be marked with articulation paper on the master model, as previously described, then adjusted and checked with dental floss in the patient’s mouth. When the first molar restorations have a passive, full seat, they can be cemented.

The patient was instructed to close into light occlusal contact on Parkell’s AccuFilm II articulating paper. One of 3 possibilities will occur: the patient will contact and mark only on the occlusal surface(s) of one or both of the posterior teeth, the patient will contact only on the incisal edges of the mandibular incisors, or there will be simultaneous contact on both posterior units and the mandibular incisor restorations.

If one or both posterior units contact first, the centric prematurity, or prematurities, are identified and adjusted using a red stripe 30-micron composite finishing diamond from Komet USA and rechecked with AccuFilm until simultaneous contact on both anterior units and posterior units were achieved. If the anterior units contact first, either the incisal edges need shortening, or the maxillary lingual concavities of the maxillary central incisors need deepening. Again, the goal is to achieve simultaneous, even closure with all of these units in place.

It is important to think of occlusal stability like a “3-legged stool.” One can sit on a 3-legged stool very easily but cut one leg off, and it gets harder to balance. Muscles are activated to maintain a stable seating position that may have been at rest before. What does this have to do with restorations? The minimal contact for a stable occlusion is a contact with the maxillary and mandibular central incisors and a posterior contact, as far posterior as possible, on each side.

This does not mean that the occlusion is considered stable with only 3 points of contact, but it’s a start. The ultimate goal is to have even and simultaneous contact of all maxillary and mandibular teeth in centric relation/occlusion (maximum intercuspation). Posterior teeth should touch only in centric relation/occlusion. Any movement from that position, such as working, balancing, and protrusive position, should result in immediate disclusion of all posterior teeth because of canine guidance and anterior coupling 

A technique has been described for methodical and predictable cementation of multiunit ceramic dental reconstruction. A 1-year, postoperative view of the completed case is shown in 

. This technique can be applied to any cementation plan, regardless of the number of units involved. It should also be mentioned that it is very important to verify final cementation with digital bitewing radiographs to ensure accuracy and complete cement removal.

How predictable cementation of full coverage dental restorations can help prevent required adjustments.


How to use the Universal Bond system for a perfect, predictable fit

Every restorative dentist will be, at some point, faced with a patient that presents with root caries apical to an existing crown margin. The choice is whether to remove the existing crown and additional decay and replace the crown, or to attempt to directly restore the affected area without crown replacement.

Let’s further assume this root caries exists on a strategic abutment of a long span bridge-this compounds the decision, especially if economics does not allow the patient to replace the bridge. What are the options now?

One critical aspect that will impact on the ability to restore an area of the tooth or root below an existing restoration will be clinical access to the area.

Often these lesions will be subgingival, so access to restore may require a gingivoplasty, or “mini flap procedure,” to access all the restorative margins. If a flap procedure is not needed for access, use of a soft-tissue dental laser is ideal for this procedure. The wavelength of a diode laser can help with localized hemostasis and is considerably less invasive as far as a zone of necrosis when compared to electrosurgery.

Also, it is difficult to use electrosurgery instrumentation safely around metallic restorations.

The second clinical problem is that the surface of the root is not a very good substrate on which to use resin-bonded dental materials. It is well documented that glass ionomer cements “seal” this type of dentin better than adhesive resins.

The difficulty in using traditional glass ionomers may be in the clinical placement into these difficult to reach areas and then maintaining the field to allow for the self-cure set of the material, which may be minutes. Light-cured resin-modified glass ionomers offer a more realistic approach utilizing command set, but often do not allow long-term diffusion of ions through the resin limiting the “healing effects” of the material.

A new RMGI restorative material (ACTIVA BioACTIVE-RESTORATIVE from Pulpdent Corp.) 

has been shown to allow continual passive diffusion of calcium, phosphate and fluoride ions through the restorative material and to have excellent compressive strength, which is unusual for light-cured RMGI materials.

Activa was chosen to restore this carious lesion on the root of this posterior tooth with a full coverage restoration.

Clinical Case: Root Surface Repair With A Bioactive Restorative Material

The patient in Figure 1 of the above slideshow presented with root surface decay apical to existing porcelain to metal crown.

She is in her late 60s and has battled periodontal disease most of her life. Having lost several maxillary posterior teeth and had them replaced with implants, the treatment goal at this time is to maintain her existing restorations as long as possible. In order to gain access to the carious area, a full thickness flap was reflected.

A SmartBur II (SS White Burs) round polymer bur is used to carefully excavate the carious area. Thirty-seven percent phosphoric acid is used to “clean the preparation” for five seconds, then rinsed away with copious amounts of water. Air dry, but do not over-desiccate the surface of the dentin.

The metal mix tip with metal cannula supplied with 

 is ideal for access in this area as it can be bent to the appropriate angle to allow for easy and precise delivery of the restorative material to the center of the preparation.

It is important not to overfill the preparation to limit the amount of finishing, since access to the restoration with finishing instrumentation will be difficult. Ideally, just enough ACTIVA Restorative should be placed so that removal of excess or finishing after curing is not needed.

Figure 2 in the slideshow shows the ACTIVA Restorative material after placement and light curing. After verifying the accuracy of placement with a bitewing radiograph, the flap will be closed with a silk suture through each side of the interproximal papilla. After one week, the suture is removed.

Figure 3 in the slideshow shows a similar type of lesion radiographically on the mesial abutment (tooth No. 31) of a long span bridge. It is financially not feasible for this patient to have the bridge replaced at this time. Rather than section away the pontics (tooth Nos. 29 and 30) from the anterior abutment and extract the distal abutment, it was decided to see if the lesion could be excavated and successfully restored using ACTIVA BioACTIVE-RESTORATIVE.

Figure 4 is a post-operative radiograph after placement of ACTIVA Restorative on the root surface of tooth No. 31. There was no pulp exposure during preparation and the patient was told, “we will see how the tooth responds to therapy.” Our hope is that by removing the caries and placing a bioactive restorative material such as ACTIVA Restorative, the ion exchange will help to remineralize any affected dentin remaining and the clinical life of this fixed prosthesis will be extended for an indefinite period of time.

These are cases where teeth with recurrent root caries in difficult to access areas have been restored with a bioactive restorative material in hopes of preventing further tooth loss and extending the life of the existing restorations.

This is one of many clinical examples where a bioactive restorative material, such as 

 will prove to be extremely useful in our quest to help patients maintain their dental health.

How to restore root caries with ACTIVA BioACTIVE-RESTORATIVE material [VIDEO]

Practicing general dentistry at a consistently high level of quality is perhaps the hardest “specialty” in our profession.

Today, many general dentists who are able to successfully perform root canal procedures find it challenging to do so efficiently enough to justify the routine in their practices.

If the procedure could be streamlined without compromising the clinical result, many more endodontic procedures would be performed within general dental practices.

In dental school, rotary instrumentation of the root canal was contraindicated because rotary instruments often ledged the canal system, created “false canals” due to a lack of flexibility and caused separation of instruments in the root canal.

With the ability to flex and follow complex canal systems, nickel-titanium (Ni-Ti) files revolutionized this process. They are easier to use and much more efficient than previous generations of hand instruments and, when properly paired with a handpiece that offers controlled rotation and torque and stops or reverses if the instrument binds in the root canal, they significantly simplify the cleaning and shaping of root canals.

 aims to further streamline endodontic procedures by combining an easy working sequence with a technique suited to both specialists and general dentists.

Most root canals can be prepared with a simplified sequence requiring just two files. Highly flexible to minimize canal transportation, the .04- taper files feature a unique S-curve design and a thin instrument core to deliver outstanding cutting efficiency while respecting natural root-canal morphology.

Curved root canals can be easily negotiated without “ledging” or “zipping,” and the presterilized, single-use files significantly reduce or eliminate the risk of file separation due to instrument fatigue.

Used with a torque-limited motor (250-300 rpm), the files are ISO color coded to match all standard endodontic file systems. The files effectively debride the root canal space while maintaining a high degree of flexibility to negotiate the “elbows” of root-canal systems.

The following is a case report on root canal therapy using Komet USA’s new F360™ file system with

Case report: a mandibular central incisor

The patient presented previously with a fractured mandibular central-incisor porcelain restoration that had been repaired with a temporary composite restoration. A periapical radiograph showed the presence of a defined periapical radiolucency necessitating root canal therapy prior to remaking the ceramic restoration.

Note: With an efficient way to perform this service, it is now possible to complete the root canal therapy, place a fiber post, prepare the tooth and take a master impression for the replacement restoration-all in one visit.

This is a major time-saver for the patient and an efficient revenue producer for the practice.

Read the detailed technique case on the next page ... 

 A lingual access cavity is made using a round diamond bur from the 

. Note: The access cavity should provide a near straight-line access to the apex of the mandibular central incisor.

 A rubber dam is placed, and cleaning and shaping of the root canal system begins.

 A number 10 endo file is used to establish the working length of the root canal.

 If a number 10 file cannot reach the apex or if additional flare to the canal is desired, the Komet Pathfinder instrument (PF03L25) is used to establish a mechanical glide path to the apex.

 The root canal is irrigated with sodium hypochlorite or other appropriate antiseptic solution to remove any remaining infected canal debris.

 The size 25 F360™ file is used with the NSK Endo Mate handpiece at 300 rpm in a slow, up-and-down motion; it is employed to the working length until the file is loose. Note: The double-S cross section of the file has very sharp cutting angles for efficiency and a large chip space for removal of infected canal debris during cleaning and shaping.

The root canal is copiously irrigated shows a periapical radiograph following completion of cleaning and shaping with the first F360™ file.

 The size 35 file is used to the full working length of the root canal. Note: If the file binds prematurely, go back to the 25 and work it around the diameter of the canal to slightly enlarge it, enabling the 35 to extend to the working length. Once the size 35 instrument is non-binding in the root canal at the working length, the cleaning and shaping is complete.

The orifice opener (AK10L19) is used to further taper the coronal third of the root canal to facilitate obturation. Note: If needed, this instrument can also be used prior to the glide-path instrument to open a restricted canal orifice.

 The obturation procedure is initiated with try-in of the 35 master gutta-percha cone. A radiograph is used to verify that the cone goes to the working length.

 Root canal sealer is mixed, and the master gutta-percha cone is covered with sealer and then placed to the working length of the root canal. A size-25 finger spreader is pushed into the orifice next to the master cone as far apically as it will go, laterally condensing the gutta-percha in the root canal.

 After the finger spreader is withdrawn, a size-25 accessory gutta-percha point is placed into the void left by the spreader. This procedure is repeated with more accessory points until the coronal third of the root canal is adequately obturated.

 A plugging instrument is heated in a flame and used to remove the excess gutta-percha in the canal access cavity. With the root canal obturated, the next clinical step is to establish post room and place a prefabricated fiber post into the coronal two thirds of the root canal space. Note: Komet’s DentinPost® system is used for this case.

Composed primarily of special glass fibers to ensure high stability while offering exceptional esthetics and radiopacity, DentinPost® prefabricated, tapered-root posts are available in four different sizes with matching instrumentation.

For this case, a DentinPost size 050 is selected.

 A Gates Glidden drill is measured 5 mm short of the radiographic apex of the root canal and used to remove the gutta-percha from that portion. The DentinPost® yellow preparation drill is measured, again 5 mm short of the working length of the root canal, to prepare the internal shape of the canal to accept the yellow fiber post.

 Once the post room is achieved, the fiber post is cemented using 

. Note: A bit of sealer has passed into the periapical area, indicative of a good periapical seal of the root canal apex.

 After the post is trimmed and the crown preparation is refined, a master impression can be made, followed by a provisional crown.

In this case, a simple, effective way of performing root-canal therapy has been demonstrated using Komet USA’s new F360™ rotary file system.

This system can add a whole new dimension to the practice by enabling doctors to combine clinical procedures and shorten treatment time for the patient. In turn, practitioners who may or may not be experienced at performing root-canal therapy can now confidently incorporate endodontics into their routine.

 is a “must have” in any general dental practice.