Lingual Orthodontics without brackets: active retainers

Dr. Anna Mariniello

It is increasingly frequent in clinical practice to treat cases of alignment in adult patients who require a treatment which is both invisible and little annoying. This has resulted in lingual brackets becoming more and more widespread. In order to carry out an invisible and little annoying therapy, a few years ago Prof. Aldo Macchi and Dr. Nunzio Cirulli (1-2) have developed an alignment technique using Nickel Titanium wires bonded on the lingual surface of the anterior teeth. These authors have carried out lingual therapies without brackets for over 15 years. This technique has been subsequently used by other authors, as well (3-4-5).

In the present work, the authors will introduce a method of alignment using retainer wires shaped and activated, according to the biomechanical principles exposed by Burstone and Melsen (6-7-8), in order to achieve the desired dental shift.

Dental Procedure

The wires used for the dental alignment are retainers made up of 5 0.175 inches thick interweaved wires. Shaping these wires was carried out following the biomechanics laws exposed by Burstone and Melsen (6-8).

To solve the dental overcrowding vertical U loops and step bends are shaped. U loops increase the elastic properties of the wire and make it possible to increase the applied force in case of more pronounced crowdings. The step bends – that can be used without U loops in case of minimal crowdings – allow the derotation of the dental elements, as well as reducing the crowding. The wire is shaped with these bends and so to adapt to the lingual surface from canine to canine. Before the bonding procedure, the loops are opened of about 2 mm to be subsequently bonded in contraction. This way, the elastic recoil of the wire will determine the reduction of the crowding.

After cleaning the dental surfaces with toothbrush and pumice, these are etched for 30”. Afterwards the adhesive is applied and polymerized. The retainer was bonded applying fluid composite till the wire was covered for about 1 mm. Considering that after the activation the retainer will not adapt passively anymore it is necessary to bond it first to the teeth that are to be moved less and are closer to the wire. Subsequently it will be bonded on the other teeth, opening or closing the loops and pushing it, with a utility tool, on the teeth where the step bends are positioned. It is obviously necessary to keep the horizontal plane of the wire, not to bring unwanted intrusive or extrusive forces in. For this reason, especially when the wire is activated opening and closing the loops, it is important to use 2 utility tools not to let the retainer turn over.

The active retainer is checked every 2-3 weeks and every time it is detached from the teeth that are to be activated, using a low rpm diamond bur to wear the composite without damaging the wire. After wearing almost all the composite the retainer is detached with a probe. The composite layer left on the teeth is coarsened with the diamond bur to improve the sticking. After the activation the wire is bonded without etching, applying the adhesive on the composite layer previously coarsened.

When the alignment is achieved the active retainer is replaced with a passive one.

Clinical Case

A clinical case performed using this procedure is presented here.

The patient, aged 62, shows a pronounced crowding of the mandibular arch, with a prior extraction of the 41 as well as prior periodontal problems: these have been treated and stabilized. On the maxillary arch there is an implant in region 21. Despite the frequent dental hygiene sessions the patient found it difficult to keep the anterior mandibular sector clean due to his dental malpositioning. Moreover he refused a visible and annoying prosthodontic treatment. For this reason he was suggested a therapy using active retainers. The alignment was achieved after 10 months of treatment, with slow shifts and frequent sessions of tartar removal.

Pic. 1-6: Photographic systematics before the treatment. Frontal view; OVJ; Right Lateral; Left Lateral; Maxillary Occlusal; Mandibular Occlusal.

Pic. 7: Bonded retainer to achieve the alignment. The loops are activated in opening for about 2 mm and bonded in closing achieve the expansion of the arch.

Pic. 8: Reduction of the crowding achieved after 6 weeks of treatment. A new retainer is applied to start the derotation of the dental elements.

Pic. 9: To derotate the 32 an elastic chain was subsequently applied bonding it on the buccal surface of elements 32 and 33 with composite. A passive retainer was bonded lingually on elements 33, 34, 35 as stabilizing sectional. In the meantime the lingually bonded retainer kept on derotating the 43.

Pic. 10: When the derotation of the 32 was achieved, a passive retainer, put upon the previous active one, was bonded on elements 32 and 33 to stabilize them. Using a turret a step bend was shaped between elements 31 and 32 to align them in buccal-lingual direction. The segment of retainer bonded on the 43 was activated so as to derotate that very element.

Pic. 11: The last stages of the alignment are carried out using a 0.12 Ni-Ti wire.





Pic. 12: Frontal view, from canine to canine, after the alignment achieved after about 10 months.




Pic. 13: Occlusal view.

Conclusions

Lingual therapy without brackets using active retainers and Ni-Ti wires bonded on the lingual surface of the teeth makes it possible to carry out alignment therapies that are completely invisible and very well tolerated by the patients. This therapy is indeed little annoying for the tongue and the soft tissues and, as reported by the patients, by far less annoying than lingual brackets. Phonetic alterations have rarely occurred and only for the first few days. To solve more complex cases (e.g. class II and class III malocclusions, bilateral cross, deep or open bite, etc.) it is possible to carry out a lingual therapy without brackets using active retainers and Ni-Ti wires in conjunction with other devices, such as micro-screws, stabilizing sectionals bonded directly on non visible surfaces of the teeth, Quad Helix, etc.

Bibliografia

1. Macchi A, Cirulli N. "Fixed Active Retainer for Minor Anterior Tooth Movement". Journal of Clinical Orthodontics, 2000.

2.Macchi A, Rania S, Cirulli . "Una proposta per la gestione di disallineamenti anteriori: il mantenitore attivo di contenzione (MAC)". Mondo Ortodontico, 1999.

3.Liou EJW, Chen LIJ, Huang CS. "Nickel-titanium mandibular bonded lingual 3-3 retainer: for permanent retention and solving relapse of mandibular anterior crowding". Am J Orthod Dentofacial Orthop 119:443-9, 2001.

4.Musilli M. The Bracketless Fixed Orthodontics: nine years of clinical Experimentation. Prog in Orthod 9:72-91, 2008.

5.Mariniello A, Cozzolino F. Lingual active retainers to achieve teeth levelling in orthodontics: case series. International Dentistry SA Vol 10 N 5, pag. 24-29, 2008. (FULL TEXT)

6.Burstone CJ, Koening HA. Creative wire bending-the force system from step and V bends. Am J Orthod Dentofac Orthop 93:59-67, 1988.

7.Burstone CJ, Koening HA. Force system from an ideal arch. Am j Orthod 65:270-289, 1974.

8.Ronay F, Kleinert W, Melsen B, Burstone CJ. Force system developed by V bends in an elastic orthodontic wire. Am J Orthod Dentofacial Orthop 96(4):295-301,1989.




For information:


Dott.ssa Anna Mariniello


anna.mariniello@libero.it

Nickel Titanium (Ni-Ti) Endowave Morita instruments

"BEST PRACTICE ASSOCIATED WITH SIMPLICITY IN ENDODONTIC THERAPY "

PART 1: THE SHAPING OF THE ENDODONTIC SPACE.

Dr. Giorgio Uccelli

INTRODUCTION:

It is undeniable and generally accepted that the success in endodontic therapy, aside from the performance of a correct access cavity aiming at removing coronal interferences, is linked to the synergistic action of three fundamental stages: the correct shaping, the cleaning-sterilization of the endodontic space and its hermetic and stable filling.

In the age of Nickel-Titanium we have to face almost every day new instruments coming out on the market that should make it possible for the operator to perform a faster and safer work and new equipment that should make the root canal filling simple, fast and predictable.

The aim of this work is to propose a new technique which, while respecting the aforementioned triad shaping-cleaning-filling, allows not only the specialist in endodontics but also the “general practitioner” to perform a fast, safe, predictable and extremely ergonomic root canal therapy.

Gutta-percha nowadays is still the most widely used root canal filling material: it is used in various ways, e.g. the warm compressing technique, the use of carriers, the low temperature side filling, the mechanical compressing, the use of expensive equipment to heat up and/or for the backfilling.

All these procedures need a long learning curve if they are to be put correctly in operation.

The “Schilderian” warm compression itself on the one hand provides wonderful radiological images when performed correctly, on the other requires such a sacrifice of dentinal structure, needed to bring the warm spreader to at least 4 mm from the apex, that can endanger the structural integrity of the treated element.

Furthermore the well known retraction of the gutta-percha (5-7%) during the cooling down, the total lack of adhesion between gutta-percha-cementum-root dentin which can lead to a high risk of subsequent coronal-apical infection are elements that are always to be taken into consideration.

SEM pictures, courtesy of Dr. Luigi Generali – University of Modena

In the last few years there has been the possibility of using a new material, the Resilon, made up of new conception polyester polymers and liable to future modifications: its characteristics of biocompatibility, ductility and ease of use are appointing it as the heir of gutta-percha (as confirmed by the worldwide sales increase).

The technique we are about to describe in this article is as easy as one can conceive, the learning curve extremely short, the results thrilling provided that all the easy required operative steps are carried out.

THE SHAPING:

The first step consists in making the correct access cavity in order to get rid of possible coronal interferences using the appropriate burs: this step is needed to get a straight and visible access to the root canals.

The second step consists in ‘scouting’ the root canal with a 0.08 K-file in bath of 20% EDTA Gel and assessing the length of the work area using an apical locator: this has to be supported with at least 3 X-rays performed with a positioning aid, 2 of which with a projection of 30 degrees.

The recent construction of a 10/12 rotary files (Morita) usable at a speed of 1000 rpm and a torque of 0.3 Ncm makes it possible to perform a totally motorized “glide path”, as well as the passing of 15/02,20/02 EndoWaves; 25/02 EndoWaves can possibly be used in wider root canals using the appropriate endodontic handpiece at a speed of 800 rpm and torque of 0.3 Ncm.

As previously mentioned EndoWaves are Ni-Ti rotary files supplied in 2 kits (A and B) by the company: kit A is to be used in wide root canals and/or with little curvature while kit B in narrow root canals and/or with severe curvature.

All the files have a triangular cross-section, the only exception being the #15/02 and the #20/02 which have a square cross-section. The triangular cross-section, along with the specific “continuous wave” spiraling design makes them extremely flexible and efficient in removing organic and inorganic debris.

The non-sharp tip and the exclusive electro-chemical conditioning provide the files with unique safety qualities minimizing cyclical and torsional fatigue stress.

In our work the Kits have been reassembled in order to get a mixed kit for the “glide-path”, a so called “uni-kit” which has proved to be useful in 90% of the operations performed and an “L-kit” to be used in the remaining cases when facing wide root canals.

THE TECHNIQUE :

Introduction: due to the very low values needed by the EndoWaves the optimum would be the use of a devoted endodontic handpiece, e.g. the Dentaport ZX II which contains, in just one instrument, the functions of engine and localizator, with 5 security devices to control torque, rpm, slow-down, screen control of the instrument progress, auto reverse .

The instrumentation is limited to 4 Ni-Ti files.

The glide path is performed using 3 manual files: the 0.08, the 0.10, the 0.12 K-Files in 19% edta gel bath, removed every time with 5.25-6% NaOCl . At this stage, after verifying, as before mentioned, the length of the root canal it is time to finish the job using the 15/02-20/02 and, if needed, the 25/02 at a speed of 800 rpm.

Now it is time to start shaping the root system: 25/06-25/04-20/06-25/02-25/04 (in atresic canals it is ok to end at this point), otherwise it is possible to finish with the 20/06. All the files are to be used at 600 rpm, alternating NaOCl and 19% liquid Edta at every round.

The torque values range from 0.6 NCm for 0.4 tapering to 0.9 for 0.6 tapering and 1.2 for 0.8 tapering.

VIDEO

In wide and straight root canals the operative sequence starts with the 35/08, then goes on with the 30/06-25/06-25/04 (to check patency) and finally ends up with the 30/06 or the 25/06.

The impression left by the EndoWaves used this way in the root canal allows the perfect fit of the Medim or Medium –Large Resilion cone, from the third coronal to the third apical, on the root canal walls leaving a 1 micron gap for cementum on all its length .

.

The pictures clearly show how the files work perfectly centered in the root canal lumen, leaving the root canal walls perfectly smooth and getting rid of the predentin .

In our subsequent article (part 2), we will be dealing with the cleaning stage, strongly linked to the shaping and, finally, the filling of the root canal system, last stage of the correct endodontic therapy (part 3).

Dr. Giorgio Uccelli

Graduated in Medicine and Surgery at the University of Pisa where he also specialized in Odontostomatology.

From 1980 to 1985 he attended the courses of the "Division of Continuing Education Endodontic series", Boston University Goldman School with Prof. H. Schilder, H.J. Levin, D.Baraban, S. Rubin, R. Rosenkranz, S. Melnick...

Member of SIE from 1980 and from 1987 as Active Member..

From 2003 to 2005 he held the role of Secretary of Culture of Tuscany’s SIE branch.

Speaker in National conferences, Endodontic days, ANDI nights, he is author of several publications.

He practices his activity within the limits of Endodontics in Marina di Carrara (MS)

For information:

dott.uccelli1@virgilio.it

Mini maxillary sinus elevation using SinCrest

Minimally invasive transcrestal maxillary sinus elevation

Dr. Fabio Cozzolino, DDS, PhD

Dr. Giuseppe Cozzolino, DDS

Inserting implants in the back of the maxilla can present considerable technical difficulties. The dentist has often to face coronally-apically reduced bone portions deriving from crestal bone reabsorption or maxillary sinus pneumatisation, especially when in the area there are extractions performed many years before.

In the case the reduced height is mainly due to crestal bone reabsorbtion, before inserting the implants it is necessary to coronally regenerate the bone. This is done in order to avoid using prosthesis with teeth which are too long and would cause an unfavourable crown/root ratio.

On the other hand, when the reabsorption is mainly due to a pneumatisation of the maxillary sinus, it is important to estimate the amount of remaining bone.

As a matter of fact, if the bone height is < 4mm, there is enough bone to achieve primary stabilization of the implant; in this case the operation will be carried out in a single stage performing a mini-elevation of the maxillary sinus and, at the same time, inserting the fixture.

The maxillary sinus mini elevation technique with osteotomes, explained by Summers in 1994, requires the implant site to be prepared up to 2 mm from the sinus floor. At this point, using a concave osteotome, it is time to break the 2 remaining mm of bone; the bio-material is then inserted with the help of the osteotomes, leading to the elevation of the Schneider membrane. In this technique it is the load of the bio-material that elevates the sinus floor: the osteotomes are never to enter in the maxillary sinus.

Once the sinus floor has been elevated, it is time to insert the implant. The mini-elevation technique, when usable, provides remarkable benefits in respect to the standard elevation of the sinus floor.

With this technique, it is indeed necessary for the patient to undergo just one operation, the morbility is considerably lower than in the standard elevation, vascular complications are noticeably reduced and prosthetic rehabilitation times are appreciably shortened.

One disadvantage of this technique is that the surgeon operates blindfold, without seeing directly: this greatly increases the risk of tearing Schneider membrane – sometimes being just a few tenths of millimeter thick.

In this work we will analyze a new device, made by Meta, that should make it possible to elevate the sinus floor in a safer and more controlled way.

The Sincrest is a transcrestal maxillary sinus floor elevation kit made up of burs for electric handpiece, depth stops of various heights and a manual osteotome. The manual osteotome was designed to achieve the controlled fracture of the sinus floor by the maxillary sinus mucosa without damaging it.

The patient, aged 64, non smoker, came to our observation complaining about a low chewing efficiency after the maxillary sixths were extracted many years before and not replaced with a prosthesis. The X-rays show a bone with reduced height because of the pneumatisation of the maxillary sinus.

From endo-oral X-rays made using Rinn Digital Sensor Positioning Aids and a CAT, the residual height is estimated to be less than 8 mm. It is thus decided to insert the implant and at the same time elevate transcrestally the sinus floor using the SinCrest device.

The crest is cut with a size 15 Bard Parker scalpel and a full thickness flap is made performing a double widening suture both buccally and palatally.

The first bur to be used is the Locator Drill, that works only for 3.5 mm and only drills the cortical bone.

Subsequently we will use the 1.2 mm diameter Probe Drill. In order to take the burs from the kit without touching them with the hands, Meta provides a tool called Drill Gripper. The Probe Drill bur, flat headed, is sharp only on the head; for this reason it is not possible to apply a lateral cutting force and correct the direction of the implant hole.

The depth of the work must be planned at about 2 mm from the maxillary sinus floor by means of endo-oral X-rays. In this case, since the distance between the crest and the floor is of about 8 mm, a 6 mm stop is inserted.

At this stage it becomes necessary to make endo-oral X-rays using the 1.2 mm RX Pin to check the correct distance from the maxillary sinus.

After the X-ray check it is possible to go down to a 6 mm depth.

After checking that distance, the 3 mm diameter Guide Drill will be used. That bur only works for a depth of 2 mm and allows for the correct centring of the following bur.

As a matter of fact, once the stop at 6 mm is inserted, the 3 mm diameter SinCrest Drill will be used: this will create a precise housing to insert the 3 mm SinCrest tool.

In the following video it is shown how the SinCrest device works.

VIDEO

At this stage, the device is manually screwed until one can see the white stripe on the probe. Seeing that stripe means that the SinCrest has reached the depth made by the burs.

The handpiece is now rotated of ½ rotation first counterclockwise and then clockwise applying a pressure axially. By repeating this “screw and unscrew” motion, the thread of the device is kept completely stationary and an osteotomy of 0.5 mm is carried out apically. At this stage it is possible to screw the SinCrest again so that it will go forward of 0.5 mm apically.

It is always necessary to check the residual resistance of the sinus floor by applying a light pressure on the probe. If the probe does not go further, it is necessary to repeat the forward movement sequence of the device.

When the white stripe disappears, it means that the bone operculum is fractured and it is possible to insert the bio-material for the elevation.

In the following video it is shown how the SinCrest device clinically works.

.

VIDEO

In this case we used Bio-Oss inserted in the sinus by means of a carrier and pushed apically using osteotomes: it is important not to go further than 8 mm. Finally the Strauman male threader is screwed in order to make a hole of 3.5 mm diameter: this is needed to insert a 10 mm long Straumann implant with a 4.1 mm diameter SLActive surface sunk for 1.5 mm due to aesthetic reasons.

After inserting a healing abutment with a height of 2 mm, a detached stitches suture using ePTFE (Tevdek 4.0) coated interweaved polyester was made.

In conclusion, SinCrest has proved to be a really effective device that makes it possible to elevate the Schneider membrane in an extremely safe way even by the non-expert.

Its limit is that it cannot be used when the vertical distance from the maxillary sinus floor to the occlusal floor of the tooth adjacent to the site of operation is more than 23 mm and when there is a type 4 bone, as it would determine a reduced stability while screwing the SinCrest device.

The authors of the present article also believe this device should not be used when dealing with very inclined sinus floors since, in these cases, the blade could damage the sinus membrane.

Another limitation of the kit is to be found in the succession of the burs. The gap between the first (1.2 mm) and the second (3 mm) when preparing the implant site is of 1.8 mm. This big gap can cause overheating of the bone and, above all, does not allow to correct the direction of the implant hole. This issue may be compensated using burs from one’s own implant kit.

Bibliography

1: Summers RB.
A new concept in maxillary implant surgery: the osteotome technique.
Compendium. 1994 Feb;15(2):152, 154-6, 158 passim; quiz 162.

2: Summers RB.
The osteotome technique: Part 2--The ridge expansion osteotomy (REO) procedure.
Compendium. 1994 Apr;15(4):422, 424, 426, passim; quiz 436.

3: Summers RB.
The osteotome technique: Part 3--Less invasive methods of elevating the sinus
floor.
Compendium. 1994 Jun;15(6):698, 700, 702-4 passim; quiz 710.

4: Summers RB.
The osteotome technique: Part 4--Future site development.
Compend Contin Educ Dent. 1995 Nov;16(11):1080, 1092 passim; quiz 1099.

5: Summers RB.
A new concept in maxillary implant surgery: the osteotome technique.
Compendium. 1994 Feb;15(2):152, 154-6, 158 passim; quiz 162.

6: Summers RB.
Sinus floor elevation with osteotomes.
J Esthet Dent. 1998;10(3):164-71.

7: Brägger U, Gerber C, Joss A, Haenni S, Meier A, Hashorva E, Lang NP.
Patterns of tissue remodeling after placement of ITI dental implants using an
osteotome technique: a longitudinal radiographic case cohort study.
Clin Oral Implants Res. 2004 Apr;15(2):158-66.

8: Woo I, Le BT.
Maxillary sinus floor elevation: review of anatomy and two techniques.
Implant Dent. 2004 Mar;13(1):28-32.

9: Diserens V, Mericske E, Schäppi P, Mericske-Stern R.
Transcrestal sinus floor elevation: report of a case series.
Int J Periodontics Restorative Dent. 2006 Apr;26(2):151-9.

10: Draenert GF, Eisenmenger W.
A new technique for the transcrestal sinus floor elevation and alveolar ridge
augmentation with press-fit bone cylinders: a technical note.
J Craniomaxillofac Surg. 2007 Jun-Jul;35(4-5):201-6. Epub 2007 Jun 20.

For information:

Dr. Fabio Cozzolino

fabio.cozzolino@fastwebnet.it