The Self-Adjusting-File (SAF) Technique

The Self-Adjusting-File (SAF) Technique

ITALIAN VERSION

Introduction

 

In 1993 the first  endodontic files, made from a nickel-titanium (NiTi) alloy,  were introduced to the dental market and definitely contributed to a radical change in the operative approach to endodontic treatment   [1]. Compared to  previous stainless steel  files, they were much more flexible,  effective and better performing in shaping   root canals. Furthermore, in recent years, advances in knowledge and technology  have  brought about  several  interesting changes in these alloys, which were made increasingly resistant to  torsional load and, therefore, safer to use.This has led to the manufacturing of  a “single file” ,  which  enables dental practitioners to shape the full length of the root canal using a single  instrument, such as  Wave One ® (Maillefer- Dentsply , Ballaugues, Switzerland) or Reciproc ® (VDW, Munich, Germany) [2].Despite these structural improvements, the file design has remained unchanged :  a solid body with more or less sharpened blades, which cut the canal from different angles and  collect treatment debris in their flutes. This suggests that, despite the different endodontic  variations recurrent in nature, we do nothing but imprint the instrument shape inside the canal, regardless  canal anatomy ; this apparently allows us  to use similar procedures with either round-shaped  and oval- shaped canals ,  as well as with  more or less tightly curved canals.From the studies carried out by  Paqué [3,] analyzing  MicroCT  sections, it is clear  that instrumentation with conventional Ni-Ti tools   does not allow  us to accomplish  a proper cleaning of the whole root canal system (fig.1). In fact, these instruments, due to their  shape, cannot contact the entire surface  of root  walls, thus  leaving within a certain amount of unremoved tissue, which also reduces the quality of subsequent obturation ,  as  highlighted by De Deus (Fig2) [4.5].

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Fig. 1 – Adapted from Paquè et Al

Adapted from DeDeus et Al.

Fig. 2 – Adapted from DeDeus et Al.

The Conservative Restoration In Critical Areas

The Conservative Restoration In Critical Areas

 

ITALIAN VERSION

 

A young patient presented to the Author with a traumatic coronal fracture of tooth 21, localized at cervical level at about 1 mm from the cementum-enamel junction.

A standardized periapical radiograph was taken and a careful treatment plan was designed. A multidisciplinary approach was chosen, based on endodontic treatment, temporary conservative restoration, orthodontic treatment and prosthetic rehabilitation of the tooth.

CERUTTI zerodonto .002

 

Invisible Orthodontics: a case report of severe open bite

Invisible Orthodontics: a case report of severe open bite

  ITALIAN VERSION

 

 

‪Many adult patients require aligned teeth to improve their aesthetics, as dental exposure and smile are fundamental for the beauty of the face.

For this reason, the orthodontic treatment plan is the result of a careful radiographic examination and related cephalometric tracing, a detailed examination of the dental casts and related space analysis, but also an accurate aesthetic facial analysis.

We want to focus our attention on the exposure of the maxillary incisors with lips at rest. This is critical, for example, when we treat a case with overbite alterations, both in excess and in defect.

The clinical case we introduce is an example of treatment in case of anterior open bite. The patient asked for a fixed invisible lingual orthodontic therapy without brackets, to completely hide the presence of the device without phonetic distortions and tongue irritations.

Ortopantomography, Latero-Lateral Teleradiography, cephalometric study, cephalometric values chart :

open bite

Complex prosthetic rehabilitation due to severe dental wear

Complex prosthetic rehabilitation due to severe dental wear

 ITALIAN VERSION

 

In collaboration with Dr. Leonardo Bacherini

Several factors affect the life of a tooth and, consequently, different causes can lead to dental wear. Unfortunately, their effects are cumulative and irreversible and, despite its main cause, tooth wear starts immediately after tooth eruption. As a consequence, clinicians have to diagnose such a condition early, particularly when dental wear occurs suddenly and progressively in young patients. The processes causing tooth wear are attrition, erosion, abrasion, demastication, abfraction and non-carious cervical lesions.

 

Patient’s expectations

  • Remote pathological anamnesis: bulimia during youth
  • Recent pathological anamnesis: gastro-esophageal reflux disease (GERD)
  • Non smoker
  • Dental anamnesis: the patient complained about severe sensitivity on all teeth and wanted to improve the esthetics of her smile; the teeth were short and abraded

Localized Management of Sinus Floor

Localized Management of Sinus Floor

 

ITALIAN VERSION

OBJECTIVES

The Localized Management of Sinus Floor is a surgical technique for transcrestal maxillary sinus floor elevation. Its aim is to create a surgical site for implants by displacing a portion of native residual below bone within the cavity of the maxillary sinus. This particular type of bone is usually found below the sinus floor and, through this technique, is displaced vertically in order to create a new implant alveolar portion. In the final configuration of the surgically created alveolus, the coronal portion of the crest must give primary implant stability. This will be completed by the coronal bone portion – pushed laterally and internally of the sinus cavity – from which, a sort of closed “tent” formed by the sinus membrane, will keep the cavity closed. The latter will be filled by blood produced by the alveolar walls.

Tissue repair of the peri-implant alveolus is totally entrusted to the physiological mechanism of bone repair on the site chosen for the implant osteotomy. 3-4-13-14

The goal is to change the height of available bone by creating an osteotomy tunnel starting from the crestal position and extending, initially transversally and medially, in a direction parallel to the palatine vault. This way, the osteotomy tunnel pushes the spongy bone against the floor of the maxillary sinus and avoids loss of the precious calcified structure.

The initially transverse direction (and not vertical, according to the normal prosthetic axis) is essential to:

1. Increase the height of native bone, interfacing the implant to improve primary stability;

2. Use the higher portion of the sinus floor which is normally found towards the medial side of the sinus cavity.

Preparation of the surgical field

According to the protocol, the preparation of the soft tissues is made with a partial thickness technique that has the objective to leave a thin layer of connective tissue which:

1. Ensures the integrity of the periosteum;

2. Allows to easily read the underlying bony anatomy.

The protection of the periosteum is critical, of course, to maintain the integrity of the blood supply15. Also the layer of connective tissue, and the interposed periosteum between tissue and bone, will be fundamental to promote the peri-implant tissue secondary intention healing. This is one of the main issues of the protocol.

This preparation enables to firmly anchor the keratinized tissue – using the sub-periosteal sutures – in an apical and vestibular position. This residual displaced tissue, previously covering the crest, has been displaced vestibularly14.

The flap preparation begins with a palatally beveled incision which slides along the bone plane, starting from the palatal angle of the crest, exactly where the palatal structure crosses the horizontal portion of the edentulous ridge. This has the aim of exposing the crest and displacing vestibularly the keratinized crestal residual tissue to the future implant emergency. This crestal tissue is the same one which has been previously moved from the palatal aspect of the surgical field. Fig. 01/05

SONY DSC

Esthetics in Total Removable Prosthodontics

Esthetics in Total Removable Prosthodontics

ITALIAN VERSION

 

From the impression tray to the denture: techniques for fabrication

 

Patients feel teeth loss as a worsening of the quality of life. Although in the last years prevention in dentistry has reached more and more comfortable levels, the lengthening of average life is often associated with an increase in the incidence of periodontal disease and loss of tooth support, causing complete edentulism over time. The overcoming of problems related to edentulous patients requires specific skills for the clinicians and stimulates the research of innovative technique and restorative materials. In fact, each laboratory and clinical step has to be performed in the respect of traditional concepts, from the extension to the basal areas to the precision of the interface between soft tissues and the impression surface of the denture, from the border molding to the modelling of the prosthesis, from a proper and physiological record of the intermaxillary relationships to the optimal mounting of the artificial teeth.

CLINICAL CASE PRESENTATION
A 58-year old female patient presented with complete edentulism; she was not a smoker and was in good general health. The patient’s complaints regarded both function and communication, referring a severe discomfort in interpersonal relationships. Consequently, she requested for a radical rehabilitation of her mouth, paying particular attention to esthetics. Consequently, the aim of the prosthetic rehabilitation was the achievement of both optimal functional and esthetical results.
1

TECHNICAL PROCEDURES
According to a conventional approach, the dentist took the study impressions by means of an irreversible hydrocolloid. The preliminary impressions have to be overextended, so as to record the whole extension of the maxillary and mandibular arch as well as of the adjacent soft tissues.

3

Digital impression by means of Itero intraoral scanning system to fabricate zirconia single crowns

Digital impression by means of Itero intraoral scanning system to fabricate zirconia single crowns

ITALIAN VERSION


Stereomicroscopic analysis of the precision of fit of PFM frameworks fabricated with traditional impression vs zirconia prostheses produced using an optical impression technique

Case presentation
A 42 year-old female patient, unsatisfied by the esthetics of her smile, asked for the rehabilitation of the maxillary incisors by means of fixed prostheses, substituting 4 previous metal-ceramic single crowns.

itero x blog.001

Controlled Split Crest and Guided Bone Regeneration (GBR) with contemporary implant placement: rationale and limits of the clinical application in esthetic areas.

Controlled Split Crest and Guided Bone Regeneration (GBR) with contemporary implant placement: rationale and limits of the clinical application in esthetic areas.

ITALIAN VERSION

The authors’ experience in the medium term.

 

Introduction

According to the current scientific literature, a prosthetically-guided approach should be the first choice for implant placement, even in case of horizontal/vertical alveolar bone resorption. In the last decade, different reconstructive techniques were described with the aim of restoring bone volume.

Among the available techniques, the authors widely experienced and achieved very satisfactory clinical outcomes with the “Edentulous Ridge Expansion” (E.R.E.), introduced by Dr. Bruschi and Scipioni in 1994.

This technique relies upon the healing potential of the spongy bone, associated with the elevation of a partial thickness flap to preserve the periosteum. The intra-bony gap is initially filled by a blood clot that turns into osteoid tissue in about 40 days. After about 90-120 days, the extracellular matrix progressively mineralizes and the osteoblasts mature into osteocytes.

In this technique, the preservation of an optimal trophism of the bone is paramount, leaving a thickness of at least 1-1.5 mm to the buccal bone; an extensive periosteal blood supply is required as well. This approach limits the risk of fenestrations, dehiscences or necrosis of the buccal bone during implant insertion and healing.

The E.R.E. technique is suitable in case of knife-edge alveolar ridges with at least a height of 10 mm and a width of 4 mm. Its main drawback is the risk of fracture during the displacement of the buccal bone plate; therefore, its predictability is not absolute. Such risk can be limited using a partial thickness flap, in order to ensure a better cortical blood supply in case of fracture.

If, on the one hand, a partial thickness flap is advisable, on the other hand, periosteal preservation does not allow to associate bone regeneration techniques that may be required during surgery, especially when a prosthetically-guided implant positioning is aimed. For this purpose, in recent years, the authors have developed a modified split-crest technique associated to a contextual guided bone regeneration (GBR), in order to compensate any dehiscence and/or fenestration, minimize the marginal bone loss and fill the gap between bone and implant. This approach is particularly important in the esthetic zone, where the stability of the buccal bone is critical for the success.

In a systematic review of the literature (Donos et al., 2008), the survival rate of implants placed in sites augmented with the split-crest technique ranged from 86.2 % to 100% after 12 months to 5 years in different studies. The success rate of the split osteotomy, measured as the achievement of adequate ridge dimensions for placement of implants, varied from 87.5% to 97.8% from 18 to 20.4 months post-loading, respectively.

The present article aimed at analyzing the clinical factors influencing the reliability of the split-crest technique as well as discussing its limits and rationale by the presentation of two clinical cases.

The technique: rationale and anatomic considerations

 

Comparing an atrophic ridge with its normal anatomy in sagittal view (Fig. 1), it can be noted that the bone volume is evidently resorbed, particularly on the buccal side. Differences in bone resorption rates between the buccal and lingual aspects are due to the greater amount of bundle-bone present on the buccal side of the alveolar ridge. The bundle-bone is strictly related to the presence of teeth, so a greater resorption rate occurs on the buccal aspect after tooth loss (Araujo & Lindhe 2005).
Frequently, in edentulous ridges an hourglass shaped alveolar process is found, due to the presence of an undercut at the base of the ridge. This anatomical peculiarity should not be underestimated in case of implants in the esthetic zone, as the drills can create fenestrations in the apical part of the implant site. Small fenestrations are not a big issue for osseointegration but can affect the achievement of optimal soft tissues esthetics, resulting in a grayish tissue transparency, particularly unpleasant in the anterior maxilla.

atrofia processo alveolare anatomia mascellare superiore  hourglass shaped alveolar bone riassorbimento post estrattivo dr. dott. dario mari sac ITI impianti in zona estetica cresta alveolare bundle bone osso fibroso araujo lindhe classificazione Cawood Howell

Minimally Invasive Surgical Technique (MIST) In Regenerative Periodontal Therapy

Minimally Invasive Surgical Technique (MIST) In Regenerative Periodontal Therapy

ITALIAN VERSION

 

Introduction

In the last decade, a growing interest for more friendly, patient oriented surgery have urged clinical investigators to focus their interest in the development of less invasive approaches. Surgical procedures in medicine and in dentistry have undergone radical changes to reduce invasivity; in parallel novel instruments and materials have been developed for the inevitable evolution of the surgical armamentarium (Cortellini 2012).

The field of periodontal surgery have been enriched with this peculiar and innovative approach rather recently (Harrel and Rees 1995). They proposed the “Minimally Invasive Surgery (MIS)” with the aim to produce minimal wounds, minimal flap reflection and gentle handling of the soft and hard tissues (Harrel and Nunn 2001, Harrel et al. 2005). Cortellini and Tonetti (2007a) proposed the Minimally Invasive Surgical Technique (MIST) to stress the aspects of wound and blood clot stability and primary wound closure for blood-clot protection. These concepts were further enforced with the Modified Minimally Invasive Surgical Technique (M-MIST, Cortellini & Tonetti 2009) that, additionally, incorporated the concept of space provision for regeneration. Minimally invasive surgery is a term that describes the application of very precise and delicate surgical procedures that require the use of magnifying devices, like operating microscopes or magnifying lenses, and microsurgical instruments and materials. Cortellini & Tonetti (2001, 2005) proposed the use of an operative microscope in periodontal regenerative surgery, reporting an increased capacity to manipulate the soft tissues that resulted in an improved potential for primary closure of the wound from an average 70% of the cases obtained with regular surgery to an excellent 92% obtained with microsurgery.

Minimally Invasive Surgical Techniques

Two different minimally invasive techniques have been proposed: 1) procedures that include the elevation of a tiny buccal flap as well as the elevation of the interdental papilla and of the palatal flap and 2) techniques that are limited to the elevation of the buccal flap.

These procedures can be applied for the treatment of shallow and deep intrabony defects (up to the apical third of the root surface).

Diagnosis of intrabony defects

The diagnosis of the intrabony defect is based on periodontal probing. The difference of attachment level between two interproximal surfaces represents the intrabony component of the defect. If the mesial surface of a tooth has an attachment level of 10 mm and the distal surface of the neighbouring tooth has an attachment level of 4 mm, the depth of the intrabony component is 6 mm.

probing GTRmodified mist mist M-mist
The diagnosis can be confirmed with a periapical radiograph that provides relevant information about the morphology of both the defect and the root. However, in many instances, the radiograph underestimates the real depth of the defect.
pre operative radiography mist


Pre-operative patient and site preparation

A critical prerequisite to periodontal regeneration is the control of periodontal disease. The patient should present with very low levels of plaque and inflammation as the result of a successful cause-related therapy. In addition the patient should not smoke or at least smoke less than 10 cigarettes per day. Systemic diseases, like diabetes, have to be under control. Intraoral prophylaxis with a low-speed rubber cup and prophylaxis paste should be performed immediately before surgery; in addition, the patient should rinse the mouth with 1% chlorexidine for 1 minute.

Oral surgery in childhood and adolescence

Oral surgery in childhood and adolescence

ITALIAN VERSION

 

Introduction

Oral surgery in children is not always an easy surgery: it is often complicated by:

– specific age-related pathologies, not always easy to recognize

– complex anatomy associated with the mixed dentition

– reduced surgical access

– difficulties in obtaining the cooperation

– the need for coordinating surgery and orthodontics

There are opportunities for oral surgery typical age-related operations and other conditions that require a different approach when patients are children:

– extraction of infraoccluded primary teeth

– extraction of impacted supernumerary teeth

– treatment of cysts

– germectomies of mandibular wisdom teeth

Invisible orthodontics: ectopic buccal canine malocclusion

Invisible orthodontics: ectopic buccal canine malocclusion

ITALIAN VERSION

 

Bracketless invisible orthodontics is a new orthodontic device to treat malocclusion, based on the use of thin wires directly bonded on invisible teeth surfaces.

Such appliance is not visible but also well comfortable for the tongue and soft tissues, thanks to the extremely personalized and anatomical modelling, and takes less space than the lingual brackets.

So it represents a possible therapeutic alternative to propose to all those patients that need an invisible and painless treatment.

The application field goes to the simple levelling therapies to the more complex, who need for example teeth extractions and bodily teeth movement. The association to miniscrews can be very useful, as it also occurs in the classical brackets therapy.

The case that we propose is an extractive treatment with a dental and a skeletal anchorage.

The patient, came to our attention, had a malocclusion characterized by:

  • first class molar and canine on the right
  • second class molar on the left
  • complete absence of space for the left ectopic buccal canine;
  • upper and lower teeth crowding
  • upper midline shifted 2,5 mm to the left
  • Overbite of 1 mm for 12, 3 mm for 11 and 21, 0 mm for 22.
  • Overjet of 2,5 mm for 12, 2 mm for 11 and 21, 0 mm for 22.

 

1 canino ortodonzia sovradente

Straumann implant guided-surgery with Codiagnostix Software and immediately-loaded prosthesis

Straumann implant guided-surgery with Codiagnostix Software and immediately-loaded prosthesis

ITALIAN VERSION

 

COMPLETE MAXILLARY AND MANDIBULAR EDENTULISM TREATED WITH IMMEDIATELY-LOADED DENTAL IMPLANTS AND SCREWED FULL-ARCH TEMPORARY PROSTHESES


INITIAL SITUATION

The patient referred a clinical history of severe adult chronic periodontitis.
- (7) ortopantomografia
She has been edentulous at the maxillary arch for about 3 years while the latest extractions at the mandibular arch had been made about 6 months before the clinical examination. The patient presented with good general health and oral hygiene. She wore two removable complete dentures unsatisfactory for both function and esthetics.
- (0)- (1)- (2)
After explaining the different prosthetic solutions and the possible complications, the patient specifically required a fixed implant prosthesis and signed a consent form. It was planned to perform an implant guided-surgery intervention with immediately loaded temporary prosthesis in each arch.

Porcelain veneers in the Esthetic zone

Porcelain veneers in the Esthetic zone

 

ITALIAN VERSION

 

RESTORATION OF MAXILLARY CENTRAL INCISORS WITH MINIMALLY INVASIVE FELDSPATHIC CERAMIC VENEERS LAYERED ON REFRACTORY MODEL.

 

 

CASE PRESENTATION

A 26 year-old female patientpresented with fractures of the incisal margins of 1.1 and 2.1.

2 affollamento inferiore

Digital photography and documentation techniques in Dentistry and Dental Technology

Digital photography and documentation techniques in Dentistry and Dental Technology


ITALIAN VERSION

 

INTRODUCTION
The digital image is completely different from the chemical (analog) one to which many were used to, the characteristics are different. The terms below are the basics or the minimum you need to know to make the best use of any camera you already have, that you want to buy or replace. These pages are a stimulus to photographically document all cases of which you should have documentation, and the reasons are many, I will express only a portion of the digital information needed for anyone who is about to start to document, but I will also give information on the practical use for the more experienced. The intention is to continue with more articles, more detailed and specific for doctors and technicians. For every important topic that I will be using multiple images to be as comprehensive as possible, so that anyone should be able to understand and put into practice the information needed to make the most of their own equipment. You have to know the subject, “Digital Photography”, which is not just about cameras, lenses and flash, but also computer terms that are often found in the menu settings of digital cameras. Some settings are often overlooked or, not having some knowledge of ??computer terms, are incomprehensible. The topics with the most images will be mainly the settings and functions that can benefit medical records which, if clearly understood (the examples with pictures are often the most understandable), may also be useful for the use of the camera outside of the medical office or laboratory.

REASON

Clinical records have always been essential and have now developed to the point where we find applications both in the medical and technician offices, the reasons are many, I will mention the most important: use pictures to train or communicate with staff, exchange of information with dental technician, to show patients the work to be carried out in their mouth with photos (“now called marketing”), consultation among colleagues and, last but not least, for any medical-legal issues. Only good documentation with photos, x-rays and models can prove that we have done good work before any judge. All the archived documentation of the treated cases have allowed those who have been working as a lecturer or speaker to pass on their own experience. The increased use of the computer in the office allows all dentists and dental technicians to be able to document their work, digital documentation has big advantages over the “old” analog (on film) documentation. I would say that the possibility to see the pictures in real time and store them later directly in the patient’s file, or with the new “WI-FI” card we can transmit and store them directly in the patient’s file at the time they are taken, this allows us to view them on the screen (or on a screen positioned on the wall visible to the patient, or on the monitor now applied on many treatment units) and to discuss them in real time with the patient. If we want, we can also print them immediately, all this can be done with the patient sitting on our chair. If we want we can make a copy of the images to give to the dental technician or the patient, these copies will be exactly the same as the originals and, no matter the type of media you use to record images, such as: Compact-Flash, SD, Memory-Stick , XD-Picture, etc. All media will be readable on any computer. With analog equipment this was not possible, so I abandoned both film and analog cameras more than fifteen years ago. The choice of digital cameras is endless, among digital compact and dSLR we can choose between three hundred different models, but here we will quote the most widely used in medical and dental technician’s offices. Digital cameras fall into three categories:

The “Compact”, are, more or less, the size of a pack of cigarettes, and vary from one compact to another or from the difference of the lens or from the sensor, often, however, among the compact cameras only some fully meet our needs.
Fig. 001 compatta

Then we have the “Bridge” ,that is, a cross between a compact and a dSLR, as some are almost as big as a dSLR with a standard lens.
Fig. 002 bridge
Lastly, the “dSLR” are bodies on which you can mount all the lenses that the camera’s manufacturer produces.

Fig. 003 reflex nikon

The reflex, if equipped with a dedicated macro lens and appropriate flash for macro photography, gives good results, or if we use the best macro lenses and the latest flashes that can be used wireless (cordless) on brackets with movable arms to direct the light where we need it the most, the results that can be achieved are outstanding.

Lingual Orthodontics without brackets for the treatment of Angle II Class malocclusions

Lingual Orthodontics without brackets for the treatment of Angle II Class malocclusions

 

ITALIAN VERSION

 

Fixed orthodontics is the elected treatment in any age permanent dentition patients.

In fact, in most of cases only with a fixed appliance is possible to achieve a precise and controlled dental movement.

When patient needs an invisible treatment the answer is a fixed lingual treatment, that could be realized with or without brackets. The appliance is so bonded on the lingual aspect and this is why it is not visible.

At first lingual fixed orthodontic without brackets was deviced to solve relapse of previous classic brackets treatment that didn’t want anymore a brackets therapy. Then was applied to treat malocclusion in patients never treated before because it does not produce tongue and soft tissues pains and phonetics diseases that usually occurred with a lingual brackets therapy.

With fixed lingual orthodontic without brackets it is possible to treat every kind of malocclusions by means of orthodontic wires directly bonded on the lingual aspect of the teeth, like the active retainers, but also other devices, like the mini-screws. Mini-screws are a recent innovation in orthodontic treatment and have a large application also in conventional brackets therapy, because they allowed a maximum skeletal anchorage and a faster dental movement.

The following clinical case is an example of dental and skeletal second class treated by means of this innovative therapy.

The patients, a 25 years old female, presented at a clinical examination (fig. 1-6)

  • an edge to edge molar and canine and a scissor bite between 24-34 on the left side
  • an edge to edge canine and a previous extraction of tooth 46 with mesialization and inclination of tooth 47 on the right side

angle II class malocclusion

Surgical extraction of mandibular third molar: a rational and safe technique

Surgical extraction of mandibular third molar: a rational and safe technique

 

ITALIAN VERSION

 

Introduction

The extraction of the mandibular third molar is the most frequent intervention in oral surgery and it is sometimes associated with less or more severe complications. Among these, the most dangerous is the damage to the inferior alveolar nerve.

 

1 panoramic x-ray impacted wisdom tooth

In the last decades, thanks to the improved expertise in identifying risky cases and the refinement of surgical techniques, the prevalence of complications has been progressively reduced.

The present paper describes a rational approach to the surgical extraction of the mandibular third molar, in order to limit surgical complications.

As to the method, several factors contribute to the clinical success, just like:

  • a correct pre-operative diagnosis;
  • a rational choice of surgical instruments;
  • a minimally invasive surgical technique.

The last two points are closely interdependent.

Pre-operative diagnosis

 

The diagnosis includes:

  • study of indications and contraindications for surgery;
  • risk and difficulty assessment;
  • intervention planning.

The orthopantomogram (OPG) is the golden standard for pre-operative diagnosis.

From the OPG it is possible to evaluate:

  • tooth position (angulation, depth, proximity to the neurovascular bundle);
  • presence of risk factors for mandibular alveolar nerve damage, according to the criteria of Rood & Shehab (1990);
  • diseases (caries, cysts etc.).

According to Rood & Shebab, the following risk indicators for damage of the mandibular alveolar nerve can be identified on OPG:

  • root radiolucency;
  • angled roots;
  • interruption of the radiopaque lines that mark the alveolar canal;
  • narrowing of the mandibular alveolar canal;
  • radiolucent and bifid roots;
  • narrowing of roots;
  • deviation of the mandibular alveolar canal.

Nowadays, since the OPG does not allow to establish the bucco-lingual position of roots and neurovascular bundle, in particular cases it is possible to recur to 3D imaging, particularly to Cone Beam technology.

Clinical indications for 3D imaging are:

  • signs of risk with complete overlapping of the roots to the alveolar canal;
  • alveolar canal crossing the roots near to the bifurcation.

From an operative point of view, one more indication for 3D imaging is the necessity to understand on which side of the tooth the alveolar canal passes, in order to plan properly the bone resection and odontotomy.

Root Canal Irrigation in Modern Endodontics: Complex Cases

Root Canal Irrigation in Modern Endodontics: Complex Cases

ITALIAN VERSION

Follows:
ROOT CANAL IRRIGATION IN MODERN ENDODONTICS:
THE ROUTINE

Anatomy: A Daily Endodontic Challenge

In my first years as a dentist, before completely dedicating myself to endodontics, I practiced all the dental disciplines. I performed extractions, amalgam restorations, composite resin restorations, crown preparations, surgical flaps and scaling. By doing this I could visibly check the working area (gingiva, core preparation, cavities before filling etc, etc) and thus I could directly verify the work as it evolved.

With endodontics I could not do this.

Even with radiology, magnification and the microscope, endodontics of the last few mm is always “in the dark” (especially with molars) meaning that we cannot for instance directly observe a K-file working as it files the apical third.

Its substantial difference from other disciplines of dentistry along with large anatomical variations and the complexities of the root canal system attracted me to this mysterious and fascinating discipline.

I decided to dedicate myself completely to endodontics. As time went by I became convinced that practicing endodontics is a daily challenge against the hidden and unpredictable microanatomy. Maybe this is what makes endodontics so attractive!

Now, after years of endodontics, I have a clear concept of complex anatomy and it seems limiting at this point to talk only of narrow, curved or long canals.

Nobel Guide Implant-Guided Surgery with Nobel Clinician Software

Nobel Guide Implant-Guided Surgery with Nobel Clinician Software

 

ITALIAN VERSION

 

MAXILLARY COMPLETE EDENTULISM TREATED WITH IMMEDIATELY LOADED STRAIGHT AND TILTED IMPLANTS AND A SCREWED FULL-ARCH TEMPORARY PROSTHESIS


INITIAL SITUATION
A 65 year-old female patient presented with maxillary complete edentulism. During the anamnestic interview, the patient reported a clinical history of adult chronic periodontitis; the patient has been edentulous for 9 years. Good general health and oral hygiene conditions were reported; the patient was a moderate smoker (about 10 cigarettes per day).
During the clinical examination, a complete maxillary denture was noticed (figg. 1-2) and it was considered satisfactory for occlusion and morphology; on the contrary, such denture was unsatisfactory from an aesthetic point of view, showing wear and pigmentation of the prosthetic teeth.

blog.001blog.002
The masticatory effectiveness was considered satisfactory both subjectively and objectively. The patient required a fixed rehabilitation but refused any sinus augmentation procedure. Consequently, after obtaining a written consent form, an implant-supported prosthesis with immediate loading was planned. According to the above mentioned functional and aesthetic considerations, the occlusal scheme and position of teeth were kept unaltered for the temporary prosthesis. The denture was relined (fig. 3) and the soft tissues conditioned for 6 weeks before implant surgery.

blog.003
The mandibular arch had been previously restored by means of an implant-supported fixed full-arch prosthesis. The mandibular occlusal scheme had been balanced and compensated in order to match the maxillary rehabilitation.

Root canal irrigation in modern Endodontics. Part one: the routine

Root canal irrigation in modern Endodontics. Part one: the routine

 

ITALIAN VERSION

 

Why do we irrigate?

Successful endodontic treatment, in agreement with what Prof. Schilder, the father of modern endodontics, enunciated, depends on the ability of the operator to mechanically and chemically clean the root canal system and subsequently obturate it three dimensionally.1

The endodontium consists of a space that is easily accessible to rotary and manual instruments (principal canals) and, as has been confirmed by numerous clinical and histological studies, there are spaces that are difficult to access or completely inaccessible (deltas, loops, isthmi, lateral and accessory canals, and dentinal tubules).

In particular lateral and accessory canals are found with significant frequency especially in the apical third of the root and in molar bifurcations.

Canal shaping is unable to reach some areas and they remain untouched by the instruments, no matter what technique is used; thus about half of the endodontium remains untreated.2

The complexity of the endodontium could, however, be one of the determining factors in failure of root canal treatment even in properly treated teeth, due to irregular and sometimes unpredictable spaces that characterize root canals.3-4

In the light of the above one of the most exciting challenges of modern endodontics is represented by the biochemical debridement of the endodontium (accessible and non accessible).
When debridement is performed according to the state of the art (three dimensional) cleaning, the endodontium can then be filled and sealed with cement and gutta-percha at the time of obturation.

Irrigation, therefore, plays a crucial role in determining the outcome of root canal treatment.

What irrigants should be used? A choice based on scientific evidence.
I remember back in my university days, I once took my father to his dentist, a general practitioner, as he had to have root canal treatment. I was particularly struck by the frenetic rinsing with a sodium chloride solution alternated with hydrogen peroxide and asked why this procedure was performed.

He answered that they had been taught to do it this way, without critically motivating his choice.

In every field of medicine, the clinical practitioner must follow logic and must be supported by literature.

Therefore, to rationally choose an irrigant you must first answer the question: “What do we want to remove from the canal?”
The answer is simple; we want to eliminate the organic tissue (pulp), bacteria and toxins, as well as organic and inorganic debris that our rotary and manual instruments inevitably produce.

At this point the choice is easy and natural.

Literature has highlighted sodium hypochlorite in a concentration of 6% as the irrigant of choice inasmuch as it is able to dissolve organic substances and eliminate the bacterial presence and the biofilm from inside the canal.5-10

Complete debridement is achieved by combining a substance capable of eliminating the inorganic component created after the instrumentation. It is
necessary to use a chelating agent namely 17% EDTA or 10% Citric Acid.11-14

A 2% Chlorhexidine aqueous solution has been suggested as an irrigant for the root canal system. This has an antibacterial action but lacks the ability to dissolve the organic and inorganic material.15-16

Furthermore mixing sodium hypochlorite and chlorohexidine generates a toxic and cancerous compound, parachloroanaline and its use as an irrigant is not recommended.17

The Membragel Straumann liquid membrane

The Membragel Straumann liquid membrane

 

ITALIAN VERSION

 

AN INNOVATIVE APPROACH TO GUIDED BONE REGENERATION.


The Straumann® Membragel™ is a technologically advanced resorbable membrane that simplifies the clinical procedures of guided bone regeneration (GBR).
The application of the liquid membrane is very easy, fast and accurate. Once it solidifies, the Membragel stabilizes the bone graft material, acting as a barrier for 4-6 months before its resorption. Preclinical data showed that the Membragel is resorbed significantly more slowly than conventional collagen membranes, offering an excellent biocompatibility to surrounding tissues. Due to its gel consistency, it can be placed accurately onto the bone defect, over the graft material. In order to stabilize the liquid membrane, it is sufficient to extend it 1-2 mm beyond the margins of the bone defect.
The use of the Straumann® Membragel™ allows for the formation of as much regenerated bone tissue as it is achieved with conventional non resorbable ePTFE membranes.
The application of such a liquid membrane is indicated in the following guided bone regeneration procedures:

  • periimplant defects (dehiscences, fenestrations);
  • post-extractive sites;
  • horizontal bone defects.

The Straumann® Membragel™ is made up of polyethylene glycol (PEG). Its gelification is activated by the combination of PEG A (containing acrylate as terminal functional group), PEG B (containing thiol as terminal functional group) and activators A (viscosity modifier) and B (isotonic chemical solution creating an optimal pH to start the chemical reaction).
The chemical components of PEG A and PEG B create a molecular network of PEG, that acts as a barrier and avoids the migration of soft tissue cells; in the meanwhile it remains permeable to nutritional substances.
The biodegradation of the membrane is due to hydrolysis and does not create any acidification of the surrounding tissues.
In Italy, the clinical experimentation of such an innovative membrane was performed by the research team of Prof. Luca Cordaro, Dean of the Eastman Institute of Rome (Italy).


CASE REPORT

A 55 years-old female patient presented with a vertical root fracture of the tooth 14. The fractured palatal fragment was immediately removed.

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