“Fence Technique”: an innovative reconstruction procedure

“Fence Technique”: an innovative reconstruction procedure

 

ITALIAN VERSION

 

Edentulism was defined as a pathological condition by the World Health Organization in 1990. The discomfort and inconvenience that this condition can generate in terms of aesthetics, function, as well as psychologically, can be so debilitating as to consider edentulism a social handicap.

Due to the gradual increase in the average age of the population, today there are more and more people in their seventies who are enjoying overall good health and intrapersonal relationships. Their expectations have significantly increased as well, and as patients are no longer satisfied with traditional removable dentures; explicit requests are now frequently made for fixed prosthetic solutions with a high level of aesthetics and correct function.

One such example is this patient who came to our observation in 2009 complaining of severe discomfort from a functional and aesthetic perspective (Fig. 1). His dentures were worn and unstable, causing frequent lacerations and sores on the gingival tissues and oral mucosa. The patient reported that this condition was causing psychological problems and lowering his self-esteem, therefore his desire was to solve this complex situation , if possible, with a fixed prosthesis. The assessment of the patient’s systemic risk profile pointed out that his general health conditions were good and that he would classify as ASA class I (Owens et al. 1978).

The evaluation of local risk factors showed the presence of few dental elements (that were in fact compromised) and a particularly marked atrophy of both the upper and lower jaw. The severe bone deficit could have been related also to infrequent readjustment of the prosthesis.

 

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].

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 :

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.

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.

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.

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.