An approach to biomimetics: the natural CAD/CAM restoration: a clinical report.

Those in the dental field have always pursued the perfect dental material for the treatment of compromised teeth. Gold, amalgam, composite resin, glass ionomer, and porcelain have been used. Tooth-like restorative materials (composite resin and porcelain) combined with an effective hard tissue bond have met the growing demand for esthetic or metal-free restorations in the past 15 to 20 years. However, none of those materials can fully mimic the unique properties of dentin (compliance and crack-stopping behavior) and enamel (wear resistance, function). The aim of this article is to report the restoration of an extensively damaged tooth with a natural restoration obtained by milling an extracted third molar tooth with a computer-aided design and computer-aided manufacturing (CAD/CAM) system. The main benefit of this novel technique is the replacement of lost tissues by actual enamel and dentin, with the potential to recover mechanical, esthetic, and biologic properties. The indication for extracting third molars and premolars because of impaction or for orthodontic reasons makes these posterior teeth readily available. The innovation of the method presented here is the optimal use of the extracted tooth substrate thanks to its positioning technique in the CAD/CAM milling chamber.

Esthetic and functional recovery of extensively decayed posterior teeth through conservative treatment.

The case exemplifies the combination of two important principles in dentistry: 1) the maintenance of pulp vitality by the partial excavation of the contaminated dentin followed by the application of a biomaterial; and 2) esthetic and functional recovery based on biological restoration. Tooth vitality was confirmed two months after pulp treatment and restoration was accomplished with a fragment of a tooth extracted from another individual. This method is easy to perform and offers esthetic, functional, emotional and social benefits to the patient.

Esthetic-functional recovery of permanent posterior tooth using autogenous biological restoration.

Occlusal morphology and difficult access for cleaning permanent molars result in the buildup of bacterial plaque and the development of caries. One method known as biological restoration was carried out. This technique known as biological restoration, has as main restorative material a fragment obtained from a duly donated extracted human tooth. This case report describes the restoration of an extensively decayed molar through the bonding of a fragment obtained from a third molar extracted from the patient himself. Biological restoration is a low-cost option that offers satisfactory aesthetic, morphological and functional results.The morphological/functional reestablishment of posterior teeth can be obtained through biological restoration, which allows the recovery of properties inherent to the dental structure, offers satisfactory aesthetic results and low cost.

Differentiation capacity of BrdU label-retaining dental pulp cells during pulpal healing following allogenic transplantation in mice.

Our recent study has demonstrated the localization of putative dental pulp stem cells in the developing molar by chasing 5-bromo-2'-deoxyuridine (BrdU)-labeling. However, their differentiation capacity subsequent to the tooth transplantation remains to be elucidated. This study aims to clarify the differentiation capacity of BrdU label-retaining dental pulp cells and their relationship to cell proliferation and apoptosis during pulpal healing following allogenic transplantation in mice. Following extraction of the mouse molar in BrdU-labeled animals, the roots and pulp floor were resected and immediately allo-grafted into the sublingual region in non-labeled animals, and vice versa. In the labeled transplants, label-retaining cells (LRCs) were increased in number and committed in nestin-positive newly differentiated odontoblast-like cells, whereas they were not committed in osteoblast-like cells. In the labeled host, on the contrary, LRCs were committed in neither odontoblast- nor osteoblast-like cells, although they were transiently increased in number and finally disappeared in the pulp tissue of the transplants. Interestingly, numerous apoptotic cells appeared in the pulp tissue including LRCs during the experimental period. These results suggest that transplanted LRCs maintain their proliferative and differentiation capacity in spite of extensive apoptosis occurring in the transplant, whereas transiently increased host-derived LRCs finally disappear in the pulp chamber following apoptosis.

Reattachment using a fragment from an extracted tooth to treat complicated coronal fracture.

Reattachment of fragment is the preferred alternative to restore the fractured teeth, offering several advantages. Partial pulpotomy has demonstrated satisfactory results as a conservative treatment for pulp exposures because of trauma. This study reports a case in which the treatment of a complicated coronal fracture was accomplished by partial pulpotomy and reattachment of a dental fragment obtained from an extracted tooth using composite resin. The results show the feasibility of the conservative pulp therapy and the restorative approach.

Biological restorations as an alternative treatment for primary posterior teeth.

A case of oral rehabilitation in a 4-year-old girl, in which the posterior teeth were restored using biological restorations, is described. The tooth fragments were selected from a bank of tooth tissues and bonded with dual-cure composite cement to prepared teeth. The results were satisfactory regarding retention, aesthetic and mastication, but disadvantages included long clinical appointments, laborious technique and possible fracture or degradation between the margins of the fragment and the tooth surface.

Clinical evaluation of allografts and homografts for restoration of missing tooth structure.

STATEMENT OF PROBLEM: The clinical performance of bonding human tooth fragments to either replace missing teeth or to restore defective teeth is unclear. Prospective studies can help to predict the success of such treatment options. PURPOSE: This study evaluated the feasibility of bonding tooth tissue homografts and allografts either to replace missing teeth or to restore defective teeth, and estimated the success rate of bonded allograft and homograft restorations 3 years after placement. METHOD AND MATERIAL: Twenty clinical cases were treated by bonding tooth fragments or crowns into 6 groups (Gp): Gp1, cervical erosion and abrasion lesions (6); Gp2, incisal edge fractures (4); Gp3, partially destroyed crowns (4); Gp4, teeth placed in a removable prosthesis (2); Gp5, missing tooth with no opposing tooth (2); and Gp6, temporary space maintenance (2). Restorations were examined using USPHS criteria every 2 months and whenever a patient called to report a failure. RESULTS: After a 3-year follow-up, the overall success rate was 80% for the 20 restorations. The 95% confidence interval was 63% to 94%. Four restorations failed by debonding (Gp2 [2]; Gp5 [1]; Gp6 [1]) during the first 4 months. The main cause of failure appeared to be excessive occlusal loading. CONCLUSION: Within the limitations of this clinical study, the results after a 3-year follow-up showed the success rate was not less than 63% for bonded allograft and homograft restorations.

Response of dental follicular cells to the exposure of denuded enamel matrix in rat molars.

Recent studies have indicated that cementum formation can be induced when dental follicular cells are exposed to enamel matrix. The purpose of the present investigation was to study this cementum formation and the appearance of the cells involved, including their expression of collagen types alpha1(I), alpha1(II) and alpha1(III) mRNAs, during this process by means of light microscopy and in situ hybridisation. The mandibular first molars of 5-d-old rats were surgically taken out, their enamel epithelium was removed, and then the crowns were re-inserted with the occlusal surface downwards in their crypts to allow the follicular cells to come in contact with the denuded enamel matrix. After observation periods of 2-14 d, the teeth were prepared for light microscopic examination and in situ hybridisation. A monolayer of follicular cells in contact with the exposed enamel matrix changed their morphology and increased their expression of collagen type I mRNA as early as 2-4 d after exposure to the enamel matrix. A cementum-like tissue was formed at the surface of the enamel matrix. Collagen type II mRNA was never expressed in the tissues studied, whereas collagen type III mRNA was weakly expressed in the follicular cells throughout the experiment.