Dental Hypotheses
Volume:2 Issue: 1, Jan-Mar 2011

Mast cells are among the first cells to get involved in periodontal inflammation. Their numbers have been shown to be increased in cases of gingivitis and periodontal disease.The hypothesis: Since mast cell stabilizers like sodium cromoglycate (SCG) and nedocromil sodium (NS) have been used in the prophylaxis of bronchial asthma without any significant adverse effects and also the fact that drugs like SCG show significant antiinflammatory activities, it would be logical to use mast cell stabilizers as host modulating drugs for the treatment and prevention of periodontal disease. Evaluation of the hypothesis: Safety and efficacy of both SCG andNS are well documented. So, it will be systemically safe to use in humans. However, oral administration SCG or delivery of the drug by means local irrigation will not be very useful because SCG may not be secreted in the gingival crevicular fluid (GCF)(as in the case of oral administraion) or the drug may get washed out from periodontal pocket due to the constant flow of GCF(as in the case of irrigation). A local or targeted drug delivery of mast cell stabilizers can be used in patients with periodontal disease. Role of mast cells in periodontal disease has been dealt in-depth in many studies and articles. However, limited amount of research has been done on using mast cell stabilizers in the prevention and control of periodontal diseases. More studies are needed to study the efficacy and effectiveness of mast cell stabilizers as an adjunct to phase I therapy in the control of periodontal disease.

The essence of dental education is not only to impart knowledge but also to equip an aspiring clinician with all the paraphernalia to face most clinical situations if not all. What becomes important here is the requirement that a student be not only observant but also have a precise idea of what a lesion or a surface should feel like under an instrument. No matter how far we have come in terms of pathogenesis and treatment of diseases of the oral cavity, there is still no one good way to teach a student about the tactile sense, be it while detecting calculus/caries or placing the incisions or detecting the smoothness of a restoration. Most often than not students learn these by a trial and error method. A not-so-recent development called Haptics may well be the answer to this predicament, at least in the near future. The concept which is extensively in use and indispensable in other fields like aviation, telecommunication etc is now making inroads into dentistry. It is essentially software which brings in the idea of giving the feedback response to applied force, be it simple exploration of caries or the fine pressure applied in placing an incision or an array of other areas/situations in dentistry where fine tactile sense becomes a prerequisite for intelligent diagnoses or cutting edge treatment procedures. The following write-up is an attempt to throw light on this new technology and the impact it may have on pre-clinical teaching in dentistry. The advantages, disadvantages between manikin based dental simulators and haptics based dental simulators are also presented.

It often takes a relatively long period for a tooth with a large periradicular lesion to recover from bone destruction; therefore, it is necessary to develop additional approaches to serve as supplementary options to RCT. One possibility is to prevent the osteoclast-induced periapical bone destruction by inhibiting osteoclastogenesis. Recently, studies have proved the receptor activator of nuclear factor κB (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) system to be an important signal pathway regulating osteoclastogenesis, and inactivation of RANKL, which blocks the RANK/RANKL pathways, is critical in anti-bone resorption. The hypothesis: OPG, a natural decoy receptor for RANKL, may be a potential clinical anti-resorptive agent for apical periodontitis. Since OPG can block the RANK/RANKL pathways, it has been demonstrated to be a good candidate against bone destruction; its local delivery through root canals may be an additional option for treatment of apical periodontitis with large periradicular lesion.Evaluation of the hypothesis: OPG is easy to produce, store and use. Using a large animal study model, recombinant OPG could be incorporated into degradable carriers such as microspheres, micelle, and delivered into experimental induced periradicular lesions in the animals by controlled release, where it can relieve bone destruction by inhibiting osteoclastogenesis and osteoclast function. As OPG is a natural protein and clinical delivery as part of RCT treatment is easy and simple, the application of OPG may provide a new avenue for the treatment of apical periodontitis with large periradicular lesion.

Periodontal disease is among the most prevalent canine diseases affecting over 75% of dogs. Strengthening of the human-animal bond and the increasing education of the average pet owner, have fostered a heightened awareness of periodontal care in dogs and cats. Industry support has further assisted the small animal veterinarian in providing quality dental treatments and prevention. As recently as the 1990’s, veterinary curriculums contained little or no dental training. That trend is changing as nearly every one of the 28 US Colleges of Veterinary Medicine offers some level of small animal dentistry during the four-year curriculum. Primary areas of focus are on client education, the treatment of periodontal disease, dental prophylaxis, dental radiology, endodontics, exodontics and pain control. Students receive instruction in dental anatomy during their didactic curriculum and later experience clinical cases. Graduate DVMs can attend a variety of continuing education courses and even choose to specialize in veterinary dentistry in both small animals and horses. Through the efforts of organizations such as the American Veterinary Dental Society, The American Veterinary Dental College and The Academy of Veterinary Dentistry, many veterinarians have been able to advance their skills in dentistry and improve animal welfare. Increasing expectations of the pet-owning public coupled with the recent advancements of training opportunities available for veterinary students, graduate DVMs and certified veterinary technicians make veterinary dentistry an emerging practice-builder among the most successful small animal hospitals.

Periodontally affected teeth are treated in one of the two ways. (1) Tooth retention after periodontal surgery, in which the degree of regeneration achieved is unpredictable. (2) Tooth extraction and implant placement. Implants have an osseointegrated surface which does not provide adequate shock absorption. Regeneration can be achieved by resecting the crown of the affected tooth and submerging the root. This technique has not had a clinical application so far as the tooth becomes difficult to restore. Placing an implant within the root can make the retained root restorable. At the same time, as the implant is placed within the root surface it achieves a periodontal integration which dampens occlusal forces better than osseointegration. Therefore, such a “tooth retained implant” may serve as an additional treatment option with significant benefits over tooth retention and implant placement alone. The hypothesis: Implants placed within retained roots have shown cementum deposition and attachment of periodontal ligament fibers over their surface. This periodontal attachment may be able to dampen forces better than in an osseointegrated implant. Moreover, since an implant is being placed, the crown of the tooth can be resected and submerged. This prevents epithelial migration, allows for the periodontal ligament cells to populate the wound and favors regeneration. Evaluation of the hypothesis: The technique of placing implants within cavities prepared in the root and then submerging them are simple for any practitioner placing implants routinely.

Candidate human dental stem/progenitor cells have been isolated and characterized from dental tissues and shown to hold the capability to differentiate into tooth-generating cells. However, advances in engineering a whole tooth by these stem cells are hindered by various factors, such as the poor availability of human primitive tooth bud stem cells, difficulties in isolating and purifying dental mesenchymal stem cells and ethical controversies when using embryonic oral epithelium. As a result it is meaningful to find other autologous dental cells for the purpose of reconstructing a tooth. The hypothesis: Previous studies demonstrated that somatic cells can be reprogrammed into induced pluripotent stem cells by exogenous expression Oct-4 and Sox-2. On the basis of these findings we can reasonably hypothesize that when transfected with specific transcription factors Oct-4 and Sox-2, dental pulp cells, the main cell in pulp, could also be reprogrammed into induced pluripotent stem cells, which are considered to be of best potential to regenerate a whole tooth.Evaluation of the hypothesis: After transfection with Oct-4 and Sox-2 into human dental pulp cells, the positive colonies are isolated and then identified according to the characteristics of iPS cells. These cells are further investigated the capability in differentiating into ameloblasts and odontoblasts and finally seeded onto the surface of a tooth-shaped biodegradable polymer scaffold to detect the ability of constructing a bioengineered tooth.

Gingival recession defects are one of the most common periodontal problems. In the past few decades there have been several attempts to treat the gingival recession defects. Among all the treatment options the sub-epithelial connective tissue graft is still the most widely used. The sub-epithelial connective tissue graft is considered to produce high percentage of root coverage and therefore considered to be the gold standard technique for the treatment of gingival recession defects. Despite many research papers favoring the use of subepithelial connective tissue graft, recent data suggests no major difference in terms of percent root coverage when various other techniques for the treatment of gingival recession defects are compared with each other. In the light of present clinical evidence the criteria to determine whether sub-epithelial connective tissue graft technique should be considered a gold standard or not for be treatment of gingival recession must be re-evaluated. This article highlights some inherent drawbacks associated with sub-epithelial connective tissue graft and emphasizes the need to consider other available techniques for the treatment of gingival recession defects.