Periodontal regeneration: myth or reality?

One of the goals of periodontal therapy is regeneration. During the past 20 years, several materials and techniques have been developed and tested for enhancing periodontal regeneration. This paper evaluates flap debridement, allogenic and alloplastic grafting, and the use of nonresorbable and resorbable barrier membranes as regenerative techniques. One of the most predictable regenerative therapies is treatment of the three-walled intrabony defect. This defect can be repaired with 2 to 2.5 mm of bone fill and results in significant gains in clinical probing attachment and decreases in probing depths. There is a slightly greater improvement in periodontal measures with barrier membranes. Commercial preparations of allogenic bone and alloplastic fillers have a long, safe history of use and are primarily osteoconductive. They decrease probing depths and provide short-term gains in clinical attachment levels. Barrier membranes provide short-term evidence of improving Class II furcation invasions, however there is insufficient evidence that these improvements are sustained long-term. Class III furcations are not predictably treated by regenerative therapies. To date, there is an absence of clinical evidence that regenerative therapy increases the long-term life span of teeth.     

Considerations of dentofacial growth in long-term retention and stability: is active retention needed?

It is extremely important to pay attention to the person's growth pattern, and a distinction must be made in the selection of retention devices on the basis of the nature and the extent of dentofacial dysplasia (growth pattern). The nature and duration of retention should depend on the maturation status of the patient and on anticipated future growth. Retention guidance is necessary for adjustment of the dentition to late growth changes and maturation of neuromuscular balance. "Active retention" is a concept we accept as readily as the orthopedic surgeon does for his scoliosis patients. There is some merit in the philosophy of those clinicians who advocate permanent retention guidance. Without always being aware of the biomechanics of growth change, they are in fact carrying the patient through the active stages of growth with their retention appliances. Finally, one may philosophize that nothing about the human morphology is stationary. Aging is a well-documented process of change. Lifetime dentitional adjustment and changing dental relationships are known to all, even in otherwise healthy persons. Then why do we expect long-term stability in every case? The answer to the question of long-term stability is long-term retention--dynamic, not static.     

Effect of β tricalcium phosphate particle size on recombinant human platelet-derived growth factor-BB-induced regeneration of periodontal tissue in dog

The aim of this study was to investigate the effect of β tricalcium phosphate (β-TCP) particle size on recombinant human platelet-derived growth factor-BB (rhPDGF-BB)-induced regeneration of periodontal tissue in dog. The control group (rhPDGF-BB alone) was characterized by incomplete, newly formed bone. The large-particle β-TCP (L-TCP(O))/rhPDGF-BB group showed a statistically significant increase in both new bone and cementum formation compared to the small-particle β-TCP (S-TCP(G))/rhPDGF-BB group. These findings suggest that L-TCP(O)-particle promotes rhPDGF-BB-induced formation of bone and cementum.     

Pay for performance: will dentistry follow?

Background  

"Pay for performance" is an incentive system that has been gaining acceptance in medicine and is currently being considered for implementation in dentistry. However, it remains unclear whether pay for performance can effect significant and lasting changes in provider behavior and quality of care. Provider acceptance will likely increase if pay for performance programs reward true quality. Therefore, we adopted a quality-oriented approach in reviewing those factors which could influence whether it will be embraced by the dental profession.     

Supraclavicular lymph node recurrence after radical surgery: is epidermal growth factor receptor a predictive marker?

The aim of this study was to evaluate the rare postoperative supraclavicular metastasis originating from oral squamous cell carcinoma (OSCC) and to discuss epidermal growth factor receptor (EGFR) as a potential predictive marker. Tumour specimens of OSCC patients divided into three groups were included: supraclavicular metastasis (n = 8), conventional cervical metastasis (n = 28), no metastasis (n = 48). Basic information and EGFR expression were compared among these groups and the data were analysed to identify potentially related risk factors for supraclavicular metastasis. In the supraclavicular metastasis group (n = 8), all primary tumours were T1–T2 and located in the tongue and buccal region; five of eight cases were pathologically N0. The median interval from the primary tumour resection to the development of supraclavicular metastases was 21.5 months. All related deaths (5/8) occurred within 2 years. In the supraclavicular metastasis group, EGFR expression was highest in the supraclavicular metastases, followed by cervical lymph nodes, and was lowest in the primary tumours (P = 0.39). In contrast, in the conventional metastasis group and the N0 group, EGFR expression was higher in the primary tumours than in the lymph nodes (P < 0.01). Supraclavicular metastasis of OSCC is infrequent and associated with a poor prognosis. EGFR might predict the occurrence of supraclavicular metastasis.     

Tissue regeneration in dentistry: Can salamanders provide insight?

The ability to regenerate damaged tissues would be of tremendous benefit for medicine and dentistry. Unfortunately, humans are unable to regenerate tissues such as teeth and fingers or to repair injured spinal cord. With an aging population, health problems are more prominent and dentistry is no exception as loss of bone tissue in the orofacial sphere from periodontal disease is on the rise. Humans can repair oral soft tissues exceptionally well; however, hard tissues, such as bone and teeth, are devoid of the ability to repair well or at all. Fortunately, Mother Nature has solved nearly every problem that we would like to solve for our own benefit and tissue regeneration is no exception. By studying animals that can regenerate, like Axolotls (Mexican salamander), we hope to find ways to stimulate regeneration in humans. We will discuss the role of the transforming growth factor beta cytokines as they are central to wound healing in humans and regeneration in Axolotls. We will also compare wound healing in humans (skin and oral mucosa) to Axolotl skin wound healing and limb regeneration. Finally, we will address the problem of bone regeneration and present results in salamanders which indicate that in order to regenerate bone you need to recruit non‐bone cells. Fundamental research, such as the work being performed in animals that can regenerate, offers insight to help understand why some treatments are successful while others fail when it comes to specific tissues such as bones.     

New oral anticoagulants: will they replace warfarin?

Vitamin K antagonists, such as warfarin, are considered to be the treatment of choice to prevent thromboembolic events, but problems, such as the need for frequent dose adjustment and monitoring of coagulation status, as well as multiple drug and food interactions, make their use difficult for both physician and patient. Two new anticoagulants are now being considered as possible replacements of vitamin K antagonists. Dabigatran, an oral direct thrombin inhibitor has already been approved in the USA for prevention of stroke in patients with atrial fibrillation. Rivaroxaban, a factor Xa inhibitor, and dabigatran are licensed in Europe and Canada for short-term thromboprophylaxis after elective hip or knee replacement surgery. The advantages of these drugs are that they are safe and effective, require no monitoring, have a direct mode of action against only one clotting factor (thrombin or factor Xa), have limited drug interactions, and have rapid peak blood levels. Based on the fact that dabigatran has already been approved for use in the USA, it would appear that it has an advantage over rivaroxaban in becoming the replacement drug for vitamin K antagonists.     

Initial bone regeneration around fenestrated implants in Beagle dogs using basic fibroblast growth factor–gelatin hydrogel complex with varying biodegradation rates

PurposeThe purpose of this study was to compare the effectiveness of fast and slow biodegradation of basic fibroblast growth factor (bFGF)–gelatin hydrogel complex on bone regeneration around fenestrated implants as a new augmentation drug delivery system.MethodsNine titanium implants (3.3 mm diameter and 10 mm length) were placed into the edentulous areas of the mandibles of three adult beagle dogs with four screws exposed at the upper buccal side. The effectiveness of bFGF–gelatin hydrogel complexes of varying degradation types used to cover implant screws without membrane were compared with 1 μg and 10 μg bFGF–98 wt% gelatin as the fast degradation type and 10 μg bFGF–95 wt% gelatin as the slow degradation type. After 4 weeks, bone regeneration around the screws was evaluated histologically and histomorphometrically.ResultsWith use of 10 μg bFGF, regenerated bone around exposed screws was clearly seen in both the fast and slow degradation type groups. In contrast, little bone formation was seen in the fast degradation-type group with 1 μg bFGF. Height of regenerated bone for the slow degradation-type complex group was significantly greater than for the fast degradation-type group with 1 μg bFGF (P < 0.05).ConclusionThese results suggest that use of slow degradation-type bFGF–gelatin hydrogel complex may accelerate bone regeneration around fenestrated implants at an early stage of bone regeneration.