Healing of Experimental Periodontal Defects Following Treatment with Fibroblast Growth Factor-2 and Deproteinized Bovine Bone Mineral

The aim of this study was to investigate the effects of fibroblast growth factor (FGF)-2 used in combination with deproteinized bovine bone mineral (DBBM) on the healing of experimental periodontal defects. Periodontal defects created in rats were treated by FGF-2, DBBM, FGF-2 + DBBM, or left unfilled. Microcomputed tomography, histological, and immunohistochemical examinations were used to evaluate healing. In vitro cell viability/proliferation on DBBM with/without FGF-2 was assessed by WST-1. Cell behavior was analyzed using scanning electron and confocal laser scanning microscopy. Osteogenic differentiation was evaluated by staining with alkaline phosphatase and alizarin red. Bone volume fraction was significantly greater in FGF-2 and FGF-2 + DBBM groups than in other groups at 2 and 4 weeks postoperatively. In histological assessment, newly formed bone in FGF-2 and FGF-2 + DBBM groups appeared to be greater than other groups. Significantly greater levels of proliferating cell nuclear antigen-, vascular endothelial growth factor-, and osterix-positive cells were observed in FGF-2 and FGF-2 + DBBM groups compared to Unfilled group. In vitro, addition of FGF-2 to DBBM promoted cell viability/proliferation, attachment/spreading, and osteogenic differentiation. The combination therapy using FGF-2 and DBBM was similarly effective as FGF-2 alone in the healing of experimental periodontal defects. In certain bone defect configurations, the combined use of FGF-2 and DBBM may enhance healing via promotion of cell proliferation, angiogenesis, and osteogenic differentiation.

Aptamers recognizing fibronectin confer improved bioactivity to biomaterials and promote new bone formation in a periodontal defect in rats

The use of alloplastic materials in periodontal regenerative therapies is limited by their incapacity to establish a dynamic dialog with the surrounding milieu. The aim of the present study was to control biomaterial surface bioactivity by introducing aptamers to induce the selective adsorption of fibronectin from blood, thus promoting platelets activation in vitro and bone regeneration in vivo. A hyaluronic acid/polyethyleneglycole-based hydrogel was enriched with aptamers selected for recognizing and binding fibronectin. In vitro, the capacity of constructs to support osteoblast adhesion, as well as platelets aggregation and activation was assessed by chemiluminescence within 24 h. Matrices were then evaluated in a rat periodontal defect to assess their regenerative potential by microcomputed tomography (µCT) and their osteogenic capacity by Luminex assay 5, 15 and 30 d postoperatively. Aptamers were found to confer matrices the capacity of sustaining firm cell adhesion (p = 0.0377) and to promote platelets activation (p = 0.0442). In vivo, aptamers promoted new bone formation 30 d post-operatively (p < 0.001) by enhancing osteoblastic lineage commitment maturation. Aptamers are a viable surface modification, which confers alloplastic materials the potential capacity to orchestrate blood clot formation, thus controlling bone healing.

[Bleeding control of periodontal mechanical therapy for patients taking aspirin]

OBJECTIVE

To investigate the feasibility of periodontal mechanical therapy for chronic periodontitis and coronary heart disease patients with low dose of aspirin.

METHODS

Sixty nine chronic periodontitis patients with coronary heart disease were randomly selected as the experimental group (medication group, group A), the control group (withdrawal group, group B) including 20 chronic periodontitis patients with coronary artery disease, stopping the drug for one week and another control group with 50 chronic periodontitis patients (group C). The three groups were examined with pocket probing, and received supragingival scaling, subgingival scaling, and root planning. Local bleeding after operation was observed. In 30 minutes after periodontal mechanical treatment, there was still a need to take some hemostatic measures (containing the oxidized cellulose putting in the periodontal pocket, gauze oppressing, and suturing). Nd:YAG laser was used to stop bleeding 60 minutes after operation.

RESULTS

At baseline, there was no significant difference in the three groups, as to the plaque index(PLI), the probing depth (PD), and the attachment loss (AL). The bleeding index (BI)in group A was significantly higher than that in group C (P=0.024), higher than that in group B (P=0.088). The platelet maximum aggregation rate (Agg(max)) was detected in some subjects. The average Agg(max) value group A was 15.2%, which was much greater than that in group B (60.7%) and group C (62.5%). The three groups were all safe in the treatment of periodontal therapy. There were five cases of active bleeding in group A, one case in group B and one case in group C in 30 minutes after operation. In 60 minutes after operation, there was one case of bleeding actively in group A. Nd:YAG laser was used to stop bleeding successfully.

CONCLUSION

The chronic periodontitis and coronary heart disease patients with long-term oral administration of low dose of aspirin can be safely treated with periodontal mechanical treatment, and the effect of local hemostasis is positive without stopping the drug.

Conditioned Medium from Periodontal Ligament Stem Cells Enhances Periodontal Regeneration

Periodontal disease is one of the most common infectious diseases in adults and is characterized by the destruction of tooth-supporting tissues. Mesenchymal stem cells (MSCs) comprise the mesoderm-originating stem cell population, which has been studied and used for cell therapy. However, because of the lower rate of cell survival after MSC transplantation in various disease models, paracrine functions of MSCs have been receiving increased attention as a regenerative mechanism. The aim of this study was to investigate the regenerative potential of transplanted conditioned medium (CM) obtained from cultured periodontal ligament stem cells (PDLSCs), the adult stem cell population in tooth-supporting tissues, using a rat periodontal defect model. Cell-free CM was collected from PDLSCs and fibroblasts, using ultrafiltration and transplanted into surgically created periodontal defects. Protein content of CM was examined by antibody arrays. Formation of new periodontal tissues was analyzed using microcomputed tomography and histological sections. PDLSC-CM transplantation enhanced periodontal tissue regeneration in a concentration-dependent manner, whereas fibroblast-CM did not show any regenerative function. Proteomic analysis revealed that extracellular matrix proteins, enzymes, angiogenic factors, growth factors and cytokines were contained in PDLSC-CM. Furthermore, PDLSC-CM transplantation resulted in the decreased mRNA level of tumor necrosis factor-α (TNF-α) in healing periodontal tissues. In addition, we found that PDLSC-CM suppressed the mRNA level of TNF-α in the monocyte/macrophage cell line, RAW cells, stimulated with IFN-γ. Our findings suggested that PDLSC-CM enhanced periodontal regeneration by suppressing the inflammatory response through TNF-α production, and transplantation of PDLSC-CM could be a novel approach for periodontal regenerative therapy.

Management of dental trauma by general practitioners

BACKGROUND

Patients who sustain dental trauma commonly present to their general practitioner (GP) or the emergency department, especial-ly to seek help after hours. It is important, therefore, for medical practitioners to correctly diagnose and manage these patients.

OBJECTIVE

The purpose of this paper is to familiarise GPs with different presentations of dental-related trauma, and a brief management plan for each condition.

DISCUSSION

Time is of the utmost importance when dealing with trauma in the dentition. Initial management of dental trauma, primarily by GPs working in rural or remote areas, can have a significant impact on the prognosis of oral hard and soft tissues.

Managing pediatric dental trauma in a hospital emergency department

PURPOSE

The purpose of this study was to: (1) examine types of dental trauma presenting to a hospital emergency department (ED); (2) describe the medical services provided to these patients; and (3) quantify time spent during ED encounters for dental trauma emergencies.

METHODS

Records of 265 patients who presented to the ED with dental trauma over a three-year period were reviewed. Demographics, injury types, triage acuity, pain scores, and dental/medical treatment and times were analyzed.

RESULTS

Patient demographics and injury types were similar to previous studies. Eighty-two percent of patients received mid-level triage scores; 41 percent of patients had moderate to severe pain. The most frequently provided medical services were administration of analgesics and/or prescriptions (78 percent). The mean times were: 51 minutes waiting for a physician; 55 minutes with dentists; and 176 minutes total time. Higher triage acuity and pain levels resulted in significantly longer wait times for physician assessment. Dental evaluation, including treatment, averaged 32 percent of time spent at the hospital.

CONCLUSIONS

A dental clinic is the most efficient venue for treating routine dental trauma. Patients in this study spent the majority of time waiting for physicians and receiving nondental services. Most patients required no medical intervention beyond prescriptions commonly used in dental practice.

Complications in implant dentistry

The mainstream use of dental implants has allowed millions of patients to benefit from the predictability of dental implant therapy and, in many instances, dental implants have become the standard of care. Even though success rates in implant dentistry are well above 90 percent, complications do occur. Most complications are preventable with proper planning and execution. Others are inherent to the risks of surgery and may require intervention. The purpose of this paper is to classify the possible complications that may occur and to discuss their prevention and management.

Microscopic evaluation of induced tooth movement after subluxation trauma: an experimental study in rats

OBJECTIVE

The objective of this study was to assess the histological alterations that occurred in the periodontal area of rat molars submitted to induced tooth movement (ITM) right after an intentional trauma (subluxation).

METHODS

Forty adult male Wistar rats (Rattus norvegicus albinus) were selected. The animals were divided into eight groups (n=5), according to the combination of variables: Group 1--control (neither trauma nor ITM); Group 2--ITM; Groups 3, 4, 5 and 6--dentoalveolar trauma groups corresponding, respectively, to 1, 3, 8 and 10 days after trauma; Groups 7 and 8 - the animals' molars were subjected to a 900 cN impact and, one and three days after the trauma event, tooth movement was induced. The rats' maxillary first molars were mesially moved during seven days with a closed coil (50 cN). After the experimental period of each group, the animals were sacrificed by anesthetic overdose and the right maxillas were removed and processed for histological analysis under light microscopy.

RESULTS

In the animals of group 3, 4, 5 and 6, the histological alterations were not very significant. Consequently, the effect of induced tooth movement right after a subluxation event (groups 7 and 8) was very similar to those described for Group 2.

CONCLUSIONS

There was no difference in the quality of periodontal repair when ITM was applied to teeth that had suffered a subluxation trauma.

Considerations on the epidemiology, etiology and profile of periodontal--dental injuries in preschool population in Iasi county

In recent years there has been a considerable increase in the number of temporary teeth injuries, this variability being determined by multiple etiologic factors, which we need to be aware of, as well as by predisposing conditions.

AIM

To characterize the epidemiology, etiology and pathology of specific types of periodontal-dental trauma in a series of preschool children from Iasi County.

MATERIAL AND METHODS

The study included a total of 672 subjects aged 3 to 7 years old, from both urban and rural areas of Iasi County. Statistical analysis was performed using STATISTICA software used in medical research.

RESULTS

Prevalence of periodontal-dental trauma in the study group was 19.64%. Gender distribution in the study group showed a preponderance of males (62.12%). The risk of periodontal-dental trauma in deciduous teeth was 1.63 times higher in boys compared to girls. Fall accidents (41.67%) closely followed by playground accidents (31.82%) were the most common causes of periodontal-dental trauma in the study group.

CONCLUSIONS

The prevalence of temporary dental trauma in the study group was relatively high, requiring the implementation of oral health promotion strategies and prevention programs, primarily addressed to parents and educators.

Lasers in dental traumatology

AIM

Dental traumas are frequent in children. They can be complex events and sometimes real emergencies. Since very little attention is devoted to this topic in the international literature and there are no well-coded laser guidelines for these specific clinical events, our aim is to consider and present those situations in which laser-assisted therapy can offer new treatment possibilities. The authors' aim is to stimulate more extensive scientific research in this area, which might not only increase the use of these technologies, but also improve outcomes and reduce complications connected to dental trauma, particularly in children. Furthermore, laser-assisted therapies drastically reduce the need for analgesics and anti- inflammatory medications compared with conventional procedures.

CONCLUSION

Using laser equipment to obtain anaesthesia is another challenge, while the use of low power setting for desensitising tissue and to obtain anaesthesia is also an open field.

Minor traumatic injuries to the permanent dentition

Treatment of traumatized teeth generally occurs in two phases: short-term emergency treatment and stabilization followed by endodontic management and review. These authors recently reviewed the endodontic considerations in the treatment of traumatized permanent anterior teeth, and in this article review the early management of traumatized permanent teeth. Preoperative assessment and emergency management are emphasized, as is the treatment of immature teeth for which continued development of the root system must be encouraged. Factors influencing long-term prognosis are discussed and the influence of various management strategies evaluated.

Management of trauma to supporting dental structures

Teeth, periodontium, and supporting alveolar bone are frequently involved in trauma and account for approximately 15% of all emergency room visits. The cause of the dentoalveolar trauma varies in different demographics but generally results from falls, playground accidents, domestic violence, bicycle accidents, motor vehicle accidents, assaults, altercations, and sports injuries. Dentoalveolar injuries should be considered an emergency situation because successful management of the injury requires proper diagnosis and treatment within a limited time to achieve better outcomes.

[Risks of orthodontic treatment]

Risks of orthodontic treatment identified in the literature are: enamel damage, root resorption, periodontal damage, temporomandibular disorders, tooth devitalization, treatment failure, and relapse. Enamel damage in the form of irreversible demineralization can take place during treatment with fixed appliances in the absence of adequate oral hygiene. Root resorption occurs, but seldom to the point of clinical relevance. Individual susceptibility and genetics are determining factors. Periodontal damage occurs as gingival recessions. Temporomandibular disorders and tooth devitalization hardly occur. Treatment failure is related to the assessed pre-treatment goals and dependent on the knowledge and skills of the care provider, patient-cooperation, and factors beyond anyone's control. Relapse is a common feature, but does not constitute a treatment risk. The greatest risk is a failure to adequately inform the patient concerning all of the (im)possibilities and their consequences.

Periodontal regeneration with multi-layered periodontal ligament-derived cell sheets in a canine model

Periodontal regeneration has been challenged with chemical reagents and/or biological approaches, however, there is still no sufficient technique that can regenerate complete periodontium, including alveolar bone, cementum, and well-oriented collagen fibers. The purpose of this study was to examine multi-layered sheets of periodontal ligament (PDL)-derived cells for periodontal regeneration. Canine PDL cells were isolated enzymatically and expanded in vitro. The cell population contained cells capable of making single cell-derived colonies at an approximately 20% frequency. Expression of mRNA of periodontal marker genes, S100 calcium binding protein A4 and periostin, was observed. Alkaline phosphatase activity and gene expression of both osteoblastic/cementoblastic and periodontal markers were upregulated by osteoinductive medium. Then, three-layered PDL cell sheets supported with woven polyglycolic acid were transplanted to dental root surfaces having three-wall periodontal defects in an autologous manner, and bone defects were filled with porous beta-tricalcium phosphate. Cell sheet transplantation regenerated both new bone and cementum connecting with well-oriented collagen fibers, while only limited bone regeneration was observed in control group where cell sheet transplantation was eliminated. These results suggest that PDL cells have multiple differentiation properties to regenerate periodontal tissues comprising hard and soft tissues. PDL cell sheet transplantation should prove useful for periodontal regeneration in clinical settings.

Ultrastructural modifications at the level of marginal periodontium in the case of incorrect dental reconstruction

Our study focused on the evolution of the marginal periodontium inflammatory process caused by an incorrect dental reconstruction. Our research studied a control group and a group of patients having traumatic and inflammatory lesions in different stages of evolution. A pronounced rarefaction of the junction desmosome structures as well as an inflammatory process pointed out by the presence of macrophages, neutrophils, Langerhans' cells, and mastocytes. The presence of altered fibroblasts and collagen fibers in the electron microscopic sections of vascular lesions represents microscopic signs of the inflammation and support the theory of local immunoglobulin synthesis.

Dentoalveolar trauma in Glasgow: an audit of mechanism and injury

Traumatic dental injuries in children often require multiple follow-up visits to the dentist and may have long-term consequences for the developing dentition. The aim of this audit was to examine age, gender, location, time of year, mechanism of injury and type of injury sustained in relation to dentoalveolar trauma in children attending the paediatric dental trauma clinic at Glasgow Dental Hospital from 2002 to 2004, and to compare our findings with data in the published literature. Males suffered 60% of all dental trauma, 79% of sporting injuries and 85% of assaults. The injuries in males were more severe, representing 65% of enamel dentine and pulp fractures, 100% of crown root fractures and 66% of crown root and pulp fractures. A peak for trauma was seen in the 8-11-year-old group (43%). The majority of injuries in the under four age group resulted from falls (87%). Taken as a whole, falls accounted for 49%, sports related injuries 18%, bicycle and scooter 13%, assault 7%, and road traffic accidents 1.5% of all injuries. They also accounted for a far higher percentage of intrusive luxations (67%). The largest proportion of injuries occurred during the summer months (33%). Sixty-four percent of children suffered trauma to more than one tooth. Fifty-eight percent of injuries involved the dental hard tissues and pulp and the majority of these (82%) were crown fractures. Most subjects (82%) suffered trauma to their periodontal tissues, (26% concussion or subluxation, 26% lateral luxation and 23% avulsion). Injuries to the supporting bone were uncommon. Sixty-six percent of all injuries occurred outdoors. Our findings were similar to a number of published studies, but in contrast to several others. More consistency is required in the collection and reporting of trauma data to be able to draw meaningful conclusions by comparison.

Severe periodontal damage by an ultrasonic endodontic device: a case report

Heat produced within a root canal during use of an ultrasonic instrument can be conducted through the dentin into periodontal ligament, bone and soft tissue. If severe in intensity or long in duration, it can induce damage to these tissues. This report describes a case in which an ultrasonic endodontic instrument apparently induced severe damage to alveolar bone, gingiva and nasal mucosa in a 42-year-old female. Overheating of a maxillary central incisor caused necrosis of soft tissue and bone on the facial and mesial aspects and triggered a protracted inflammatory response in the adjacent nasal cavity. To relieve the severe discomfort associated with this damage, the patient chose to have her maxillary incisors extracted and replaced by a removable partial denture. A defect in the soft tissue and bone was present at a follow-up visit 10 months after the extractions. While morbidity of this nature is rare, this case reinforces the need to maintain adequate cooling of ultrasonic instruments.

The role of gene therapy for craniofacial and dental tissue engineering

Basic science advances in bone tissue engineering using osteoinductive protein therapy have already been translated to the use in patients with selected orthopedic problems. The story of the development of bone morphogenetic protein (BMP) osteoinductive therapy, from the discovery of this class of molecules in 1965 to the publication of randomized clinical trials in 2001 for tibial non-unions and 2002 for spinal fusion, is truly fascinating. Both clinical studies showed healing equivalence of the BMP-bioimplant compared to a free non-vascularized bone graft but without the associated donor site morbidity. These advances unfortunately have not lead to rapid application of using BMP osteoinductive protein therapy for reconstructing most craniofacial bone defects, with clinical case series beginning to be reported only for limited small-sized defects. This is a reflection of the complexity and unique characteristics of most craniofacial defects, which will likely require a more robust osteoinductive signal than delivering recombinant protein on a scaffold for clinically meaningful bone regeneration. Gene therapy approaches are promising for overcoming the unique challenges that are characteristic of craniofacial and dental defects.

The importance of splinting of teeth in the therapy of periodontitis

AIM

The deep periodontal disease often leads to dental mobility with further aggravation of the symptomatology. The aim of the paper is to verify the importance of splinting of teeth in the therapy of periodontitis on the basis of parameters commonly studied [probing depth (PD), bleeding on probing (BOP), plaque index], and the role of the occlusal trauma as primary factor or second leading factor in periodontal diseases.

METHODS

Thirty patients suffering from periodontitis have been treated with the splinting of teeth, neither preceded nor followed from topical and systemic pharmacological therapy, nor from surgical or non surgical treatment of the periodontal tissues involved. During the 4 visits provided by the study, T0 (0 days), T1 (30 days), T2 (90 days) and T3 (180 days), PD, BOP and plaque index have been estimated.

RESULTS

From the comparison of the T0 PD and BOP with the T3 PD and BOP, a significant improvement of these parameters is observed (P<0.05).

CONCLUSION

On the basis of the clinical data obtained in this research, the authors suggest that the therapy by means of splinting improves the prognosis of teeth affected by periodontal disease; occlusal trauma and dental mobility cause the aggravation of periodontal lesions.

Reactive oxygen species scavenging activity during periodontal mucoperiosteal healing: An experimental study in dogs

Excessive release of reactive oxygen species (ROS) in wounded tissue due to inflammation and ischaemia is a deleterious and destructive phenomenon for the healing process. Hence, scavenging of ROS is one of the essential steps in normal wound repair. In this study, we presented a profile of free radical scavenging enzyme (FRSE) activity of periodontal mucoperiosteal wounds in order to investigate ROS activity during periodontal wound healing. Mucoperiosteal periodontal flaps were elevated in the mandibular buccal region of seven dogs between the first premolar and first molar teeth, creating acute incisional wounds in the inner side of the flaps and they were replaced 30 min after elevation. Gingival samples taken from certain biopsy regions at baseline (before flap elevation), day 3, 12, 21 and 30 were processed for detection of active amounts of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX). All enzyme activities had increased by more than 100% of their baseline levels by day 3. SOD activity decreased gradually from days 3 to 30 and reached a level lower than the baseline value. The increase in CAT activity continued until day 21, and decreased to a level higher than the baseline value by day 30. GPX also decreased from day 3, and reached a level less than its baseline value by day 30. Our results suggest that FRSEs may contribute to the detoxification of ROS during periodontal mucoperiosteal healing. This relationship may be utilized to facilitate soft tissue and/or flap management in periodontal or intra-oral treatments.

Relationship between position of probe tip and periodontal tissues after periodontal surgery in dogs

The aim of this study was to investigate postsurgical periodontal probe penetration by using clinical information and histometric data. Thirty-eight three-walled defects were created in four dogs, then maintained for 3 months. Subsequently, 26 defects were subjected to periodontal surgery (surgical group), while 12 defects served as controls. The dogs were sacrificed at 4, 8, 12, and 16 weeks. Immediately before sacrifice, endodontic silver points were placed in the gingival crevices as substitutes for periodontal probes and fixed on the teeth. Following block sections, histologic and histomorphometric evaluations were undertaken: location of the probe tip in relation to the apical termination of the junctional epithelium, length of new junctional epithelium in relation to the apical junctional epithelium, and mean length of connective tissue adhesion in relation to the apical junctional epithelium. Probe tips were located -1.37 +/- 1.73 mm and -0.20 +/- 0.15 mm apical to the apical junctional epithelium for the surgical and control groups, respectively, at 4 weeks, while the probe tip was located 0.58 +/- 0.31 mm and 0.40 +/- 0.20 mm coronal to the apical junctional epithelium, respectively, at 16 weeks. Length of new junctional epithelium in relation to apical junctional epithelium was significantly less for the surgical than the control group at 4 weeks (0.73 +/- 0.60 mm vs 1.19 +/- 0.02 mm) and 8 weeks (1.77 +/- 0.52 mm vs 2.15 +/- 0.00 mm). There were no significant differences between the groups in regard to connective tissue relationship to the apical junctional epithelium. Periodontal probing is not recommended for at least 2 months after surgical procedures; before this stage, probing forces may damage the soft tissue-tooth interrelationship.

Analgesic effect of sustained-release flurbiprofen administered at the site of tissue injury in the oral surgery model

Nonsteroidal anti-inflammatory drugs produce their analgesic and adverse effects through interaction with cyclooxygenase in a variety of tissues. The authors evaluated the therapeutic potential of administering a sustained-release formulation of flurbiprofen into a surgical wound following oral surgery to produce analgesia at the site of injury while minimizing exposure to potential targets for toxicity. Subjects (N = 98) received 1 of 8 treatments: flurbiprofen in a microparticle formulation in doses of 3.125 mg, 6.25 mg, 12.5 mg, 25 mg, or 50 mg; PO flurbiprofen 25 mg or 50 mg; or placebo. The flurbiprofen microparticle formulation or matching placebo was placed into the extraction sites at the end of surgery (removal of 2 lower impacted third molars). The sum of the pain visual analog scale over the 6-hour observation period demonstrated significantly less pain (P < .05) for flurbiprofen microparticle in comparison with placebo. Fewer subjects remedicated in the flurbiprofen microparticle drug groups, primarily for the 12.5-mg and higher doses. The incidence of adverse effects and local complications did not differ across groups. These data suggest that direct administration of flurbiprofen in a microparticle formulation at a site of tissue injury delays the onset and lowers the intensity of postoperative pain at lower doses than usually administered orally.

Influence of the type of dental trauma on the pulp vitality and the time elapsed until treatment: a study in patients aged 0-3 years

The purpose of the present study was to determine the influence of the type of trauma on the pulp vitality and the time elapsed until seeking dental care in children aged 0-3 years seen at the Baby Clinic of the Araçatuba Dental School, UNESP. A total of 1813 records were analyzed. Two hundred and three patients, corresponding to 302 traumatized teeth, were assessed clinically and radiographically. Hard-tissue injuries were the most frequent (52%), with a predominance of enamel crown fractures (41.4%), followed by concussions (12.6%) and intrusions (11.6%). Clinical and radiographic examination revealed that 72% of the traumatized teeth maintained pulp vitality. In the case of supporting-tissue lesions, 51.1% of the patients sought care within 1-15 days after injury, while in the case of hard-tissue injuries, 52.7% sought care only after 16 days. The results showed that supporting-tissue injuries had a significant influence on the faster seeking of dental care.

The effect of partial damage to the enamel-related periodontium combined with root resection on eruption of the rat incisor eruption

Previous work has indicated that the enamel-related periodontium (ERP) has a role in the eruptive process of the rat lower incisor. By combining partial damage of this tissue with resection of the odontogenic organ, we examined the effect of the damage on subsequent incisor eruption. The connective tissue of the enamel-related periodontium was regenerated in less than 2 weeks, showing morphology close to normal. The injured part of the enamel organ was neither regenerated nor repaired, and a cement-like tissue, continuous with the true acellular cement, was formed on the denuded enamel. Before tooth exfoliation, the operated teeth erupted at a slower rate compared with root-resected and sham-operated incisors, probably because of the absence of a substantial part of the enamel organ due to surgical damage. As with the coronal dental follicle and the enamel organ in rat molars, the enamel-related periodontium and the enamel organ of rat incisors may have some control on their eruptive process.

Treatment delays in paediatric dento-alveolar trauma at a tertiary referral hospital

BACKGROUND

Paediatric dento-alveolar trauma is a common event. Delays in treatment can have adverse effects on long term outcomes and the aim of this study was to quantify the treatment delays in paediatric dento-alveolar trauma in a tertiary referral hospital.

METHODS

All cases of paediatric dento-alveolar trauma over a two year period from July 2000 to June 2002 were identified and the charts were reviewed retrospectively. All children presenting to the emergency department with dento-alveolar trauma within 48 hours of injury during the time period were included.

RESULTS

Forty-three patients were identified. The average age was 5.51 years, though there was a bias towards one and two year olds. Males were injured 1.5 times more frequently than females. There was an average delay of 9.6 hours between injury and treatment for all patients. Transit time from outside practitioners to hospital and waiting times in hospital made up the greatest delays. Children injured an average of 2.37 teeth and only 14 per cent were uncomplicated crown fractures.

CONCLUSIONS

Children who present to children's hospitals for treatment of dento-alveolar trauma have more severe injuries than those treated elsewhere. They have large but potentially reducible delays between injury and treatment.

Orthodontics. Part 6: Risks in orthodontic treatment

Orthodontics has the potential to cause significant damage to hard and soft tissues. The most important aspect of orthodontic care is to have an extremely high standard of oral hygiene before and during orthodontic treatment. It is also essential that any carious lesions are dealt with before any active treatment starts. Root resorption is a common complication during orthodontic treatment but there is some evidence that once appliances are removed this resorption stops. Some of the risk pointers for root resorption are summarised. Soft tissue damage includes that caused by archwires but also the more harrowing potential for headgears to cause damage to eyes. It is essential that adequate safety measures are included with this type of treatment.

Transient root resorption after dental trauma: the clinician's dilemma

The diagnostic shortcomings encountered in the clinical evaluation of pulpal and periodontal healing subsequent to trauma comprise a major problem in dental traumatology. An acute dental trauma may imply impact to the hard dental tissues and damage to the pulp and periodontium (including surrounding alveolar bone). In the case of luxation injuries, the trauma often results in rupture of the neurovascular supply at the level of the apical foramen, whereas in a root fracture, the same occurs at the level of the fracture. Conventional diagnostic criteria for pulpal status (coronal discoloration, loss of pulpal sensibility, tenderness to percussion, and radiographic change [i.e., resorption]) reflect, only indirectly, certain parameters of healing. These parameters are based empirically on clinical findings after dental caries and dental restorative techniques, where the pulp has an intact neurovascular supply apically. In these situations, long-standing bacterial or chemical attack can lead to irreversible change. In contrast, following traumatic impact, a presumably intact pulp is deprived of its neurovascular supply instantaneously. In the absence of infection, events following acute dental trauma aim at either tissue repair or regeneration. Thus, based on a series of long-term clinical studies, it was found that all conventional signs, with the exception of tenderness to percussion, could be signs of pulpal healing, as well as signs of pulpal death. Based on the results of these studies, this report discusses the significance of radiographic change (resorption) in relation to pulpal and periodontal healing following acute trauma. Moreover, implications of tooth luxation with respect to the long-term prognosis following crown, crown-root, and root fractures are discussed.

CLINICAL SIGNIFICANCE

Whenever possible, it is to the patient's advantage that pulp vitality be preserved. Correct diagnostic techniques and patient selection enable the clinician to decide when endodontic therapy is appropriate and when intelligent observation is the "treatment" of choice.

Comparative assessment of two methods used for interdental immobilization

AIM

This investigation was carried out to compare Dimac wires with arch bars for interdental immobilization.

MATERIAL AND METHODS

The assessment was conducted on 50 patients who had mandibular fractures and in whom intermaxillary fixation was required as a part of the treatment. The time required for applying each method of fixation, the needle-stick injuries that occurred during their application, and the periodontal damage that followed interdental immobilization was investigated.

RESULTS

The mean time required for the application of Dimac wires was significantly less than that required for arch bars. The needle-stick injuries were significantly less with Dimac wires. Patients reported difficulty with oral hygiene with arch bars in place. This was associated with periodontal damage following removal of fixation.

CONCLUSION

Dimac wires is safer to use and less traumatic to the periodontium

Accidentally induced periodontitis in primary dentition: longitudinal examinations of periodontal bacteria and clinical conditions

Periodontitis is very rare in the primary dentition although it can be accidentally induced in young children. The purpose of this study was to describe a case of periodontitis in a 4-year-old child, which was accidentally induced by insertion of small plastic tubes into the dental cervix of the primary incisors during play, and to discuss the clinical, radiographic, and microbiological findings. Removal of the plastic tubes resulted in resolution of the periodontal condition. Prevotella nigrescens and Campylobacter rectus were detected in subgingival plaque samples from the affected teeth at every examination, whereas Porphyromonas gingivalis, Treponema denticola, Prevotella intermedia, and Bacteroides forsythus were never found during the two-year observation period. The clinical and microbiological results suggest that the type of periodontitis caused by such an incidence is not progressive, unlike other periodontal diseases such as prepubertal and juvenile periodontitis.

Obliteration of pulp canal space after concussion and subluxation: endodontic considerations

Concussion and subluxation injuries to permanent teeth lead to obliteration of the pulp canal space in 3% to 11% of cases, depending on the severity of the injury and the developmental stage of the tooth. Obliteration of the pulp canal space may make root canal treatment necessary because of the development of apical periodontitis or for cosmetic reasons. If carefully executed, root canal treatment in teeth with an obliterated pulp canal space is highly successful and may act as a basis for internal bleaching.

A survey of dental and oral trauma in south-east Queensland during 1998

BACKGROUND

This project investigated the aetiology of dental and oral trauma in a population in south-east Queensland. The literature shows there is a lack of dental trauma studies which are representative of the general Australian population.

METHOD

Twelve suburbs in the south-east district of Queensland were randomly selected according to population density in these suburbs for each 25th percentile. All dental clinics in these suburbs were eligible to participate. Patients presenting with dental and oral trauma were eligible to participate.

RESULTS

A total of 197 patients presented with dental/oral trauma over a 12 month period. The age of patients ranged from 1-64 years whilst the most frequently presenting age group was 6-10 years. There was a total of 363 injured teeth with an average of 1.8 injured teeth per patient. Males significantly outnumbered females in the incidence of trauma.

CONCLUSIONS

The highest frequency of trauma occurred in the 6-10 year age group. Most injuries in this group occurred while playing or riding bicycles. In the next most prevalent trauma group, 16-20 years, trauma occurred as a result of fighting and playing sport. Overall, males significantly outnumbered females by approximately 1.8:1.0. The majority of injuries in the deciduous dentition were to periodontal tissues. In the secondary dentition most injuries were to hard dental tissue and pulp.

Reattachment of an autogenous tooth fragment in a fracture with biologic width violation: a case report

An 11-year-old patient that fractured her maxillary left central incisor is presented. The fracture involved two thirds of the crown, compromising the pulp, and extended subgingivally on the palatal aspect, invading the biologic width. The procedure used to repair the fracture included flap surgery with a slight ostectomy and endodontic treatment. The reattachment of the tooth fragment and the restoration were performed with a bonding system and a resin composite. Examination 6 months after treatment revealed periodontal health, good esthetics, and normal function.

Some effects of enamel matrix proteins on wound healing in the dento-gingival region

OBJECTIVE

The aim of the present study was to evaluate by clinical means the effect of enamel matrix proteins on the healing of a soft tissue wound produced by periodontal pocket instrumentation.

MATERIAL AND METHODS

The study was performed as an intra-individual, longitudinal trial of 3 weeks duration with a double-masked, split-mouth, placebo-controlled and randomized design. The patient material was comprised of 28 subjects with moderately advanced, chronic periodontitis. Each patient presented with 3 sites in each of 2 jaw quadrants with a probing pocket depth (PPD) of >or=5 mm and bleeding following pocket probing (BoP). Baseline examination, including assessments of plaque, gingival inflammation, PPD, BoP and root dentin sensitivity, was carried out one week after oral hygiene instruction and careful self-performed plaque control. All experimental sites were scaled and root planed, and the soft tissue wall of the pocket was curetted to remove the pocket epithelium and adjacent granulation tissue. The site was carefully irrigated with saline. When the bleeding from the pocket had ceased, a 24% EDTA gel was applied in the site and retained for 2 min. This was followed by careful irrigation with saline. Left and right jaw quadrants were then randomized to subgingival application of enamel matrix derivative (Emdogain) or vehicle-control. All sites were re-examined after 1, 2 and 3 weeks. In addition, a visual analogue scale (VAS) was used to score the degree of post-treatment discomfort. The primary endpoints of treatment success were defined as (i) pocket closure (PPD <or=4 mm), (ii) no bleeding following pocket probing, (iii) no sign of gingival inflammation (GI score =0) and (iv) low degree of post-treatment discomfort (VAS <or=20). Statistical analyzes of intra-individual differences between the test and control treatments were performed by the use of Wilcoxon signed rank test. For comparison of the proportions of sites reaching the defined endpoints of treatment success, a site-based analysis was performed using 2x2 tables and the Fisher exact test.

RESULTS

The endpoint "GI score =0" was reached at 16% of the sites subjected to application of Emdogain at 1 week and at 2% of the control sites (p=0.001). At 2 weeks, the corresponding figures were 25% versus 12% (p =0.028). Absence of BoP was at 1 week 57% for the Emdogain treated sites compared to 35% for the control sites (p=0.003). At 2 weeks, this endpoint was reached in 73% and 59% of the test and control sites, respectively (p=0.051). In terms of the endpoint defined for probing pocket depth, PPD <or=4 mm, no differences between test and control sites were found. At 1 week, the proportion of patients reporting a VAS score <or=20 was significantly higher for the Emdogain treated quadrants than for controls (p=0.002).

CONCLUSION

The results indicated that Emdogain topically applied in instrumented pockets enhance the early healing of periodontal soft tissue wounds.

Oral trauma in Brazilian patients aged 0-3 years

The aim of the present investigation was to gather data pertaining to dental trauma in 1654 patients aged 0-3 years, attended at the Baby Clinic of the School of Dentistry at Araçatuba-UNESP, Brazil. The prevalence of traumatic injuries was 16.3%. There was greater involvement of boys (62.6%), of children aged 1-2 years (39.9%) and of the maxillary central incisors (86%). Falls were more often the etiology for dental injuries (58.3%). There was a predominance of uncomplicated crown fractures (48.4%).

Pulpal healing following acute dental trauma: clinical and radiographic review

Successful treatment of tooth luxations, crown fractures, and root fractures is often compromised by the emergency nature of the injury. Precise radiographic and clinical evaluation is required to facilitate healing and treatment selection. While traditional treatment protocols indicate that dental injuries implying pulpal ischemia require immediate endodontic therapy to avoid healing complications, the clinical investigations discussed herein suggest that a variety of etiologies for pulp survival/pulp necrosis exist. This article discusses the long-term prognosis of pulp necrosis following traumatic dental injuries, and clinical and radiographic criteria for its diagnosis.

Comprehensive treatment of traumatic fracture and luxation injuries in the anterior permanent dentition

The increased incidence of traumatic injuries in anterior teeth is a consequence of modern leisure activities. The key factors to successful functional and aesthetic rehabilitation of such injuries are proper diagnosis and adequate primary and subsequent treatment. In severe cases, sequential multidisciplinary treatment is required. All-ceramic crown and post-and-core systems allow for superior aesthetics without compromising function. This article addresses fractures and luxation injuries in the anterior permanent dentition and discusses updated treatment options. The multidisciplinary rehabilitation of a clinical case for optimal function and aesthetics is presented.

[Experimental study of periodontal tissue regeneration after the application of enamel matrix derivative in rat periodontal defects]

The purpose of this study was to evaluate periodontal wound-healing after the application of enamel matrix derivative (EMD) in rats. Periodontal defects were surgically created on the mesial side of the first maxillary molar of 24 male Long-Evans rats. EMD was applied to cover the denuded root surfaces in the experimental group. The contralateral molar was used for the control group, which received the same treatment without EMD. The rats were sacrificed at 2 weeks (8 rats), 4 weeks (8 rats), and 8 weeks (8 rats) after the surgery. Demineralized paraffin sections were stained with Masson's trichrome. Histological analysis and histomorphometric measurements were performed on the periodontal sections. Using an immunohistochemical technique, the localization of osteocalcin (OC) was also examined. The formation of new cementum was statistically significant in the experimental group, especially new cementum with extrinsic fiber. Both acellular and cellular cementum were also rather strongly observed in the experimental group. Epithelial down growth was also strongly inhibited in the experimental group at 8 weeks after the surgery. OC-positive cells and matrix were limited at the bottom of the defects in the control group, while positive reaction was detected not only at the bottom but also spreading to the coronal portion of the defects in the experimental group. These results suggest that EMD has potential to promote cementum regeneration, especially fiber-inserted cementum, and to create a favorable environment that will promote periodontal regeneration.

Space maintenance--a review of treatment options to repair the iatrogenic perforation

Management of intra-canal and furcation perforations can pose a significant clinical challenge. In such cases a biological matrix can provide the framework for healing of injured periodontal tissues and will facilitate placement of the perforation repair material. As a consequence the long-term prognosis for treatment of the iatrogenic perforation can be significantly improved and the need for surgical intervention can often be eliminated.

Treatment of luxation traumatic injuries: definition and classification in the literature

Luxation traumatic injuries affect the hard tissues and may involve periodontal tissues in severe cases. Periodontal healing must be considered during treatment of traumatic injuries that result in total luxation of the teeth. Pulpal healing is essential for the endodontic prognosis of a reimplanted tooth, as well as for its periodontal healing. Luxation injuries can be further classified as intrusive, extrusive, and/or lateral; this categorization further facilitates the mode of splinting and repositioning utilized during treatment. This article reviews various types of dentoalveolar traumatic injuries and discusses commonly incorporated treatment modalities.

Chitosan film enriched with an antioxidant agent, taurine, in fenestration defects

A natural polysaccharide, chitosan (poly-N-acetyl glucosaminoglycan), which is a nontoxic and bioabsorbable polymer, has been shown to have hemostatic and antibacterial effects. An amino acid, taurine, is considered to be beneficial for regulating the inflammation process. The purpose of this study was to investigate the synergistic effects of taurine and chitosan in the experimental defects at the vestibular bone of maxillary canine teeth in six dogs. Chitosan films were prepared as delivery system with or without taurine and placed in the randomly chosen defects. Biopsies were performed on the postoperative seventh day and routine histological procedures were performed for light and electron microscopic evaluations. For each group, 30 different microscopic areas were examined and the numbers of macrophages and neutrophils in these areas were counted. The mean numbers of both macrophages and neutrophils were found statistically different between the chitosan film incorporated with taurine and free chitosan groups (p < 0.0001 p > 0.05). In addition to the increase in cell counts in both groups, the cytological alterations were more obvious in the chitosan film group incorporated with taurine. Accordingly, taurine appears to enhance the acceleration effect of chitosan on wound healing at early periods. This effect could be considered beneficial in tissue repair in destructive diseases like periodontitis.

Epidemiology of dental trauma: a review of the literature

This article reviews recent reports describing the aetiology of dental trauma from national and international studies as well as the different classifications currently used to report dental injuries. It also discusses possible preventive measures to reduce the increasing frequency of dental trauma. Reported studies demonstrate that males tend to experience more dental trauma in the permanent dentition than females, however, there does not appear to be a difference between the sexes in the primary dentition. Accidents within and around the home were the major sources of injury to the primary dentition, while accidents at home and school accounted for most of the injuries to the permanent dentition. The most frequent type of injury was a simple crown fracture of the maxillary central incisors in the permanent dentition while injuries to the periodontal tissues were more common in the primary dentition. When preventive measures are being planned, knowledge of aetiology is important. More prospective studies from representative populations are required to understand the complexities of dental trauma epidemiology and to allow implementation of preventive strategies to reduce the increasing frequency of dental trauma.

An analysis of 58 traumatically intruded and surgically extruded permanent teeth

Fifty-eight traumatically intruded and mainly surgically extruded permanent teeth were followed up for 3 years and 4 months (mid-term results: 29 teeth) and 9 months (short-term results: 29 teeth) on average. Statistically, the mid-term results showed more cases of severe crown discoloration (54%) than the short-term results (9%), but no difference in pulpal and periodontal healing. Three teeth (5%) were lost. Factors which positively influenced pulpal healing were shallow intrusion depth, intact crown and immaturity of the root. Factors which positively influenced periodontal healing were shallow intrusion depth and minimal surgical manipulation. Alveolar bone healing was positively influenced only by shallow intrusion depth.

Tooth-borne distraction of the mandible. An experimental study

Two mini-pigs and 6 micropigs were fitted with a dentally fixed device for osteodistraction of the mandible. Following bilateral osteotomy and after a latency period of 7 days, the apparatus was activated 1 mm per day. A 9 mm lengthening of the mandible was achieved. After a retention period of 6 weeks, the device was removed followed by a consolidation period of 6 weeks. During the experiment, the callus and bone formation and potential dental and periodontal reactions were radiologically examined. Polychrome sequential labelling was performed by injecting calcein green and xylenol orange for histological assessment of bone. The animals were killed at the 14th postoperative week and the area of distraction and the roots of the adjacent teeth were histologically studied. After 12 weeks, the osteogenesis in the distraction gap was complete, showing lamellar bone. No detrimental effects at the roots or in the periodontium of the adjacent teeth were seen. Thus, lengthening or widening of the mandible using a tooth-borne distraction device seems feasible in selected cases.

Invasive cervical resorption following trauma

Invasive cervical resorption is an insidious and often aggressively destructive form of external root resorption which may occur as a late complication following dental trauma particularly where it involves damage to cementum and supporting tissues. While this resorption may be evident clinically as a pink coronal discolouration, later with cavitation of the enamel, often there are no obvious external signs and the condition is only detected radiographically. It is characterised by the invasion of the cervical region of the root by fibrovascular tissue which progressively resorbs dentine, enamel and cementum. The dental pulp remains protected by an intact layer of dentine and predentine until late in the process. Ectopic calcifications can be observed in advanced lesions both within the invading fibrous tissue and deposited directly onto the resorbed dentine surface. The aetiology of invasive cervical resorption is unknown but trauma has been documented as a potential predisposing factor. A recent study by the author of 222 patients with a total of 257 teeth which displayed varying degrees of invasive cervical resorption showed that trauma alone was a potential predisposing sole factor in 14% of patients and 15.1% of teeth. Trauma in combination with bleaching, orthodontics or delayed eruption was found in an additional 11.2% of patients or 10.6% of teeth and of these a combination of trauma and bleaching occurred in a relatively high proportion of 7.7% of patients or 7.4% of teeth. This study also revealed that of other potential predisposing factors orthodontics was the most common sole factor constituting 21.2% of patients and 24.1% of teeth examined. Successful treatment of invasive cervical resorption is dependent on the extent of the resorptive process. Teeth with invasive cervical resorption have been divided into four classes. Whilst several treatment modalities are possible, a clinical evaluation of the treatment of this condition by the topical application of a 90% aqueous solution of trichloracetic acid, curettage, endodontic therapy where necessary and restoration with a glass ionomer cement has been evaluated on 94 patients with a total of 101 teeth with a minimum follow-up period of three years. Results indicate a satisfactory treatment outcome can be anticipated in Class 1, 2 and 3 cases. In Class 4 resorption no treatment or alternative therapy is recommended. Diagnosis of lesions at an early stage of development is highly desirable and therefore the patients who have a potential for the development of this condition by virtue of a history such as trauma should be monitored radiographically at intervals throughout life.