Plasma Cell Gingivitis: Clinical and Pathological Case Report.

INTRODUCTION: Plasma cell gingivitis (PCG) is a rare benign condition usually found on marginal and attached gingiva. This case details a generalized PCG, to include the management of the patient and clinicopathologic characteristics of the disorder. CASE PRESENTATION: The patient, a 24-year-old African American female, was referred to the periodontics clinic for severe generalized gingival erythema and edema. Past medical history review was remarkable for sickle cell anemia and systemic lupus erythematosus. The patient was initially prescribed dexamethasone oral rinse (0.5 mg/5 ml) pending biopsy and medical consult for potential causes of any hypersensitivity reaction. The patient also was instructed to discontinue her current type of oral mouthrinse and dentifrice. Biopsy results confirmed a diagnosis of PCG. Resolution of signs and symptoms started 1 month later, and approximately 2 years after initial diagnosis the patient was clinically stable. CONCLUSION: This report describes the management of a diffuse plasma cell gingivitis and reviews pertinent literature on the lesion. The etiology of PCG, although unclear, may be attributable to a hypersensitivity reaction. PCG may mimic other pathological entities, which underscores the importance of microscopic examination in establishing a definitive diagnosis before treatment initiation.

Prader-Willi syndrome: Periodontal-prosthodontic rehabilitation in an adult patient.

INTRODUCTION: Prader-Willi syndrome (PWS) is a rare genetic multisystemic disease that is the most common inherited cause of severe childhood obesity. PWS patients are prone to significant oral and systemic health issues that detrimentally affect quality of life and decrease longevity. This report documents full-mouth pre-prosthetic surgical and restorative care in an adult PWS patient. CASE REPORT: The patient, a 29-year-old male, presented to the clinic accompanied by his guardians (parents) with the chief complaint that "My Teeth are breaking down and I would like to get them fixed". Periodontal and prosthetic comprehensive clinical and radiographic exams revealed a severely worn dentition, deep anterior overbite, altered passive eruption with generalized biofilm-induced gingivitis, and altered occlusal vertical dimension. Full mouth crown lengthening surgery combined with full mouth prosthodontic reconstruction was performed under parenteral sedation and local anesthesia. Completion of treatment was successful, and the patient was placed on a 3-month periodontal maintenance interval. DISCUSSION: Full mouth periodontal surgical and prosthodontic reconstruction on a PWS patient has not previously been reported in the literature. This case underscores the potential need for complex dental care in patients with this syndrome.

Resolution of Abfraction-Associated Gingival Fenestration Utilizing Connective Tissue Grafting.

INTRODUCTION: Gingival fenestration (GF) is a distinct clinical entity of uncertain etiology that is seldom documented in the literature. It has been associated mainly with submucosal mechanical irritants such as calculus that subsequently create an opening in the oral soft tissue, usually at facial anterior sites. Surgical correction may be indicated to address functional and/or esthetic concerns. CASE PRESENTATION: The patient, a 74-year-old male, presented to the clinic with a chief complaint of "something is poking through my gum." Clinical exam revealed a gingival fenestration on the facial of tooth #11, associated with what appeared to be a pronounced noncarious cervical lesion (NCCL). Surgical treatment consisted of a connective tissue graft and odontoplasty of the sharp protruding edge of the root surface. Healing was uneventful with excellent closure of the fenestration and no evidence of recurrence after 18 months of follow-up. CONCLUSION: GF is a perforation of the mucosa typically associated with underlying sharp mechanical etiology. This report describes a fenestration that developed from a probable abfractive lesion, which later was successfully closed and exhibits long-term stability.

The influence of vitamin D supplementation on local and systemic inflammatory markers in periodontitis patients: A pilot study.

OBJECTIVES: Vitamin D deficiency/insufficiency is a worldwide public health issue that has been linked to numerous inflammatory disorders, including periodontitis. There is increasing support for a role for adequate vitamin D levels in overall health. Populations with darker skin color have a higher prevalence of vitamin D deficiency/insufficiency and periodontitis. The purpose of this small pilot study was to investigate the influence of 12 weeks of 25(OH)D vitamin D supplementation (VDS) on mediators of systemic inflammation in dark-skinned, periodontitis patients. MATERIALS AND METHODS: A total of 23 patients with moderate to severe periodontitis were randomly assigned to the vitamin D group or placebo group and received intensive single visit scaling and root planning to elicit a systemic inflammatory response. RESULTS: Vitamin D supplementation increased serum 25(OH)D levels approximately 2-fold over baseline levels; moreover, VDS group had reduced peripheral blood CD3 and CD3+CD8+ cytotoxic T lymphocyte (CTLs) counts and reduced pro-inflammatory salivary cytokines. In contrast, VDS group had higher levels of the autophagy-related proteins and other proteins crucial for anti-microbial autophagy in whole blood PBMCs. CONCLUSION: In conclusion, VDS has multiple benefits for reducing systemic inflammation and promoting induction of autophagy-related proteins related to anti-microbial functions.

Enhancing Periodontal Regenerative Outcomes With Simultaneous Orthodontic Tooth Movement.

Periodontal regeneration of lost tissue, including periodontal ligament (PDL), cementum, and bone, has evolved with regard to surgical techniques, biomaterials, and growth factors. Simultaneous orthodontic therapy and periodontal surgical treatment has been documented previously and shown to enhance the regenerative outcome due to stimulation of the PDL by tooth movement. This combined strategy is becoming increasingly common as clinicians explore the capabilities of a collaborative approach. This article presents a case series that documents three cases in which combined orthodontic and surgical procedures were used to enhance the regenerative outcome in challenging clinical scenarios. The article includes a review of the literature and discusses clinical factors related to increasing predictability in such cases.

Lingual Gingival Cyst of the Adult.

INTRODUCTION: Gingival cysts of the adult (GCAs) are rare developmental soft tissue cysts usually found on the facial attached gingiva. Documented cases on the lingual aspect are extremely uncommon. This report details a lingual GCA along with distinguishing characteristics of this lesion. CASE PRESENTATION: The patient, a 37-year-old female, presented with a firm, round-shaped, bluish swelling on the lingual gingiva in the interproximal area between teeth #21 and #22. Radiographs revealed a circular radiolucency at the osseous crest. Surgical exploration showed cystic-appearing tissue with accompanying bone resorption. Histologic examination, along with clinical presentation, confirmed a diagnosis of gingival cyst. Healing was uneventful with no evidence of recurrence at a 5-month recall. CONCLUSIONS: A GCA is usually of odontogenic origin and occurs typically in the attached gingiva of the mandibular premolar region. Occasionally, it demonstrates radiographic evidence of bone loss from pressure resorption. Its more frequent intraosseous counterpart, the lateral periodontal cyst, shares histopathologic characteristics with the GCA. These findings underscore the importance in establishing a definitive diagnosis.

Retrospective study on idiopathic bone cavity and its association with cementoosseous dysplasia.

OBJECTIVE: The goal of this study was to reveal clinical and pathologic findings on idiopathic bone cavity lesions (IBC). STUDY DESIGN: A retrospective analysis of 20 IBC cases diagnosed from 2004 to 2014 from a university-based maxillofacial pathology service was performed and included all pertinent clinical, histologic, and radiographic findings. RESULTS: Eleven women (age = 36 ± 12.7) and 9 men (age = 23 ± 17.9) diagnosed with IBC were selected for analysis. There was a higher African-American female predilection (40%). Thirty percent of the cases were associated with florid cementoosseous dysplasia (COD) (all middle-aged African-American women). The location of the lesions was mandibular in 85% of the patients. All symptomatic patients (25%) had concomitant COD. Only 1 patient reported previous trauma, and only 1 patient had prior orthodontic treatment. Follow-up period ranged from 1 to 8 years, with only 1 recurrence 3 years after surgery. CONCLUSIONS: The results suggest that IBC concurrent with COD may not be as rare as the literature implies. Clinicians must be attentive to this possible relationship to ensure accurate diagnosis and appropriate treatment.

Transient hiccups associated with oral dexamethasone.

Hiccups, or singulata (hiccup is singultus), are commonly experienced by most people at one time or another and are usually brief and self-limiting. Although pharmacotherapeutic agents are not generally considered causal in the etiology of hiccups, many clinicians empirically associate episodic hiccups in their patients as being drug induced. The two classes of drugs most often cited as causing hiccups are corticosteroids and benzodiazepines. This report involved a patient who was given preoperative dexamethasone and developed hiccups before anesthesia and surgery commenced. He at no time was in distress, and the surgical procedure was completed without complication. By the second postsurgical day his hiccups were resolved completely. Although the association may be anecdotal, many clinicians consider hiccups a potential side effect of steroid therapy, especially high doses of steroids. Of interest in this case is the relatively low dose of corticosteroid used, albeit apparently linked to his hiccups. Practitioners should be aware of this potential condition.

Influence of matrix-suspended demineralized bone on osseous repair using a critical-sized defect in the rat (Rattus norvegicus) calvarium.

Demineralized freeze-dried bone (DFDB) in matrix form must be rehydrated with a carrier medium which allows for easy manipulation during periodontal surgery. The purpose of this study was to evaluate how human DFDB suspended in a polyol matrix affects new bone formation in the rat calvarium critical-sized defect (CSD) model. Fifty-five adult male Harlan Sprague-Dawley rats were assigned to 1 of 5 treatment groups: polyol, 100% DFDB, 47% DFDB/polyol, 47% DFDB, or an unfilled control. They were then placed into 8-m calvarial CSDs. The bone donor source company for the DFDB and DFDB/polyol groups was the same. Calvaria were harvested 10 weeks after surgery and evaluated histomorphometrically. The diameter of bone particles from the 3 groups containing DFDB was measured by scanning electron microscopy. There was no statistically significant difference in the percentage of bone fill between any of the groups, although the 100% DFDB group exhibited the most bone fill. The 47% DFDB/polyol and 47% DFDB groups had similar amounts of bone formation. The average size of the demineralized bone particles from the 100% DFDB group was significantly smaller than that of the other 2 groups containing DFDB. Adding a polyol to DFDB produced similar osseous regeneration in the rat calvarium defect model vs DFDB alone. Yet from a clinical standpoint, the polyol enhanced graft handling and stability. Graft particle size may have an effect on bone fill.

Gingival recession treatment with connective tissue grafts in smokers and non-smokers.

BACKGROUND: Cigarette smoking can adversely affect the results of many periodontal procedures. The purpose of this study was to determine whether cigarette smoking affects wound healing of subepithelial connective tissue grafts. METHODS: Seventeen systemically healthy patients with 22 Miller Class I or II mucogingival defects were divided into a non-smoker group or smoker group. Patients were regarded as smokers if they reported smoking 10 to 20 cigarettes per day. The following parameters were documented at the surgery date and 3 and 6 months postoperatively: recession depth (RD), recession width (RW), keratinized gingiva height measured apico-coronally (KG), relative attachment level (RAL), probing depths (PD), bleeding on probing (BOP), and the full-mouth plaque score (FMP). Salivary cotinine samples were taken at the surgery to confirm the smoking history and to quantify cigarette use. RESULTS: Non-smokers (0- to 10-ng/ml cotinine level) healed with statistically more recession coverage than the smokers (>10-ng/ml cotinine level) (98.3% versus 82.3%, respectively; P=0.001). Six months postoperatively, the non-smokers healed with a 0.2-mm mean recession depth compared to a 1.0-mm mean recession depth for the smokers. This difference in recession depth was statistically significant (P=0.014). CONCLUSIONS: Root coverage with connective tissue grafts appears to be negatively associated with cigarette smoking. Smokers should consider smoking cessation or reducing the use of cigarettes for optimal results with connective tissue grafts.

The effect of residual calcium in decalcified freeze-dried bone allograft in a critical-sized defect in the Rattus norvegicus calvarium.

Demineralized freeze-dried bone allograft (DFDBA), a widely used graft material in periodontal regenerative procedures, is processed with hydrochloric acid in the attempt to expose proteins located within the bone matrixes that are capable of inducing new bone formation. However, the degree of DFDBA demineralization varies between tissue banks, which may have an effect on clinical regeneration. This study uses the critical-sized defect (CSD) model to evaluate the wound-healing response to the residual calcium of donor bone. If the percentage of residual calcium in a graft were demonstrated to significantly enhance wound healing, then periodontal patients may benefit from further standardization of human-allograft processing. Sixty adult, male, Harlan Sprague-Dawley rats (Rattus norvegicus) were randomly and equally divided into 4 test groups (ie, DFDBA at 1%, 2%, and 3% to 6% residual calcium levels and FDBA at 23% residual calcium) and a control group (no allograft). An 8-mm-diameter craniotomy was made in the rat calvarium, and polytetrafluoroethylene membranes with pore sizes of 0.50 microm were placed intracranially and ectocranially. Treatment materials were carefully placed into the CSD with a new sterilized dental amalgam carrier. Tetracycline hydrochloride was injected intraperitoneally for labeling new bone growth, and animals were euthanized 12 weeks postsurgery. As a result, histomorphometric bone fill at 12 weeks showed a statistically significant increase in the 2% DFDBA group as compared to all other groups. The authors conclude that a 2% residual calcium level in human DFDBA appears to significantly (P < or = .05) enhance osseous wound healing in the rat calvarium.

Effect of a hydroxyapatite tricalcium phosphate alloplast on osseous repair in the rat calvarium.

BACKGROUND: Bony defects caused by periodontitis are often treated by regenerative therapy using autografts and/or allografts. Alloplasts, such as hydroxyapatite or ceramics, are also used as osteoconductive materials that serve as a scaffold for new bony ingrowth. The purpose of this study was to determine the effect of hydroxyapatite tricalcium phosphate (HA-TCP) on osseous repair in the rat calvarium. METHODS: Forty-four adult male Harlan Sprague-Dawley rats were assigned to one of four treatment groups: HA-TCP macroporous disk, HA-TCP microporous disk, HA-TCP granules, and demineralized freeze-dried bone (DFDB). The materials were placed into 8-mm calvarial critical-size defects (CSD). Calvariae were harvested at 10 weeks post-surgery and evaluated histomorphometrically. RESULTS: The DFDB group had significantly (P <0.05) more new bone formation (47%) than any other group. The HA-TCP macroporous disk group had significantly (P <0.05) more new bone formation (19.7%) than the HA-TCP microporous disk (8.5%) or HA-TCP granule (6.9%) groups. CONCLUSIONS: The HA-TCP macroporous disk may elicit significant new bone formation due to its rigid space-maintaining scaffold and pore size for vascular ingrowth. It is well tolerated by host tissues and may be a suitable carrier for growth factors.

Severe localized periodontal destruction associated with cervical cemental separation.

Cemental separations and tears are secondary etiological factors that may lead to rapid periodontal destruction if the lesion communicates with the oral cavity and allows bacterial invasion. Although many cemental tears that occur on proximal surfaces can be diagnosed radiographically, separations on the facial or lingual surface that cannot be detected on radiographs may present a diagnostic dilemma. This article describes a case of lingual cemental separation on a maxillary incisor, with subsequent successful surgical correction utilizing an osseous graft.

Perioral angioedema associated with angiotensin-converting enzyme inhibitor.

BACKGROUND: Angioedema is a non-pruritic swelling usually limited to the skin and mucous membranes of the face and perioral soft tissues. It can be life threatening but usually is not, and can be managed with conservative medical treatment unless the airway is endangered. Recent reports suggest that angiotensin-converting enzyme (ACE) inhibitors can predispose and/or precipitate angioedema, with a predilection toward patients of African American ancestry. METHODS: This case report involved a 65-year-old African American female who was being treated surgically for localized chronic periodontitis. The procedure was performed without incident, and the patient was alert and stable when released. The next day, the patient called and reported that her lips were swollen. She stated that this had happened a number of times over the past several years, sometimes related to eating shellfish and other times without any known precipitating factor. All previous episodes of perioral swelling occurred after ACE inhibitor therapy had been initiated. RESULTS: The patient was in no distress, with no other site involvement. She was prescribed oral hydroxyzine and her appearance returned to normal after 5 days. Although the patient had experienced previous episodes of angioedema, none had been in response to any dental procedure. She was referred to the Allergy and Immunology Clinic for skin testing, the results of which were negative to shellfish with good controls. Other potentiating etiologies were also ruled out by the allergist. CONCLUSIONS: Angioedema is a recognized possible side effect of ACE inhibitor therapy. The exact mechanism by which ACE inhibitors induce angioedema is not known, although the risk of occurrence is much greater in African Americans. Practitioners should be alert to this potentially fatal condition in patients who take ACE inhibitors or the newer angiotensin II receptor blockers (ARBs).

In vivo effectiveness of a glycerol-compounded demineralized freeze-dried bone xenograft in the rat calvarium.

BACKGROUND: Demineralized freeze-dried bone (DFDB) is commonly hydrated with sterile water into a paste-like consistency for improved clinical handling or reconstituted with biodegradable barriers, such as glycerol, to promote handling and wound stability following human periodontal surgery. The purpose of this study was to evaluate the in vivo effects of glycerol-compounded human DFDB on bone formation in the rat calvarial critical-sized defect (CSD) model. METHODS: Forty-eight adult male Harland Sprague-Dawley rats were assigned to one of four treatment groups: glycerol, DFDB, DFDB plus glycerol, or a non-grafted control, and placed into 8 mm calvarial CSDs. DFDB (particle size 0.106 to 0.5 mm), glycerol, and their combination were from identical sources. Calvaria were harvested at 8 weeks postsurgery and evaluated histomorphometrically. RESULTS: A statistically significant increased percentage of total bone fill was detected in the glycerol plus DFDB group and DFDB group as compared to glycerol group or the control. However, no significant difference was noted between the DFDB plus glycerol group and the DFDB group. CONCLUSION: The addition of glycerol to DFDB results in comparable osseous regeneration in the rat calvarium defect model versus DFDB alone; however, based upon clinical judgment, handling characteristics of DFDB were greatly improved.

Nicotine stimulates osteoclast resorption in a porcine marrow cell model.

BACKGROUND: Combustible tobacco use is generally linked with accelerated periodontal bone loss and diminished post-surgical wound healing; however, the pathogenesis of this process at the cellular level remains unclear. Nicotine is known to affect human gingival fibroblast orientation, attachment, and beta1 integrin expression, yet little is known about its effects on osteoclasts, the cells most responsible for bone resorption. The purpose of this study was to determine the effects of physiologically relevant nicotine levels on porcine osteoclast function as measured by resorption of calcium phosphate. METHODS: Pure nicotine was diluted in medium to the following concentrations: 0.03 microM, 0.15 microM, 0.30 microM, 0.60 microM, and 1.50 microM. Porcine osteoclasts were seeded onto calcium phosphate multi-test slides and incubated at 37 degrees C with half media changes every 24 hours. Cells received 0, 0.15, 0.30, 0.60, and 1.50 microM nicotine, or 25 nM parathyroid hormone (PTH). Osteoclast resorption was quantified by measuring the resorbed surface area of the calcium phosphate substrate. RESULTS: Osteoclast cultures resorbed bone slices and calcium phosphate substrate. All nicotine concentrations and PTH resulted in statistically significantly greater mean percent resorptions than the control group (P < 0.05). However, no statistical difference was found between the various nicotine doses or PTH. The number of osteoclasts increased in a linear relationship to the increasing nicotine concentrations; however, no correlation was found between osteoclast number and the amount of resorption. CONCLUSIONS: Nicotine is non-toxic to osteoclasts at the clinically relevant levels tested. Nicotine appears to stimulate osteoclast differentiation and resorption of calcium phosphate, the major component of bone. Nicotine-modulated osteoclast stimulation may, in part, explain the increased rapidity of periodontal bone loss and refractory disease incidence in smokers.

Evaluation of a novel alloplast for osseous regeneration in the rat calvarial model.

BACKGROUND: Alloplasts are inert foreign bodies acting as osteoconductive space maintainers during osseous wound healing. They may also function as carriers for growth factors that are known to enhance neovascularization and osteoinduction; human recombinant transforming growth factor beta (rhTGF-beta1) is one such factor. The purpose of this study was to evaluate di-vinyl styrene beads (DVSb) and rhTGF-beta1 effects on osseous regeneration in the rat calvaria critical-sized defect model. METHODS: Di-vinyl styrene beads (DVSb) with and without rhTGF-beta1 were placed between gelfilm membranes in a critical-sized defect in the rat (Rattus norvegicus) calvaria. Actual bone fill; percentage bone fill; bone formation rate (BFR); and mineralization at 3, 6, and 12 weeks postsurgery were measured using densitometry, histomorphometry, scanning electron microscopy (SEM), and vital staining with tetracycline-HCl. RESULTS: Mean radiographic density and percentage fill were statistically greater for DVSb treatment groups as compared with controls (P < or = 0.05). BFR was consistently between 3 and 7 microm per day for all groups; alloplast group BFR was significantly greater than controls or the rhTGF-beta1 groups at 6 weeks (P < or = 0.05); however, at 3 and 12 weeks, the control BFR was greater than treatment groups (P < or = 0.05). Membranes often collapsed and little bone fill or mineralization occurred in defects without DVSb. Mineralization appeared to occur adjacent to the alloplast by 12 weeks in the histologic and SEM sections. While DVSb fibrous attachment occurred in some specimens, there was no evidence of an inflammatory response. CONCLUSION: Di-vinyl styrene beads, with or without rhTGF-beta1, significantly enhance bone regeneration in the rat calvaria defect model.

External root resorption following partial-thickness connective tissue graft placement: a case report.

We report an unusual case of external root resorption (ERR) that developed in a 37-year-old black male approximately 1 year following routine partial thickness connective tissue graft surgery. The lesion was accessed via flap surgery, thoroughly root planed, and the mucoperiosteal flap replaced. The site healed uneventfully and the patient has been closely observed for over 1 year without symptoms or recurrence of the resorptive lesion and the affected tooth remained vital. Clinicians performing partial-thickness connective tissue grafts should be alert to the possible occurrence of root resorption over extended periods of time. The authors speculate that retention of the donor periosteum with placement on the recipient dentin and root biomodification may limit the resorptive response following connective tissue graft procedures to treat tooth root recession.

Evaluation of pluronic polyols as carriers for grafting materials: study in rat calvaria defects.

BACKGROUND: Pluronic polyols are a family of non-ionic surfactants currently used as drug carriers for antibiotic, anti-inflammatory, and anti-neoplastic agents. Therapeutic administration of non-ionic surface-active agents is known to facilitate early collagen synthesis and microcirculation, thus promoting wound healing. The purpose of this study was to determine the in vivo effects of pluronic polyols combined with either an allograft or an alloplast on the healing of critical-sized calvarial defects. METHODS: One hundred fifty (150) adult (95 to 105 days old) male Sprague-Dawley rats weighing between 375 and 425 g were randomly and evenly assigned to each of 15 separate treatment groups and anesthetized, and 8 mm calvarial critical-sized defects were created. Pluronic F-68 (F-68) or pluronic F-127 (F-127) was administered either topically or systemically and in conjuction with demineralized bone powder (DBP), tricalcium phosphate (TCP), or non-grafted controls. Pluronic polyols are easily mixed with either DBP or TCP to improve handling ease. Calvaria were harvested at 12 weeks postsurgery and evaluated histomorphometrically, by contact radiography with subsequent densitometric analysis, through energy spectrometry utilizing a scanning electron microscope, and by fluorescent microscopy. RESULTS: There was a significant difference in the percentage of bone fill among the control, TCP, and DBP only groups, P <0.05. The only significant difference within any of these groups was between the TCP control and TCP plus systemic F-127, P<0.05. CONCLUSIONS: Although there were isolated differences, the overall trend was that the pluronic polyol and the mode of administration did not result in a significant change in bone wound healing as measured by the percentage of bone fill. Pluronic polyols may be considered as carriers for osseous graft materials.

The effects of varying degrees of allograft decalcification on cultured porcine osteoclast cells.

BACKGROUND: Demineralized freeze-dried bone allograft (DFDBA) is widely used in periodontal therapy as a scaffold for new bone formation in periodontal defects. It is demineralized, theoretically, to expose osteoinductive or osteoconductive bone matrix proteins that should facilitate osteogenesis. The degree of DFDBA demineralization varies between tissue banks and may affect clinical regeneration. A 2% residual calcium level in DFDBA has been shown to result in the highest alkaline phosphatase activity levels in cultured human periosteal cells and is optimally osteoinductive or osteoconductive for new bone formation. The purpose of this study was to evaluate the effect of 4 different residual calcium levels in commercially available DFDBA samples on porcine osteoclast activity as measured by resorption on calcium phosphate-coated disks. METHODS: Bone marrow was harvested from the femurs of 3-week-old farm pigs and cultured for 3 weeks. Hematopoietic stem cells were allowed to differentiate into mature active polykaryons displaying genuine osteoclast characteristics. The osteoclast cells displayed a dense actin band inside the margins of the cytoplasm under light microscopy. Culture media was decanted and collagenase added to free the attached cells. Equal cell samples were pipetted onto calcium phosphate-coated disks in 24-well plates. DFDBA samples with 1.44%, 2.41%, and 5.29% residual calcium; FDBA (30% residual calcium); and control cultures without allograft samples were prepared and all samples incubated for 1 week. Cells were fixed and stained for tartrate-resistant acid phosphatase (TRAP), Oregon Green 488-phalloidin, a stain for cytoskeletal proteins, and counterstained with propidium iodide. Specimens were examined by light and fluorescence microscopy using epi-illumination. Calcium phosphate disks were then rinsed in 5% sodium hypochlorite to remove adherent osteoclasts, and substrate surface changes were measured by white light interferometry and image analysis. RESULTS: A higher yield of TRAP-positive cells was produced without DFDBA; however, resorptive activity appears to be significantly increased in the presence of 2.41% residual calcium as compared to all other experimental groups (P<0.0065). CONCLUSION: In this in vitro model, porcine osteoclasts show significantly more resorptive activity as measured on calcium phosphate-coated disks in the presence of 2.41% residual calcium in DFDBA than in other DFDBA residual calcium levels.