Avinoam Yaffe - Academia.edu (original) (raw)

Papers by Avinoam Yaffe

Research paper thumbnail of A modified cavity preparation for restoring interproximal caries

Compendium (Newtown, Pa.), 1987

Research paper thumbnail of Strain Reduction of Human Gingival Fibroblasts Induces the ATP Pathway

JBR Journal of Interdisciplinary Medicine and Dental Science, 2015

Studies in rats demonstrated that surgical detachment of marginal gingiva from root surfaces indu... more Studies in rats demonstrated that surgical detachment of marginal gingiva from root surfaces induced alveolar bone resorption via activation of ATP receptor P2X4. Our aim was to study the effects of strain release of human gingival fibroblasts by detachment of collagen coat from culture dishes. Changes in cell shape, extracellular ATP, cell calcium and genes relevant to trigger alveolar bone resorption were measured. HGF cells from human marginal gingiva explants were seeded on collagen coated culture dishes. In the test group, the collagen coat was detached from culture dish 4-5 days after seeding. Quantification of extracellular ATP was measured by Bioluminescent Assay Kit and changes of intracellular calcium by FLU-AM fluorescence. Real-time PCR was used to examine expression of purinergic receptor P2X4 and P2X7, RANK-L and STC1. Cell length of HGFs grown on plastic surface and on collagen was similar. Reduction in cell length of 45% was measured after detachment of collagen coat. Extracellular ATP raised 10 folds 1 minute after detachment of collagen coat, then declined and returned to control levels 60 minutes later. Ionomycin increased extracellular ATP, while, pretreatment by EGTA, or BAPTA-AM, 30 minutes prior to Ionomycin, reduced significantly extracellular ATP. Reciprocally, addition of ATP increased influx of calcium into HGFs. At the molecular level elevated expression of STC-1, RANK-L and P2X7 was recorded by RT-PCR in detached HGFs, while expression of P2X4 was unchanged. Expression of STC-1, a modulator of cellular calcium and phosphate, P2X7 a calcium ionic channel purinergic receptor and RANK-L a powerful regulator of osteoclastic activity, all were up-regulated significantly. Conclusion: We propose that drop of strain of HGF cells and change in their shape stimulated release of cellular ATP which is signaling through Pi/Ca modulators the molecular activation of osteoclasts.

Research paper thumbnail of Restoration of Periodontal Attachment Employing Enriched Collagen Solution in the Dog*

Journal of Periodontology, 1984

Three wall intrabony defects were produced in 11 dogs using a round bur followed by curettes and ... more Three wall intrabony defects were produced in 11 dogs using a round bur followed by curettes and hoes. A copper band was fixed to the tooth with stainless steel ligature wire. Six weeks later, the copper band was removed and the defect was treated with an enriched collagen solution (ECS) prepared from acid-extracted dog skin collagen. Thirty-three defects were treated with ECS and 33 defects were controls. Healing was assessed histologically 4 and 6 weeks after treatment for the presence of new cementum, periodontal ligament and alveolar bone, as well as arrested epithelial downgrowth along the dental root. Unlike the controls, treatment with ECS resulted in restoration of periodontal attachment after 4 weeks. This included formation of new cementum, new alveolar bone and dense connective tissue fiber running between bone and cementum. Control sections showed epithelial migration along the root, separating it from the adjacent connective tissue and thus preventing new attachment.

Research paper thumbnail of Dysfunctional Habit Patterns

Research paper thumbnail of Extracellular ATP is a key modulator of alveolar bone loss in periodontitis

Archives of oral biology, Jan 13, 2017

Periodontal diseases are initiated by pathogenic bacterial biofilm activity that induces a host i... more Periodontal diseases are initiated by pathogenic bacterial biofilm activity that induces a host inflammatory cells immune response, degradation of dento gingival fibrous tissue and its detachment from root cementum. It is well accepted, that osteoclastic alveolar bone loss is governed exclusively through secretion of proinflammatory cytokines. Nevertheless, our findings suggest that once degradation of collagen fibers by MMPs occurs, a drop of cellular strains cause immediate release of ATP from marginal gingival fibroblasts, cell deformation and influx of Ca+2. Increased extracellular ATP (eATP) by interacting with P2×7 purinoreceptors, present on fibroblasts and osteoblasts, induces generation of receptor activator of nuclear factor kB ligand (RANKL) that further activates osteoclastic alveolar bone resorption and bone loss. In addition, increased eATP levels may amplify inflammation by promoting leukocyte recruitment and NALP3-inflammasome activation via P2×7. Then, the inflammat...

Research paper thumbnail of Contribution of Oral Habits to Dental Disorders

CRANIO®, 1992

Oral habits or parafunction may contribute to dental, periodontal, or neuromuscular damage. Such ... more Oral habits or parafunction may contribute to dental, periodontal, or neuromuscular damage. Such habits, of which the patient is often unaware, may cause considerable damage. Habits may be occlusal or non-occlusal, and may affect the dentition and/or the oral soft tissues. Drawing a patient's attention to the damage caused by some habits of which he or she is unaware often leads to cessation, whereas with certain conscious habits, such as nail or finger biting, success is much more limited.

Research paper thumbnail of Device and Method for Gingival Attachment Associated with Endosseous Implants

Research paper thumbnail of Topical Bisphosphonates for Prevention of Bone Resorption

Research paper thumbnail of Tissue engineering of bone: an ectopic rat model

Frontiers in Bioscience, 2011

Research paper thumbnail of The effects of mechanical loading on hard and soft tissues and cells

Biological mechanisms of tooth movement, 2015

Research paper thumbnail of Un commentaire sur : le mouvement orthodontique accéléré par stimulation ostéogénique du parodonte – une alternative clinique

International Orthodontics, 2010

It is apparent that tooth movement is enhanced by procedures that elevate the remodeling of alveo... more It is apparent that tooth movement is enhanced by procedures that elevate the remodeling of alveolar bone, and of periodontal and gingival fibrous tissues. The periodontally accelerated osteogenic orthodontics (PAOO) also termed as Wilckodontics, involves full-thickness labial and lingual alveolar flaps accompanied with limited selective labial and lingual surgical scarring of cortical bone (corticotomy). Most of the authors suggest that the RAP is the major stimulus for alveolar bone remodeling, enabling the PAOO. However, we propose that detachment of the bulk of dentogingival and interdental fibers from coronal part of root surfaces by itself should suffice to stimulate alveolar bone resorption mainly on its PDL surfaces, leading to widening of the periodontal ligament space which largely attributes to accelerated osteogenic orthodontics. Moreover this limited fiberotomy also disrupts transiently the positional physical memory of dentition (PPMD), allowing accelerated tooth movement.

Research paper thumbnail of Physiologic occlusion vs pathologic occlusion and rationale for treatment

Compendium of continuing education in dentistry (Jamesburg, N.J. : 1995), 1996

Treatment concepts in dentistry are generally based on a preconceived normal state derived from c... more Treatment concepts in dentistry are generally based on a preconceived normal state derived from clinical observation and theories rather than scientific evidence. Before treatment is proposed, the clinician should observe physiologic signs and symptoms to determine the presence of a particular pathology. This article presents different theories of occlusion, diagnostic characteristics that can be used to distinguish between physiologic occlusion and pathologic occlusion requiring treatment, and guidelines for reconstructive occlusal therapy.

Research paper thumbnail of Crown contour variation in gingival health

The Compendium of continuing education in dentistry

Research paper thumbnail of Rehabilitation of anterior teeth--esthetics and functional considerations

Quintessence international, dental digest, 1984

Research paper thumbnail of Functional and esthetic rehabilitation of an adolescent cleft lip and palate patient

Quintessence international (Berlin, Germany : 1985), 1991

Many patients with clefts that also affect the alveolar ridge present with congenital absence of ... more Many patients with clefts that also affect the alveolar ridge present with congenital absence of the permanent maxillary lateral incisors. This paper describes the treatment of an adolescent cleft lip and palate patient whose missing and unesthetic maxillary incisors were replaced by a combination of fixed and removable partial dentures.

Research paper thumbnail of Occlusal traumatism as a factor in periodontal disease and tooth loss

Refuʾat ha-peh ṿeha-shinayim (Tel Aviv, Israel : 1969), 1976

Research paper thumbnail of Tissue Engineering of Bone: Critical Evaluation of Scaffold Selection

Research paper thumbnail of Commentary on: Periodontally accelerated osteogenic orthodontics (PAOO) – a clinical dilemma

International Orthodontics, 2010

It is apparent that tooth movement is enhanced by procedures that elevate the remodeling of alveo... more It is apparent that tooth movement is enhanced by procedures that elevate the remodeling of alveolar bone, and of periodontal and gingival fibrous tissues. The periodontally accelerated osteogenic orthodontics (PAOO) also termed as Wilckodontics, involves full-thickness labial and lingual alveolar flaps accompanied with limited selective labial and lingual surgical scarring of cortical bone (corticotomy). Most of the authors suggest that the RAP is the major stimulus for alveolar bone remodeling, enabling the PAOO. However, we propose that detachment of the bulk of dentogingival and interdental fibers from coronal part of root surfaces by itself should suffice to stimulate alveolar bone resorption mainly on its PDL surfaces, leading to widening of the periodontal ligament space which largely attributes to accelerated osteogenic orthodontics. Moreover this limited fiberotomy also disrupts transiently the positional physical memory of dentition (PPMD), allowing accelerated tooth movement. During retention period, a new biological and physical connectivity is generated that could be termed as new positional memory of the dental arch.

Research paper thumbnail of Prosthodontics in Clinical Practice

1. Dysfunctional Habit Patterns 2. Periodontal Breakdown 3. Extensive Loss of Teeth 4. Congenital... more 1. Dysfunctional Habit Patterns 2. Periodontal Breakdown 3. Extensive Loss of Teeth 4. Congenital Disorders

Research paper thumbnail of Fiberotomy enhances orthodontic tooth movement and diminishes relapse in a rat model

Orthodontics & Craniofacial Research, 2013

Objectives-Accelerated orthodontic tooth movement is triggered by procedures that include mucoper... more Objectives-Accelerated orthodontic tooth movement is triggered by procedures that include mucoperiosteum flap surgery and surgical scarring of cortical bone. Our aim was to test whether fiberotomy by itself will accelerate orthodontic tooth movement and diminish relapse. Materials and Methods-In 34 Wistar rats, alveolar bone resorption and molar tooth movement were measured after fiberotomy, apical full-thickness flap without detachment of gingiva from the roots, or no surgery. Orthodontic appliance was installed at time of surgery and activated for 14 days, generating movement of the first maxillary molar buccal and then removed. Results-Percent of sections in which alveolar bone resorption was detected was significantly higher (p < 0.05) after fiberotomy (27%) in comparison with apical flap surgery (12%) or no surgery (6%), after 30 days. Also, at the end of active phase, the molar moved significantly faster (p < 0.01) and twice the distance after fiberotomy (0.54 AE 0.33) in comparison with apical surgery (0.26 AE 0.12) or no surgery (0.3 AE 0.09). Sixteen days after the appliance was removed, only 12% relapse was recorded in the fiberotomy group, while almost total relapse in other two groups. Conclusion-We conclude that fiberotomy solely accelerated orthodontic tooth movement and diminished relapse.

Research paper thumbnail of A modified cavity preparation for restoring interproximal caries

Compendium (Newtown, Pa.), 1987

Research paper thumbnail of Strain Reduction of Human Gingival Fibroblasts Induces the ATP Pathway

JBR Journal of Interdisciplinary Medicine and Dental Science, 2015

Studies in rats demonstrated that surgical detachment of marginal gingiva from root surfaces indu... more Studies in rats demonstrated that surgical detachment of marginal gingiva from root surfaces induced alveolar bone resorption via activation of ATP receptor P2X4. Our aim was to study the effects of strain release of human gingival fibroblasts by detachment of collagen coat from culture dishes. Changes in cell shape, extracellular ATP, cell calcium and genes relevant to trigger alveolar bone resorption were measured. HGF cells from human marginal gingiva explants were seeded on collagen coated culture dishes. In the test group, the collagen coat was detached from culture dish 4-5 days after seeding. Quantification of extracellular ATP was measured by Bioluminescent Assay Kit and changes of intracellular calcium by FLU-AM fluorescence. Real-time PCR was used to examine expression of purinergic receptor P2X4 and P2X7, RANK-L and STC1. Cell length of HGFs grown on plastic surface and on collagen was similar. Reduction in cell length of 45% was measured after detachment of collagen coat. Extracellular ATP raised 10 folds 1 minute after detachment of collagen coat, then declined and returned to control levels 60 minutes later. Ionomycin increased extracellular ATP, while, pretreatment by EGTA, or BAPTA-AM, 30 minutes prior to Ionomycin, reduced significantly extracellular ATP. Reciprocally, addition of ATP increased influx of calcium into HGFs. At the molecular level elevated expression of STC-1, RANK-L and P2X7 was recorded by RT-PCR in detached HGFs, while expression of P2X4 was unchanged. Expression of STC-1, a modulator of cellular calcium and phosphate, P2X7 a calcium ionic channel purinergic receptor and RANK-L a powerful regulator of osteoclastic activity, all were up-regulated significantly. Conclusion: We propose that drop of strain of HGF cells and change in their shape stimulated release of cellular ATP which is signaling through Pi/Ca modulators the molecular activation of osteoclasts.

Research paper thumbnail of Restoration of Periodontal Attachment Employing Enriched Collagen Solution in the Dog*

Journal of Periodontology, 1984

Three wall intrabony defects were produced in 11 dogs using a round bur followed by curettes and ... more Three wall intrabony defects were produced in 11 dogs using a round bur followed by curettes and hoes. A copper band was fixed to the tooth with stainless steel ligature wire. Six weeks later, the copper band was removed and the defect was treated with an enriched collagen solution (ECS) prepared from acid-extracted dog skin collagen. Thirty-three defects were treated with ECS and 33 defects were controls. Healing was assessed histologically 4 and 6 weeks after treatment for the presence of new cementum, periodontal ligament and alveolar bone, as well as arrested epithelial downgrowth along the dental root. Unlike the controls, treatment with ECS resulted in restoration of periodontal attachment after 4 weeks. This included formation of new cementum, new alveolar bone and dense connective tissue fiber running between bone and cementum. Control sections showed epithelial migration along the root, separating it from the adjacent connective tissue and thus preventing new attachment.

Research paper thumbnail of Dysfunctional Habit Patterns

Research paper thumbnail of Extracellular ATP is a key modulator of alveolar bone loss in periodontitis

Archives of oral biology, Jan 13, 2017

Periodontal diseases are initiated by pathogenic bacterial biofilm activity that induces a host i... more Periodontal diseases are initiated by pathogenic bacterial biofilm activity that induces a host inflammatory cells immune response, degradation of dento gingival fibrous tissue and its detachment from root cementum. It is well accepted, that osteoclastic alveolar bone loss is governed exclusively through secretion of proinflammatory cytokines. Nevertheless, our findings suggest that once degradation of collagen fibers by MMPs occurs, a drop of cellular strains cause immediate release of ATP from marginal gingival fibroblasts, cell deformation and influx of Ca+2. Increased extracellular ATP (eATP) by interacting with P2×7 purinoreceptors, present on fibroblasts and osteoblasts, induces generation of receptor activator of nuclear factor kB ligand (RANKL) that further activates osteoclastic alveolar bone resorption and bone loss. In addition, increased eATP levels may amplify inflammation by promoting leukocyte recruitment and NALP3-inflammasome activation via P2×7. Then, the inflammat...

Research paper thumbnail of Contribution of Oral Habits to Dental Disorders

CRANIO®, 1992

Oral habits or parafunction may contribute to dental, periodontal, or neuromuscular damage. Such ... more Oral habits or parafunction may contribute to dental, periodontal, or neuromuscular damage. Such habits, of which the patient is often unaware, may cause considerable damage. Habits may be occlusal or non-occlusal, and may affect the dentition and/or the oral soft tissues. Drawing a patient's attention to the damage caused by some habits of which he or she is unaware often leads to cessation, whereas with certain conscious habits, such as nail or finger biting, success is much more limited.

Research paper thumbnail of Device and Method for Gingival Attachment Associated with Endosseous Implants

Research paper thumbnail of Topical Bisphosphonates for Prevention of Bone Resorption

Research paper thumbnail of Tissue engineering of bone: an ectopic rat model

Frontiers in Bioscience, 2011

Research paper thumbnail of The effects of mechanical loading on hard and soft tissues and cells

Biological mechanisms of tooth movement, 2015

Research paper thumbnail of Un commentaire sur : le mouvement orthodontique accéléré par stimulation ostéogénique du parodonte – une alternative clinique

International Orthodontics, 2010

It is apparent that tooth movement is enhanced by procedures that elevate the remodeling of alveo... more It is apparent that tooth movement is enhanced by procedures that elevate the remodeling of alveolar bone, and of periodontal and gingival fibrous tissues. The periodontally accelerated osteogenic orthodontics (PAOO) also termed as Wilckodontics, involves full-thickness labial and lingual alveolar flaps accompanied with limited selective labial and lingual surgical scarring of cortical bone (corticotomy). Most of the authors suggest that the RAP is the major stimulus for alveolar bone remodeling, enabling the PAOO. However, we propose that detachment of the bulk of dentogingival and interdental fibers from coronal part of root surfaces by itself should suffice to stimulate alveolar bone resorption mainly on its PDL surfaces, leading to widening of the periodontal ligament space which largely attributes to accelerated osteogenic orthodontics. Moreover this limited fiberotomy also disrupts transiently the positional physical memory of dentition (PPMD), allowing accelerated tooth movement.

Research paper thumbnail of Physiologic occlusion vs pathologic occlusion and rationale for treatment

Compendium of continuing education in dentistry (Jamesburg, N.J. : 1995), 1996

Treatment concepts in dentistry are generally based on a preconceived normal state derived from c... more Treatment concepts in dentistry are generally based on a preconceived normal state derived from clinical observation and theories rather than scientific evidence. Before treatment is proposed, the clinician should observe physiologic signs and symptoms to determine the presence of a particular pathology. This article presents different theories of occlusion, diagnostic characteristics that can be used to distinguish between physiologic occlusion and pathologic occlusion requiring treatment, and guidelines for reconstructive occlusal therapy.

Research paper thumbnail of Crown contour variation in gingival health

The Compendium of continuing education in dentistry

Research paper thumbnail of Rehabilitation of anterior teeth--esthetics and functional considerations

Quintessence international, dental digest, 1984

Research paper thumbnail of Functional and esthetic rehabilitation of an adolescent cleft lip and palate patient

Quintessence international (Berlin, Germany : 1985), 1991

Many patients with clefts that also affect the alveolar ridge present with congenital absence of ... more Many patients with clefts that also affect the alveolar ridge present with congenital absence of the permanent maxillary lateral incisors. This paper describes the treatment of an adolescent cleft lip and palate patient whose missing and unesthetic maxillary incisors were replaced by a combination of fixed and removable partial dentures.

Research paper thumbnail of Occlusal traumatism as a factor in periodontal disease and tooth loss

Refuʾat ha-peh ṿeha-shinayim (Tel Aviv, Israel : 1969), 1976

Research paper thumbnail of Tissue Engineering of Bone: Critical Evaluation of Scaffold Selection

Research paper thumbnail of Commentary on: Periodontally accelerated osteogenic orthodontics (PAOO) – a clinical dilemma

International Orthodontics, 2010

It is apparent that tooth movement is enhanced by procedures that elevate the remodeling of alveo... more It is apparent that tooth movement is enhanced by procedures that elevate the remodeling of alveolar bone, and of periodontal and gingival fibrous tissues. The periodontally accelerated osteogenic orthodontics (PAOO) also termed as Wilckodontics, involves full-thickness labial and lingual alveolar flaps accompanied with limited selective labial and lingual surgical scarring of cortical bone (corticotomy). Most of the authors suggest that the RAP is the major stimulus for alveolar bone remodeling, enabling the PAOO. However, we propose that detachment of the bulk of dentogingival and interdental fibers from coronal part of root surfaces by itself should suffice to stimulate alveolar bone resorption mainly on its PDL surfaces, leading to widening of the periodontal ligament space which largely attributes to accelerated osteogenic orthodontics. Moreover this limited fiberotomy also disrupts transiently the positional physical memory of dentition (PPMD), allowing accelerated tooth movement. During retention period, a new biological and physical connectivity is generated that could be termed as new positional memory of the dental arch.

Research paper thumbnail of Prosthodontics in Clinical Practice

1. Dysfunctional Habit Patterns 2. Periodontal Breakdown 3. Extensive Loss of Teeth 4. Congenital... more 1. Dysfunctional Habit Patterns 2. Periodontal Breakdown 3. Extensive Loss of Teeth 4. Congenital Disorders

Research paper thumbnail of Fiberotomy enhances orthodontic tooth movement and diminishes relapse in a rat model

Orthodontics & Craniofacial Research, 2013

Objectives-Accelerated orthodontic tooth movement is triggered by procedures that include mucoper... more Objectives-Accelerated orthodontic tooth movement is triggered by procedures that include mucoperiosteum flap surgery and surgical scarring of cortical bone. Our aim was to test whether fiberotomy by itself will accelerate orthodontic tooth movement and diminish relapse. Materials and Methods-In 34 Wistar rats, alveolar bone resorption and molar tooth movement were measured after fiberotomy, apical full-thickness flap without detachment of gingiva from the roots, or no surgery. Orthodontic appliance was installed at time of surgery and activated for 14 days, generating movement of the first maxillary molar buccal and then removed. Results-Percent of sections in which alveolar bone resorption was detected was significantly higher (p < 0.05) after fiberotomy (27%) in comparison with apical flap surgery (12%) or no surgery (6%), after 30 days. Also, at the end of active phase, the molar moved significantly faster (p < 0.01) and twice the distance after fiberotomy (0.54 AE 0.33) in comparison with apical surgery (0.26 AE 0.12) or no surgery (0.3 AE 0.09). Sixteen days after the appliance was removed, only 12% relapse was recorded in the fiberotomy group, while almost total relapse in other two groups. Conclusion-We conclude that fiberotomy solely accelerated orthodontic tooth movement and diminished relapse.