Hi there! This may be not your answer but kind of proof that the periodontal system is working in somehow....Recently , we had a review on the nerve regeneration around implants: A systematic review on the innervation of peri-implant tissues with special emphasis on the influence of implant placement and loading protocols.

The interesting results we found is that while implants were placed, there would be, more or less, nerve regeneration in the surrounding. It is a series of studies focusing on Osseoperception.

Thnx Mr Yan...I was not aware of tht..can u please tell me any reference or any article on d literature regarding this study...

Regards,

Dr Manoj

Hello, Yan Huang,

seems that you lost your -go ;-)

Could you place a link to your article, or even upload it?

edit: found it on your rg-home.

Concerning nerve regeneration in planted teeth two articles of my former teacher Prof. Horst Kirschner, director and head of department for Oral Surgery at the University of Gießen, Germany, from the early 1980ies. There are even some more articles concerning PDL regeneration, I have to look for them...

(in German language)

If I remember correctly, it takes around 9 months until nerv regeneration in the PDL is completed in an extraction-replantation model in monkeys. Prerequisite is to prevent any influence of healing by either necrotic or even infected pulp tissues, or by dental materials used during conventional (delayed, orthograde) root canal treatment (i.e. toxic or otherwise damaging substances like NaOCl or Ca(OH)2, which may escape via the apical foramen into the healing PDL). Thus, the observations are only valid in cases with a prophylactic endo (here: extraoral insertion of posts into the root canal from a retrograde direction).

Unbound MEDLINE

[Micromorphological studies of new nerve formation in peri-implant tissues after auto-alloplastic tooth replantation with carbon fiber-reinforced polysulfone in cynomolgus (Macaca) fascicularis].

Kirschner H, Geiger G

Deutsche Zeitschrift für Mund-, Kiefer- und Gesichts-Chirurgie 9:5 pg 331-5

http://www.unboundmedicine.com/medline/citation/3868461/%5BMicromorphological_studies_of_new_nerve_formation_in_peri_implant_tissues_after_auto_alloplastic_tooth_replantation_with_carbon_fiber_reinforced_polysulfone_in_cynomolgus__Macaca__fascicularis%5D_

[Micromorphological studies of nerve regeneration in the healing desmodont of the crab-eating macaque (Cynomolgus)].

Kirschner H, Michel G

Deutsche zahnärztliche Zeitschrift 37:11 1982 Nov pg 929-36

link: http://www.unboundmedicine.com/medline/citation/6959808/%5BMicromorphological_studies_of_nerve_regeneration_in_the_healing_desmodont_of_the_crab_eating_macaque__Cynomolgus_%5D_

[Histological examination of the regeneration of the periodontium in the Java macaque (Cynomolgus)].

Kirschner H

Bulletin du Groupement international pour la recherche scientifique en stomatologie & odontologie 24:4 1981 Dec pg 255-68

http://www.unboundmedicine.com/medline/citation/6948593/%5BHistological_examination_of_the_regeneration_of_the_periodontium_in_the_Java_macaque__Cynomolgus_%5D_

BTW: there are quite a number of studies with this extraction-replantation- or extraction-transplantation-model, from different working-groups.

Most important authors are Hammer and Axhausen (1930ies),..., Andreasen, Andersson, Armitage, Barbakow, Blomlöf, Cvek, Hammarström, Heithersay, Kirschner, Melcher, Nasjleti, Zachrisson. List definitely incomplete, hope nobody will blame me for not mentioning further important names. Was just a quick recall from my mind, and that is always leaking...

Interesting discussion.

We look to periodontal regeneration from a total different point of view. We're working on equine teeth, which are hypsodont. These teeth are subjected to abrasion/attrition of some mm per year which is compensated by continuous and lifelong eruption. For that reason the PDL has to "remodell" at a very high rate almost every day.

Some colleagues started to treat extracted teeth - apicoectomy and filling of the dental cavity (as good as possible in the large equine teeth). After that the teeth are replaced into the alveolar socket. Most of these teeth become defintely reattached by an ligamtentous structure (no ankylosis) and - remarkably - start to erupt again at a normal rate. These first clinical observations suggest that - in the horse - we do see an astonishing regeneration of the PDL not just an reparation.

Hi, Carsten,

two topics, related and therefore somewhat mixed together.

** of common interest **

[ of interest for the scientist in/the inhabitant of Gießen ]

**Oh no, I'm quite familiar with your view. It is mine since 30 years - as it is of every dentist who is interested in dental traumatology. Gießen seems to be a breeding point for this topic. And there are even some relations to the veterinary clinic.**

[ One of my former colleagues in Gießen studied veterinary medicine, worked at the clinic there, and later studied dentistry and then worked at the department for oral surgery lateron. His scientific interest was comparing species in regard of different dental aspects. He is one of the co-authors of the above-mentioned articles (Gerd Geiger). He has retired some years ago, and I lost contact.

Already in the 1960ies Prof. Keil (?), at that time at the "Dental Institute", which lateron developed to the Medical Centre of Dentistry at the University, worked on a similar topic. In the building of the Dental Clinic there are still some examples of teeth of different animals exposed.]

**In humans (and in animals as well, the typical species used for experiments are monkeys, dogs, rats, and I guess it is the same issue for horses as well) it is depended on the combination of time and storage conditions during the extraoral / extraalveolar period whether you get regeneration (we call it functional healing: while on a histologic level it is still not clear whether there is a complete regeneration of all tissues, yet the tooth is functioning as it would be sound, main criterium is the continued growth of the alveolar process, or, in horses, continued eruption) or whether you get reparation (ankylosis/replacement resorption with the consequence of a cessation of alveolar growth or, in horses, cessation of eruption).**

**I have quite a good knowledge on that topic, my doctorate and my habilitation (see links at the end of this post) are on dental trauma, in particular tooth avulsion, extraoral storage, treatment of the damaged periodontal ligament, replantation and transplantation. In humans. And that is also my favorite topic in daily work. In humans, teeth are of extraordinary importance for facial esthetics. Mainly children sustain injuries to their teeth, and definite dental treatment to replace a lost tooth is mostly not possible before the end of growth. Thus, tooth trauma/tooth avulsion and the treatment are of high interest.

Meanwhile we have a storage medium ( a real tissue culture medium, not only a salt solution) readily available, storable at room temperature, with a shelf life of 3 years, which allows the storage of avulsed teeth for at least 48 hours (according to experiments) and up to 53 hours clinically (longest storage time observed up to now) without compromising the healing. This medium is available as so called tooth rescue box (a little flask containing 20ml medium) and can be bought in pharmacies (around 15 Eur). Thanks to sponsoring and special prices meanwhile all schools in most states in Germany are equipped with these boxes. Maybe we overlooked to equip horse stables as well ;-) The sad thing is that accidents with horses result in very bad injuries for the patients.**

[ Does the "Pferdestall" still exist? Used to be there once a week, they had the best ribs of Gießen there. ]

**Furtheron we use some medicaments (corticoids, tetracyclines, enamel matrix derivative) to support periodontal healing/to suppress unwanted resorption activities. We use a special bur-post-sytem to perform a - very easy, very fast and very safe - prophylactic endodontic treatment to avoid any infection of the root canal. Which is in my eyes a prerequisite for healing and for the applied medicaments to work as expected.**

[ All that is based on the scientific and clinical work of Prof. Kirschner, who is living just about 500 m from your clinic, and who had and has terrifically good ideas, an exceptional knowledge and special interest in oral biology/pathology. Since he has retired he is quite often abroad; therefore I lost contat last year, but I'm just about to reestablish that - he was always an excellent source for knowledge and ideas. ]

[ I was not aware that this topic is of interest also for horses/animals. And I don't have much knowledge about the teeth of animals (despite those studies of Geiger). Nevertheless, the healing prerequisites should be not too different, as far as I learned from your post. Thus, perhaps we could exchange some knowledge. Since my family still resides in Gießen, I'm spending my weekends (well, most of them) there - and sometimes a day during the week...]

A selection of articles of possible interest

https://www.researchgate.net/publication/7960856_Results_after_replantation_of_avulsed_permanent_teeth._I._Endodontic_considerations?ev=prf_pub

https://www.researchgate.net/publication/7960857_Results_after_replantation_of_avulsed_permanent_teeth._II._Periodontal_healing_and_the_role_of_physiologic_storage_and_antiresorptive-regenerative_therapy?ev=prf_pub

https://www.researchgate.net/publication/7960858_Results_after_replantation_of_avulsed_permanent_teeth._III._Tooth_loss_and_survival_analysis?ev=prf_pub

https://www.researchgate.net/publication/6722359_Treatment_of_replacement_resorption_by_intentional_replantation_resection_of_the_ankylosed_sites_and_Emdogain--results_of_a_6-year_survey?ev=prf_pub

https://www.researchgate.net/publication/6620760_Interrelation_between_endodontic_status_pathologic_cemental_granules_and_periodontal_ligament_adhering_to_the_root_of_extracted_teeth?ev=prf_pub

https://www.researchgate.net/publication/23188263_Practicability_of_a_tooth_rescue_concept--the_use_of_a_tooth_rescue_box?ev=prf_pub

https://www.researchgate.net/publication/5675699_Expression_of_proliferating_cell_nuclear_antigen_in_pulp_cells_of_extracted_immature_teeth_preserved_in_two_different_storage_media?ev=prf_pub

Kind regards

Yango

Article Results after replantation of avulsed permanent teeth. I. En...

Article Results after replantation of avulsed permanent teeth. II. P...

Article Results after replantation of avulsed permanent teeth. III. ...

Article Treatment of replacement resorption by intentional replantat...

Article Interrelation between endodontic status, pathologic cemental...

Article Practicability of a tooth rescue concept - The use of a toot...

Article Expression of proliferating cell nuclear antigen in pulp cel...

Yes It works provided you respect few key aspects regarding patient's overall systemic condition, environmental factors such as smoking and local factors such as dimensions of the defect such as depth, width and remaining walls etc. Last but not the least, appropriate surgical technique and handling of tissues.

I agree with Muhammad. I can answer Your question, Manoj, paraphrasing the president of USA: "Yes it can". As for all aspects of periodontology, there are some conditions. Most important are proper selection (of the patient, of the techniques utilised etc.), host response (risk factors evaluation, also the potential of healing an independent variable, I hope that not for long) and cooperation (patient's ability to maintain proper hygiene in a long term, his/her discipline in attending control visits). In general: 1) histological studies show that regeneration works; 2) we cannot guarantee the patient it will work in his case. We can just both (us and patient) do our best for it to let it happen. I hope it will help You, Manoj. Kind regards.

I agree with Muhammad Haseeb and Dimitris N Tatakis. It does works, but certain aspects must be evaluated before choosing a method. Check our paper on a topographically complex space maintainer device for periodontal regeneration (animal model). Periodontal regeneration using a bilayered PLGA/calcium phosphate construct. Emily C. Carlo Reis, Andréa P.B. Borges, Michel V.F. Araújo, Vanessa C. Mendes, Limin Guan, .John E. Davies. Biomaterials 32 (2011) 9244-9253.

Manoj,

The answer to your question and can be found in the classic 3 part Bowers HENA studies.

 J Periodontol. 1989 Dec;60(12):664-74.

Histologic evaluation of new attachment apparatus formation in humans. Part I.

Bowers GM1, Chadroff B, Carnevale R, Mellonig J, Corio R, Emerson J, Stevens M, Romberg E.

Abstract

Part I of this three-part human study evaluated the formation of a new attachment apparatus (bone, cementum, and periodontal ligament) on pathologically exposed root surfaces in an open and closed environment. The most apical level of calculus on the root served as a histologic reference point to measure regeneration on root surfaces exposed to the oral environment. Attempts were made to initiate the formation of a new attachment apparatus by flap curettage, root planing, coronectomy, and submersion of vital roots beneath the mucosa. Nonsubmerged defects were treated by the same surgical technique and served as controls. Biopsies were obtained at 6 months and regeneration was evaluated histometrically by two investigators who were unaware of the treatment performed. Data from 9 patients with 25 submerged and 22 nonsubmerged defects were submitted for statistical analysis. Results indicate that a new attachment apparatus did not form in any of the 22 nonsubmerged teeth; a new attachment apparatus did form in a submerged environment (0.75 mm); significantly more new attachment apparatus (P less than 0.05), new cementum (P less than 0.01), new connective tissue (P less than 0.05), and new bone (P less than 0.02) formed in submerged defects; new cementum was cellular in nature and formed equally well on old cementum and dentin. Greater percent positive regeneration of the attachment apparatus and all component tissues occurred in submerged defects and no extensive root resorption, ankylosis, or pulp death was observed on submerged or nonsubmerged roots.

J Periodontol. 1989 Dec;60(12):675-82.

Histologic evaluation of new attachment apparatus formation in humans. Part II.

Bowers GM1, Chadroff B, Carnevale R, Mellonig J, Corio R, Emerson J, Stevens M, Romberg E.

Abstract

There is conflicting evidence regarding the value of graft materials in enhancing the formation of new bone, cementum, and periodontal ligament (new attachment apparatus). Part II of this study compared the healing of intrabony defects with and without the placement of decalcified freeze-dried bone allograft (DFDBA) in a submerged environment. The most apical level of calculus on the root served as a histologic reference point to measure regeneration on root surfaces exposed to the oral environment. Biopsies were obtained at 6-months and evaluated histometrically by two investigators unaware of the treatment performed. Data from 9 patients with 30 grafted defects and 13 nongrafted defects were submitted for statistical analysis. Results indicate that in a submerged environment significantly more new attachment apparatus (P less than .05) and new bone (P less than .05) formed in grafted than nongrafted sites. Significantly greater loss of alveolar crest height occurred in nongrafted than grafted defects (P less than .05); regeneration of new attachment apparatus, new bone, and new cementum occurred more frequently in grafted than nongrafted defects. There was a greater chance for the regeneration of a connective tissue attachment in nongrafted intrabony defects than in grafted defects; new cellular cementum formed equally well on old cementum, dentin, or both old cementum and dentin in the same defect. The periodontal ligament was oriented parallel, perpendicular, or both parallel and perpendicular in the same defect; and, no extensive root resorption, ankylosis, or pulp death was observed in grafted or nongrafted defects.

J Periodontol. 1989 Dec;60(12):683-93.

Histologic evaluation of new attachment apparatus formation in humans. Part III.

Bowers GM1, Chadroff B, Carnevale R, Mellonig J, Corio R, Emerson J, Stevens M, Romberg E.

Abstract

There is still controversy as to the role of bone grafting materials in the formation of a new attachment apparatus and component tissues (bone, cementum, and periodontal ligament). The purpose of this study was to compare the healing of intrabony defects with and without the placement of decalcified freeze-dried bone allograft (DFDBA) in a nonsubmerged environment in humans. The most apical level of calculus on the root served as a histologic reference point to delineate root surfaces exposed to the oral environment and to measure new attachment apparatus and new component tissue formation. Free gingival grafts were placed over grafted and nongrafted defects to retard epithelial migration. Biopsies were obtained at 6 months and regeneration was evaluated histometrically. Data from 12 patients with 32 grafted and 25 nongrafted defects were submitted for statistical analysis. Results indicate that in nongrafted defects, a long junctional epithelium formed along the entire length of exposed root surfaces and often extended apical to the calculus reference notch. Free gingival grafts did not enhance regeneration of a new attachment apparatus, new cementum, new connective tissue, or new bone in nongrafted defects. The formation of a new attachment apparatus was observed when intrabony defects were grafted with DFDBA (x1.21 mm); significantly more new attachment apparatus (P less than .005), new cementum (P less than .005), new connective tissue (P less than .05), and new bone (P less than .0001) formed in intrabony defects grafted with DFDBA than in nongrafted defects. There was a greater chance for regeneration of a new attachment apparatus and component tissues in grafted defects than in nongrafted defects. New cellular cementum formed on old cementum and dentin but more often formed over both in the same defect). The periodontal ligament was more frequently oriented perpendicular to the root; there was greater loss in alveolar crest height in nongrafted than grafted defects (P less than .05); and extensive root resorption, ankylosis, and pulp death were not observed in grafted or nongrafted defects.