Regenerative Endodontics

Transcription

1 Regenerative Endodontics Dental infections in immature teeth: ü Arrested dental development ü Premature tooth loss Classic Treatments: 1. Conventional Root Canal Therapy -Teeth no longer develop becoming susceptible to fractures and re-infections Anibal R Diogenes, DDS, MS, PhD diogenes@uthscsa.edu 2. Extractions Impairs function, cranio-skeletal development and leads to severe psychosocial deficits Implant therapy is contraindicated Premature Tooth Loss and Implant Placement 4yr after implant Root formation 1) Patient traumatized central incisor #8 in a bicycle accident when he was 10 2) A root canal therapy in the tooth that was still undergoing development 3) At age 13, he re-traumatized #8 while playing basketball 4) Tooth was extracted and replaced with an implant Case courtesy of Dr. Bloyce Britton (Britton Orthodontics)- San Antonio, TX 1

2 Regenerative Endodontics Biologically-based procedures designed to replace damaged structures, including dentin and root structures, as well as cells of the pulp-dentin complex Regenerative Endodontic Procedures (REPs) First reported in 2001 Performed in multiple visits Most procedures rely on intracanal bleeding and formation of a blood clot 2

3 Bleeding in REPs Pioneer Study No Bleeding Bleeding 29yo Male with pulpal necrosis, bleeding established Fibrous C.T. 23% Pre-op 14 months 2mm Cementum Kontakiotis EG. et al., J Endodon 77% Open Apex Just before extraction Nygaard-Ostby Acta Odont Scan 19:323, 1961 Collagen Bundles in main canal In the 2000 s Regenerative Endodontics Used Double Antibiotic (Ciprofloxacin and Metronidazole) Used Triple Antibiotic (Ciprofloxacin, Minocycline and Metronidazole) Pre-op 5mo 30mo Iwaya et al., 2001 Pre-op 18mo Banchs and Trope 2004 Pre-OP 1 year recall 4 years recall EPT + EPT + Cold + Diogenes et al., JADA

4 4 year recall CBCT Contemporary REP 11 year old female patient with history of pain and swelling related to tooth #20 Coronal view Sagittal view Diogenes et al., JADA 2016 Courtesy of Dr. Jeeraphat Jantarat (Mahidol University, Thailand) Long-Term Follow-up 11 yo with failed direct pulp capping EPT Cold + EPT Cold + Pre-OP 1 year recall 3years recall Pre-Op WL Intracanal medicament Courtesy of Dr. Jeeraphat Jantarat (Mahidol University, Thailand) Post-OP 7 month recall Case by Dr. Alelyani (1 st year resident UTHSCSA) 4

5 ARE REPS STEM CELL-BASED THERAPIES? STEM CELLS Lovelace et al., 2011 J Endodon Chrepa et al., 2016 JDR STEM CELLS Cells with the ability to divide for indefinite periods in culture and to give rise to specialized cells (NIH) 1- Self Renewal 2-Differentiate into more specialized cells Oh and Nor, Front Physiol 5

6 DIFFERENT POTENCIES OF STEM CELLS Totipotent can make all cells in a body plus the extraembryonic cells that are required for maintenance of life, such as the plascenta Example: Embryonic cells up to 2 cell divisions after fertilization Pluripotent-can make all cells in a body (all three germ layers). Example : Embryonic cells and induced pluripotent cells (ipscs) Multipotent can develop into more that a cell type (from a single germ layer) but not all cells in a body Example : Adult stem cell (including all oral stem cells ) and cord blood stem cells ARE STEM CELLS DELIVERED INTO THE RC SYSTEM? Local Stem Cell Delivery Lovelace et al., JOE

7 ADD VAMPIRE 2! STEM CELLS LIKELY INVOLVED IN REPS DPSCs BMSCs: Bennet et al., 1991 ( J Cell Sci) DPSCS : Gronthos et al., 2000(PNAS) PDLSCs: Gronthos et al., 2000 (PNAS) SCAP: Sonoyama et al., 2006 ( PLoS One) IPAPCs: Liao et al., 2011 ( J Endodon) SCAP BMSCs ipapcs PDLSCs Diogenes et al., Endodontic Topics 2013 Fate of Apical Papilla in Pulpal Necrosis Is it still viable? Understanding the Niche 7

8 Apical Papilla Survival and Apical Periodontitis Apical Papilla Survival and Apical Periodontitis J Endodon, 2014 Surviving Apical Papilla 90 days after pulpal exposure Substantial Inflammatory Infiltrate within the apical papilla Complete Liquefaction Necrosis of the pulp Da Palma, Diogenes et al J Endodon 2011 MECHANICAL DISRUPTION OF APICAL TISSUES Trauma and the mechanical disruption of apical tissues ( intentional evoked trauma ) have the potential to separate vital apical papilla and Hertwig s root sheath from the root end Chrepa, Pitcher and Diogenes J Endodon 8

9 Chrepa, Pitcher and Diogenes, 2017 ; J Endodon Langer and Vacanti Tissue Engineering Diogenes and Hargreaves J Endodon 9

10 HOW IMPORTANT IS DISINFECTION IN TREATING IMMATURE TEETH? 2015 PERSISTENT BIOFILMS ASSOCIATED WITH LACK OF REGENERATION/REPAIR Actinomyces naeslundii Porphyromonas endodontalis Parvimonas micra Fusobacterium nucleatum Porphyromonas gingivalis Prevotella intermedia Tannerella forsythia Filifactor alocis Treponema denticola % incidence N=15; Traumatized teeth Verma et al (Fouad), 2016-JDR 10

11 THE IMMATURE TOOTH 2016 Challenges Aggressive mechanical Instrumentation is contra-indicated due to already thin fragile dentinal walls. Large canals harbor large concentration of microorganisms Young immature teeth are more susceptible to bacterial colonization Advantages Root canal anatomy is less complex Larger volume improves fluid dynamics of solutions and greater medication reservoir Young healthy individuals Greater vascularity and angiogenic potential Is the microbial flora different? IRRIGATION

12 Trevino et al., 2011 WHAT CONCENTRATION OF HYPOCHLORITE SHOULD BE USED? 60 SCAP seeded onto conditioned dentin Not direct chemical effect SCAP Number (X1,000) Survival 0 - NaOCl (%) % EDTA Proliferation Martin et al., J Endodon NaOCl+EDTA EDTA 12

13 SODIUM HYPOCHLORITE VS STEM CELLS INTRACANAL MEDICAMENTS Prevents SCAP survival and differentiation in an organotype root canal model (Trevino et al., 2011 and Martin et al 2014) Prevents odontoblastic differentiation and co-determines MSC fate in vivo (Casagrande et al., 2010; Galler et al., 2011) Deleterious effects are reversed by EDTA (Martin et al., 2014) Denatures growth factors in dentin (Zhao et al, 2000) USE OF ANTIBIOTIC PASTE Not a new concept in Endodontics, several formulations have been used for decades in root canal therapy. The combination of metronidazole, ciprofloxacin and minocycline (Triple Antibiotic Paste, TAP) was introduced by Dr. Hoshino in 1990 s. 1.5mg total of drug mixture was placed in extracted teeth inoculated with E. coli directly on plates (25mg/ml) and it was found to sterilize canals The medication penetrated 1mm and killed bacteria into tubules Teeth were deemed sterile after 48hrs 13

14 DIRECT EFFECT OF INTRACANAL MEDICAMENTS ON SCAP SURVIVAL CALCIUM HYDROXIDE IS CONDUCIVE TO STEM CELL SURVIVAL Ruparel, Teixeira, Ferraz and Diogenes J Endodon Ruparel, Teixeira, Ferraz and Diogenes J Endodon ARE LOWER CONCENTRATIONS OF ABS ANTIMICROBIAL? Reyhani et al., 2015; JODDD wk 2 wk 3 wk 4 wk 225 Minimal Bactericidal Concentration (MBC): TAP =0.3mg/ml DAP= 0.14mg/ml Clinically used concentrations as a paste slurry are ~3,000 to 10,000 times greater than concentrations found effective against bacteria Bacterial CFU , saline Concentration of TAP 14

15 Indirect Effect of Medicaments on SCAP survival ,000mg/ml 1mg/ml Althumairy RI, Teixeira FB, Diogenes A., 2014 J Endodontics DISINFECTION ADJUVANTS Use of Negative Pressure (Da Silva et al., 2010; OOOOE) Use of Passive Ultrasonic Irrigation (Galler et al., 2016;Clin Oral Invest ) EVALUATION OF OUTCOMES CLINICAL VS SCIENTIFIC Photodynamic disinfection (Johns et al., J Con Dent) Chitosan Nanoparticles (Shresta et al., 2016; J Endodon) 15

16 AAE goals for REP ANALYZING REGENERATIVE ENDODONTIC STUDIES Tertiary goal Positive response to pulp vitality tests Secondary goal Increased root wall thickness and/or length Primary goal Elimination of symptoms, bone healing Use of standardized protocols Use of quantitative methods Equal distribution of etiologies for non-randomized studies Adequate recall rate What is the criteria for success (AAE vs self-defined) STANDARDIZING AND QUANTIFYING Primary Outcome The pooled survival rates MTA plug: 97.1% REPs: 97.8%. The pooled success rates MTA Plug: 94.6% REPs: 91.3%

17 Secondary AAE Goal Continued Root Development % Change in Root Width Bose et al., 2009 Quantitative Studies n/a Jeeruphan et Nagy et al., Kahler et al., al., n/a Sauod et al., 2014 Lin et al., 2017 Apex Regen RETè n=69 Apexification è n=34 Primary outcome (healing) Secondary outcome (development) 1 year recall using CBCT analysis of healing and root development Canals were irrigated with 1.5% NaOCl, 17% EDTA and medicated with 0.1mg/ml modified TAP RET Apexification 100% 100% >0.24mm In 82.6% No change Tertiary Outcome: Vitality Responses Regenerative Endodontics Apexification Procedures Apical Types Root length foramen size I Increased Decreased Root Development Responses Dens Trauma Not Reported 32% YES 34% NO 100% II Increased Unchanged III Unchanged Decreased IV Unchanged Unchanged Type 1 Type 2 Type 3 Type 4 NO 34% Diogenes et al., 2013-Endodontic Topics 17

18 NERVE REGENERATION? Trilevel outcome pyramid Lei et al., 2015, J Endodon Diogenes, Ruparel, Shiloah and Hargreaves. JADA 2016 Patient Centered Outcome-Esthetics Discoloration in Regenerative Endodontic Procedures: Use of antibiotic pastes Use of MTA (white and grey)* Bleeding in esthetic zones Discoloration can be avoided by: Use of calcium hydroxide instead of antibiotic pastes Use of non-staining pro-mineralizing materials (eg. Biodentine or BC putty) Bonding the coronal dentinal tubules in the chamber with a dental adhesive Discolored teeth can be bleached with walking bleach techniques 18

19 Restorative material staining Staining with white MTA is worse with contact with blood (Felman and Parashos, 2013; J Endodon) MTA but not biodentine changes color in contact with dentin treated with hypochlorite (Marciano et al., 2015; Clin Oral Investig) MTA from different brands lead to coronal discoloration (Ioannidis et al., 2012; IEJ) MTA staining is worsened with curing light application (Valles et al., 2013; Clin Oral Invest ) No Staining with Biodentine in human teeth (Valles et al., 2015; J Endodon), but minimal staining detected in bovine teeth (Beatty and Svec 2015; J Endodon) Which Biocermic should be used in addition to MTA? Biodentine Zanini et al., J Endodon 19

20 HISTOLOGIC EVIDENCE OF PULP REGENERATION Pulpal Regeneration in Uninfected Canal (J Endod 2013;39: ) 20

21 Summary of Histologic Findings Diagnosis Findings Shimizu et al Shimizu et al., 2013 dentin like tissue and odontoblast Symptomatic Irreversible Pulpitis like cells. Blood vessels and innervation Pulp Necrosis and Chronic Apical Un-inflammed CT, cementum and Abscess bone-like tissue Half Full or Half-empty? Nosrat et al., 2013 Martin et al., 2013 Becerra et al., 2014 Nosrat et al., 2015 Peng et al., 2017 Pulp Necrosis and Acute Apical Abscess Pulp Necrosis and S. Apical Periodont Pulp Necrosis and S. Apical Periodont Normal, Normal Symptomatic Irreversible Pulpitis Empty Canal Un-inflammed CT, cementum and bone-like tissue Fibrous Ct, acellular cementum, dentin spicules, bacterial cells Un-inflammed CT, cementum and bone-like tissue dentin like tissue, odontoblast like cells, presence of cementum Clinical Significance of Tissue Histology Pulp canal obliteration (PCO) is a common finding following trauma (Andreasen et al., 1987; McCabe and Dummer., 2012) Approximately 91.5% of teeth with PCO do not require endodontic intervention (Robertson et al., 1996) Mineralized Coronal Barrier After Direct Pulp Capping Tertiary Reparative Dentin is not dentin but mineralized tissue formed by recruited cells Form an atubular mineralized bridge Histological findings suggest that the irregular tissue formed resembles, in certain cases, tissues formed after regenerative endodontic procedures (Zhao et al., 2007) Different zip code = different name? Ricucci et al., J Endodon 21

22 MECHANICAL PROPERTIES OF MINERALIZED TISSUES Sakai et al., 2010 Iohara et al., 2010 Arola et al., Int J Fatigue 2010 Rosa et al.,2010 Casagrande et al.,2010 Kim et al., 2010 Regenerative Endodontics Guided-Endodontic Repair (GER) Diogenes et al., 2016 JADA CLAIM replace regenerating damaged damaged structures, including: dentin and root structures, as well as cells of the pulp-dentin complex 22

23 THE AMAZING DENTAL PULP 10yo boy 2 years later EPT + Thank Y ALL! Dx Necrotic pulp; sympt apical Periodontitis Dx : normal pulp normal periradicular tissues 23