8-01 an introduction to tooth microanatomy and caries.pdf

An Introduction to Tooth Microanatomy and Caries DSPM1: Fall 2023, Unit 1 Todd Parco, D.D.S. (Pediatrics): [email protected] Cheryl Samaniego, Ph.D. (Histology): [email protected] Robert Danforth, D.D.S. (Radiology): [email protected]...

An Introduction to Tooth Microanatomy and Caries DSPM1: Fall 2023, Unit 1 Todd Parco, D.D.S. (Pediatrics): [email protected] Cheryl Samaniego, Ph.D. (Histology): [email protected] Robert Danforth, D.D.S. (Radiology): [email protected] Also reviewed by: Marcos Ortega, Ph.D. (Biochemistry): [email protected] Sehrish Javaid, B.D.S., M.A., Ph.D. (Pathology) [email protected]  Learning Objectives LO1: Describe the epidemiology and clinical appearance of caries. (TP) LO2: Describe the anatomy and histology of a tooth: layers & features. (CS) LO3: Describe the radiographic progression and staging of the disease (RD) Questions to open discussion 1. What are carious lesions? 2. How do they develop? 3. How do they progress? 4. How are they detected? 5. How are they prevented? https://www.absolutedental.com/blog/tooth-decay-in- kids-signs-of-cavities-and-treatment-options/ Todd M. Parco DDS, MSD Board Certified Pediatric Dentist Some questions you should be able to answer by the end of this lecture… “Why did this happen?” “How did this happen?” “Is this common”? “The benefits of taking dental radiographs?” “Could this have been avoided?” causesofcaries calculus Pathophysiology of Dental Caries You -- today Upon retiring from dentistry HAHAHAHAH Discussing caries and o The Merriam-Webster dictionary defines caries as, “progressive destruction of bone prevalence or tooth”. o Caries is a noun. Caries? o The layman term used to describe dental caries would be “tooth decay” Caries o This image reveals “caries” on a maxillary left lateral incisor. o Notice the cavitated enamel along with the gray area revealing dentinal caries. incisors 1st are upper molars most common for places caries to ofsalivaryglandsducts due location Caries o In this image, caries is present in the pits and fissures of a permanent mandibular right molar. o Notice the chalky white color surrounding the enamel caries. o As caries deepen, it darkens due to the more yellowish darker color of the dentin (dentinal caries) layer along with the exposure to oral environment. Caries o Caries can present with minor visible clinical defects on the enamel. o Dental x-rays or radiographs are used to diagnose the depth of the dental caries. o These localized demineralization areas opened a pathway to the dentin. Layers of a tooth Enamel. This is the protective outer layer of each tooth. Enamel helps shield your teeth from cavity-causing bacteria. Enamel is the hardest substance in the human body. Dentin. Just underneath your enamel, there’s a layer of dentin. Dentin isn’t as strong as enamel. When missing enamel exposes dentin, your risk for cavities increases. Cementum. Cementum covers your tooth root. Along with your periodontal tissues, it helps anchor your tooth firmly in your jaw. Tooth pulp. This is the innermost layer of your tooth. It contains nerves, blood vessels and connective tissues. – Cleveland Clinc cervical decalcification So what contributes to a tooth being in a state of demineralization or remineralization?  tartarhardenedplaque calculus Causes of caries o Diet carbonadrat plaque o Oral hygiene taxesan tocalm nrs o Genetics o Dental anatomy80of cavities happen inpitsfissures o Use of fluorides or other chemotherapeutic agents o Salivary flow (xerostomia)dry mouth o Buffering capacity saliva pit o Number and type of microbial flora area itin trial Demineralization and Remineralization o On a pH scale, 7 is neutral with pH below 7 is acidic. o You will learn about the biofilm that organizes on teeth. o If acid is present in the biofilm ecosystem for extended periods of time, it can lower the pH in the biofilm below critical levels (5.5 {enamel} and 6.2 {dentin}). strepmutans m utant ofstreptococci forms most have toothpastes s ameamount oftin oriae So who gets caries? o Globally, an estimated 2 billion people suffer from caries of permanent teeth and over 500 million children suffer from caries of primary teeth. Mar 14, 2023, WHO Prevalence of dental caries in primary and permanent teeth in children in different continents How common is tooth decay? More than 90 percent of American adults have cavities in their permanent teeth. More than 25 percent of American adults have untreated dental decay. US Dental Health Statistics, Dec 29, 2022 Cheryl S. Samaniego, PhD Cell Biology and Microanatomy  MicroAnatomy of the Tooth Ten Cate’s Oral Histology. Figure 1-2 (L) and Figure 1-5 (R)  TOOTH ANATOMY DENTITION Anatomy of the Posterior tooth (from superior to inferior position). A: Apices BI: bifurcation of roots PC: pulp canal CEJ: cementoenamel junction PCH: pulp chamber PH: pulp horn F: fissure entum I met junction line CU: cusp gum mrecession stanange The four tooth tissues are enamel (white) , cementum, dentin, and pulp. Wheeler’s Dental Anatomy, Physiology and Occlusion.  TOOTH MICROANATOMY: DENTITION Overview The four tooth tissues (from deep to superficial) are enamel, cementum, dentin, and pulp. The first three are known as hard in iii tissues, the last as soft tissue. 1. The enamel tissue is a hard, thin, mineralized, translucent acellular layer covering the crown. 2. The cementum tissue is a pale yellow layer of calcified material covering dentin in the root of the tooth. It is softer a cementum and more permeable than dentin. 3. The dentin tissue is the most abundant tissue; it supports the Periodontal rigid enamel and cementum. membrane 4. The pulp tissue furnishes the blood and nerve supply to the tooth. suply  TOOTH MICROANATOMY: DENTITION Enamel Ten Cate’s Oral Histology. Figure 1-3 (L) Histology: A Text and Atlas. Figure 16-9 (L)  TOOTH MICROANATOMY: DENTITION Cementum covers cementum roots Histology: A Text and Atlas. Figure 16-16 (L)  TOOTH MICROANATOMY: D E N T IDentin T I O N & Pulp dentinisyellow antibiotics metalexposure dentin white demineralization toomuentinoriae tissue c onnective loose bloodvessels Ten Cate’s Oral Histology. Figure 1-4 Carious Lesions: Progression and Staging rcrowns manage oot canal https://www.dentalhealth.ie/your-oral-health/terms/dental-caries-tooth-decay/ ENAMEL CARIES: ELECTRON D E N T I TMICROGRAPH ION identim Eradi ing demineralization Ten Cate’s Oral Histology. Figure 15-11 TRANSLUCENT ZONE DIN E NDENTAL T I T I O N CARIES iiiiiiii.iniiiseauinm tofight invasion Ten Cate’s Oral Histology. Figure 15-12 HEALTHY PROCESS: REMINERALIZATION D E N T I T I OIN N DENTAL TUBULES Ten Cate’s Oral Histology. Figure 15-13 DENTINAL CARIES: DEMINERALIZATION D E N T I T AND I O N MICROBIAL ESCAPE Ten Cate’s Oral Histology. Figure 15-14 CARIES Progression IfDNo E N TIntervention ITION Occurs References: Tooth anatomy images/content: Wheeler’s Dental Anatomy, Physiology and Occlusion. Chapter 1: Introduction to Dental Anatomy: Nomenclature, pages 1-11. https://microcopydental.com/blog-posts/item/308-the-anatomy-of-a-tooth image Nanci’s Ten Cate’s Oral Histology. Chapter 1: Structure of the Oral Cavity. Pawlina’s Histology: A Text and Atlas. Chapter 16: Digestive System I: Teeth and Supporting Tissues, Caries images/content Nanci’s Ten Cate’s Oral Histology. Chapter 15: _____ https://www.dentalhealth.ie/your-oral-health/terms/dental-caries-tooth-decay/ image Pitts, N., Zero, D., Marsh, P., Ekstrand, K., Weintraub, J., Ramos-Gomez, F., Tagami, Junji, Twetman, Svante, Tsakos, G., and Ismail, Amid. “Dental Caries.” Nature Reviews Disease Primers. Vol. 3. Article 17030. 2017. For more reading on this theme, please consider the following resource ( NOT REQUIRED!): Pitts, N., Zero, D., Marsh, P., Ekstrand, K., Weintraub, J., Ramos-Gomez, F., Tagami, Junji, Twetman, Svante, Tsakos, G., and Ismail, Amid. “Dental Caries.” Nature Reviews Disease Primers. Vol. 3. Article 17030. 2017. Introduction to Dental Imaging and Cariology DSPM 5701 Dental Scientific Principles of Medicine 1 Robert A. Danforth, D.D.S. Dental imaging is an important Professor component of the process for delivering patient care of the Oral and Maxillofacial Imaging hard tissue of the head and neck region. This introductory presentation August 01, 2023 will show the relationship Tuesday, 09-11 am between imaging and the interpretation and treatment specifically of dental caries.  TTU WLHSDM DSPM-1 Material in this lesson, as presented, is designed solely for the educational use of the students at the Texas Tech University Woody L. Hunt School of Dental Medicine. Use of this material other than as stated is not permitted. The format follows the lesson outlines as developed by Dr. Danforth. Slide material is from the teaching files of Dr. Danforth and has many sources. General acknowledgment is given to the Kodak Radiographic Series as a primary reference source. Multi-media Publishing, Inc., Denver, CO and the Oral Radiology text by Goaz and White 3rd ed., are additional reference sources.  The objectives of this lesson are: These 2 objectives are focused To introduce the student to the upon imaging techniques that dental imaging techniques use to allow you/the dentist to determine produce interpretive/diagnostic how extensive your treatment images for dental caries treatment needs to be in order to eliminate planning. dental caries from the tooth structure. This determination also lets the To learn how the imaging patient know how much time they techniques are used to assist will be in your dental chair, what treatment planning and the difficulties may or may not be delivery of the actual treatment. expected, and what it will cost.  The Universal tooth numbering system Permanent dentition #s 1-32 Primary dentition letters A-T RIGHT LEFT A B C D E F G H I J Maxilla 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Mandible 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 T S R Q P O N M L K The Universal numbering system is the one used by WLHSDM. There are other systems, When identifying a tooth…. List the side, arch, tooth name, and this one is used by all of the insurance number companies. This is important when dealing with other dentists from different They have the money ($$$). Follow the money. schools. Numbers and letters can be different. Using the full list of identifiers will specifically identify a particular tooth when your are involved with a referral to another dentist especially if an R L extraction of the tooth is the treatment of choice.  Dental caries, the tooth, the dental radiograph Tooth coronal morphology- Similar to a house The coronal portion of the tooth Roof= Occlusal has a roof and sides just like a Walls= Surfaces house. Buccal These are identified in the slide. Lingual Remember that any bone/tooth Proximal surface or anything that is directed mesial towards the anterior portion or the distal midline of the patient is termed as a mesial object or surface. Anything directed to the posterior is termed as distal.  Dental caries, the tooth, the dental radiograph Performing a Class I occlusal prep will be your first Dental Skill Set operation in the Simi Lab. As you can see, the occlusal surface of the Occlusal caries pictured molar has numerous irregularities in which bacteria, as depicted in the tooth diagram, can set-up housekeeping. The Pits and fissures exist on occlusal surface is difficult to keep clean and the occlusal and lingual bacteria that burrow deep into a pit or fissure surfaces of most teeth. are next to impossible to remove just by tooth brushing. Operative procedures intervention is indicated to prevent further bacterial changes to the tooth. Bacteria can live in Such could be simple a sealant material over these areas and start the surface irregularities. carious lesions. Another approach is using the dental drill to remove the decay tooth structure in the form of a prep design and fill it with a dental material. Your Class I prep is this latter approach.  Dental caries, the tooth, the dental radiograph Occlusal caries Demineralization occurs at depth of pit or fissure. Spreads through enamel towards DEJ in a triangular pattern apex at pit or fissure base at DEJ NOTE* This area of demineralization may not be detected by a radiograph. The growth pattern of occlusal caries is depicted in the slide. The spread of caries expands laterally/horizontally along the DEJ. When this can be detect by a radiograph, it is the first visible sign that decay can be recognized as invading into the dentin. The above radiographs do not show definitive DEJ evidence and, as such, pit and fissure caries may exist but it lacks visible confirmation.  Dental caries, the tooth, the dental radiograph Occlusal caries Generally, caries in enamel is obscured by cusp outlines and is not seen in the radiograph. Therefore, the FIRST RADIOGRAPHIC EVIDENCE of occlusal caries is a dark (radiolucent) Treatment : Sealants, Class I Occlusal restoration Amalgam line along the DEJ. Composite As depicted in this diagram, demineralization has now begun at the DEJ and with loss of the calcified structure becomes the opportunity to see the carious lesion using a radiograph. Think of this early manifestation as observing a #2 pencil line drawn along the DEJ. Early visualization is a thin line as seen at the end of the green arrow beneath the enamel. When it starts to become a downward trending triangular towards the pulp, as seen in the tooth histology section, then the lesion is becoming more advanced and more difficult to treat. Diligent scrutiny is required to intercept this process early in order to avoid caries entering the pulp.  Dental caries, the tooth, the dental radiograph Occlusal caries Once passed DEJ takes a triangular pattern route to the pulp Memory Gem: base to base Growth pattern U Here we see the sequelae of non-treatment. The carious lesion has reached the pulp chamber. An abscessed tooth is now in progress. If not treated, pain will develop and abscess infection will flourish and will eventually drain out the root apex and start to dissolve the surrounding periapical bone. At a certain point, the amount of dissolved bone will be detected by the radiograph and a radiolucent area will be seen at the root apex. The “base to base” concept is a method to describe the untreated occlusal caries growth pattern. The first molar teeth as seen in the dental radiographs are the 6 year molars. These are supposed to last a lifetime. Extensive carious lesions as seen in the these radiographs condemn these teeth to extensive operative/restorative procedures which are not always successful thus resulting in even a worse scenario which is early tooth loss.  Dental caries, the tooth, the dental radiograph Smooth surface, proximal surface dental caries Coronal morphology- Similar to a house Now, it is time to look at dental caries that develops on the proximal surfaces. This is termed smooth Roof= Occlusal surface caries since it develops just beneath the Walls= Surfaces contact point between to adjacent teeth where there are no grooves or pits. Buccal These are referred to as mesial interproximal caries Lingual or distal interproximal caries depending upon the Proximal surface. mesial When caries develops on a surface of one tooth, it is not uncommon to see it on the proximal surface distal of the adjacent tooth. This results in the lesions touching one another and hence the term “kissing lesions”.  Dental caries, the tooth, the dental radiograph Smooth surface, proximal surface dental caries Most common explanation for caries development. Let’s party! Bacterial accumulations (Biofilms) on tooth surface produce acids which D M demineralize the enamel area increases in size Right mandibular molar, if not treated, bacteria enters dentinal First #30, Second #31 tubules to reach pulp Susceptible party host The development of caries on the proximal surface is seen in this diagram. In this initial stage of demineralization, a white chalky appearing plaque can sometimes be detected on the enamel surface. This does not correlate with radiographic detection which generally occurs later in the development process. Note: The position of a project tooth, such as shown, or a radiograph should match the dentition arrangement as we look at one another or as depicted in dental charting or insurance forms. Hence you should be able to look at a tooth and identify the name of the tooth, by side of the dental arch, maxilla or mandible, correct name of the tooth, and lastly the universal number(#) of the tooth.  Dental caries, the tooth, the dental radiograph Smooth surface, proximal surface dental caries Decalcification from The reason dental carious lesions are called “cavities” is because of bacterial acid produces a what initially occurs on the tooth “nick” or concave defect surface. This can be seen using (cavitation) on the enamel radiographs but not always. surface. However, it does remain one of the various radiographic features This is the earliest to aid your interpretation of radiographic evidence of the proximal surface dental caries. As carious lesion before, the actual process of “incipient lesion” demineralization has developed beyond the ability of the 40% demineralization must radiograph to detect it. occur before radiographic ALWAYS REMEMBER- the actual detection lesion is bigger than what it seen on the radiograph.  Dental caries, the tooth, the dental radiograph Smooth Surface Caries in Enamel Starts just beneath the interproximal contact point and above the free gingival margin. Caries does not start below free gingival margin. Clinically, the area appears as a “WHITE CHALKY” spot. This slide just reiterates some of the radiographic features that were mentioned in earlier slides. Lesions on both proximal surfaces across from one another would be termed “kissing lesions”.  Dental caries, the tooth, the dental radiograph DET Smooth Surface Caries in Enamel Triangle pattern: based at tooth enamel surface and apex towards DEJ. When pattern is half way across enamel, it is considered early or an “incipient lesion”. Early caries may be treated in a noninvasive manner. Larger lesions must be mechanically treated(drilled). Again from a diagram perspective, the growth pattern of proximal surface caries is seen in terms of various expanding triangles. As seen in the top diagram, when a cavitation is no more than half way across the radiographic image of the enamel it is considered to be an incipient lesion and may be treated by remineralization thus avoiding using the drill. However, when passes the halfway point in the enamel, mechanical treatment is most likely the method of choice. Good radiographic images, usually bitewings, are essentially to make such determinations.  Dental caries, the tooth, the dental radiograph Smooth surface, proximal surface dental caries This slide visibly shows the previous mentioned features. Develops a triangular shape Histology The cavitation eats its as it advances through the of tooth: way through the enamel. Surface cavity enamel enamel to near the DEJ as seen in the dentin tooth histology DEJ section. The radiograph shows 2 kissing lesions which are currently confined to the enamel. Note that these are just beneath the contact point of the two teeth. Radiographic Evidence of the Incipient Carious Lesion- Confined to enamel  Dental caries, the tooth, the dental radiograph Smooth surface, proximal surface dental caries in dentin First evidence is a thin Enamel caries radiolucent line at DEJ. This indicates demineralization is occurring at DEJ. Dentin caries The initial demineralization of dentin spreads laterally along DEJ As indicated in this slide, the demineralization associated with the lateral spread of caries at the DEJ becomes the first visible radiographic evidence of caries into the dentin. The histology section of the tooth shows the triangular enamel pattern and the initial lateral spread in the dentin. This is the sign for which you are looking. Treatment at this level is more efficient being under better control and less expensive to the patient. However, caries at this level is no longer a non-invasive treatment procedure. Surgically prepping the tooth is indicated. The filling material however is still a choice between amalgam or composite.  Dental caries, the tooth, the dental radiograph oncebacteriana Smooth surface, proximal surface dental caries in dentin apulpnav invade beaetense control hasto system roots go from Next is bacterial invasion of the dentinal tubules towards the pulp. Advance of carious along dentinal tubules large deeper radiolucent area Here we see the lesion expanding towards the pulp chamber. The radiograph now shows larger dark areas in the dentin. These teeth may or may not have clinical symptoms. Treatment becomes more complex at this point. Larger deeper prep design and the possible used of based materials to protect the pulp such as shown on the distal portion of molar #30.  Dental caries, the tooth, the dental radiograph Smooth surface, proximal surface dental caries in dentin and pulp Bacterial in the dentinal tubules reaches pulp prior to radiographic evidence. This diagram shows the sequela of untreated dental caries. Bacteria are in the pulp. This will occur before there is radiographic evidence. As such there may be symptoms while the radiographically the lesion doesn’t appear that serious. Treatment Radiolucent area superimposed upon choices are based upon the principle pulp. Pulp is abscessed- nonvital to remove the disease process. If the tooth can be saved, then- Root canal/endodontic treatment followed by a restoration intended to preserved the remaining tooth structure is the treatment of choice. If the tooth can’t be saved or the patient doesn’t want to save it, then- Extraction of the tooth is the treatment. By eliminating the tooth, you have also eliminated the carious disease process.  Dental caries, the tooth, the dental radiograph Smooth surface, proximal surface dental caries in dentin and pulp Diagrammatic pattern of development: 2 triangular patterns base at surface of enamel and along DEJ Here is the memory gem to remember the Memory gem* triangle configuration for proximal smooth apex to base surface caries. apex to pulp (ABAP aaaaa  Dental caries, the tooth, the dental radiograph 3 Methods/techniques for visually detecting caries using radiographs. 1. Dark (radiolucent) area (triangle) across the white enamel 2. Concave surface/cavitation 3. DEJ darkened/thickened (like pencil line) Interproximal and occlusal Do you need all 3? NO These are the 3 steps/methods for detecting radiographic caries. This approach must be meticulously applied to each proximal and occlusal surface of each tooth seen on the radiograph. You must answer the question…. do I see this? Yes or No You don’t need all 3 to come to a conclusion. The mesial interproximal surface of the second mandibular molar has caries into the dentin. You do not see a darkened area clear across the enamel surface (Step 1), however, there is a radiolucent surface defect (Step 2) next to the amalgam restoration and here is a darkened line along the DEJ (Step 3). The fact that kissing lesions can exist, as previous described, lets you come to the conclusion that mesial interproximal surface caries is present. This may be subtle but the second molar depends upon you being aware of this lesion in order for the molar to survive with a reasonable size restoration rather than being subject to extensive treatment or worse yet an extraction due to neglect.  Dental caries, the tooth, the dental radiograph Treatment: Occlusal surface, Class I restoration- Prep design Occlusal Sealant-composite, Amalgam Proximal surface, Class II restoration- Prep design MO, DO, MOD, Slot Amalgam, Composite Here are some suggest treatment options for those carious lesions that can be treated using basic dental materials. Composites with acid-etching bonding to the tooth structure are preferred these days to seal margins better while preventing recurrent decay. The bonding feature also means that the prep design is more conservative thus sparing more tooth structure. Lastly, the composite materials are tooth colored and people like that rather than the older amalgams which turn dark over time.  Dental caries, the tooth, the dental radiograph The end of Lesson NOTE: You will have 3 exam slide x-ray radiographs to analyze for dental caries during your future exam session. This will be a multiple choice question exam. There is an attached slide upon which you can practice.  examQ's Practice Slide Use the 3 visualization techniques to: Evaluate the radiograph for occlusal, enamel and dentin caries Then answer the question. Select the correct statement (s) from the following: 1. The right maxillary first premolar shows distal surface enamel and dentin dental caries. 2. The black arrow is identifying mesial dentinal caries for the left maxillary second premolar. 3. Enamel caries is seen for the distal surface of the right mandibular second premolar and mesial surface of the first molar. 4. The left maxillary first premolar shows distal surface enamel and dentin dental caries. A. 1, 2, 3 B. 1 and 3 C. 2 and 4 D. Only 2 E. Only 3 Answer for Practice radiograph next slide. Don’t sneak a peek!!! Commit to answer first- then look  Practice Slide Use the 3 visualization techniques to: Evaluate the radiograph for occlusal, enamel and dentin caries Select the correct statement (s) from the following: This is a right bitewing 1. The right maxillary first premolar (#5) shows distal surface enamel and dentin dental caries. Shows both dental arches 2. The black arrow is identifying mesial dentinal caries for the left maxillary second premolar. 3. Enamel caries is seen for the distal surface of the right mandibular second premolar (#29) Any statement about the and mesial surface of the first molar (#30). left side is incorrect. 4. The left maxillary first premolar shows distal surface enamel and dentin dental caries. A. 1, 2, 3 B. 1 and 3 C. 2 and 4 D. Only 2 E. Only 3 Discussion led by Dr. Parco For more reading on this theme, please consider the following resource (NOT REQUIRED!): Caries etiology: Pitts, N., Zero, D., Marsh, P., Ekstrand, K., Weintraub, J., Ramos-Gomez, F., Tagami, Junji, Twetman, Svante, Tsakos, G., and Ismail, Amid. “Dental Caries.” Nature Reviews Disease Primers. Vol. 3. Article 17030. 2017.