Tooth preparation involves reducing tooth structure to restore teeth to their original form and contour. The objectives of tooth preparation are to provide retention, resistance form, and acceptable margins while preserving healthy tooth structure. The basic steps of tooth preparation are incisal/occlusal reduction, facial reduction, lingual reduction, proximal reduction, finishing line establishment, and rounding sharp line angles. Interferences in occlusion can occur in centric, working, non-working, or protrusive positions and should be avoided.
This document provides information on retainers, clasp assemblies, and indirect retainers used in removable partial dentures. It discusses different types of direct retainers including "I-bar" and circumferential clasps. It describes the components of clasp assemblies including rests, clasps, minor connectors, and proximal plates. It also covers the concepts of reciprocation, which provides resistance to forces on teeth, and encirclement, where the clasp assembly needs to engage more than 180 degrees of the tooth circumference.
Centric relation is a controversial concept in dentistry that refers to the maxillomandibular relationship where the condyles are in their most anterior and superior position against the articular eminences, allowing purely rotary movement of the mandible. There have been many changes to the definition of centric relation over time as understanding has evolved. It is important for proper functioning and to develop centric occlusion in artificial dentures. However, accurately recording centric relation can be difficult due to various biological, psychological and mechanical factors that must be addressed. Common methods include using interocclusal records with or without central bearing devices as well as functional recording techniques.
A RPD derives support from two main sources periodontally sound natural teeth & residual alveolar processes and associated soft tissues.
A RPD that is supported by healthy natural teeth possesses adequate stability and retention to resist functional displacement.
However, a RPD that is not entirely bounded by natural teeth will move when a load is applied.
1. The functionally generated pathway technique involves recording the paths of tooth movement during excursive jaw motions using wax or other materials.
2. This recording is used to develop the occlusal morphology for dental restorations like crowns, ensuring optimal occlusion during all jaw motions.
3. Studies have found that the functionally generated pathway technique results in restorations with better functional articulation compared to conventional single casting techniques, with less adjustment needed and higher patient satisfaction.
This document summarizes key concepts regarding occlusion for implant-supported fixed dental prostheses. It notes that unlike natural teeth which have periodontal ligaments to absorb forces, implants lack this and forces are concentrated at the crestal bone. As such, implant occlusion schemes aim to reduce bending moments and distribute forces axially. Recommendations include using flat fossa and grooves, narrow occlusal tables, reduced cuspal inclines, stiffer materials, and avoiding excursive contacts to protect the implant and surrounding bone.
3 basic principles for designing class ii and iii and ivAmal Kaddah
Designing Kennedy class II partial dentures usually follows the same basic principles as class I partial dentures. The main challenges are lack of proper posterior support and retention due to the absence of a posterior saddle. Indirect retention is important to counteract rotational forces on the denture. Problems with class II dentures can be reduced by adding retention on the dentulous side, using a clasp line that divides the denture in half, and indirect retainers to reduce lateral loading and denture rotation. Stress on the residual ridge and abutment teeth is minimized through broad denture base coverage, accurate impressions, improving the ridge condition, using narrow teeth, and proper choice of direct retainers.
This document describes the monoplane occlusion concept, also known as neutrocentric occlusion. Some key points:
- The plane of occlusion is completely flat and parallel to the denture foundation, with no compensating curves. There is no vertical overlap of anterior teeth.
- When setting up the teeth, the horizontal and lateral condylar guidances should be set at zero.
- Specific landmarks on the casts are used to establish the flat plane of occlusion. Both anterior and posterior teeth are set on this single plane.
- Overlaps between teeth are minimized. Posterior teeth may require ramps or adjustments to improve excursive function depending on the patient's condyl
This document provides information on retainers, clasp assemblies, and indirect retainers used in removable partial dentures. It discusses different types of direct retainers including "I-bar" and circumferential clasps. It describes the components of clasp assemblies including rests, clasps, minor connectors, and proximal plates. It also covers the concepts of reciprocation, which provides resistance to forces on teeth, and encirclement, where the clasp assembly needs to engage more than 180 degrees of the tooth circumference.
Centric relation is a controversial concept in dentistry that refers to the maxillomandibular relationship where the condyles are in their most anterior and superior position against the articular eminences, allowing purely rotary movement of the mandible. There have been many changes to the definition of centric relation over time as understanding has evolved. It is important for proper functioning and to develop centric occlusion in artificial dentures. However, accurately recording centric relation can be difficult due to various biological, psychological and mechanical factors that must be addressed. Common methods include using interocclusal records with or without central bearing devices as well as functional recording techniques.
A RPD derives support from two main sources periodontally sound natural teeth & residual alveolar processes and associated soft tissues.
A RPD that is supported by healthy natural teeth possesses adequate stability and retention to resist functional displacement.
However, a RPD that is not entirely bounded by natural teeth will move when a load is applied.
1. The functionally generated pathway technique involves recording the paths of tooth movement during excursive jaw motions using wax or other materials.
2. This recording is used to develop the occlusal morphology for dental restorations like crowns, ensuring optimal occlusion during all jaw motions.
3. Studies have found that the functionally generated pathway technique results in restorations with better functional articulation compared to conventional single casting techniques, with less adjustment needed and higher patient satisfaction.
This document summarizes key concepts regarding occlusion for implant-supported fixed dental prostheses. It notes that unlike natural teeth which have periodontal ligaments to absorb forces, implants lack this and forces are concentrated at the crestal bone. As such, implant occlusion schemes aim to reduce bending moments and distribute forces axially. Recommendations include using flat fossa and grooves, narrow occlusal tables, reduced cuspal inclines, stiffer materials, and avoiding excursive contacts to protect the implant and surrounding bone.
3 basic principles for designing class ii and iii and ivAmal Kaddah
Designing Kennedy class II partial dentures usually follows the same basic principles as class I partial dentures. The main challenges are lack of proper posterior support and retention due to the absence of a posterior saddle. Indirect retention is important to counteract rotational forces on the denture. Problems with class II dentures can be reduced by adding retention on the dentulous side, using a clasp line that divides the denture in half, and indirect retainers to reduce lateral loading and denture rotation. Stress on the residual ridge and abutment teeth is minimized through broad denture base coverage, accurate impressions, improving the ridge condition, using narrow teeth, and proper choice of direct retainers.
This document describes the monoplane occlusion concept, also known as neutrocentric occlusion. Some key points:
- The plane of occlusion is completely flat and parallel to the denture foundation, with no compensating curves. There is no vertical overlap of anterior teeth.
- When setting up the teeth, the horizontal and lateral condylar guidances should be set at zero.
- Specific landmarks on the casts are used to establish the flat plane of occlusion. Both anterior and posterior teeth are set on this single plane.
- Overlaps between teeth are minimized. Posterior teeth may require ramps or adjustments to improve excursive function depending on the patient's condyl
1. Forces acting on removable partial dentures can cause the denture to move in various directions.
2. Key movements are tissue-ward, which are resisted through support from rests and a rigid major connector, and tissue-away, which are resisted through retention features like clasps and attachments.
3. Other movements include horizontal forces that can cause lateral or back-and-forth motion, resisted through bracing from clasps and connectors and ensuring balanced occlusion. Proper design of components is important to control stresses from forces on the denture.
This document provides an overview of removable partial denture (RPD) design, with a focus on the RPI and RPA systems. It discusses the challenges of tooth-tissue supported prostheses and how RPD design can control damaging forces. The RPI system aims to minimize stress using components like I-bar retainers, mesial rests, and proximal plates. Variations like Krol's modification require less tooth alteration. Indirect retention through rests helps redistribute forces. The document reviews factors like clasp design, material, and position that also influence stress control.
Occlusion concepts in fixed partial dentures / dental implant courses by Ind...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
This document discusses the key factors involved in developing balanced occlusion for complete dentures. It outlines five main factors: 1) Condylar guidance, 2) Incisal guidance, 3) Plane of occlusion, 4) Compensating curves, and 5) Cusp angle. It describes how each factor influences mandibular movement and must be considered in relation to the others to achieve balanced occlusion without trauma to tissues. Formulas from Hanau and Theilmann relate these five factors and how modifying one requires adjusting the others to maintain occlusion balance.
5- Basic principles for designing the removable partial denture (class i part...Amal Kaddah
This document discusses principles and factors related to removable partial denture (RPD) design. It addresses:
- Biomechanical principles to minimize damaging effects to teeth, bone, and soft tissues from forces of the RPD.
- Factors that influence RPD design, including abutment conditions, ridge properties, forces, and patient needs.
- Types of RPD support and problems associated with tooth-mucosa supported designs.
- Techniques to control problems in distal extension bases, such as reducing forces, distributing loads, and providing posterior abutments.
The document discusses various concepts related to complete denture occlusion including:
- The history of dental occlusion in mammals and its development.
- Andrews' six keys to normal occlusion which are seen in natural dentition.
- Differences between natural tooth occlusion and artificial denture occlusion.
- Various occlusal schemes for complete dentures including balanced, lingualized, and monoplane occlusion.
- Requirements for incisive, working, and balancing units in occlusal schemes.
This document discusses the history and classification of precision dental attachments. It begins by outlining some of the early developments in attachment designs from the 19th century. It then classifies attachments based on their fabrication method, relationship to abutment teeth, stiffness, and geometric configuration. The advantages and disadvantages of attachments are provided. Key factors in selecting abutment teeth are identified. Requirements for ideal abutment teeth are outlined. Contraindications and the role of attachments in different types of prosthodontic treatments are summarized.
Centric relation is a maxillomandibular relationship where the condyles are positioned at the anterior-superior position against the posterior slopes of the articular eminences, allowing purely rotary movement. There are several theories regarding what determines centric relation, including muscle, ligament, osteofiber, and meniscus theories. It is important to record centric relation for complete dentures as it provides a reproducible reference position and orients the lower cast on the articulator. Common methods to record centric relation include interocclusal records, graphic tracings, and functional methods.
This document summarizes information from a lecture on removable partial dentures (RPDs), attachments, and rotational path RPDs. It discusses the advantages and disadvantages of different types of attachments, including ERA attachments, magnetic attachments, and overlay dentures. It also describes rotational path RPDs and lateral rotational path RPDs, highlighting how they can eliminate visible clasps while providing retention and stability. Examples are provided of different RPD designs incorporating various attachments and rotational paths of insertion.
This document provides an overview of surveying and surveying tools used in the process of designing removable partial dentures (RPDs). It discusses the history and development of surveying, types of surveyors, principles of surveying including survey lines and path of insertion. The document outlines the step-by-step survey process including orienting the cast, tilting, marking survey lines, measuring undercuts, identifying interferences, and tripoding the cast for future reference. Various surveying tools such as the analyzing rod, carbon marker, undercut gauges, and wax trimmers are also described.
This document discusses rests and rest seats for removable partial dentures. It defines a rest as a component that transfers forces along the long axis of abutment teeth. There are three main types of rests: occlusal rests on posterior teeth, lingual/cingulum rests on canines, and incisal rests on canines. The dimensions and ideal shapes of the rest seats are described for each type. Preparation techniques using diamonds and carbide burs are also outlined.
This document discusses principles of tooth preparation. It begins by defining tooth preparation as the process of removing tooth structure to receive a restoration. The principles of tooth preparation aim to satisfy biologic, mechanical, and esthetic needs. Specifically, it is important to preserve tooth structure, provide adequate retention and resistance form, maintain structural integrity of the restoration, ensure marginal integrity, and preserve the periodontium. Factors like taper, surface area, and roughness influence the retention of a restoration. Care must also be taken to avoid damaging adjacent teeth, soft tissues, or the pulp during preparation.
1) The document discusses different types of occlusion including mutually protected occlusion, group function occlusion, balanced occlusion, and occlusion for complete dentures, removable partial dentures, fixed partial dentures, and osseointegrated prostheses.
2) It describes the desirable characteristics of occlusion for each type of prosthesis, such as bilateral simultaneous contacts, anterior guidance, disclusion of posterior teeth on protrusion, and distribution of forces.
3) The key advantages of different occlusal schemes like mutually protected occlusion and group function occlusion are minimizing tooth contacts and distributing lateral pressures.
Mandibular major connectors and minor connectorsAmal Kaddah
This document discusses different types of mandibular major connectors for removable partial dentures. It describes the structural requirements and functions of lingual bars, sublingual bars, Kennedy (double lingual) bars, cingulum bars, labial bars, and lingual plates. Key requirements for mandibular major connectors include providing cross-arch stabilization, avoiding impingement of tissues, and distributing forces broadly. The document also briefly discusses minor connectors and their functions in connecting parts of the prosthesis.
Centric relation relevance and role in complete denture construction NAMITHA ANAND
This document discusses centric relation, which refers to the relationship between the mandible and skull when the condyles are in their most superior position in the mandibular fossa against the posterior slope of the articular eminence. It has gone through various changing definitions but is now widely accepted to mean the anterior-superior position. Recording centric relation is important for complete denture construction as it provides proprioceptive feedback and acts as the starting point for occlusion. There are various passive and active methods to retrude the mandible as well as intraoral and extraoral graphic methods to record the position.
MAJOR CONNECTORS AND MINOR CONNECTORS IN RPD - Dr Prathibha PrasadDr Prathibha Prasad
The document discusses different types of major and minor connectors used in removable partial dentures. Major connectors discussed include palatal bar, strap, U-shaped, and plate connectors for maxillary arches and lingual bar, linguoplate, sublingual bar, and double lingual bar connectors for mandibular arches. Key factors in choosing a major connector are the number of teeth being replaced, available space, and need for rigidity or support. Minor connectors help stabilize and retain components on one side of the dental arch to the other.
This document discusses occlusion in removable partial dentures. It outlines several types of occlusion including static and dynamic occlusion. Desirable occlusal contacts are bilateral contacts of posterior teeth in centric occlusion. Methods for establishing occlusion include direct apposition of casts if enough teeth remain, interocclusal records with posterior teeth, or using occlusal rims. The functionally generated path method can also be used to develop a dynamic occlusion record without an articulator. Proper occlusion is important for the success, comfort and longevity of removable partial dentures.
Description of Biomechanics of occlusion, Effect of anatomical determinants, Ideal occlusion, Evolution of occlusion, Concepts of Occlusion in FPD such as Group function occlusion, canine guided occlusion, Occlusal contacts, Occlusal Interferences, Patient"s adaptability, Pathogenic occlusion and Philosophies of full mouth rehabilitation. Added references for further readings.
This document provides instructions for constructing an Adams clasp, which is used in orthodontics. It has three main parts: two arrowheads that engage the mesial and distal undercuts of a tooth, and a bridge connecting the arrowheads at a 45 degree angle to the long axis of the root. The 27 steps described include: preparing the undercuts on the tooth, bending wire to form the basic shape, checking fit on the model, forming the arrowheads and adjusting their angle, adapting the wire across occlusion, and finishing with distal tagging. Key requirements are that the arrowheads fully engage the undercuts and the bridge is parallel to the occlusal plane.
This document presents classification systems for complete edentulism, partial edentulism, and completely dentate patients. For complete edentulism, it describes 4 classes based on factors like residual bone height, ridge morphology, muscle attachments, and occlusal relationships. Partial edentulism classes are determined by location/extent of edentulous areas, abutment conditions, occlusion, and residual ridges. Completely dentate classes consider tooth condition and occlusal scheme, with higher classes requiring more extensive pre-prosthetic therapy.
Different gingival finish lines (margins) of crowns and bridgesSana Mateen Munshi
The document discusses various considerations for margin placement in tooth preparations, including biological, mechanical, and aesthetic factors. It describes advantages and disadvantages of different margin types such as supragingival and subgingival margins. Common margin designs like shoulder, bevel, and chamfer margins are explained. Guidelines are provided for reducing tooth structure during preparation in a systematic manner.
This document discusses different concepts of occlusion including bilaterally balanced occlusion, unilaterally balanced occlusion, and mutually protected occlusion. It describes the key features of each concept and compares their advantages and disadvantages. The document also discusses factors that influence occlusion like condylar guidance, anterior guidance, and patient adaptability. It defines pathogenic occlusion and lists potential signs and symptoms. Finally, it outlines objectives and techniques for occlusal treatment, including the use of occlusal splints or devices.
1. Forces acting on removable partial dentures can cause the denture to move in various directions.
2. Key movements are tissue-ward, which are resisted through support from rests and a rigid major connector, and tissue-away, which are resisted through retention features like clasps and attachments.
3. Other movements include horizontal forces that can cause lateral or back-and-forth motion, resisted through bracing from clasps and connectors and ensuring balanced occlusion. Proper design of components is important to control stresses from forces on the denture.
This document provides an overview of removable partial denture (RPD) design, with a focus on the RPI and RPA systems. It discusses the challenges of tooth-tissue supported prostheses and how RPD design can control damaging forces. The RPI system aims to minimize stress using components like I-bar retainers, mesial rests, and proximal plates. Variations like Krol's modification require less tooth alteration. Indirect retention through rests helps redistribute forces. The document reviews factors like clasp design, material, and position that also influence stress control.
Occlusion concepts in fixed partial dentures / dental implant courses by Ind...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
This document discusses the key factors involved in developing balanced occlusion for complete dentures. It outlines five main factors: 1) Condylar guidance, 2) Incisal guidance, 3) Plane of occlusion, 4) Compensating curves, and 5) Cusp angle. It describes how each factor influences mandibular movement and must be considered in relation to the others to achieve balanced occlusion without trauma to tissues. Formulas from Hanau and Theilmann relate these five factors and how modifying one requires adjusting the others to maintain occlusion balance.
5- Basic principles for designing the removable partial denture (class i part...Amal Kaddah
This document discusses principles and factors related to removable partial denture (RPD) design. It addresses:
- Biomechanical principles to minimize damaging effects to teeth, bone, and soft tissues from forces of the RPD.
- Factors that influence RPD design, including abutment conditions, ridge properties, forces, and patient needs.
- Types of RPD support and problems associated with tooth-mucosa supported designs.
- Techniques to control problems in distal extension bases, such as reducing forces, distributing loads, and providing posterior abutments.
The document discusses various concepts related to complete denture occlusion including:
- The history of dental occlusion in mammals and its development.
- Andrews' six keys to normal occlusion which are seen in natural dentition.
- Differences between natural tooth occlusion and artificial denture occlusion.
- Various occlusal schemes for complete dentures including balanced, lingualized, and monoplane occlusion.
- Requirements for incisive, working, and balancing units in occlusal schemes.
This document discusses the history and classification of precision dental attachments. It begins by outlining some of the early developments in attachment designs from the 19th century. It then classifies attachments based on their fabrication method, relationship to abutment teeth, stiffness, and geometric configuration. The advantages and disadvantages of attachments are provided. Key factors in selecting abutment teeth are identified. Requirements for ideal abutment teeth are outlined. Contraindications and the role of attachments in different types of prosthodontic treatments are summarized.
Centric relation is a maxillomandibular relationship where the condyles are positioned at the anterior-superior position against the posterior slopes of the articular eminences, allowing purely rotary movement. There are several theories regarding what determines centric relation, including muscle, ligament, osteofiber, and meniscus theories. It is important to record centric relation for complete dentures as it provides a reproducible reference position and orients the lower cast on the articulator. Common methods to record centric relation include interocclusal records, graphic tracings, and functional methods.
This document summarizes information from a lecture on removable partial dentures (RPDs), attachments, and rotational path RPDs. It discusses the advantages and disadvantages of different types of attachments, including ERA attachments, magnetic attachments, and overlay dentures. It also describes rotational path RPDs and lateral rotational path RPDs, highlighting how they can eliminate visible clasps while providing retention and stability. Examples are provided of different RPD designs incorporating various attachments and rotational paths of insertion.
This document provides an overview of surveying and surveying tools used in the process of designing removable partial dentures (RPDs). It discusses the history and development of surveying, types of surveyors, principles of surveying including survey lines and path of insertion. The document outlines the step-by-step survey process including orienting the cast, tilting, marking survey lines, measuring undercuts, identifying interferences, and tripoding the cast for future reference. Various surveying tools such as the analyzing rod, carbon marker, undercut gauges, and wax trimmers are also described.
This document discusses rests and rest seats for removable partial dentures. It defines a rest as a component that transfers forces along the long axis of abutment teeth. There are three main types of rests: occlusal rests on posterior teeth, lingual/cingulum rests on canines, and incisal rests on canines. The dimensions and ideal shapes of the rest seats are described for each type. Preparation techniques using diamonds and carbide burs are also outlined.
This document discusses principles of tooth preparation. It begins by defining tooth preparation as the process of removing tooth structure to receive a restoration. The principles of tooth preparation aim to satisfy biologic, mechanical, and esthetic needs. Specifically, it is important to preserve tooth structure, provide adequate retention and resistance form, maintain structural integrity of the restoration, ensure marginal integrity, and preserve the periodontium. Factors like taper, surface area, and roughness influence the retention of a restoration. Care must also be taken to avoid damaging adjacent teeth, soft tissues, or the pulp during preparation.
1) The document discusses different types of occlusion including mutually protected occlusion, group function occlusion, balanced occlusion, and occlusion for complete dentures, removable partial dentures, fixed partial dentures, and osseointegrated prostheses.
2) It describes the desirable characteristics of occlusion for each type of prosthesis, such as bilateral simultaneous contacts, anterior guidance, disclusion of posterior teeth on protrusion, and distribution of forces.
3) The key advantages of different occlusal schemes like mutually protected occlusion and group function occlusion are minimizing tooth contacts and distributing lateral pressures.
Mandibular major connectors and minor connectorsAmal Kaddah
This document discusses different types of mandibular major connectors for removable partial dentures. It describes the structural requirements and functions of lingual bars, sublingual bars, Kennedy (double lingual) bars, cingulum bars, labial bars, and lingual plates. Key requirements for mandibular major connectors include providing cross-arch stabilization, avoiding impingement of tissues, and distributing forces broadly. The document also briefly discusses minor connectors and their functions in connecting parts of the prosthesis.
Centric relation relevance and role in complete denture construction NAMITHA ANAND
This document discusses centric relation, which refers to the relationship between the mandible and skull when the condyles are in their most superior position in the mandibular fossa against the posterior slope of the articular eminence. It has gone through various changing definitions but is now widely accepted to mean the anterior-superior position. Recording centric relation is important for complete denture construction as it provides proprioceptive feedback and acts as the starting point for occlusion. There are various passive and active methods to retrude the mandible as well as intraoral and extraoral graphic methods to record the position.
MAJOR CONNECTORS AND MINOR CONNECTORS IN RPD - Dr Prathibha PrasadDr Prathibha Prasad
The document discusses different types of major and minor connectors used in removable partial dentures. Major connectors discussed include palatal bar, strap, U-shaped, and plate connectors for maxillary arches and lingual bar, linguoplate, sublingual bar, and double lingual bar connectors for mandibular arches. Key factors in choosing a major connector are the number of teeth being replaced, available space, and need for rigidity or support. Minor connectors help stabilize and retain components on one side of the dental arch to the other.
This document discusses occlusion in removable partial dentures. It outlines several types of occlusion including static and dynamic occlusion. Desirable occlusal contacts are bilateral contacts of posterior teeth in centric occlusion. Methods for establishing occlusion include direct apposition of casts if enough teeth remain, interocclusal records with posterior teeth, or using occlusal rims. The functionally generated path method can also be used to develop a dynamic occlusion record without an articulator. Proper occlusion is important for the success, comfort and longevity of removable partial dentures.
Description of Biomechanics of occlusion, Effect of anatomical determinants, Ideal occlusion, Evolution of occlusion, Concepts of Occlusion in FPD such as Group function occlusion, canine guided occlusion, Occlusal contacts, Occlusal Interferences, Patient"s adaptability, Pathogenic occlusion and Philosophies of full mouth rehabilitation. Added references for further readings.
This document provides instructions for constructing an Adams clasp, which is used in orthodontics. It has three main parts: two arrowheads that engage the mesial and distal undercuts of a tooth, and a bridge connecting the arrowheads at a 45 degree angle to the long axis of the root. The 27 steps described include: preparing the undercuts on the tooth, bending wire to form the basic shape, checking fit on the model, forming the arrowheads and adjusting their angle, adapting the wire across occlusion, and finishing with distal tagging. Key requirements are that the arrowheads fully engage the undercuts and the bridge is parallel to the occlusal plane.
This document presents classification systems for complete edentulism, partial edentulism, and completely dentate patients. For complete edentulism, it describes 4 classes based on factors like residual bone height, ridge morphology, muscle attachments, and occlusal relationships. Partial edentulism classes are determined by location/extent of edentulous areas, abutment conditions, occlusion, and residual ridges. Completely dentate classes consider tooth condition and occlusal scheme, with higher classes requiring more extensive pre-prosthetic therapy.
Different gingival finish lines (margins) of crowns and bridgesSana Mateen Munshi
The document discusses various considerations for margin placement in tooth preparations, including biological, mechanical, and aesthetic factors. It describes advantages and disadvantages of different margin types such as supragingival and subgingival margins. Common margin designs like shoulder, bevel, and chamfer margins are explained. Guidelines are provided for reducing tooth structure during preparation in a systematic manner.
This document discusses different concepts of occlusion including bilaterally balanced occlusion, unilaterally balanced occlusion, and mutually protected occlusion. It describes the key features of each concept and compares their advantages and disadvantages. The document also discusses factors that influence occlusion like condylar guidance, anterior guidance, and patient adaptability. It defines pathogenic occlusion and lists potential signs and symptoms. Finally, it outlines objectives and techniques for occlusal treatment, including the use of occlusal splints or devices.
Fixed prosthodontics problems and solutions in dentistryPrivate Office
This document discusses common problems that can occur with dental impressions and stone models, and their potential causes and solutions. It describes issues such as voids, tears or pulls in impressions that could result in poor fitting restorations. Specific problems covered include inhibited or slow setting impressions, lack of detail, voids or tears at margins, facial-lingual pulls, tray-tooth contact, delamination, poor bonding to trays, and discrepancies in stone models. For each problem, potential causes such as expiration, contamination, inadequate technique, or material incompatibility are identified along with recommended solutions.
Principles of tooth preparation in Fixed Partial DenturesVinay Kadavakolanu
The document discusses principles of tooth preparation for dental restorations. It summarizes that the all-ceramic crown preparation design requires the highest percentage of tooth structure reduction at 65.26%, while ceramic veneers require the lowest at 30.28%. Proper tooth preparation aims to preserve tooth structure, provide retention and resistance, maintain structural durability and marginal integrity, and preserve the periodontium. The amount and location of tooth reduction impacts these factors.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Biologic width understanding and its preservationSah Oman
This document discusses the biologic width, which refers to the dimensions of the dentogingival junction including the epithelial attachment and underlying connective tissue. It was first described as being on average 2.04mm, consisting of 0.97mm of epithelial attachment and 1.07mm of connective tissue. Placing restorative margins within the biologic width can lead to gingival inflammation, clinical attachment loss, bone loss, and gingival recession. The document discusses different options for margin placement and how to evaluate whether the biologic width has been violated.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Principles of tooth prep /certified fixed orthodontic courses by Indian denta...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
Mech. & esth. principles of preparation ( crown )Ahmed Elhlawany
The document discusses factors that influence retention and resistance form of dental restorations. It describes 6 factors that influence retention: 1) magnitude of dislodging forces, 2) geometry of the tooth preparation, 3) roughness of the restoration surface, 4) materials being cemented, 5) type of luting cement, and 6) film thickness of the cement. It also outlines 3 factors that influence resistance form: 1) magnitude and direction of dislodging forces, 2) geometry of the tooth preparation, and 3) physical properties of the luting cement. The document emphasizes how proper preparation design and material selection can optimize retention, resistance, and prevent deformation of the restoration.
- Dental crowns are restorations that cover and encase teeth. They are used to rebuild broken or decayed teeth, strengthen teeth, or improve cosmetic appearance.
- The process of making a crown typically takes two appointments - the tooth is prepared, an impression is made, and a temporary crown is placed at the first visit. At the second visit, the permanent crown is cemented.
- Studies have shown that crowns with shoulder finish lines have better marginal fit than those with chamfer finish lines. However, crowns with chamfer finish lines have greater fracture strength. The type of finish line used depends on the specific tooth and restoration.
This document is a catalog from Clipco Exports (India) showcasing various promotional products including ball pens, highlighters, paperweights, and other office supplies. The catalog is divided into 17 sections with each section describing 2-4 related products through their item numbers and short descriptions. Materials featured include plastic, metal, glass and paper. Product shapes include bones, bottles, capsules, injections and tubes.
This document discusses crown lengthening procedures and biological width. It notes that crown lengthening surgery should remove enough bone to allow for 2mm of tooth structure, the biological width of 2mm, and 1mm sulcus depth for non-post-core teeth. For teeth requiring posts, an additional 1.5mm ferrule effect space is needed. The document outlines factors to consider for crown lengthening like tissue biotype, tooth anatomy, and restorability. It recommends more conservative bone removal lingually and waiting at least 20 weeks after surgery before final crown preparation.
This document provides an overview of human oral morphology. It identifies and describes the features of each tooth type, including incisors, canines, premolars, and molars. For each tooth, the document highlights distinguishing characteristics such as shape, size, number of roots, cusp patterns, and developmental features to aid in identification. Proper orientation of teeth is also discussed to determine whether a tooth is from the right or left side of the dental arch.
Gingival finish lines /certified fixed orthodontic courses by Indian dental ...Indian dental academy
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
00919248678078
A 40-year-old female presented with an inability to eat properly due to a fractured crown. Upon examination, the remaining tooth structure was below the gumline and not accessible. The procedure involves adjusting the gum tissue and bone around the tooth to provide better access and ensure a proper restoration fit. Biologic width and ferrule effect must be considered to prevent inflammation, bone loss, and future issues. Complications can include an unaesthetic appearance, sensitivity, and loss of bone or papilla.
The document discusses various concepts of occlusion for fixed partial dentures, including bilaterally balanced occlusion, unilaterally balanced occlusion, and mutually protected occlusion. Bilaterally balanced occlusion aims for simultaneous contact on both sides but is difficult to achieve, while unilaterally balanced occlusion distributes forces to multiple teeth on the working side only. Mutually protected occlusion relies on anterior guidance to prevent posterior contact during excursive movements. The concepts vary in their distribution of forces and indications depending on a patient's needs.
The biological width refers to the dimensions of the junctional epithelium and connective tissue attachment above the alveolar crest, which averages 2.04mm. Placement of restoration margins within 1mm of the gingival sulcus is ideal to preserve this biological width, while subgingival placement can lead to inflammation, recession, or bone loss by violating the biological width. When a violation occurs, it can be corrected by surgery to remove bone away from the margin by the ideal biological width distance, or by orthodontic extrusion. Maintaining the biological width is essential for periodontal health.
This document discusses the development of occlusion from early childhood through adulthood. It begins by defining occlusion and reviewing literature on occlusion concepts. It then describes the development of occlusion from the neonate mouth with gum pads through the deciduous dentition and mixed dentition periods. Key aspects discussed include the eruption sequence and characteristics of primary teeth, transitional periods in mixed dentition, and Baume's classification of occlusal relationships in primary dentition. The document will continue discussing occlusion aspects related to the permanent dentition.
The document discusses the temporomandibular joint (TMJ), providing definitions and describing its key components, development, movements, age-related changes, and clinical applications. The TMJ is a synovial joint that allows hinge-like opening and closing of the mouth. It has unique features like an articular disc and fibrocartilage covering. Development occurs in three stages from weeks 7-17. The joint faces clinical issues like ankylosis, pain disorders, and limited mobility with age. Surgical treatments aim to create gaps and prevent re-fusion for improved function.
Biology of bone in complete dentures, removable partial denture, overdenturePiyaliBhattacharya10
describes the biology of bone in physiologic condition, about bone remodeling, bone resorption in complete denture, combination syndrome, bone resorption in immediate denture and overdenture
The document provides information about the temporomandibular joint (TMJ) including its definition, development, anatomical components, movements, vascular supply, innervations, and prosthodontic implications. It defines the TMJ as the articulation between the temporal bone and mandible. The TMJ is a bilateral diarthrodial and ginglymoid joint that develops later than other joints. It has articular disc, condyle, articular eminence, ligaments, muscles and other components that allow various movements like opening, closing, and lateral excursions. Occlusal discrepancies can affect the TMJ and its treatment may involve occlusal splints or orthodontics/orthognath
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The document defines various anatomical structures and movements of the temporomandibular joint (TMJ). It describes the TMJ as a synovial joint that allows hinge-like and sliding movements between the condyle of the mandible and temporal bone. Key terms defined include the articular disc, ligaments, muscles of mastication, and different movements such as protrusion, retrusion, and lateral excursions.
The document discusses several direct and indirect factors related to tooth morphology that influence periodontal health. The direct factors include proximal contact areas, interproximal spaces, embrasures, and facial and lingual contours of tooth crowns. Indirect factors involve crown form, root form, angulation of crowns and roots, self-cleaning ability, cusp form, and continuity of marginal ridges and central grooves. Specific anatomical features like proximal maximal contour, root outline, and lingual angulation of posterior crowns are described in detail due to their significance. Maintaining proper tooth morphology through these factors helps prevent periodontal issues.
This document discusses the temporomandibular joint (TMJ), including its classification, development, anatomy, disorders, and examination. It begins by classifying joints in the body and describing the development of the TMJ from mesenchymal condensation in the embryo. It then details the bony and soft tissue anatomy of the TMJ, including the articular disc, ligaments, muscles, and vascular supply. Common TMJ disorders like disc displacement, subluxation, dislocation, and ankylosis are outlined. The document concludes with descriptions of examining the TMJ through inspection, palpation, range of motion testing, and imaging modalities.
Osteology and mucose membrane of maxi & mandiblepranav verma
This document discusses the anatomy and histology of structures that support complete dentures. It describes the key stress bearing and peripheral/sealing areas that dentures rely on for support. The residual ridge and hard palate are identified as primary stress bearing regions due to their thick, keratinized mucosa firmly attached to underlying bone. In contrast, peripheral areas like the vestibule and lips have thin, movable mucosa with loose tissue unsuitable for supporting denture forces. A thorough understanding of oral tissues is essential for dentists to design complete dentures that respect the anatomical and physiological limitations of the edentulous mouth.
The document discusses contact areas and contours of teeth. It defines contact area as the area between adjacent teeth that touches. Contours are the vertical curvatures on facial and lingual surfaces. Ideal contacts and contours are important for dental and periodontal health. They prevent food impaction and decay, and maintain occlusal harmony. The document describes the different types of contours and contact areas for different teeth. It also discusses procedures for separating teeth to establish proper contacts and contours, including wedges and matrices. Maintaining ideal contacts and contours has benefits like conserving periodontal health and improving restoration longevity.
Examination of tmj &muscles of mastication (2)rachitajainr
The temporomandibular joint (TMJ) connects the mandible to the temporal bone. It is a synovial joint that allows hinge-like and gliding motions. The articular disc separates the joint into upper and lower compartments. Ligaments such as the collateral, temporomandibular, and sphenomandibular ligaments stabilize and limit movements of the joint. Examination of the TMJ involves history taking, inspection, palpation of the joint and muscles, and assessing maximum mouth opening.
The temporomandibular joint (TMJ) connects the mandible to the temporal bone and enables opening and closing of the jaw as well as lateral and protrusive movements. It is composed of the mandibular condyle, articular disc, articular surfaces, capsule, ligaments, and muscles. The articular disc separates the condyle from the temporal bone and aids smooth jaw movement. Proper functioning of the TMJ is essential for effective dental practice as any disorders can impact occlusion.
The document discusses key concepts related to occlusion and the stomatognathic system. It defines occlusion, centric relation, and centric occlusion. It describes the temporomandibular joint and muscles of mastication that control jaw movement. Balanced occlusion between the maxillary and mandibular teeth is important for stability of removable prostheses. The relationship between centric relation and centric occlusion is also discussed.
This document provides an overview of factors affecting the stability of complete dentures. It defines stability and discusses several key factors, including:
- Residual ridge anatomy (height, shape, arch form)
- Denture base adaptation to underlying tissues
- Relationship of denture bases to muscles like the buccinator and mylohyoid
- Opposing occlusal surfaces
- Contours and extensions of denture borders
Stability results from a balance of forces from muscles that can displace dentures and those that resist displacement. Proper consideration of these anatomic and muscular factors during denture fabrication can enhance stability.
The document discusses the relationship between tooth form and function. It explains how characteristics like root size and shape, crown size, contact areas, and embrasures are proportional to each other and related to jaw movements. Tooth form directly influences jaw morphology and movements. For example, humans have more complex tooth anatomy and jaw movements compared to animals with simpler conical teeth. The positions of contact areas, contours, embrasures, and occlusal curves are adapted for functions like mastication, protection of tissues, and self-cleansing of teeth.
The document provides information on dental anatomy. It begins by stating the objectives of identifying major dental structures. It then describes the types of teeth as primary or permanent, and classifications by characteristics. The major dental tissues are enamel, dentin, cementum, and dental pulp. Teeth have a crown, neck and root. Periodontal structures include the gingiva, alveolar bone, cementum and periodontal ligament. Teeth receive blood supply from the maxillary and mandibular arteries and are innervated by branches of the trigeminal nerve.
The document summarizes the structure and characteristics of the alveolar bone that supports teeth. It has two main parts: the cortical plates and spongy bone between them. The cortical plates are thin layers of compact bone that form the outer shells of the alveolar processes. Spongy bone fills the area between the cortical plates, containing trabeculae of bone surrounded by marrow. The alveolar bone undergoes remodeling and resorption with age, tooth movement, periodontal disease, and loss of tooth function.
This document discusses bone considerations for dental implant therapy. It describes the different types of bone, including cortical, cancellous, woven bone and their properties. It also discusses factors like available bone height, width, density and their effect on implant treatment planning and surgical protocols. Insufficient bone requires augmentation procedures like bone grafts or sinus lifts to provide adequate support for dental implants. The success of implants placed in deficient bone depends on careful treatment planning and surgical skill.
8 Surprising Reasons To Meditate 40 Minutes A Day That Can Change Your Life.pptxHolistified Wellness
We’re talking about Vedic Meditation, a form of meditation that has been around for at least 5,000 years. Back then, the people who lived in the Indus Valley, now known as India and Pakistan, practised meditation as a fundamental part of daily life. This knowledge that has given us yoga and Ayurveda, was known as Veda, hence the name Vedic. And though there are some written records, the practice has been passed down verbally from generation to generation.
Travel Clinic Cardiff: Health Advice for International TravelersNX Healthcare
Travel Clinic Cardiff offers comprehensive travel health services, including vaccinations, travel advice, and preventive care for international travelers. Our expert team ensures you are well-prepared and protected for your journey, providing personalized consultations tailored to your destination. Conveniently located in Cardiff, we help you travel with confidence and peace of mind. Visit us: www.nxhealthcare.co.uk
Breast cancer: Post menopausal endocrine therapyDr. Sumit KUMAR
Breast cancer in postmenopausal women with hormone receptor-positive (HR+) status is a common and complex condition that necessitates a multifaceted approach to management. HR+ breast cancer means that the cancer cells grow in response to hormones such as estrogen and progesterone. This subtype is prevalent among postmenopausal women and typically exhibits a more indolent course compared to other forms of breast cancer, which allows for a variety of treatment options.
Diagnosis and Staging
The diagnosis of HR+ breast cancer begins with clinical evaluation, imaging, and biopsy. Imaging modalities such as mammography, ultrasound, and MRI help in assessing the extent of the disease. Histopathological examination and immunohistochemical staining of the biopsy sample confirm the diagnosis and hormone receptor status by identifying the presence of estrogen receptors (ER) and progesterone receptors (PR) on the tumor cells.
Staging involves determining the size of the tumor (T), the involvement of regional lymph nodes (N), and the presence of distant metastasis (M). The American Joint Committee on Cancer (AJCC) staging system is commonly used. Accurate staging is critical as it guides treatment decisions.
Treatment Options
Endocrine Therapy
Endocrine therapy is the cornerstone of treatment for HR+ breast cancer in postmenopausal women. The primary goal is to reduce the levels of estrogen or block its effects on cancer cells. Commonly used agents include:
Selective Estrogen Receptor Modulators (SERMs): Tamoxifen is a SERM that binds to estrogen receptors, blocking estrogen from stimulating breast cancer cells. It is effective but may have side effects such as increased risk of endometrial cancer and thromboembolic events.
Aromatase Inhibitors (AIs): These drugs, including anastrozole, letrozole, and exemestane, lower estrogen levels by inhibiting the aromatase enzyme, which converts androgens to estrogen in peripheral tissues. AIs are generally preferred in postmenopausal women due to their efficacy and safety profile compared to tamoxifen.
Selective Estrogen Receptor Downregulators (SERDs): Fulvestrant is a SERD that degrades estrogen receptors and is used in cases where resistance to other endocrine therapies develops.
Combination Therapies
Combining endocrine therapy with other treatments enhances efficacy. Examples include:
Endocrine Therapy with CDK4/6 Inhibitors: Palbociclib, ribociclib, and abemaciclib are CDK4/6 inhibitors that, when combined with endocrine therapy, significantly improve progression-free survival in advanced HR+ breast cancer.
Endocrine Therapy with mTOR Inhibitors: Everolimus, an mTOR inhibitor, can be added to endocrine therapy for patients who have developed resistance to aromatase inhibitors.
Chemotherapy
Chemotherapy is generally reserved for patients with high-risk features, such as large tumor size, high-grade histology, or extensive lymph node involvement. Regimens often include anthracyclines and taxanes.
10 Benefits an EPCR Software should Bring to EMS Organizations Traumasoft LLC
The benefits of an ePCR solution should extend to the whole EMS organization, not just certain groups of people or certain departments. It should provide more than just a form for entering and a database for storing information. It should also include a workflow of how information is communicated, used and stored across the entire organization.
Histololgy of Female Reproductive System.pptxAyeshaZaid1
Dive into an in-depth exploration of the histological structure of female reproductive system with this comprehensive lecture. Presented by Dr. Ayesha Irfan, Assistant Professor of Anatomy, this presentation covers the Gross anatomy and functional histology of the female reproductive organs. Ideal for students, educators, and anyone interested in medical science, this lecture provides clear explanations, detailed diagrams, and valuable insights into female reproductive system. Enhance your knowledge and understanding of this essential aspect of human biology.
Lecture 6 -- Memory 2015.pptlearning occurs when a stimulus (unconditioned st...AyushGadhvi1
learning occurs when a stimulus (unconditioned stimulus) eliciting a response (unconditioned response) • is paired with another stimulus (conditioned stimulus)
Are you looking for a long-lasting solution to your missing tooth?
Dental implants are the most common type of method for replacing the missing tooth. Unlike dentures or bridges, implants are surgically placed in the jawbone. In layman’s terms, a dental implant is similar to the natural root of the tooth. It offers a stable foundation for the artificial tooth giving it the look, feel, and function similar to the natural tooth.
DECLARATION OF HELSINKI - History and principlesanaghabharat01
This SlideShare presentation provides a comprehensive overview of the Declaration of Helsinki, a foundational document outlining ethical guidelines for conducting medical research involving human subjects.
Travel vaccination in Manchester offers comprehensive immunization services for individuals planning international trips. Expert healthcare providers administer vaccines tailored to your destination, ensuring you stay protected against various diseases. Conveniently located clinics and flexible appointment options make it easy to get the necessary shots before your journey. Stay healthy and travel with confidence by getting vaccinated in Manchester. Visit us: www.nxhealthcare.co.uk
5-hydroxytryptamine or 5-HT or Serotonin is a neurotransmitter that serves a range of roles in the human body. It is sometimes referred to as the happy chemical since it promotes overall well-being and happiness.
It is mostly found in the brain, intestines, and blood platelets.
5-HT is utilised to transport messages between nerve cells, is known to be involved in smooth muscle contraction, and adds to overall well-being and pleasure, among other benefits. 5-HT regulates the body's sleep-wake cycles and internal clock by acting as a precursor to melatonin.
It is hypothesised to regulate hunger, emotions, motor, cognitive, and autonomic processes.
These lecture slides, by Dr Sidra Arshad, offer a simplified look into the mechanisms involved in the regulation of respiration:
Learning objectives:
1. Describe the organisation of respiratory center
2. Describe the nervous control of inspiration and respiratory rhythm
3. Describe the functions of the dorsal and respiratory groups of neurons
4. Describe the influences of the Pneumotaxic and Apneustic centers
5. Explain the role of Hering-Breur inflation reflex in regulation of inspiration
6. Explain the role of central chemoreceptors in regulation of respiration
7. Explain the role of peripheral chemoreceptors in regulation of respiration
8. Explain the regulation of respiration during exercise
9. Integrate the respiratory regulatory mechanisms
10. Describe the Cheyne-Stokes breathing
Study Resources:
1. Chapter 42, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 36, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 13, Human Physiology by Lauralee Sherwood, 9th edition
The Nervous and Chemical Regulation of Respiration
Iv.tooth prep v. occlusion
1. IV. TOOTH PREPARATION
A. Definition of Tooth Prep
-Tooth Preparation is the
mechanical treatment of dental
disease or injury to hard tissues
that restores a tooth to its original
form or contour
2. IV. TOOTH PREPARATION
B. Objectives of Tooth Prep
1. Reduction of the tooth in miniature to provide
retainer support
2. Preservation of healthy tooth structure to secure
resistance form
3. Provision for acceptable finish lines
4. Performing pragmatic axial tooth reduction to
encourage favorable tissue response from artificial
crown contours
3. IV. TOOTH PREPARATION
C. Principles in Tooth Prep
1. Preservation of tooth structure
2. Retention and resistance form
3. Structural durability of the restoration
4. Marginal integrity
5. Preservation of the periodontium
4. IV. TOOTH PREPARATION
D. Basic Steps of Tooth Prep
1. Incisal/ Occlusal Reduction
2. Facial Reduction
3. Lingual/ Palatal Reduction
4. Proximal Reduction
5. Gingival Margins/ Finishing Lines
6. Rounding up of Sharp Corners and Line Angles
7. Finishing
9. BIOLOGIC
Conservation of tooth structure MECHANICAL
Avoidance of overcontouring Maximum surface area
Supragingival margins Apical extension
Harmonious occlusion Adequate thickness of metal
Protection against tooth fracture Bulk at margins
ESTHETIC
Minimum display of metal
Maximum thickness of porcelain
Porcelain occlusal surfaces
Subgingival margins
10. Depth Guides /
Orientation Grooves
Help dentists in the preparation of teeth
Prevent overreduction as well as
underreduction
11. 1. Incisal/ Occlusal Reduction
Anterior teeth – 1.5 – 2mm or 2/3 of the
incisal 3rd
Posterior teeth –
-metal occlusal
1.5-2mm
-metal and porcelain/ fiber reinforced
FC-1.5-2mm
GC-1-1.5mm
30. BIOLOGIC WIDTH
What is Biologic Width?
It is a band of soft tissue attachment
What is its composition?
It is composed of approximately 1mm
of junctional epithelium and 1mm of
connective tissue fibers.
31. The dentogingival junction includes the gingival sulcus (A-B) approximately 0.8 mm .
The junctional epithelium (B-C) 0.7 to 1.3mm (average 1mm)
The connective tissue attachment (C-D) 1.07mm.
The biologic width (B-D) averages 2mm in occlusogingival height.
D
C
B
A
32. “When you bury the collar,
You attend the funeral of the
periodontium”
33. BIOLOGIC WIDTH
What is its significant clinical implication?
Crown margins can be placed
subgingivally but should not encroach
the Biologic Width.
34. IF VIOLATED …
Inflammation
and
Osteoclastic Activity
Bone Resorption
and
Pocket Formation
39. Most Common Errors in Tooth
Preparation
Over reduction
Under reduction
Undercuts
Rough tooth preparations
Lack of parallelism
Failure to contour proximal surfaces of
adjacent teeth
40. Type of CVC Facial Lingual Incisal/
Reduction Reduction Occlusal
Reduction
Acrylic Jacket .75-1mm .75-1mm Ant. 1.5-2 mm
Crown shoulder shoulder
Porcelain Jacket 1.2-1.5mm .75 – 1mm Ant. 1.5-2 mm
Crown shoulder shoulder Post.
Porcelain Fused 1.2-1.5 mm .75-1mm FC-1.5-2 mm
to Metal crown shoulder chamfer GC-1-1.5 mm
Fiber Reinforced 1.2-1.5mm .75-1mm
Metal Crown shoulder chamfer
Acrylic Fused to 1.2-1.5 mm .75-1mm Ant. 1.5 – 2 mm
Metal Crown shoulder chamfer Post. 1-1.5 mm
Complete Veneer .75-1mm .75-1mm Post. 1-1.5mm
Metal Crown chamfer
chamfer
42. A joint is a joining together of two bones. The temporomandibular joint (TMJ) is
the articulation between the temporal bone and the mandible. It is bilateral, and
movement of the right and left sides are interrelated and function as a single
unit..
The condyle of the mandible articulates with the mandibular
(GLENOID) fossae of the temporal bone. The specific location is the posterior
slope of the articular tubercle and the anterior portion of the mandibular
(glenoid) fossae. The condyle does not fit into the center of the mandibular
fossae but rests closer to the articular tubercle. The condyle and articular
eminence do not actually touch, the articular disc (meniscus) rests between
them. This disc is a pad of dense fibrous connective tissue that is thickest at the
posterior ends, thinnest in the middle and thicker again at the anterior ends. The
articular disc, in effect, separates the temporomandibular joint into upper and
lower joint spaces. Laterally and medially, the disc is attached to the condyle
itself, so that whenever the condyle glides forward and backward, the disc
moves with it.
The condyle and articular eminence are covered by dense
collagenousconnective tissue, which contains no blood vessel or nerves.
Synovial fluids bathes this structures, providing nourishment and lubrication
that enables the bones to glide over each other without friction.
A thick fibrous capsule surrounds and encloses the entire joint. The
43. disc and capsule are fused anteriorly, and some fibers of the lateral pterygoid
muscle insert into the disc. Posteriorly, the disc and capsule are not directly
attached but are connected by means of a retrodiscal pad, a pad of loose
connective tissue that allows for anterior movement of the joint.
Nerve and blood supply- Innervation is supplied by two nerves, the
auriculotemporal and ,masseteric nerves, which are branches of the mandibular
nerve (V3), blood supply is provided by branches of the superficial temporal and
maxillary arteries.
Movement- TMJ movement within the temporomandibular joint is essentially of
two types: Hinge (swinging) motion and gliding movement.
The condyle of the mandible articulates with the
mandibular (glenoid) fossae of the temporal bone. The
specific location is the posterior slope of the articular
tubercle and the anterior portion of the mandibular
(glenoid) fossae. The condyle does not fit into the center of
the mandibular fossae but rests closer to the articular
tubercle . The condyle and articular eminence do not
actually touch, the articular disc (meniscus) rests between
them. This disc is a pad of dense fibrous connective tissue
that is thickest at the posterior ends, thinnest in the
middle, and thicker again at the anterior ends. The
articular disc in effect, separates the teemporomandibular
joint into upper and lower joint spaces. Laterally and
medially, the disc is attached to the condyle itsel, so that
whenever the condyle glides forward and backward, the
disc moves with it.
The condyle and articular eminence are covered by dense collagenous connective tissue, which contain s no blood vessel or
nerves. Synovial fluid bathes these structures, providing nourishment and lubrication that enables the bones to glide over each
other without friction. A thick fibrous capsule surrounds and encloses the entire joiunt. The disc and capsule are fused
anteriorly....(contiued above)
44. Mandibular movement
Mandibular movement can be broken down into a series of motions that
occur around three axes:
2.Horizontal
This movement, in the saggital plane occurs when the retruded
mandible produces a purely rotational opening and closing movement
around the hinge axis, which extends through both condyles.
45. 2. Vertical
The movement occurs in the horizontal plane when the
mandible moves into a lateral axcursion. The center for this
rotation is a vertical axis extending through the working side
condyle.
46. Sagittal
When the mandible moves to one side, the condyle on the side
opposite from the direction of movement travels forward. As it does, it
encounters the eminentia of the glenoid fossa and moves downward
simultaneously. When viewed in the frontal plane, this produces a
downward arc on the side opposite the direction of movement, rotating
about an anteroposterior (sagittal) axis passing through the other
condyle.
47. Various mandibular movements are comprised of motions occuring about one or
more of the axes. The up and down motion of the mandible is a combination of
two movements...
...There is a purely rotational component
produced by the condyle rotating in the lower
compartment of the temporomandibularjoints.
...There is also some gliding movement in the
upper compartment of the jaw.
48. When the mandible slides forward so that the maxillary and
mandibular teeth are in an end to end relationship, it is in a protrusive
position. Ideally, the anterior segment of the mandible will travel a path
guided by contacts between the anterior teeth.
49. Mandibular movement to one side will place it in a working, or
laterotrusive relationship on that side and a nonworking or mediotrusive
relationship on the opposite side;e.g., if it moves to the left, the left side is
the working side, and the right side is the nonworking side. In this type of
movement, the condyle on the nonworking sidewill arc forward and
medially (A). Meanwhile, the condyle on the working side will shift
laterally and usually slightly posteriorly (B). This bodily shift of the
mandible in the direction of the working side was first described by
Bennet.
The presence of an immediate
or early side shift has been
reported in 86% of the
condyle studied. In addition to
demonstrating the
predominant presence of early
side shift, Lundeen and Wirth
have shown its median
dimension to be approximately
1.0, with a maximum of
3.0mm. Following the
immediate side shift, there is
gradual shifting of the
mandible.
50. The determinants of mandibular movement
The two condyles and the contacting teeth are analogous to the three legs of
an inverted tripod suspended in the cranium.
The determinants of the movements of that tripod are:
-posteriorly, the right and left temporomandibular joints;
-anteriorly, the teeth of the maxillary and mandibular arches;
- And overall, the neuromuscular system.
The dentist has no control over the posterior determinants, the temporomandibular
joints.they are unchangeable.
However, they influence the movements of the mandible, and of the teeth, by the paths
which the condyles must travel when the mandible is moved by the muscles of
mastication. The measurement and reproduction of those condylar movements is the
basis for the use of the articulator.
The anterior determinant, the teeth, provides guidance to the mandible in several ways.
The posterior teeth provide the vertical stops for mandibular closure. They also guide
the mandible into the position of maximum intercuspation, which may or may not
correspond with the optimum position of the condyles in the glenoid fossae. The
anterior teeth (canine to canine) help to guide the mandible in right and left lateral
excursive movements and in straight protrusive movements.
Dentists have direct control over the tooth determinant by orthodontic movement of
teeth; restoration of the occlusal surfaces ;and equilibration, or selective grinding, of
any teeth which are not in harmonious relationship. Intercuspal position and anterior
guidance can be altered, for better or for worse, by any of these means.
51. The Determinants of Occlusion
The closer to a determinant that a tooth is located, the more it will be
influenced by the determinant. A tooth placed near the anterior region
will be influenced greatly by anterior guidance, and only slightly by the
temporomandibular joint. A tooth in the posterior region will be
influenced partially by the anterior guidance.
The neuromuscular system,
through proprioceptive nerve
endings in the periodontium,
muscles, and joints, monitors the
position of the mandible and its
paths of movement. Through
reflex action, it will program the
most nearly physiologic paths of
movement possible under the set
of circumstances present. Dentist
have indirect control over this
determinant. Procedures done to
the teeth may be reflected in the
response of the neuromuscular
system.
52. The Determinants of Occlusion
Condylar Guidance
Anterior/Incisal Guidance
Occlusal Plane
Occlusal Curve
Cusp Height
54. The Types of Occlusal
Interferences
Centric Interference
Working Interference
Non-Working Interference
Protrusive Interference
55. One of the objectives of restorative dentistry is to place the teeth in harmony
with the temporomandibular joints. This will result in minimum stress on the
teeth, and only a minimum effort need be expended by the neuromuscular
system to produce mandibular movements.
When the teeth are not in harmony with the joints and with the movements of the
mandible, an interference is said to exist.
Occlusal interferences
Interferences are undesirable occlusal contacts which may produce deviation
during closure to maximum intercuspation, or which may hinder smooth
passage to and from the intercuspal position. There are four types of occlusal
interferences:
5.Centric
7.Working
9.Nonworking
4. Protrusive
56. The centric interference is a premature contact which occurs when the mandible
closes wit the condyles in a retruded, superior position in the glenoid fossa.
It will cause deflection of the mandible in a forward and/ or lateral direction.
57. A working interference may occur when there is contact between the maxillary
and mandibular posterior teeth on the same side of the arches as the direction
in which the mandible has moved. If that contact is heavy enough to disclude
anterior teeth, or interfere with the smooth progress of the nonworking side
condyle, it is an interference.
58. A nonworking interference is an occlusal contact between maxillary and
mandibular teeth on the side of the arches opposite the direction in which the
mandible has moved in a lateral excursion. The nonworking interference is of a
particularly destructive nature. The potential for damaging the masticatory
apparatus has been attributed to changes in the mandibular leverage, the
placement of forces outside the long axes of the teeth, and disruption of normal
muscle function.
59. The protrusive interference is a premature contact occurring between the
mesial aspects of the mandibular posterior teeth and the distal aspects of
maxillary posterior teeth. The proximity of the teeth to the muscles and the
oblique vector of the forces make contacts between opposing posterior teeth
during protrusion potentially destructive.
60. The protrusive interference is a premature contact occurring between the mesial
aspects of mandibular posterior teeth and the distal aspects of maxillary
posterior teeth. The proximity of the teeth to the muscles and the oblique vector
of the forces make contacts between opposing posterior teeth during protrusion
potentially destructive.
61. There may be anis lowered, the
If the threshold occlusal
disharmony which versus pathologic occlusion
disharmony
Normal had been
(shaded bar) which ismay ideal,
previously tolerated not produce
but which only slightlyby the normal of the population is
symptomsis tolerated more than 10%
In in the patient. (a
patient there complete a pathologic
occlusion can become harmony between the teeth and the
because it is below his
threshold ofSimple muscle joints. Only in that small group
occlusion). perception and
temporomandibular
discomfort. teeth give waymaximum intercuspation when
hypertonicity may achieve to muscle
do the
spasm, the mandible headaches and position with the
with chronic is in a retruded
localized tenderness. optimal superior retruded position in
condyles in the
the fossae.
Treatment is then
then rendered by 90% of the population,And position of
In the other nearly the
then decreasing or
eliminating the
first raisingintercuspation is 1.25+mm forward of the retruded
maximum the disharmony
patient’s
position.
threshold,
62. ARTICULATORS
-is a mechanical device which of the simulates
the movements of the mandible
The principle employed in
the use of articulators is the
mechanical replication of the
paths of movement of the
posterior determinants, the
twmporomandibular joints.
The instrument is then used
in the fabrication of fixed
and removable dental
restorations which are in
harmony with those
movements.
63.
64. As the mandible closes around the hinge axis ( m h a ), the
cusp tip of each mandibular tooth moves along an arc
65. The large dissimilarity between the hinge axis of the small
articulator ( a h a ) and the hinge axis of the mandible ( m h a ) will
produce a large discrepancy between the arcs of closure of the
articulator (broken line) and of the mandible (solid line).
67. The dissimilarity between the hinge axis of the full size
semi-adjustable articulator ( a h a ) and the mandibular hinge axis
( m h a ) will cause a slight discrepancy between the arcs of
closure of the
articulator
(broken line)
and of the
mandible
(solid line)
68. There is only a slight
difference between cusp paths
on a full size articulator
(c)and those in the mouth
(m), even though the cast
mounting exhibits a
slight discrepancy
69. The condyle travels a curved path in mandibular movements ( A )
This is reproduced in semi-adjustable articulators as a straight
path ( B ).
70. ..However, the angle changes between an open (C) and a closed
(D) nonarcon instrument <a3 not equal to <a4. For the amount of
opening illustrated, there would be a difference of 8 degrees
between the condylar inclination at an open position ( where the
Thearticulator settings are adjusted ) and a closed position (at which
angle between the condylar inclination and the
.
Occlusal plane of is used ).
the articulator the maxillary teeth remains
constant between an open (A) and a closed (B)
articulator <a1=<a2.
71. Transfer of the tooth hinge-axis relationship
Two caliper-style face-bows are in
use at the present time:
the Quick mount Face-bow
When a precision face-bow transfer is made,
both side arms are adjusted so that the stylus
at the end of each arm is located over the
hinge axis (arrow). A third reference point,
such as the plane indicator shown here, is
used.
An air activated pantograph for
recording mandibular movements
the Slidematic Face-bow
There may be an occlusal disharmony(shaded bar) which is not ideal, but which is tolerated by the patient because it is below his threshold of perception and discomfort (A). If the threshold is lowered, the disharmony which has been previously tolerated may produce symptoms in the patient. (B). Treatment is then rendered by first raising the patient’s threshold, and then decreasing or eliminating the disharmony (C).