Dental technology students on holiday

When you are on holiday is your brain still focused on Dental Technology and interesting things you could include into your portfolio or are you on h-o-l-i-d-a-y. Let me know your thoughts

Thank you 2013

I would like to thank all my students for their participation on the blog and for interacting with each other so well. I would like to urge each and every one of you to keep on coming to the blog and helping each other to improve and become better dental technicians for the future. Peer review is very important.

Interesting blog on articulators

http://martinelliluca.blogspot.it/2013/07/25-basic-aspects-regarding.html?m=1

Adams cribs

Please comment on the Adams crib

Your examples of a moment; Orthos

Post a picture that best illustrates this for you

This pic is from Blom as example 

These 2pics are examples from Mouton

Pic example from Van den Heever

Your examples of a couple; Orthos

Please post a picture that illustrates this the best in your opinion

Mouton's example's of a couple

This is example from Van den Heever

Class II malocclusion

Give a general description of the factors that characterize Class II malocclusion.

Changes that occur in wire because of manipulation

Explain the changes that occur to the different types of orthodontic wires when subjected to strain hardening as well as annealing processes.  (where applicable)

Rotation of teeth with orthodontics

Assuming that the centre of resistance in a tooth is in the middle of the apical third of that tooth;

Explain the effect the following lines of distal force will have on the position of the rotational centre and the movement of the tooth, when applied to a maxillary molar by means of a face bow.

(a)        A line of force passing through the centre of resistance.

                  

(b)        A line of force apical to the centre of resistance.                   

(c)        A line of force further apically to the centre of resistance.

(d)       A line of force passing occlusally to the centre of resistance. 

                                                                                                                

Translation of a free body

“A force which passes through the centre of resistance will produce pure

 translation of a free body”.

Give a short description of

           

(a)                The result if the force vector does not pass through the centre of resistance.                                                                                    

(b)               How the degree of translation (rotation) is effected by the perpendicular distance from the force vector to the centre of resistance.

Orthodontics in 3 millennia. Chapter 9: Functional appliances to midcentury

Download the article from Google drive and provide your comments below

Why would you agree or disagree with the following statement. Provide references to support your arguments

Any orthodontic appliance is a force system

Desirable characteristics of Orthodontic wires

Below is listed the main criteria for the selection of an orthodontic wire (Desirable characteristics)

(O’Brien W.J., Dental Materials and their selection, Pg 284)

• A large springback
• Low stiffness
• Good formability
• High stored energy
• Corrosion resistance
• Biocompatibility and environmental stability
• Low surface friction
• Capability to be welded or soldered to auxillaries
• Cost                                                                                                                   

Discuss each of these characteristics and why you think they are listed as desirable criteria for orthodontic wire.

Case 6 - Discuss the appropriate components you would place on this case and why?

Case 5 - Discuss the appropriate components you would place on this case and why?

Case 4 - Discuss the appropriate components you would place on this case and why?

Case 3 - Discuss your suggested treatment

Case 2 Discuss appliance you would fabricate for this case

Discuss the appropriate components you would place on this case and why?

Expectations for the Advanced Orthodontics block

Please post your expectations for this block regarding Orthodontics.

Reflective comment on Advanced Dentures block

Please provide a reflective comment on the Advanced denture block which we just completed.
Please comment on the following:

1. Workload
2. Portfolio
3. Lab week
4. Presentations
5. Feedback provided by me during the block
6. What could be done better, in future by you, to improve your chances of success?
7. What could I do better to improve your chances of success?

Lingualized Occlusion

Why do you think some dental technicians and dentists consider Lingualized occlusion a valuable occlusal concept? Remember why Niel Du Plessis discussed with you and also what he said about the selection of teeth for this type of scheme also see what literature says.

Lab Week - Experience

All of you have or are about to experience working in a commercial Dental Laboratory. The week was introduced to allow you, the student, to experience actual cases and actual laboratory experience and input from other qualified dental technicians as to how you can improve on your speed and quality.

I would like to know what your experiences were (2nd yrs) and are (3rd yrs) for Lab week.

What could be improved on for 2014 when you are in 3rd yr and 4th yr repectively. 3rd yrs please complete this after you have completed your Lab week.

Lab Week - Expectations

All of you have or are about to experience working in a commercial Dental Laboratory. The week was introduced to allow you, the student, to experience actual cases and actual laboratory experience and input from other qualified dental technicians as to how you can improve on your speed and quality.

I would like to know what your expectations were (2nd yrs) and are (3rd yrs) for Lab week.  

Overdentures

Discuss the benefits for a patient from the use of an overdenture.

Implants

Discuss the advantages of the use of implants to create better retention and stability in mandibular complete dentures. What are the vital factors that have to be taken into account when choosing a specific implant.

Incisal guidance

Discuss the factors for which the incisal guidance adjustment is used when setting teeth up for complete dentures in balanced occlusion. Also how/in which way this influences the anterior tooth arrangement and the choice of posterior teeth. Each student to comment in their own words and do not repeat or copy someone elses comments.

Compensating curve

I would like each of you to give me your understanding of what the role is of the compensating curve is, when setting the posterior teeth in balanced occlusion. You are not to copy-paste from textbooks and do not repeat another students comments.

For full dentures teeth should be set on the middle of the ridge - According to literature

Why do you think this is?
If the teeth are not set on the middle of the ridge how does it affect the entire denture as well as the opposing denture?

Comment on improvements that can be made

Post your peer review

Comment on pics

Comment on the occlusal plain and how you would recommend it be fixed

Comment on the following try in

picture will be added please comment

Using literature discuss the differences between an Arcon and a Non-Arcon articulators

Also provide the advantages and disadvantages for each

Discuss the temporomandibular joint movement and how these movements are accommodated or simulated by the different types of articulators

 (a) Non-adjustable articulator
(b) Semi-adjustable articulator
(c) Fully adjustable articulator

Immediate Dentures - choice for flange length

Discuss the factors that would influence your choice in flange length for an immediate denture.

What are your views on the portfolio?

Please comment

Fears for this block

Each student is required to post their fears for the block

Your expectations for this block

Each student is required to post their expectations for the block

Surgical stents and its importance

What is a surgical stent? In which circumstances are stents required? Why is it important to use one for edentulous cases? All 2013 third year students are required to comment.

Second Year Dental Technology Student group who's work has been represented in the last 8 weeks

Thank you guys for your contributions over the last 8 weeks. You have been very supportive and co-operative with all thw tasks and challenges presented to you. Well done on the completion of your portfolio's and presentations. I am so proud of you guys for your efforts and perseverance and for trusting me to get you through this block.

Requirements of a Resilient liner

• They should be of a biological inert material that is compatible with the oral tissue and does not support bacterial or fungal growth.
• They should be resilient and capable of maintaining this characteristic - a 2 year period of service is usually expected from a resilient liner.
• After curing the liner should be dimentionally stable and insoluble in oral fluid to maintain proper tissue contact.
• They should be colour stable throughout their useful life, resistant to staining and impervious to odours
• Though flexible they should resist abrasion anf thereby allow the practice of proper hygiene of the fitting surface.
• On curing they should maintain their bond to the denture base without damaging it.
• The manufacturing process should be relatively easy, it is not essential for the liner to be chairside material.

Occlusal schemes vs Occlusal concepts

Occlusal concepts relates to the maxillary and mandibular edentulous jaw relationship to each other from a buccal view.

Occlusal schemes relates to the relationship between the artificial teeth that is set for a completely edentulous jaw relationship.

Lingualized Occlussion as a concept

• Lingualized Occlusion is a setup technique developed to enhance denture stability for patients with severe alveolar bone resorption resulting in little or no ridge, or resulting in a discrepancy between the size of the narrowing and receding upper ridge compared with the widening and receding lower jaw. 
• This setup technique is also indicated for patients with implant-supported overdentures to eliminate lateral forces that can rock abutments loose over time. 
• Lingualized occlusion is appropriate for free-end attachment cases to reduce stress on distal extension, or for intra-coronal attachments to avoid breakage. 
• In a lingualized occlusion scheme, the objective is the elimination of buccal cusp contacts in order to alleviate lateral stresses or lateral dislodging forces. 
• In lingualized occlusion, the lingual cusps of the upper posteriors make contact in centric relation in the central fossae of the lower posteriors. 
• The buccal cusps are out of contact; however the lingual cusps are in contact in centric, working and balancing movements. 
• For this reason, all the stresses created during working and balancing motions are of a downward nature, thus creating stability.

Ref: Jim Collis

Class III occlusal schemes and cross bites

• In this type of occlusion the maxillary posterior teeth are crossed over to the mandibular posterior teeth so that the buccal cusps of the maxillary teeth are articulating in the mandibular central fossa instead of the palatal cusps.
• This occlusal relationship could be either unilateral or bilateral depending on the posterior ridge relationship.
• The mesio-distal tooth position is the same as in a Class I (but in all likelihood requiring mandibular incisors of slightly greater width).
• This posterior tooth relationship brings about that the mandibular teeth are always set on the ridge creating a reverse overbite and overjet, thereby preventing cheek biting.
•  The first mandibular premolar in most Class III cross bite cases is set in a near edge to edge position to the maxillary first premolar and canine.  (This crossing point varies depending on the bucco lingual vertical relationship of each particular case.  It often occurs in the mandibular second premolar region.)

Post Dam and its importance in a maxillary denture

• The relevance of the posterior palatal seal to the retention of the maxillary complete denture should be clearly understood.  Hardy and Kapur maintain that the retention and stability that is achieved from adhesion, cohesion and interfacial surface tension are able to resist only those dislodging forces that act perpendicular to the denture base.  
• Horizontal forces and lateral torquing of the maxillary denture can be resisted only by adequate border seal. 
• Terminating the denture borders on soft resilient tissues will allow the mucosa to move with the denture base during function and thereby maintain the denture seal. 
• The peripheral seal of the maxillary denture is the area of contact between the mucosa and the peripheral polished surfaces of the denture base; the seal prevents passage of air between the denture and the tissues. 
• This seal depends upon the proper extension of the denture borders, both in width and height, so that they fill the muco-buccal space and contact the cheek tissues laterally. 
• At the posterior aspect of the denture, in the area of the soft palate, there are no cheek tissues to seal the denture border.
• Therefore, the proper placement of the posterior palatal seal commands a definite clinical procedural protocol if one is to create an optimally retentive complete maxillary prosthesis. 
• The function of the posterior palatal seal in the completed maxillary prosthesis is to maintain contact with the anterior portion of the soft palate (the tissues that undergo shallow displacement) during functional movements of the stomatognathic system (that is, mastication, deglutition and phonation). 
• Therefore, the primary purpose of the posterior palatal seal is the retention of the maxillary denture. 
• The posterior palatal seal that has been correctly diagnosed and incorporated into prosthesis also will reduce patient awareness of this area with a subsequent reduction in the gag reflex, since there should be no separation of the denture base and soft palate during “normal” functional movements; reduce food accumulation beneath the posterior aspect of the denture, owing to proper utilization of tissue compressibility (palatal glandular tissue can withstand mild compressive forces); reduce patient discomfort when contact occurs between the dorsum of the tongue and the posterior end of the denture base, as the posterior denture border will closely approximate the soft palatal tissues, and compensate for the volumetric shrinkage that occurs during the polymerisation of methyl methacrylate resin. 
• The correctly placed posterior palatal seal will not impinge upon the non-displaceable tissues of the hard palate, nor will it limit the muscular movements of the soft palate.  It will, however, create a partial vacuum beneath the maxillary denture. 
• This partial vacuum is activated only when horizontal or tipping forces are directed against the denture base. 
• The duration of time that the partial vacuum acts on the tissues is extremely small and consequently little or no irreversible alterations to the underlying mucosa will take place.

(See S. Winkler)

Balanced Occlusion

What are the factors that affect balanced occlusion and how does it affect each other, see S. Winkler. For exams 

Please discuss all the problems a patient with a Class II jaw relationship could possibly encounter if a full maxillary and mandibular denture were set up in a Class I occlusion.

I will start off the discussion by naming one;

Exaggerated labial and buccal position of mandibular teeth would create:

• Labial lip infringement of mandibular anteriors if set into normal Class I relationship.

Requirements of/for an Immediate denture

Requirements:

• A denture is not living tissue but it must be accepted as part of a system composed of living tissue.

For success the following requirements:

1. compatibility with surrounding oral environment
2. restoration of masticatory (with in limits)
3. harmony with the function of speech, respiration (breathing), deglutition (swallowing)
4. aesthetic acceptability
5. preservation of the remaining hard and soft tissue support

(Biggest challenge – to occlude and evaluate)

For an Immediate denture the teeth can be replaced in the same position as natural teeth, there are however factors that affect the placement and function

*Remember from first year (Changes due to loss of teeth) 

The two areas of concern:

a)      esthetics

b)      occlusion

a)      Difficulty

·         Over erupted teeth (no opposing teeth)

·         Migration (loss of teeth)

·         Natural teeth in protrusion not desirable to be reproduced (place for better appearance, more compatible to surrounding oral environment

Problem mainly arises when attempts are made to correct mal-related jaws especially Class III or heavy overbite (steep vertical overlap)

b)      Occlusion

·         When it comes to occlusion we find that a lot of research has been done in this part and is still done today. Often the terminology used could be defined differently depending where it was used. Or new terminology was introduced abbreviation, new definition – leading to a lot of confusion.

·         What aggravated the confusion was that occlusal principles for natural teeth were applied to the occlusion of artificial teeth – and we know that the anatomical and physiological aesthetics are not the same.

                                                              i.      With artificial teeth the principles of mechanics and physics are more involved.

                                                            ii.      Complete dentures rest on tissue that is movable and displaceable in varying degree from one mouth to another.

                                                          iii.      Natural teeth are embedded in bone and can move or be displaced only to the degree allowed by the periodontal attachments. Artificial teeth are fixed to a movable base that is capable of moving with tissue and over the tissue – a big difference between these two movements.

                                                          iv.      Natural teeth can act singly or as a unit. Artificial teeth always act as a unit with the entire denture base, in its relation to the supporting tissue is affected.

                                                            v.      Also the fact of the somatic nerve receptors of touch and pressure of natural teeth which are lost (to neuromuscular system) when teeth are extracted. 

When doing an Immediate denture, we recommend you do the following as preparation

Preparing the cast: (Anterior teeth)

1. Thin pencil line around gingival.
2. Pencil line on long axis of each standing tooth onto labial area.
3. Measure 15mm from incisal edge of each tooth and mark on tissue and then at same distance onto model base 

A students perspective of Lingualized occlussion - video clip S. Fundani

Students perspective of a Class II demo - by V. Baiden

Students perspective of a clear palate demo - by S. Brooker

Students perspective on an Immediate denture demo - H. Gagiano

Factories that could affect the dimensional stability of a denture

1. Name a factor then discuss why you think it affects the dimensional stability of denture base material.
Post your comments by Thursday.

Porosity in heat polymerized denture base material

What would you say are the causes of porosity in heat polymerized denture base material?
Post by Wednesday, to discuss in class on Thursday

For your information - S. Madadi

Watch "30 Setting Denture Teeth - Reference Lines" on YouTube - https://www.youtube.com/watch?v=eBDVAuEbzV0&feature=youtube_gdata_player

Students perspective of a Class II try in demo by D. Joseph

Students perspective of processing a Soft liner demo - by M. Van der Merwe

Students perspective of a clear palate demo - by Somi Madadi

Class II demo video clip from a students perspective - M. Rawoot

Tooth Contact

Identify each of t the contacts. A, B, C

Video/ Picture clips

You have been documenting all the procedures for your class work. Put a picture clip together for 3 May 2013 and I will post it on the blog. Some instructions should be incorporated into the clips.
The topics for the clips are as follows;
1. Immediate dentures
      W. Adams
      H. Gagiano
      S. Orso
2. Class 1 Try in
      A. Appollis
      V. Gobeni
      Y. Ramdhari
3.  Class 2 Try in
      V. Baiden
       D. Joseph
      M. Rawoot
4. Class 3 Try in
       T. Kobo
       P. Reichert
       T. Bazire
5. Clear palate
       S. Brooker
       S. Madadi
       J. Rex
6. Soft liner to new denture
      M. van der Merwe
      L. Matthyse
      I. Burnett
7. Lingualised occlusion
      JP van Niekerk
      M. Naidoo
      S. Fundani

Festooning

Denture wax up

Case 20 - F / F Try in

Each student shoud post a comment as to their thoughts regarding correctiins that could be made. You will be evaluated on your reviews.

Case 19 - F / F Try in

Each student shoud post a comment as to their thoughts regarding correctiins that could be made. You will be evaluated on your reviews.

Case 18 - F / F Try in

Each student shoud post a comment as to their thoughts regarding correctiins that could be made. You will be evaluated on your reviews.

Case 17 - F / F Try in

Each student shoud post a comment as to their thoughts regarding correctiins that could be made. You will be evaluated on your reviews.

Case 16 - F / F Try in

Each student shoud post a comment as to their thoughts regarding correctiins that could be made. You will be evaluated on your reviews.

Case 15 - F / F Try in

Each student shoud post a comment as to their thoughts regarding correctiins that could be made. You will be evaluated on your reviews.

Case 14 - F/F Try in

Each student shoud post a comment as to their thoughts regarding correctiins that could be made. You will be evaluated on your reviews.

Case 13 - F / F Try in

Each student shoud post a comment as to their thoughts regarding correctiins that could be made. You will be evaluated on your reviews.

Case 12 - F / F Try in

Each student shoud post a comment as to their thoughts regarding correctiins that could be made. You will be evaluated on your reviews.