Excess cementation

This work was carried out by Dr Shantanu Jambhekar and me.  A special thanks to him.

Introduction of osseointegrated implants has changed the way partially and completely edentulous patients

can be treated. Although the reported success rates are high, implant treatments are not entirely risk free and may

result in a range of reversible and irreversible complications.

Restorations supported by implants can be either cement retained or screw retained.

prostheses have gained preference in many cases, making them the restoration of choice for the treatment of implant

patients.

3 Cement-retained

One of the drawbacks of cement retained restorations is extrusion of excess cements into the peri-implant

sulcus with subsequent complications.

The soft tissue attachment onto the implant surface is more delicate than that seen at the natural tooth surface

due to the lack of Sharpey

fibers run.

’s fiber insertion, the reduced number of collagen fibers, and the direction in which these

Both the detection and the subsequent removal of the excess cement are significantly complicated by the

depth of the gingival sulcus and by the contours of the abutment and the implant crown.

Several methods are used to prevent cement-related complications for cement-retained prostheses.

Placement of the abutment collar margin should be just apical to the gingival crest in the esthetic zone and at the

gingival crest or slightly occlusal elsewhere to allow unimpeded ability of cement to escape coronally. A lingual

escape hole can also be used to provide an escape route for the cement.

Control of cement volume has been documented previously using the ITI solid abutment (Straumann USA,

Andover, Mass).This requires an implant analog or practice abutment, as described by the authors. When a custom

abutment is to be used under the crown, this becomes more challenging. The dental laboratory may be instructed to

make a duplicate analog using an acrylic resin, but this is time consuming for the technician and involves additional

laboratory costs.

A simple chair side technique to minimize the overflow of cement at the time of cementation by use of a

custom-made abutment replica is described here.

Technique:

1. Evaluate the implant restoration for the fit with the abutment.

2. Attach the abutment to a lab analogue.

[Fig1]-Abutment and lab analogue

3. Line the abutment

with polytetrafluoroethylene (PTFE) tape commonly known as Plumber’s tape or Teflon

tape or TFE (tetrafluoroethylene) threaded seal tape which provides a space of approximately

                                                                         [Fig2]-Lining of abutment with Plumbers tape
 ) and the catalyst and using an applicator with a smaller diameter tip, completely fill the implant                                            

4. Seat the implant restoration completely onto the abutment to facilitate the transfer of the tape to the intaglio

surface of the implant restoration.

[Fig3]-Transfer of tape to intaglio surface

5. Mix small amount of condensation silicone putty(Zhermack C-Silicones Zetaplus - Putty Impression

Material

restoration and form a handle.

[Fig4]-Forming a handle with putty

6. Remove the putty material along with the PTFE and compare the implant abutment to the putty model;

ensure that no voids are present and that the abutment finish line has been accurately duplicated .This is the abutment replica.

[Fig 5]-Abutment replica

7. Place the abutment intraorally. Torque it in place and block the access holes.

[Fig6]-Abutment intraorally

8. Use the luting agent of choice line the intaglio of the implant restoration. Place the crown onto theabutment replica and wipe off the excess cement immediately.

                                                                        

                                                                          [Fig7]-Excess cement present in the crown

9. While the cements is still fluid, remove the crown from the abutment replica (there will be a layer of

residual cement on the abutment replica), and add a thin layer of cement in the intaglio of the

restoration.

[Fig.8]-Residual cement on abutment replica

10. Place the implant restoration onto the implant abutment intraorally. There will be little or no excess cement

 thus minimizing the amount of excess cement extruded into peri-implant tissues.

                  

[Fig 9,10 - Post cementation)             

50 μm, which represents the cement space and may be used for both custom and prefabricated abutments.

IWSSCGGC-2010

The International Workshop and Symposium on Synthesis and Characterisation of Glass/Glass Ceramics -2010 was organised by the C-MET (Centre for Materials for Electronics Technology,Pune and MRSI (Materials Research Society of India) on 9th and 10th July 2010 at YASHADA,Pune.

This was conference dedicated to Ceramics, Ceramic technologies and Research trends in Ceramics.

I presented a poster on Dental Porcelain Crown technology - What, Why , How.
I chose a basic topic and highlighted the porcelain material used in our dental purposes and specifically how we get the porcelian to bond to the alloy used as a substructure in out dental crowns.

The poster came as a refreshing change for the delegates attending the conference as they were primarily scientists with engineering backgrounds , all involved in heavy-duty research on glass ceramics. Needless to say, I got lots of questions, and very frankly it was nice to juggle between the role of a dentist (when I used to explain what crowns are and why they are used etc) and a scientific delegate explaining my poster. Many a delegate left a little bemused, but definitely wiser about Dental Porcelain Technology... which unless I've made a serious error in judgment is the most happening field in Dental materials science research of today and the future.

A New Classification of Palatal vaults: A Clinical Approach

I am presenting here a new classification for the Palatal vault in a completely edentulous patient.

Need for a classification: The general classification of palatal vaults as given by House is High, Medium and Low.
What does this indicate? It gives some idea about the depth of the palate, but so long as this information cannot be applied to a particular step in the fabrication of the denture, it has limited value! Should we do something different if a patient is categorised as House's High palate? or low?... In which area of the maxilla do we actually measure and assess that the vault is high or medium or low?

Therefore I have come up with a new classification that co relates the palatal vault to phonetic requirements.

In this classification the depth of the palate is measured at the 1st canine - premolar level, assuming that the tongue makes maximum contact in that zone of the palate during speech, especially linguo-palatal sounds.

Methodology employed :
After denture try-in, the region of the canine-1st premolar is marked on
 the ridge of the cast. An imaginary line joining these bilateral points is
 used as a reference and a perpendicular drawn from this line to the
 surface of the palate on the cast gives us the depth of the palate.



Based on this depth as measured in a large section of edentulous patients in our society, 3 categories of palatal vaults have been derived:

  SK1 - Shallow palatal vault. Depth : 0-5mm

SK2 - Medium palatal vault. Depth : 6-10mm 

                

SK3 - Deep palatal vault. Depth : greater than 11mm

This classification was derived from a study of measuring palatal depths by the above method for 50 patients.


Significance of the new classification:
Since it is based on the palatal depth in the region of the canine-1st premolar,(which is the most common region of the articulation of the tongue with the palate)it can be directly linked to phonetic requirements of complete dentures.
The canine-1st premolar region is the region where the palate can give an L beam effect to a denture. One would expect that SK3 category patients will have greater denture stability. The classification can thus give a prognosis of the denture stability.I am presently studying whether in patients with varying palatal depths, (Whether a patient is SK1 or SK2 or SK3 category); does the incorporation of palatal rugae make any difference to the speech of the patient or not?

Palatal Rugae and Speech in Completely Edentulous cases of varying palatal vault depth.

This project is ongoing. Presented here is a report of my Pilot study:
The role of palatal rugae in speech of complete denture patients has been debatable. While some authors have questioned their role in the past, a few authors have also said that rugae incorporated on the palatal surface of                        a denture enhance pronunciations.

I have found that going the extra mile with edentulous patients to give them better speech is worth it as:

• It is our responsibility
• It is often neglected and left for the patient to adjust to.
• Patients often complain that rugae has been replaced by smooth surface resulting in improper articulation.
• Psychological comfort.

What I basially did was derived my own new classification for palatal-vault depths and tried to assess whether the presence or absence of rugae affects the speech in patients with varying depths of the palate.

Objectives of my project:
To compare and evaluate pronunciation of linguo-palatal sounds in
patients with high, medium and low palatal vault depths using trial
record bases with and without palatal rugae.

Inclusion Criteria for my patients:

-Normal speech.
-Normal hearing.
-Good neuromuscular control ;voluntary control of tongue,lips and cheek.
-Read standard paragraph given for recital for speech assessment.
-Normal ridge relationship.
-Ridges without prominent undercuts.

Exclusion criteria for my patients:

-Speech abnormalities.
-Impaired hearing.
-Poor neuromuscular control.
-Inability to read.
-Undercuts which would needed to be blocked prior to fabrication.
-Previous denture wearers who have developed adjusted speech patterns.
-Unwilling/uncooperative patients.



Methodology:

Impressions were made using routine standard procedures.
Record bases were fabricated for each patient using a uniform thickness of autopolymerising acrylic resin.
Jaw relation recording and mounting on a Mean Value articulator was done.
Denture teeth were selected and set up on the rims.
The trial dentures were approved by the patient for their esthetic value.

Following this step the patients were divided in 3 categories (see separate blog for details):
SK1 - Shallow palatal vault
SK2 - Medium depth palatal vault
SK3 - Deep palatal vault.

Each patient underwent speech testing. Initial testing was done using maxillary and mandibular trial dentures with rugae incorporated with wax. Subsequently the rugae were eliminated and speech test was repeated using a smooth palatal contour.

Speech testing : Each patient was made to read a paragraph containing and stressing on 't', 'd', 'n', 'l' sounds.

Assessment was done in a sound proof room by 2 experienced speech pathologists and 1 lay person.

The testing procedure was double blinded as the assessors and the patients were not told about which set of record bases were being used (with or without the rugae).


1 patient was tested of each palatal vault depth.

The Speech Rating Scale used (Developed by Speech language Pathology Dept, AYJNIHH,1984)

0-Normal.

1-Can understand without difficulty. However feels speech is not normal.

2-Can understand with little efforts.

3-Can understand with concentration and effort, especially by a sympathetic listener.

4-Can understand with difficulty and concentration by family, but not by others.

5- Can understand with effort if context is known.

6-Cannot understand at all, even when context is known.


The results of the 3 patients can be summarised as follows


                         Without dentures       Dentures with rugae        Dentures without rugae
SK1(Shallow) -       1.6                                  2 .0                                     2.3

SK2(Medium) -       1.0                                  1.3                                      0.6

SK3 (Deep) -           0.6                                 1.0                                      1.3

The shallow and deep palate showed an improvement in phonetics when rugae was incorporated.
More studies and more patients need to be assessed to reach a definite conclusion

The project is ongoing and will be updated when I finish 10 patients in each SK category.

Belfast - Sept 09 IMPT Conference

The Institute of Maxillofacial Prosthetists and Technologists (IMPT) held their biannual conference at Belfast in September 2009. I was thrilled to be able to go to this Congress and read my research paper.

This conference is organised by the IMPT, UK and their website can be accessed at www.impt.org


It was a scary thought to go and lecture to a bunch of specialists about their own speciality, but they all put me at ease.

I presented my work on the Hardness changes in Maxillofacial elastomers.

    The conference was vastly different from the ones I have attended in India. Different in terms of its punctuality, organisation and execution. No long boring inauguration with the boring speeches, no crowded lecture schedule with multiple halls having multiple speakers talking to empty seats, and above all the emphasis on starting sessions on time with all conference delegates in attendance!

My first international presentation was a delight and I cant wait to grab an           oppurtunity to go overseas and present my next project.

Ceramic veneers: Colour change in luting agents used for bonding them.

Ceramic Veneer

Tooth preparation

Veneer bonded to tooth surface

This work is ongoing.

I am working on the hypothesis that there is a change in the colour of a resin luting agent upon curing.

Resin based luting agents are used to bond ceramic veneers to teeth. It is well known that the thinness of the veneer will allow the shade of the luting agent to affect the over all shade of the final restoration.

So, basically I am making veneers of a standard thickness using E max (Ivoclar-Vivadent)on prepared, freshly extracted human central incisors.I will be bonding these veneers using 2 luting agents- Variolink II (dual cured) and Choice 2 (light cured). The colour of the tooth with the veneer placed on it will be assessed in terms of the L , a, b values using a spectrophotometer. This assessment will be done after placing the veneer without the luting agent and after that, before and after the curing of the luting agent.

The study should give us insights about the colour change in the tooth-veneer complex that we should expect after the veneer is bonded, using different types of luting agents.

The pilot study is done and we are quite surprised by the results as of now.

What interested me in this project?... Well, the chance of learning and prepping teeth for veneers, discovering how to make a porcelain veneers, the aspect of bonding and spectrophotometric testing... and above all- Its Prosthodontics!!

Medicon 2009

I was delighted to be given an oppurtunity to present my research at a National Conference dedidcated to research presentations only, that too in all disciplines of medicines, not just dentistry. This event is an annual event called Medicon



Medicon 2009 was an event where young scientists and future doctors met to present their research papers and share ideas in the fields of clinical and fundamental medicine, biomedicine and public health. A number of leading scientists and medical researchers gave encouraging and thought provoking talks to delegates.


I presented this poster which detailed the pilot study of my Project on Weathering of Silicone elastomers in Indian Climatic Conditions. Besides the poster and the research that I detailed in it, I also carried with me samples of Artificial prostheses such as Silicon Ears, Eyes and Noses. It was a great novelty for all the scientists and medical students there to see such prostheses for the first time!!. A lot of them felt the noses and ears in their hands and were amazed at the soft, skin-like texture of the silcione material used.

I would strongly urge you to take a look at the following organisation and sign up at the earliest.


INFORMER : informer.org.in

Medicine is a field constantly brimming with advances, the advances being investigative, diagnostic,therapeutic or otherwise. In a profession which demands a constant awareness of these advances, our aim is to consolidate and assess what a young medical researcher has to offer.

If India has to emerge as a global leader in medicine and health it is necessary that its medical research and education should be of global quality. Medical research continues to be a highly neglected area that should be strengthened urgently.



The need of a students' body to host the conference in various parts of the country in rotation and to promote research activities among the medical students at a national level was increasingly felt. It was decided that this should be an annual event finally converting it into a Medical Students' Science Congress in line with the Indian Science Congress. It was further recommended by the participants of the second conference that a National Body be founded. Subsequently a group of students under the able guidance of Dr Madhav G Deo worked out the Constitution of Indian Forum For Medical Students' Research (INFORMER) which is now a registered organization under the Societies Registration Act 1860 & B.P.T. Act 1950.

Objectives of INFORMER

1. To promote research and research-embedded education amongst undergraduate students both at the national and international level.
2. To secure and manage funds and endowments for the promotion of these objectives.
3. To perform all other acts that may assists in, or be necessary for the fulfillment of the above mentioned objectives as well as any additional objectives as approved by the Society.

I dashed down for a couple of days after finishing my exams. It was a joy to interact with so many students (mostly doing MBBS), staying at a hostel and above all, presenting my poster (thats the picture above) to the senior faculty who were experts from so many chosen fields!

A venture I would recommend highly!! I couldnt go for Medicon 2010 due to my final exams, but am keenly awaiting their next event and looking forward to enriching myself there. Cheers