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                    D e n t a l    F o l l i c l e               

             The        Monthly     E-newsletter                   Vol - I       Number- X I          April  2007

In this Issue:

  • Editorial

  • News

  • Laughter - The best Medicine

  • Research ties gum disease to a host other major medical conditions

  • Breakthrough technology to hit the detection of Dental Caries

  • Evaluation of the efficacy of a collagen GBR membrane (BioMend Extend) supported by autogenous bone grafts,     for the treatment of peri-implant bony defects, during implant placement."Part III- Dr.Yousef Abd ElGhaffar

  • Laser Dentistry - How you can bring the children more happy to visit the dentist? - Dr.Maziar Mir
     

 

Editorial :

      Dear Fellow Dentist,

                          We are happy to bring the new edition of Dental Follicle .Yahoo groups has pretty active ! A lot of questions and a lot of answers!I thought why not incorporate the best answer in the Dental Follicle!

                           When the discussion on "Enamel Microabrasion" came up one good doctor "Dr.Ramesh Kanna" from India posted a small paragraph on the "method of doing Enamel Microabrasion"

 For Enamel Micro abrasion i use Opallusture from Ultradent, its 6.6% HCL, we have to select only mild to moderate flourosis cases, clean and polish them with shade matching ( Routine) then apply Opalluture on the enamel surface of the tooth to be microabraded ( entire labial surface) , and we get microabrading brushes with the kit, so we have to use them on the Enamel  surface in a round polishing motion as in tooth prophylaxis after scaling , with a little bit of firm pressure. use it for 60 sec to 90 sec and with a pause if you want use again. clean and observe, if not satisfied you can repeat for 2 - 3 times, be aware of sensitivity. after microabrasion you can ask the patient to use flouride gel and continue home bleaching for  more whiter teeth.

For macroabrasion its the same procedure, only difference is, its used for moderate to above moderate flourosis cases, in which the Enamel surface of the  tooth/teeth to be treated is roughened slightly by using Fine diamond bur( yellow ), then the procedure is as same as microabrasion.

 

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Yours truly

Dr.S. Nabeel

Editor of Dental Follicle & WebMaster www.DentistryUnited.com

News :

         

                       

Laughter - The Best Medicine :

A young Dentist had just started his own Clinic. He rented a beautiful office and had it furnished with antiques. Sitting there, he saw a man come into the front office. Wishing to appear the "busy dentist", the gentleman picked up the phone and started to pretend he had to give an appointment.

 Finally he hung up and asked the visitor, "Can I help you?"

The man said, "Yeah, I've come to activate your phone lines."

                                         

Research ties gum disease to a host other major medical conditions

"Research compiled over the last five years suggests that gum disease — especially if the condition has persisted for a long time without treatment — can contribute to diabetes, cardiovascular disease and stroke, pregnancy complications, and perhaps even Alzheimer's disease, osteoporosis and some types of cancers," the paper says. "Infections in the mouth also may increase the risk to people undergoing several types of surgery, including transplantation and cardiac valve replacement."

But as recently as last month, a study published in the New England Journal of Medicine found that treating severe gum disease can improve the function of blood vessel walls, improving heart health. And in this month's Journal of Periodontology, two studies found periodontal bacteria (bugs normally found in inflamed gums) in the arteries of people with heart disease and in the placentas of pregnant women with high blood pressure.

 

                                      Breakthrough technology to hit the detection of Dental Caries

Neks Technologies Inc,  announced that the Food and Drug Administration (FDA) has approved the D-Carie™ mini caries detection device as an aid in the diagnosis of interproximal caries.

The D-Carie mini is a lightweight, easy-to-use, cordless device that can be used as an aid for clinicians to quickly locate and diagnose caries. The D-Carie mini uses Light Emitting Diode (LED) and fiber optic technologies to accurately detect both occlusal and interproximal caries. The device requires no calibration and is easy to sterilize. The D-Carie mini is not a laser, and therefore can also be operated by hygienists.
 

When used as a diagnostic aid in conjunction with an X-ray, the neks D-Carie mini allows dentists to assess a third dimension - the volume of caries - prior to opening the tooth. The device also provides dentists with an option for examining and diagnosing children, pregnant women and patients who prefer to forgo X-rays or limit their exposure to them for health or personal reasons. For more information on the D-Carie mini and the DetecTar mini, clinicians can register online and participate in an archived Web Seminar entitled "Introduction to the Art of Detection" at http://www.neks.ca/web_seminars_en_edit.htm  For a detailed product demonstration on the D-Carie mini, an online video is available at: www.neks.ca/forms/video           

            

Evaluation of the efficacy of a collagen GBR membrane (BioMend Extend) supported by autogenous bone grafts, for the treatment of peri-implant bony defects, during implant placement."

Part - III

Dr . Yousef Abd ElGhaffar ,   

BDSc, MDSc,  Cairo University, Egypt

Fellow of ICOI and Member of AAID.

Email : dr_yousefabdelghaffar@hotmail.com

 

 Besides having the same criteria of a non-resorbable barrier, special demands must be added to a resorbable barrier because of the bioresorption process. To some extent, the bioresorption process will always be associated with a cellular response from the surrounding tissue, irrespective of whether the material has been degraded by enzymatic activities or has been hydrolyzed. Since this process entails some inflammatory response, the subsequent inflammation should be minimal, reversible, and not interfere with regeneration. Moreover, the bioresorption process must be controlled so that membrane is maintained for a sufficient length of time to perform its function for tissue guidance during the initial healing period (Gottlow 1998).
Ideally, a bioabsorbable material should be safe, cost effective, easy to use, remain in place until regeneration has occurred, and not to interfere with newly formed tissue. Furthermore, they should be limited to areas with minimal gingival recession and sufficient width and thickness of keratinized gingiva, where primary closure is sure to be achieved (Becker et al., 1996). Bioresorbable barrier membranes used for GBR include collagen, oxidized cellulose and polylactic-polyglycolic acid co-polymers.
A study was carried out to evaluate the efficacy of polylactic acid and polyglycolic acid (PLA/PGA) resorbable membranes in conjunction with autogenous bone grafts when used for the treatment of implant dehiscences and/or fenestrations versus (e-PTFE) non-resorbable membranes. A slightly higher percentage of bone fill was found in the e-PTFE group (98.20%) than in the PLA/PGA group (88.56%), but the difference was not statistically significant (Simion et al. 1997).
Hurzeler et al. 1997 performed a study on GBR around dental implants placed in atrophic alveolar ridges using an experimental, nonporous bioresorbable barrier made of poly D, L-lactid-co-trimethylencarbonate and non-resorbable (e-PTFE) membranes were used as a control group. The mean direct mineralized bone-to-implant contact length fraction was 32% of the total implant length in the test sites and 58% in the control sites. Control sites exhibited significantly greater bone fill compared to the experimental sites. Histologic observations of test specimens demonstrated a moderate inflammatory reaction related to the degradation and resorption products of the barrier.

Synthetic bio-resorbable membrane barriers were claimed to cause clinical problems. Infections and inflammatory reactions were observed around breakdown debris of Guidor membrane barriers (polylactic acid type) (Schmitz et al. 2000).
Among the bioabsorbable materials, collagen which is the most important structural protein component of the body, naturally bioabsorbable, with proven medical applications, the use of collagen as a biomaterial has been advocated based on several factors such as its favorable role in cellular development, wound healing, and blood coagulation (Zahedi et al. 1998).
Because collagen is the most abundant protein in the body the search for a biodegradable material has lead to the development of collagen membranes, which have been used in medical fields for decades (Chen et al. 1995).
It had been reported that there is a similarity between collagen in human skin and certain animal tissues. Since human body enzymes can degrade animal collagen, so animal collagen is attractive as a GBR barrier material. Collagen membranes currently available are of various subtypes, but usually fabricated with type I collagen derived from various bovine, porcine or equine animal sources and harvested from tendon or dermis (Tripletti et al. 2001).
Collagen barriers are manufactured using extrusion-coagulation and air drying which forms sheets of material from dilute collagen solutions. The collagen is dissociated, purified and reconstituted before final sheet forming to reduce the potential for antigenic response when the material is implanted. Most collagen barriers are cross-linked to increase their strength, extend their resorption time and reduce their potential antigenicity (Wang et al. 1998).
Collagen is bioresorbable. During enzymatic degradation it will incorporate with the flap to support the new connective tissue attachment. This may result in augmenting tissue /flap thickness to further protect underlying bone formation and prevent future bone loss. Unlike some acid-based resorbable membrane materials, it does not release acid byproducts into the wound areas as the material breaks down (Pitaru et al. 1989).
In order to evaluate the biocompatibility and resorption pattern of a human collagen graft material in both in vitro and in vivo, human collagen extracted from placenta was implanted subcutaneously in 10 Sprague Dawley rats. The graft was encapsulated by day 7 and was slowly resorbed over 56 days with minimal inflammatory response (Quteish et al. 1991).
Ideal barrier membrane should stay in place for at least 4 to 6 weeks before being surgically removed, so the bioresorbable membranes as collagen barrier membrane should not degrade before a sufficient time to enhance regeneration. Many steps have been taken to delay its degradation process. This could be achieved either by increasing their structural integrity by cross-linking or by delaying the degradation process using metalloproteinase inhibitors which inhibit metalloproteinases responsible for degradation. Various cross-linking techniques have been developed. These include ultraviolet light (Pitrau et al. 1988), hexamethylene diisocyanate (HMDIC) (Minabe et al. 1989 and Kodma et al. 1989), glutaraldehyde plus irradiation (Quteish et al. 1992), and diphenylphosphorylazide (DPPA) (Brunel et al. 1996 and Zahedi et al. 1998). The glutaraldehyde technique was reported to leave cytotoxic residue during the process and to overcome the drawback of this technique, the diphenylphosphorylazide (DPPA) technique was developed.
The use of collagen membranes has not yet been approved by the United States Food and Drug Administration (FDA) for treatment of dehiscences associated with implants due to lack of researches concerning this matter (Wang and Carroll 2001).
Some animal studies were carried out to evaluate the efficacy of collagen barrier membranes in GBR. In a pilot study, Colangelo et al. 1993, created through and through defects on the lateral aspect of rabbit mandibles and then treated them with either a cross-liked bovine tendon type І collagen membrane or no-treatment control. The histologic evaluation at 30 days demonstrated a nearly complete continuous layer of lamellar bone with osteoblastic activity in the collagen membrane-treated group compared to only fibrous connective tissue in the control group.
Another study was carried out in 1993 by Sevor et al. Buccal dehiscences were surgically induced in dog mandibles. Implants were then placed in a random pattern in both sides of the mandibles (two of each type of implant in each side of the mandible). A resorbable collagen barrier membrane (CollaTec) was placed around one pair of implants on each side. The other two implants on each side served as controls. The sites were examined clinically and histologically after 4 or 8 weeks to assess bone regeneration. At 4 weeks, the mean defect fill was 69.16% in the collagen membrane-treated group compared to 24.07% in the control group. At 8 weeks, the mean defect fill was 80.29% in the collagen membrane-treated group compared to 38.62% in the control group. The author also reported excellent wound healing at experimental sites in contrast to results with other materials. He suggested that as collagen products have been extensively utilized to heal burns and to dress surgical wounds, collagen has been found to be a chemoattractant for fibroblasts and connective tissue elements. Examination of certain histologic sections in the present study showed that bone and bone elements proliferated in close approximation to the collagen membranes.
Zahedi et al. 1998 performed a study to evaluate the potential of Calfskin origin collagen membrane (Paroguide) in the healing of mandibular bone defects. The experiment was carried out on 25 Wistar rats. After exposing the mandibular ramus bilaterally, 5 mm diameter full-thickness circular bone defects were surgically created. Defect on one side was covered by the membrane (experimental), the defect on the other side was left uncovered (control) before closure of the overlying soft tissues. In the 90 and 180 day animals, all experimental defects were completely closed. While in control defects, no statistically significant increase in bone regeneration was observed.
Francisco et al. 2000 have clinically evaluated an absorbable a porcine dermis origin collagen membrane (Bio-Gide) and a non resorbable (PTFE) membrane, associated with or without deproteinized bovine bone mineral xenografts (BioOss), for the treatment of ligature-induced peri-implantitis defects in dogs. The results showed percentage vertical bone fill with use of the resorbable membrane alone (21.78±16.19) and with the use of resorbable membrane together with BioOss (27.77±14.07). With use of non-resorbable membrane the percentage of vertical bone fill was (18.86±10.63) and with use of non-resorbable membrane togther with BioOss it was (19.57±13.36). However, he concluded that no significant statistical difference was detected among treatments.
A comparative analysis between two different collagen membranes to treat peri-implant buccal dehiscence defects in eight mongrel dogs was performed. The study compared Bio-Gide to BioMend Extend (Bovine tendon origin) collagen barriers, also the study included control sites which were left without barrier. Clinical reentry was carried out after 4 weeks and after 16 weeks. After 4 weeks the defect height was 3.08±0.10 mm in BioGide barrier group, 3.28±0.11 mm in BioMernd Extend barrier group, and 3.41±0.12 mm in control group. After 16 weeks the defect height was 3.29±0.12 mm in BioGide barrier group, 3.11±0.11 mm in BioMernd Extend barrier group, and 3.091±0.15 mm in control group. The sites treated with barriers showed higher percentage of bone fill and bone-to-implant contact, however, sites treated with BioMend Extend demonstrated significantly greater bone-to-implant contact than sites treated with Bio-Gide barriers (Oh et al. 2003).
Few clinical studies were carried out to evaluate the efficacy of collagen barriers for treating dehiscence defects around dental implants. Zitzmann et al. 1997 studied GBR using Bio-Gide collagen membrane versus (e-PTFE) for treating 84 exposed implant surfaces, both were supported with BioOss. Bone fill was achieved for the collagen membrane group was 92% against 78% bone fill for the (e-PTFE) membrane group. In the latter group, 44 % wound dehiscences and/or premature membrane removal occurred.
Paroguide collagen membrane was evaluated for GBR to treat patients with insufficient ridge width (less than 5 mm). The membranes were supported by collagen sponges to maintain the space buccally and lingually. The defects which demonstrated sufficient width for implant placement were 75%. Mean increase in the size of the crest was 2.5 mm (3 to 5.5 mm) (Parodi et al. 1998).
Another study was performed by Nemcovsky et al. 2000, where buccal dehiscence defects were treated with GBR procedures using resorbable Bio-Gide collagen membrane supported by bovine bone mineral after the placement of 28 implants in 21 patients. Mean defect area at the time of implant placement was 23.7 mm². Implants were uncovered 6 to 8 weeks later. The mean defect area at the time of uncovering was 0.7mm². The mean percentage of defect reduction (clinical bone fills) was 97%.
Carpio et al. 2000 compared the efficacy of a porcine-derived bioresorbable Bio-Gide collagen membrane versus an (e-PTFE) membrane for GBR using a bovine bone xenograft/autograft composite in defects surrounding dental implants. Defect size was recorded at stage 1 and 2 surgeries (performed 6 months apart). At baseline, the defect height in the group treated with collagen barriers had a mean of 4.63±0.49 mm and the defects width had a mean of 3.36±0.28 mm. The defects height in the group treated with (e-PTFE) barriers had a mean of 4.18±0.39 mm and the defects width had a mean of 4.36±0.40. After 6 months reduction in defect height was 2.65±0.61 mm and reduction in defect width was 1.95±0.60 in group treated with collagen barriers. The reduction in defects height was 2.26±0.61 mm and reduction in defects width was 2.65±0.56 in group treated with (e-PTFE) barriers.
Hämmerle and Lang 2001 carried out a study to evaluate efficacy of Bio-Gide collagen membrane supported by BioOss for GBR to treat buccal dehiscence defects around dental implants. The study included 10 patients. At baseline, the deepest extensions of the defects were located at the buccal aspects (mean 7.8 mm, SD 1.9 mm). At re-entry, the mean defect had decreased to 2.5 mm (SD 0.6 mm). This difference was statistically significant (P < 0.01). Initially, in 62% of sites the depth ranged from 0-3 mm, in 23% it ranged from 2-4 mm, and in 15% it amounted to more than 6 mm. Six to 7 months later, at re-entry, 95% of sites were 3 mm and less in depth and 5% ranged from 4-6 mm. Defect resolution, as assessed by the amount of coverage of the initially exposed rough implant surface reached a mean value of 86% (SD 33%). One hundred percent resolution was accomplished at 8 out of 10 implants, 60% at one and 0% at another implant.

Brunel et al. 2001 performed 7-year follow up for GBR prior to implant placement using Paroguide collagen membranes supported by hydroxyapatite (HA) crystals. The results showed bone filling at a treated sites and osseointegration rate of 86% after 7-year observation period. He concluded that these results confirm the possibility of regenerating bone by means of bioresorbable membranes, assuring at the same time the long-term success for implants inserted in regenerated sites.
Tawil et al. 2001 evaluated the efficacy of a bioresorbable collagen membrane (Bio-Gide) in combination with autogenous bone graft in the treatment of peri-implant dehiscences, fenestrations, or limited vertical defects. Autogenous bone was used in all cases to fill the defect and maintain the space underneath the barrier. The membrane absorbed the blood and easily covered and adhered to the underlying bone. It was not stabilized by any retentive means. Sixteen to 32 months postoperatively, the sites were re-entered and the amount of bone regenerated was measured. The mean defect height and width respectively were 5.28mm and 3.11mm at the time of the first surgery. At the time of second surgery the mean defect height and width respectively were 0.61 mm and 0.94 mm. The results showed significant bone gain (average 87.6%) in the treatment of peri-implant bony defects with Bio-Gide and autogenous bone.
Regarding the quality of bone gained through GBR by the use of collagen barriers, it was proved that collagen barriers provided qualitative bone regeneration comparable to the standard (e-PTFE) material as assessed by histological examination (Friedmann et al. 2002).
Zahran and Al-Shirbiny 2003 studied the efficacy of a bioabsorbable collagen membrane (BioMend Extend) in combination with decalcified freeze-dried bone allograft (DFDBA) in the treatment of peri-implant dehiscence defects. Ten patients having twelve endosseous implants with buccal dehiscence defects were included in the study. Surgical re-entry was carried out 6 to 9 months post surgically, in conjunction with abutment connection. The initial height of the dehiscence defects ranged from 3 to 6 mm with an average of 3.95 mm. On re-entry, the height of the residual defects varied between 0 to 1.5 mm with a mean value of 0.66 mm with an average of 84.76% ±11.81% of defect fill. Four defects out of 12 showed 100% vertical bone gain. The initial width of the dehiscence defects ranged from 2 to 3 mm with an average of 2.33 mm. The residual width of defects varied between 0.0 to 1.00 mm with a mean value of 0.08 mm.

 

 

                                                                   

 

 

 

Laser Dentistry - How you can bring the children more happy to visit the dentist?

Maziar Mir

DDS, MSc, PhD

Assistant Prof. ZPP, RWTH Hospital, Aachen, Germany



 

We learned a lot to control the behavior of our child and adolescent patients during our studies. In experience a lot of dentists just refer the Children to Paedodontists while do not like to spend a lot of time for making the patient co-operative.As a dentist, who loved to be able to have a young boy or girl happy on the dental chair, I have been trying to prepare the tooth cavities just by the help of Lidocaine gel or soray and hand instruments. With hatchet of chisel, a lot of dentists just remove the soft caries and use Glass Ionomers to fill such a cavity in a primary tooth whcih maybe is going to be replaced with a permanent tooth in some years. But most of such a filled cavities will show the recurrence and poor child will come back to the dentist with pain after a year or less. So, pulpotomy as a secondary health providing level of treatment will not be possible to be done painless even with hand instruments!

Last year, the dean of our school asked me to start some clinical studies with primary teeth and provide my peadiatric dentistry service with the assistance of Er:YAg and Nd:YAG lasers. So, we started to do pulpotomies and following the methods that were earlier introduced by Gutknecht et al. did the procedures in this steps:

1- Local anesthesia

2- Isolation with rubber dam

3- Sterile deep caries removal and pulp chamber exposure following by removing the roof of pulp chamber with Er:YAG laser (400 mJ, 10-15 Hz).

4- Surgical removal of coronal pulp with excavators or sharp Black’s spoons.

5- Coagulation and fixation of root canal orifices with Nd:YAG (2 W, 20 Hz, 10 Sec, 2-3 mm distance from the orifice).

6- Placement of capping material (Ca(OH)2 plus Iodoform)

7- Final filling ( Phosphate cement following by SSC)

The local anesthesia here is also as first step, but there was no need to any additionnal injection during the procedures as is routine while just preparing the cavity and removing the pulp soft tissue with rotary instruments. The same procedure is possible to be done with Diode lasers instead of Nd:YAG as well. Also, the Co2 lasers are in trial in our clinics to see the advantages and disadvantages in next 4 years. In current studies reported by Hugo et al on 2006 the success rate of the mentioned protocol, is reported as 62 out of 65 (95.38%). Wilder-Smith and her research group have shown also in another study that CO2 laser (Duolase™), emitting at 9.3 mm, used in the Superpulse, noncontact mode (macropulse duration:300 ms, spot size: 250 mm, average energy: 3.5 W, peak energy: 20 W, pulse repetition rate: ~500 Hz) results in hemostasis when irradiated to exposed pulps with the exposure of up to 5 mm. In this study also they reported significant better clinical and radiographic results comparing the routine methods. According to the animal and clinical studies that are done, these procedures could be used successfully for pulpotomy, but there is no report to show if Er:YAG with the pulse durations of more than 500 us could have the same or even better effects. This wave length has received the FDA clearance for pulpotomy on 2002, but there is no detail about the most efficient pulse length. We are working strongly on this topic and would be happy if the investigators or clinicians who have a similar reaserch or clinical experience work keep in touch with our group via email: mir.maziar@gmail.com

Also, all the literature of this suggested applications of lasers in pedodontics are available and will be sent in request.