Lokendra Gupta

Implant crest module: A review of biomechanical considerations

The success of dental implants has long been established through various studies with a particular emphasis laid on an implant design. Crest module is that portion of a two-piece metal dental implant, designed to hold the prosthetic components in place and to create a transition zone to the load bearing implant body. Its design, position in relation to the alveolar crest, and an abutment implant interface makes us believe that, it has a major role in integration to both hard and soft tissues. Unfortunately, in most clinical conditions, early tissue breakdown leading to soft tissue and hard tissue loss begins at this region. Early crestal bone loss is usually highest during the first year after placement ranging from 0.9 to 1.6mm and averaged 0.05-0.13 mm in the subsequent years . Various hypotheses have been stated to reason it however, none has been proved convincingly. In light of this, various attempts have been made to overcome this undesirable bone loss, by varying an implant design, the position, surgical protocol, and the prosthetic options. Irrespective of an implant system and designs that are used, crestal bone loss of up to the first thread is often observed. The purpose of this review is to look into the various designs and treatment modalities, which have been introduced into the crest module of an implant body to achieve the best biomechanical and esthetic result.

Does the size matter? Evaluation of effect of incorporation of silver nanoparticles of varying particle size on the antimicrobial activity and properties of irreversible hydrocolloid impression material

OBJECTIVES The main objective of the present in vitro study is to evaluate the antimicrobial activity and properties of irreversible hydrocolloid impression material incorporated with silver nanoparticles of varying size at different concentrations. METHODS Silver nanoparticles of 80-100, 50-80, 30-50 and 10-20nm size were added to irreversible hydrocolloid impression material at 0.5, 1.0, 2.0 and 5.0wt%. Antimicrobial activity of the silver nanoparticle incorporated irreversible hydrocolloid was measured using disk diffusion method. The gel strength, flow, gelation time and permanent deformation were measured according to American Dental Association specification #18. Data were analyzed using analysis of variation at a confidence interval of 95% (α=0.05). RESULTS Silver nanoparticles of 80-100nm size have imparted superior antimicrobial activity to the irreversible hydrocolloid in a dose-dependent manner whereas finer nanoparticle size did not exhibit any antimicrobial activity. The addition of silver nanoparticles did not alter the properties of irreversible hydrocolloid at 0.5 and 1.0wt% whereas at higher concentrations significant differences in flow, gelation time and strength were observed. SIGNIFICANCE The results of the present study indicate that silver nanoparticles of size range 80-100nm are superior in imparting antimicrobial activity to irreversible hydrocolloid compared to finer particle size range.

Effect of comonomer of methacrylic acid on flexural strength and adhesion of Staphylococcus aureus to heat polymerized poly (methyl methacrylate) resin: An in vitro study

Aims and Objective: The purpose of the present study was to evaluate and compare flexural strength and Staphylococcus aureus adhesion of heat-activated poly (methyl methacrylate [MMA]) resin modified with a comonomer of methacrylic acid (MAA) and MMA monomer. Materials and Methods: Comonomer preparation was done with the addition of varying concentration of MAA (0, 15, 20, and 25 wt %) to the MMA of conventional heat-activated denture base resin to prepare the specimens. Prepared specimens were stored in distilled water at 37°C for 1 day and 1 week before the evaluation of flexural strength and microbial adhesion. Flexural strength was measured using a universal testing machine at a crosshead speed for 2 mm/min (n = 10). Microbial adhesion (colony-forming unit [CFU]) was evaluated against S. aureus using a quadrant streaking method (n = 5). Data were subjected to one-way ANOVA, and the significant differences among the results were subjected to Tukeys HSD test. P < 0.05 was considered statistically significant. Results: Addition of MAA to the MMA monomer was found to significantly reduce the adhesion of S. aureus for all the groups. Reduction of CFU of S. aureus was found be more significant for Group 3 as compared to control, both at 1-day (P < 0.001) and 1-week (P < 0.002) storage in distilled water. However, no statistically significant changes in the flexural strength were observed with the addition of MAA at 1-day (P = 0.52) and 1-week (P = 0.88) time interval. Conclusion: Addition of MAA to conventional denture base resin reduced the microbial adhesion without significantly affecting the flexural strength.

Lobule separator prosthesis to prevent adhesion of reconstructed ear lobe

An adhesion is a band of scar tissue that binds two parts of the tissue together, which develops when the bodys repair mechanisms respond to any tissue disturbance, such as surgery, infection, trauma, or radiation. Prevention of unwanted scar bands is of utmost importance to develop esthetic and healthy tissue. This article describes a technique to prevent the adhesion of the surgically reconstructed ear lobule with facial skin, using novel lobule separator prosthesis.

Three‐Dimensional Orientation of Iris in an Ocular Prosthesis Using a Customized Scale

The success of an ocular prosthesis depends largely on the correct orientation of the iris disk. Various methods have been put forth to achieve this. This article emphasizes one such simplified method, wherein a customized scale has been used to orient the iris disk mediolaterally, superoinferiorly, and anteroposteriorly in an ocular prosthesis. A scleral wax pattern was fabricated. The customized scale was used to measure the dimension and orientation of the natural iris. These measurements were then transferred to the scleral wax pattern with the customized scale. An iris disk was fabricated using black crayon on the scleral wax pattern according to the measurements. The scleral wax pattern, including the iris disk, was then placed in the eye socket to verify its dimension and orientation. A prefabricated iris disk was modified according to the measured dimensions and transferred to the final scleral wax pattern. The transfer of these dimensions to the definitive prosthesis was achieved successfully, ultimately improving the patients social and psychological well being.

Fabrication of a Surgical Splint in an Emergency Situation: A Clinical Report

Fractures involving pediatric jaws most often require a splint to prevent the fragments from being displaced; however, impression making presents a challenge. This article describes the fabrication of a surgical splint over an ideal cast, which is subsequently refitted with a tissue conditioner onto the patients jaw. The highlight of this technique is the elimination of an impression procedure, thereby reducing clinical and laboratory time and easing pain in the child.Fractures involving pediatric jaws most often require a splint to prevent the fragments from being displaced; however, impression making presents a challenge. This article describes the fabrication of a surgical splint over an ideal cast, which is subsequently refitted with a tissue conditioner onto the patients jaw. The highlight of this technique is the elimination of an impression procedure, thereby reducing clinical and laboratory time and easing pain in the child.

Comments regarding: Nanda A, Krishnan S, Kaur H, Koli D, Manak K, Verma M, Gill S. Correction of microstomia in an edentulous patient. J Prosthet Dent 2016;115:137-40

Dear Editor: I read the article, “Correction of microstomia in an edentulous patient” in the February 2016 issue of Journal of Prosthetic Dentistry. It is always very interesting to read about newer techniques and innovations in prosthodontics, especially maxillofacial prosthetics. The technique discussed is a good illustration for patients who have microstomia and need rehabilitation; however, a few points regarding the technique were unclear to me. First, the authors recorded the impressionwith polyvinyl siloxane (Aquasil Ultra, Putty; Dentsply Caulk) in putty consistency. If they can clarify how the impression material was supported intraorallywithout a customtray andhowthe preparation of master cast for splint was fabricated, it would be helpful to apply these techniques in our clinical practice. The second comment is in regard to themouth opening visualized in Figure 8, which shows the stretched appearance of mouth opening using the Vernier calliper, compared to Figure 2 (especially on the patient’s left side), which shows the unstretched appearance. It is difficult to understand the actual outcome of this innovative

Pneumatic impression: Improving dental arch impression with an inflatable balloon

Purpose: The purpose of this impression technique is to overcome the problem associated with restricted mouth opening in association with high arched palate by employing pneumatic impression technique using latex balloon. Methods: A stock tray was modified with auto polymerizing acrylic resin. On the modified tray, a latex balloon was attached with aid of cyanoacrylate. The outlet of the balloon was then connected to a clinical sphygmomanometer bulb with the rubber pipe for air passage which would aid in inflating the balloon. The prepared tray assembly was then equipped for recording the impression. An adequate amount of addition polysiloxane impression material, sufficient to cover the entire area of the balloon was loaded onto the tray. The balloon was then inflated with the help of a sphygmomanometer bulb which transferred the air only in one direction. On completion of setting time of the impression material, the air pressure was relieved by deflating of balloon which helped in the easy removal of the impression. The impression was subsequently removed from the oral cavity and disinfected. Conclusion: This novel technique was helpful for recording impression in patients presenting with restricted mouth opening and high arched palate.

Functional and aesthetic rehabilitation of a geriatric patient with cleft palate: a case report.

Cleft palate defect with complete edentulism in elderly patients presents a prosthodontic challenge for complete denture fabrication. Such large defects are very difficult to restore by surgical intervention and have direct consequence on such functions as mastication and speech, on aesthetics, and on the patients mental attitude. This article describes a case report in which a 76-year-old female patient underwent restoration with a closed hollow bulb obturator for a large cleft palate defect.

Cranioplasty with custom made alloplastic prosthetic implant: A case report

Cranial defects often occur due to trauma. The treatment of such defects is a challenge to the skill and knowledge of the practitioner. This article presents one such case, where a 15-year-old boy had suffered extensive loss of the right cranium following a road traffic accident. The patient required rehabilitation of the right fronto-temporal cranial anatomy and was managed using a custom made heat polymerized acrylic alloplastic implant.