Dental Materials Commons^™

The Effect Of Calcium Hydroxide Pastes On Root Dentin Fracture Resistance, Kurt W. Sturz

Loma Linda University Electronic Theses, Dissertations & Projects

Calcium hydroxide is a common intracanal medicament used in the treatment of immature teeth that have been subjected to trauma or decay prior to root canal therapy. The effect of calcium hydroxide on immature root dentin is important. One area of concern is the effect that calcium hydroxide has on the fracture resistance of an immature tooth. It is the aim of this study to compare the effect of four different commercially available calcium hydroxide pastes on the fracture resistance of bovine teeth. Seventy-five freshly extracted, intact bovine incisors were prepared according to a modified Haapasalo and Orstavik technique. Each …

Stability Of The Miniscrew-Bone Interface: Reverse Torque Values In Rabbits, Daniel John Drye

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Miniscrews are used in orthodontics as practical temporary anchorage devices (TAD's). The purpose of this animal study was to measure reverse torque values for Absoanchor 1.2 mm and Micerium 1.5mm miniscrews at 0, 2, and 12 weeks under loaded and unloaded conditions.

Methods: Ninety-six miniscrews were placed in the femora of twelve rabbits and allowed to heal for either two or twelve weeks. Half of the fixtures were loaded immediately with NiTi open coil springs producing a force of 150-200g and the other half served as unloaded controls. For each of the healing times, two and twelve weeks, …

Histological Comparison Of White And Gray Mta In Repair Of Furcation Perforations, Miguel Elias Mego

Loma Linda University Electronic Theses, Dissertations & Projects

Mineral trioxide aggregate (MTA) has been shown to promote regeneration of the periodontal apparatus when used as a repair material in furcation perforations. Two variations of MTA (Gray and White) have been introduced to the dental market. The purpose of this study was to histologically compare the in vivo response to immediate furcation perforation repair using gray or white MTA in beagle dogs.

Under general anesthesia, non-surgical root canal therapy and furcal perforations were performed on sixteen mandibular premolars of eight 2-year old beagle dogs. The perforations were immediately repaired with either white (n=8) or gray (n=8) MTA. The animals …

The Effect Of Naocl, Ca(Oh)2, Mta And Mtad On Root Dentin Fracture Resistance, Sunil Ilapogu

Loma Linda University Electronic Theses, Dissertations & Projects

Various materials are used for the treatment of immature teeth that have been subjected to trauma or decay. It is not well established what effect these materials may have on the immature root dentin. A concern would be the resistance to fracture of the remaining root dentin. The purpose of this study was to compare the resistance of fracture of bovine teeth treated with sodium hypochlorite, calcium hydroxide, gray MTA and gray MTA in conjunction with MTAD after certain periods of time. One hundred and ninety five freshly extracted, intact bovine incisors were prepared using a modified Haapasalo and Orstavik …

Bone Formation Using Platelet-Rich Plasma + Allograft: An Experimental Study In Sheep, Edgar Grageda

Loma Linda University Electronic Theses, Dissertations & Projects

Recently Platelet-Rich Plasma has been proven to be an effective regeneration adjunct when combined with autogenous bone in the reconstruction of mandibular defects. However, little is known about the effect of PRP when combined with a bone allograft in the maxillary sinus.

The purpose of this study was to quantitatively evaluate the ability of PRP to enhance bone regeneration in the maxillary sinus of sheep when combined with DFDBA + CCFDBA. Ten sheep were selected for bilateral sinus augmentation DFDBA + CCFDBA + PRP (test) and DFDBA + CCFDBA (control). Five were sacrificed at 3 months and the other five …

Comparison Of Bracket Bond Strength By Total, Self-Etch And Laser Treatment, Kyo Sung Shawn Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Laser etching of enamel surfaces alters the physical and chemical characteristics of the enamel. These changes in characteristics enhance the bonding to enamel. The purpose of this study was to compare the shear and tensile bond strength of Er,Cr:YSGG hydrokinetic laser system (Biolase) with 37% phosphoric acid and self etching primer 30 minutes and 72 hours after bonding. Four different laser power output setting was observed: 1.5W, 2.0W, 2.5W, and 3.0W. Two hundred forty bovine teeth free of defect, caries, and dentin exposure were mounted in acrylic resin and divided into 24 groups of 10 teeth. Sixteen groups of 10 …

A Bond Strength Comparison Of Led And Halogen Light Curing Units, John Richard Kavanagh

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this research was to compare the tensile bond strength of orthodontic flat based buttons bonded to bovine teeth with four commercial light-emitting diode (LED) curing lights and one conventional quartz tungsten halogen (QTH) curing light.

The dental market has recently been introduced to a number of commercially available light-emitting diode (LED) curing lights. Tensile bond strength was evaluated for LED curing lights (Rembrandt® Allegro^TM, Den-Mat Corp, Santa Maria, CA), (LEDemetron, Kerr/Demetron Corp, Danbury, Conn), (Ortholux LED, 3M^TMESPE^TM, St. Paul, MN),and (FLASH-lite 1001, Discus Dental, Culver City, CA) are compared with one …

Identification Of Hard Tissue Using Dentin Sialoprotein (Dsp) As A Marker, Wallis E. Andeline

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to identify the early hard tissue formed in experimental pulp exposures capped with calcium hydroxide, mineral trioxide aggregate (MTA) or bone morphogenetic protein-7 (BMP-7) using dentin sialoprotein (DSP) as a marker. The pulps of eighty-five maxillary first, second and third molar teeth from twenty male rats were experimentally exposed. The exposed pulps were capped with calcium hydroxide followed by restoration with amalgam (n = 20), with MTA alone as a pulp capping agent and final restoration (n = 20) or with BMP-7 followed by restoration with MTA (n = 20). Ten teeth with Class …

Hard Tissue Healing Adjacent To Fresh Or Set Mta As Root-End Filling Material, Erol S. Apaydin

Loma Linda University Electronic Theses, Dissertations & Projects

Mineral trioxide aggregate (MTA) has been shown to promote regeneration of periradicular tissues when used as a root-end filling material. The purpose of this study was to compare the effect of fresh MTA with set MTA on hard tissue healing following periradicular surgery.

Under general anesthesia, the root canals of twenty-four mandibular premolars in four 2-year-old beagle dogs were filled with MTA. Two weeks later the root-ends of half of the samples were surgically exposed and resected to the level of set MTA within the canals. After exposing and resecting the other 12 root-ends, class I cavities were prepared in …

The Effect Of Root End Demineralization On Cementogenesis : A Long Term Investigation, Hamid R. Abedi

Loma Linda University Electronic Theses, Dissertations & Projects

Craig and Harrison¹² examined the effect of demineralization of resected root ends on wound healing following periradicular surgery. Based on its microscopic evaluations from 4-45 days, it was proposed that demineralization of resected root ends enhances cementogenesis. The purpose of this study was to investigate the longer term effects of demineralization on cementogenesis using Mineral Trioxide Aggregate (MTA) or amalgam as root end filling materials. After completion of root canal therapy and endodontic surgery on seventy-two roots of mandibular second, third and fourth premolars of six beagle dogs, 32/72 of the root ends at random were etched with 50% …

Histologic Host Response To Polyoxymethylene Prosthesis As A Temporomandibular Joint Condylar Replacement, Frederick R. Mathews

Loma Linda University Electronic Theses, Dissertations & Projects

Polyoxyinethylene (Delrin) is a polyacetyl homopolymer which has been used successfully in many orthopedic joint replacements. To determine histologic host response to Delrin as a temporomandibular joint condylar replacement condyles were removed from ten fully mature macaca fasicularis monkeys. The condyles were replaced with a total prosthetic Delrin condyle attached to a titanium mesh. Specimens obtained at one, two, and six months indicated total acceptance of the Delrin, remodeling of the glenoid fossa and formation of bone between the middle cranial fossa and the roof of the glenoid fossa. These findings would indicate Delrin is a viable option for condylar …

An Ultra-Violet Light Microscopic Study Of The Hydroxylapatite Ceramic-Bone Interface Phenomena, Leonard W. Pierce

Loma Linda University Electronic Theses, Dissertations & Projects

Preparations used in this study were obtained from an investigation which had undertaken the following:

Durapatite, a hydroxylapatite ceramic was implanted in 24 mature Beagle dogs to study its maintenance effect on the alveolar bone of the mandible.

After dividing the dogs into two groups, a fresh socket and a healed socket group, the posterior teeth were removed and alveolectomies were performed. Eight ceramic implants were then placed in the right mandible of each animal in each group. The healed group received the implants five weeks after tooth removal and the fresh socket group received implants immediately after extraction.

The …

Determination Of Lead Content In Apical Tissue Following Root Canal Obturation With Sargenti's Formula, G. Merle Hickok

Loma Linda University Electronic Theses, Dissertations & Projects

Four Stump-tail monkeys were used to help determine if the lead in Sargenti's formula diffuses out into the apical tissue while confined entirely within the root canal. In each animal two teeth were filled with Sargenti's formula 1-2 millimeters short of the radiographic apex, and two teeth were filled with gutta percha and Proco-Sol sealer for controls, making a total sample size of sixteen. The time ranged from 48 hours to 120 days. Lead analysis using the spectrophotometric method showed a higher lead content in the teeth filled with Sargenti's formula than with the gutta percha controls.

Histologic Comparison Of Apical Tissue Response To Endodontic Overfills With Gutta Percha And Grossman's Sealer Vs. Sargenti Method (N₂), Donald L. Brewer

Loma Linda University Electronic Theses, Dissertations & Projects

This study compared endodontic overfills of N₂ and gutta percha-Grossman's Sealer from a histopathological basis. The study employed four male rhesus monkeys and a sample of 31 teeth.

The most obvious difference between the samples filled with N₂ and the gutta percha-Grossman's Sealer samples was the recurring presence of ankylosis in the N₂-treated teeth. Results also included bone necrosis, inflammation and root and bone resorption.

The N₂ samples were considered to have evidenced greater violence of reaction apically.

The Effect Of Post-Operative Use Of Chlorhexidine On Periodontal Regeneration In Monkeys With Chronic Bifurcation Defects, J. Pat Bishop

Loma Linda University Electronic Theses, Dissertations & Projects

Periodontal regeneration and inflammation was evaluated histometrically in 36 paired teeth in six macque(sic) monkeys with chronic bifurcation defects. Daily topical TL Chlorhexidine was applied to one-half of the teeth, saline to the other half for six weeks after the bifurcation defects were surgically debrided. Measurements were made from a section taken from the mid-bifurcation for each tooth. The results demonstrated no significant difference in the area of inflammatory response or the degree of regenerative capacity of post-operative healing between Chlorhexidine treated and paired nontreated control teeth.

Effect Of Post-Operative Use Of Chlorhexidine On Regeneration Of Bifurcation Defects In Dogs, Gary Bogle

Loma Linda University Electronic Theses, Dissertations & Projects

The daily post-operative use of topical chlorhexidine application has been compared to daily toothbrushing. Periodontal defects were experimentally created in the bifurcations of lower premolars in dogs. The defects were treated by surgical debridement. Chlorhexidine application and toothbrushing were performed post-operatively for six weeks on contralateral pairs of teeth. The amounts of connective tissue and bone regeneration were evaluated from microscopic sections of the bifurcation areas. No difference between chlorhexidine and tooth brushing was found for the connective tissue attachment. However, significantly more bone had regenerated in the chlorhexidine treated areas than the tooth brushed area.

The Effect Of Oral Allografts Of Cancellous Bone And Marrow In Mice, George E. Deeb

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was: to develop a model for testing oral bone transplantation; to study the healing of a surgically produced defect with and without the transplantation of strongly allogeneic cancellous bones and marrow; and to determine the fate of the allogenic grafts. Twenty-eight CBA/H mice served as experimental animals. Intra-oral defects were made and in 14 of the animals strongly allogenic cancellous bone and marrow were transplanted. The 14 remaining animals served as controls. It was observed that the healing was delayed in the experimental animals as compared to the controls and that the grafted material was …

Microscopic Evaluation Of Topically Applied Chlorhexidine Gluconate On Gingival Wound Healing In Dogs, Robert C. Hirst

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate microscopically the effect of topically applied 2% chlorhexidine gluconate on the healing of gingival wounds in dogs.

One week after the teeth were scaled and polished, seven experimental wound sites were prepared in the facial gingiva adjacent to the four premolars on each side of the maxillary arch in six young Labrador dogs. From this point the dogs were fed a soft plaque-inducing diet. Chlorhexidine solution was applied daily to either the right or left maxillary premolars while on the opposite side of the arch in three dogs the first and second …

Marrow Isografts In The Oral Cavity Of Mice, Robert L. Merin

Loma Linda University Electronic Theses, Dissertations & Projects

The objectives of this study were to develop an animal model for testing oral bone and marrow transplantation that is adaptable to immunological studies; to determine the effect of an isogeneic graft of cancellous bone and marrow on the healing of surgically created defects; and to determine the fate of grafted isogeneic cancellous bone and marrow transplanted into defects. Fourteen CBA/H mice served as experimental animals and bilateral intraoral defects were prepared. The experimental side received isogeneic graft material while the other side served as a control. Osseous healing was found to be accelerated in the defects receiving graft material …

Oral Bandage Tissue Reaction In Dogs, John Rozema

Loma Linda University Electronic Theses, Dissertations & Projects

This experiment was designed to evaluate an oral surgical dressing which may be used as an aid to healing tissue. The parameters of evaluation were directed toward wound healing enhancement, duration, and stability of the bandage. A histological evaluation of the surgical wounds protected with the bandage as compared to the control wounds was made.

The surgeries were performed on eight dogs in a double controlled experiment and were in the form of bilateral maxillary gingivectomies and mandibular molar tooth extractions. The surgery sites on the left were covered with the Orahesive Bandage while the right side remained exposed to …