bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of a Mechanical Barrier on the Integration of Cortical Onlay Bone Grafts Placed Simultaneously with Endosseous Implant
Authors: Salata Luiz Z. , Rasmusson Lars , Kahnberg Karl‐Erik
Published: October 2006

Background: Previous experimental studies on onlay bone graft integration have shown either advantages or disadvantages to the use of mechanical barriers. This indicates that the role played by the biologic properties of transplanted bone and membrane in graft revascularization and bone remodeling has not yet been established. The outcomes regarding osseointegration of titanium dental implants applied in such a condition are still contradictory.

Purpose: The rabbit's radius model that is grafted onto the mandibular lower border and covered by membrane can reproduce a challenging experimental situation to preliminarily study the factors involved in osseointegration under deprived blood vessels source.

Materials and Methods: Fourteen New Zealand White rabbits had a 2.5‐cm segment of the right radius osteoectomized and fixed onto the right mandibular lower border using titanium screws. Two screw‐shaped titanium implants (2.5 mm wide 2.5 mm long) were installed 7 mm apart in the mid length of the grafted bone. In experimental sites, the graft with the implants and graft‐host bone junction were covered by expanded polytetrafluoroethylene (e‐PTFE) membrane; control sites were left uncovered. Eight animals from the experimental group and six animals from the control group were sacrificed at 6 and 24 weeks after surgery. Ground sections obtained from en bloc tissues containing graft, implants, and recipient bone were subjected to histologic evaluation and histomorphometric analysis (area occupied by the graft and bone‐to‐implant contact).

Results: The graft showed significantly more resorption after 24 weeks than at 6 weeks (p .05) irrespective of the treatment (with or without membrane), although the amount of new bone was greater at 24 weeks in sites where a membrane was covering the graft. Compared with 6 weeks postoperatively, the bone‐to‐implant contact was considerably improved at 24 weeks (p .05), and the membrane seemed beneficial for implant osseointegration when compared with unprotected sites (p .05). As a result of graft resorption, the amount of soft tissue was considerably expanded in sites beneath membrane, accompanied by a sustained process of trabecular bone deposition close to the barrier.

Conclusions: Cortical onlay grafts covered by membrane demonstrated delayed remodeling, probably as a consequence of a hindered process of graft revascularization. Grafts covered by membrane might rely on previous host bone resorption both to become revascularized and to remodel. The findings that the membrane‐protected grafts were most resorbed at 24 weeks might be attributable to better implant osseointegration, because the fixtures were exposed to greater mechanical stimulation in these sites.
Early Loading of Four or Five Astra Tech Fixtures with a Fixed Cross‐Arch Restoration in the Mandible
Authors: Collaert Bruno , De Bruyn Hugo
Published: October 2006

Background: A change in implant placement has emerged recently from two‐stage to one‐stage surgery and to earlier and even immediate loading of the fixtures.

Purpose: The aim of this study was to verify whether four or five fixtures installed in the edentulous mandible were suitable for early loading with a cross‐arch fixed restoration.

Materials and Methods: In 25 consecutively treated patients (28–88 yr), four or five Astra Tech fixtures (Mölndal, Sweden) were installed in edentulous mandibles. During the same surgical procedure, the abutments were connected. An impression was taken immediately after surgery. All patients received a fixed prosthetic rehabilitation of 10 to 12 teeth made of a cast metal framework and acrylic teeth/gingiva within a month. The fixtures were followed up clinically and radiographically for 7 to 24 months. Bone level was measured from the most coronal point of the vertical part of the fixture to the most apical bone level mesially or distally.

Results: No fixtures were lost during follow‐up. No postoperative complications occurred. Radiographic analysis showed a mean bone level of 0.6 mm after 7 to 12 months. Fixtures followed up from 13 to 18 and 19 to 24 months showed a mean bone level of 0.7 mm. Around two fixtures, the bone level was found at the first implant thread. All other fixtures showed the bone level somewhere along the vertical unthreaded part of the fixture.

Conclusions: Early loading within 1 month of four or five Astra Tech fixtures in the edentulous mandible is a predictable procedure for a follow‐up period of 6 to 24 months.
A Study of Dental Implants in Medically Treated Hypothyroid Patients
Authors: Attard Nikolai J. , Zarb George A.
Published: October 2006

Purpose: The purpose of this study was to investigate the success outcomes of implants and prosthodontic treatment placed in patients with a previous history of hypothyroidism that was being controlled with medications.

Materials and Methods: Twenty‐seven female patients with a medically confirmed history of primary hypothyroid disease who were on replacement medications at the time of implant surgery were selected as the study group. They were matched with 29 control patients by age, gender, location (jaw and zone) of implants, type of prosthesis, and dental status of the opposing arch. Additional factors studied were medical history, medications, smoking habits, and bone quality and quantity.

Results: There was no statistical difference in the number of implant failures between the two groups (p =.781). The hypothyroid patients had more soft tissue complications (p =.018) following stage 1 surgery. More bone loss around implants in the hypothyroid patients was recorded after year 1 of loading when compared with loss in their matched controls (p =.017).

Conclusions: This study suggests that medically controlled hypothyroid female patients treated with dental implants are not at higher risk of implant failure when compared with matched controls, and that a history of controlled hypothyroidism does not appear to be a contraindication for implant therapy with endosseous implants.
“All‐on‐Four” Immediate‐Function Concept with Brånemark System® Implants for Completely Edentulous Mandibles: A Retrospective Clinical Study
Authors: Maló Paulo , Rangert Bo , Nobre Miguel
Published: October 2006

Background:

Immediate‐function Brånemark System® implants (Nobel Biocare AB, Gothenburg, Sweden) have become an accepted alternative for fixed restorations in edentulous mandibles, based on documented high success rates. Continuous development is ongoing to find simple protocols for their use.

Purpose:

The purpose of this study was to develop and document a simple, safe, and effective surgical and prosthetic protocol for immediate function (within 2 hours) of four Brånemark System implants supporting fixed prostheses in completely edentulous mandibles: the “All‐on‐Four” concept.

Materials and Methods:

This retrospective clinical study included 44 patients with 176 immediately loaded implants, placed in the anterior region, supporting fixed complete‐arch mandibular prostheses in acrylic. In addition to the immediately loaded implants, 24 of the 44 patients had 62 rescue implants not incorporated in the provisional prostheses but incorporated in final prostheses later on.

Results:

Five immediately loaded implants were lost in five patients before the 6‐month follow‐up, giving cumulative survival rates of 96.7 and 98.2% for development and routine groups, respectively. The prostheses' survival was 100%, and the average bone resorption was low.

Conclusions:

The high cumulative implant and prostheses survival rates indicate that the “All‐on‐Four” immediate‐function concept with Brånemark System implants used in completely edentulous mandibles is a viable concept.
Early Function of Splinted Implants in Maxillas and Posterior Mandibles Using Brånemark System® Machined‐Surface Implants: An 18‐Month Prospective Clinical Multicenter Study
Authors: Vanden Bogaerde Leonardo , Pedretti Giorgio , Dellacasa Paolo , Mozzati Marco , Rangert Bo
Published: October 2006

Background:

There are limited clinical data available for immediately or early loaded implants placed in posterior mandibles and maxillas. This is probably because bone density often is low in these areas, making it difficult to establish good initial implant stability. By eliminating countersinking and using slightly tapered implants (Brånemark System®, Mk IV, Nobel Biocare AB, Gothenburg, Sweden), however, high initial implant stability might be achieved in these regions.

Purpose:

The aim of this study was to investigate the possibility of early application of implant function in oral locations where the bone density is often low, namely the maxilla and posterior mandible.

Materials and Methods:

Thirty‐one patients were included consecutively in the study, and 36 edentulous areas in maxillas and posterior mandibles were treated. All patients were nonsmokers in good general health. Bruxism and uncontrolled periodontal disease were exclusion criteria. One hundred twenty‐four machined‐surface implants were placed using an insertion torque of at least 40 Ncm. Temporary prostheses with narrow occlusal platforms, flat cusps, and light occlusal contacts were generally placed within 1 week and not exceeding 20 days from implant placement.

Results:

Of the 124 implants installed, 4 failed, 1 in each of four patients, giving an overall survival rate of 96.8% after 18 months. Two implants failed in maxillas and two in mandibles. One implant in a maxilla and one in a mandible were lost in an early stage, and the other two were lost a few months after placement. The prostheses' survival was 100%.

Conclusions:

This study shows that early implant function rehabilitation in maxillas and posterior mandibles is viable using the present clinical protocol. The results are comparable with those of conventional two‐stage protocols.
Nobel Perfect™ Esthetic Scalloped Implant: Rationale for a New Design
Authors: Wöhrle Peter S.
Published: October 2006

Background:

Over the past 20 years, there have been relatively few changes in implant designs. Most systems are manufactured from commercially pure titanium with turned threads, are sprayed with plasma, are coated with hydroxyapatite, or have an oxide surface. The majority of dental implants have not been designed for differing bone morphologies. Today patients have high esthetic demands that require modifications of implant designs to fulfill their expectations.

Purpose:

This article evaluates the problems encountered when trying to achieve an optimum esthetic outcome with dental implants. Implants and abutment designs, biologic width, ridge anatomy, and timing of implant placement all affect esthetic results. Each of these factors is discussed and is related to the introduction of a new scalloped implant design. The purpose of the scalloped design is to keep or create interdental bony peaks that support the soft tissue, thereby maintaining or creating interimplant papillae.

Methods:

Clinical documentation of patients treated with the scalloped implant is presented. The esthetic outcome can be determined by comparing clinical documentation prior to and after treatment.

Conclusions:

The scalloped implant provides clinicians and patients with the option of improving esthetic outcomes. Placement and restoration of this implant are important when planning implant treatment in the esthetic zone.
3‐Year Prospective Multicenter Study on One‐Stage Implant Surgery and Early Loading in the Edentulous Mandible
Authors: Raghoebar Gerry M. , Friberg Bertil , Grunert Ingrid , Hobkirk John A. , Tepper Gabor , Wendelhag Inger
Published: October 2006

Background: The long‐term success rates achieved in dental implantology suggest that flexibility might well exist within the various implant systems to a degree that an altered protocol (ie, one‐stage surgery and immediate or early loading) can be performed under controlled conditions. However, before variations of the protocol can be considered for general use, they must be subjected to critical analysis, particularly with respect to the predictability of osseointegration, alteration of soft tissue barrier, and relative change in bone height around the implants.

Purpose: The aim of this prospective multicenter study was to evaluate implant survival and periimplant conditions around endosseous implants placed in a one‐stage surgical procedure and early loading.

Materials and Methods: A total of 170 implants were placed in 40 patients with mandibular edentulism and were functionally loaded within 6 weeks with overdentures (n = 30) or fixed prostheses (n = 10). All patients and prosthetic constructions were evaluated according to a standardized protocol during 3 years of follow‐up. Cumulative implant survival rates were calculated, and implant loss in relation to implant size and bone quality and quantity were evaluated. Furthermore, the protocol included assessment of clinical (plaque and bleeding scores, prosthesis stability) and radiographic parameters.

Results: Over a period of 3 years, the implant survival rate was 93% for both implants and prostheses (fixed or removable). No implants were lost after the first year of loading. The periimplant tissues were in a healthy condition. Mean marginal bone resorption from the time of loading to the 3‐year follow‐up was 0.41 mm (SD 0.52).

Conclusions: From this study it may be concluded that early loading results in good implant survival and proper periimplant health in edentulous mandibles.
Immediate/Early Loading of Dental Implants: a Report from the Sociedad Espanola de Implantes World Congress Consensus Meeting in Barcelona, Spain, 2002
Authors: Aparicio Carlos , Rangert Bo , Sennerby Lars
Published: October 2006

Background: Immediate/early loading protocols are becoming frequently used in implant dentistry, but the prerequisites for achieving good results and the limitations of such protocols are not fully known. Moreover, the terminology used in immediate/early loading is still confusing.

Purpose: The purpose of this article is to present the outcome of a consensus meeting on immediate/early loading.

Materials and Methods: A consensus meeting was organized during the Sociedad Espanola de Implantes World Congress in Barcelona on May 23, 2002, with the objective to present and discuss the experiences from immediate/early loading protocols in dental implant treatment. The purpose was also to discuss definitions of the terminology used in immediate/early loading. The consensus meeting agenda included presentations from invited experts, followed by a consensus discussion.

Results: A consensus statement was agreed on.

Conclusions: Multiple independent investigators have demonstrated that immediate/early loading of implants is possible in many clinical situations; however, additional documentation is required.
Measurements of Buccal Tissue Volumes at Single‐Implant Restorations after Local Bone Grafting in Maxillas: A 3‐Year Clinical Prospective Study Case Series
Authors: Jemt Torsten , Lekholm Ulf
Published: October 2006

Purpose: The purpose of this study was to measure changes in buccal and proximal tissue volumes after local bone grafting and single‐implant treatment.

Materials and Methods: Ten patients were provided with buccal bone grafts 6 months prior to implant treatment in central upper incisor regions. Following a healing time of 6 months, abutments and single‐implant crowns were installed and followed up for 2 years. Clinical photographs and impressions were taken prior to the surgical intervention as well as after crown placement and at first and second annual checkups. The photographs and study models were analyzed with regard to papilla regeneration and changes in buccal crest volume during the study period by means of a clinical papilla index and optical scanning of study models.

Results: All bone grafts healed without problems. A significant reduction of the buccal crest volume (‐50%, p <.01) was observed in the grafted area before abutment connection. However, a significant increase of tissue volume (+100%, p <.05) was noticed at the subsequent crown placement, followed by a second but slow reduction of the volume during the following 2 years of function. The interdental papillae increased significantly (p <.05) in volume during the first year, almost completely filling up the embrasure areas after 2 years.

Conclusions: It may be concluded that local bone grafting seems to be a valuable protocol to create sufficient bone volume for implant placement. However, significant resorption of the graft may be present, which reduces the impact of grafting on the esthetic outcome. Instead, placement of the abutment cylinder and the crown seems to play a more important role for reestablishing the tissue volume at the implant‐supported single crowns.
Histologic Analysis of Clinically Retrieved Immediately Loaded Titanium Implants: A Report of 11 Cases
Authors: Degidi Marco , Scarano Antonio , Petrone Giovanna , Piattelli Adriano
Published: October 2006

Background: Several investigators have reported high survival rates for early or immediately loaded dental implants.

Purpose: The aim of the present study was to analyze histologically the periimplant tissue reactions and the bone‐titanium interface of clinically retrieved immediately loaded titanium implants.

Materials and Methods: Eleven implants were inserted in the posterior jaw regions of six patients, serving as the most distal abutments of fixed provisional bridges and subjected to immediate occlusal loading. After a 10‐month loading period, all 11 implants were retrieved with a trephine.

Results: Mature bone was present at the interface of all implants. Some vertical bone loss was observed; this was more pronounced for cylindric implants. The bone‐implant contact was approximately 60 to 65 for all implants.

Conclusions: The results demonstrate that osseointegration of dental implants can occur during immediate loading.
Periimplant Bone Healing under Experimental Hepatic Osteodystrophy Induced by a Choline‐Deficient Diet: A Histomorphometric Study in Rats
Authors: Gorustovich Alejandro , de los Angeles Esposito Maria , Guglielmotti María Beatriz , Juan Giglio Maximo
Published: October 2006

Background: Osseointegration and success of an implant involve the interaction of local and systemic factors such as bone metabolic diseases.

Purpose: The purpose of this study was to evaluate the effect of experimental hepatic osteodystrophy induced by a choline‐deficient diet on periimplant bone healing.

Materials and Methods: Laminar titanium implants were placed in the tibias of five groups of Wistar rats: those with a (1) controlled diet for 15 days; (2) choline‐deficient diet for 15 days; (3) controlled diet for 30 days; (4) choline‐deficient diet for 30 days; (5) choline‐deficient diet for 15 days and a controlled diet for 15 days (refeeding). Body weight and food intake, hematocrit, and hemoglobinemia were evaluated. The animals were killed at 15 or 30 days post implantation. The liver, kidneys, and tibias were resected and fixed in 20% formalin solution. The tibias were radiographed and processed for histomorphometric evaluation of the periimplant bone area.

Results: Histologic studies revealed steatosis in the liver but no alterations in the kidneys. Rats fed a choline‐deficient diet showed periimplant bone healing with marked qualitative and quantitative alterations. The periimplant bone area was 28% and 75% lower in experimental animals than in controls at 15 and 30 days, respectively.

Conclusions: Liver alterations caused by a choline‐deficient diet alter periimplant osteogenesis qualitatively and quantitatively.
Enhancement of Osseointegration of Implants Placed into Extraction Sockets of Healthy and Periodontally Diseased Teeth by Using Graft Material, an ePTFE Membrane, or a Combination
Authors: Tehemar Sherif , Hanes Philip , Sharawy Mohamed
Published: October 2006

Background: Advanced periodontal disease as well as failed endodontic teeth are the most common reasons for tooth removal and simultaneous implant placement.

Purpose: To determine whether the addition of a bone substitute graft material and/or a guided bone regeneration membrane added to the site of an immediately placed implant would increase the development of lamellated bone, particularly in the presence of bone defects.

Materials and Methods: Four treatment modalities associated with the immediate placement of hydroxyapatite‐coated endosteal screw implants into extraction sockets of healthy (C/H) and periodontally diseased teeth (T/PD) were tested. Five dogs with healthy teeth and five dogs with naturally occurring periodontitis were chosen for the study. Each dog received eight implants after extraction of four mandibular and four maxillary premolars. Four implants were submerged for 3 months and four for 6 months. The implants were either inserted alone (subgroup A); surrounded by a GORETEX membrane (subgroup B; W.L. Gore & Associates Inc., Flagstaff, AZ, USA); surrounded by PepGen P‐15 (Dentsply Friadent CeraMed Dental Co. Denver, CO, USA) at coronal area (subgroup C); or surrounded by a combination of graft material and the ePTFE membrane (subgroup D). Implants in group A were osseointegrated in both C/H and T/PD groups with similar bone‐implant contact ratios (BICRs).

Results: ePTFE membrane significantly improved the BICR of the 6‐months implants, whereas graft material significantly increased the BICR at 3 months and maintained the gain thereafter. The graft material and membrane combination further improved the BICR and significantly increased lamellated bone in crestal bone of all implants.

Conclusions: This study provides experimental evidence in support of use of graft material with immediately placed implants, particularly in presence of bone defects that initially reduce the BICR such as in periodontitis. Adding an ePTFE membrane to graft material resulted in a greater replacement of woven bone by lamellated bone. Clinical trials in humans are recommended as a follow‐up of this experimental study.
A 5‐Year Prospective Follow‐Up Study of Implant‐Supported Fixed Prostheses in Patients Subjected to Maxillary Sinus Floor Augmentation with an 80:20 Mixture of Bovine Hydroxyapatite and Autogenous Bone
Authors: Hallman Mats , Zetterqvist Lars
Published: October 2006

Background:

Prospective long‐term follow‐up studies evaluating the use of bone substitutes to enable dental implant placement and integration are rare.

Purpose:

This study was undertaken to evaluate the survival rate of dental implants placed 6 months after maxillary sinus floor augmentation using a mixture of 80% bovine hydroxyapatite (BH) and 20% autogenous bone (AB).

Material and Methods:

Twenty patients subjected to 30 maxillary sinus floor grafting procedures using fibrin glue and an 80:20 mixture of BH and AB to enable placement of dental implants 6 months later were followed for 5 years of functional loading. Clinical and radiographic examinations of the grafts and implants were performed.

Results:

After 5 years of functional loading with fixed bridges, 15 of 108 implants had been lost, giving a cumulative survival rate of 86%. The mean marginal bone loss after 5 years was 1.3 ± 1.1 mm.

Conclusion:

Grafting of the maxillary sinus with a mixture of BH and AB and later placements of turned implants could be performed with predictable long‐term results. All but one of the patients who were observed had functional fixed bridges after 5 years of functional loading.
Biomechanical Measurements of Calcium‐Incorporated Oxidized Implants in Rabbit Bone: Effect of Calcium Surface Chemistry of a Novel Implant
Authors: Sul Young‐Taeg , Byon Eung‐Sun Eung‐Sun , Jeong Yongsoo Yongsoo
Published: October 2006

Background:

In oral implantology there has been a general trend away from machine‐turned minimally rough and acid‐etched and blasted implants toward intermediary roughened surfaces. Mechanical interlocking at micron resolution is claimed to be the dominant reason for the fixation of such implants in bone. However, clinical demands for stronger and faster bone bonding to the implant (eg, in immediately loaded and compromised bone cases) have motivated the development of novel surfaces capable of chemical bonding.

Purpose:

The purpose of the present study is to investigate bone tissue reactions to a newly developed calcium‐incorporated oxidized implant. The specific aim is to assess the effect of calcium surface chemistry on the bone response.

Materials and Methods:

Calcium (Ca) ion‐incorporated implants were prepared by micro arc oxidation methods. Surface oxide properties were characterized by using various surface analytic techniques involving scanning electron microscopy, x‐ray diffractometry, x‐ray photoelectron spectroscopy, and optical interferometry. Twenty screw‐shaped commercially pure (CP) titanium implants (10 turned implants [controls] and 10 Ca‐incorporated implants [tests]) were inserted in the femoral condyles of 10 New Zealand White rabbits.

Results:

After a healing period of 6 weeks, resonance frequency analyses and removal torque measurements of the Ca‐incorporated oxidized implants demonstrated statistically significant improvements of implant integration with bone in comparison to machine‐turned control implants (p = 0.013 and p = 0.005, respectively).

Conclusions:

The Ca‐reinforced surface chemistry of the oxidized implants significantly improved bone responses in a rabbit model. The present study suggests that biochemical bonding at the bone‐implant interface, in combination with mechanical interlocking, may play a dominant role in the fixation of Ca‐incorporated oxidized implants in bone. The observed rapid and strong integration of test Ca implants may have clinical implications for immediate or early loading and improved performance in compromised bone.
An Image‐Guided System‐Drilled Surgical Template and Trephine Guide Pin to Make Treatment of Completely Edentulous Patients Easier: A Clinical Report on Immediate Loading
Authors: Fortin Thomas , Isidori Michel Michel , Blanchet Eric Eric , Perriat Michel Michel , Bouchet Hervé Hervé , Coudert Jean Loup Jean Loup
Published: October 2006

Purpose:

An image‐guided system has been developed to drill a conventional surgical guide following a preoperative three‐dimensional plan for accurate placement of implant on bone. The aim of this study is to illustrate how this system facilitates treatment of completely edentulous patients by modifying both surgical and prosthetic protocols, thereby making flapless surgery possible as well as the preparation of the transitional prosthesis before surgery.

Materials and Methods:

This system was tested on 10 consecutive patients, placing all planned implants without raising the mucoperiosteal flap and with the connection of all implants to pre‐angulated abutments.

Results:

A 1‐year follow‐up demonstrated stable and properly functioning prostheses in all cases.

Conclusions:

This technique can be expected to flourish because implantology makes the highest demands on comfort, precision, and safety.
Clinical Experiences of Computer Numeric Control‐Milled Titanium Frameworks Supported by Implants in the Edentulous Jaw: A 5‐Year Prospective Study
Authors: Örtorp Anders , Jemt Torsten
Published: October 2006

Background:

Few long‐term follow‐up studies on treatment concepts using computer numeric control‐milled titanium frameworks have been conducted.

Objective:

To evaluate the clinical and radiographic performance of implant‐supported prostheses provided with computer numeric control‐milled titanium frameworks in the edentulous jaw and to compare their performance during the first 5 years of function with that of prostheses provided with conventional cast gold alloy frameworks.

Materials and Methods:

A consecutive group of 126 edentulous patients were randomly provided with 67 prostheses with titanium frameworks (test group) in 23 upper jaws and 44 lower jaws and with 62 conventional prostheses with gold alloy castings (control group) in 31 upper jaws and 31 lower jaws. Clinical and radiographic 5‐year data were collected for the test and control groups.

Results:

The frequency of problems was low, and clinical and radiologic performances were similar in both groups. In the test group, the 5‐year cumulative survival rates (CSRs) were 94.9% and 98.3% for implants and titanium prostheses, respectively. The respective corresponding CSRs for the control group were 97.9% and 98.2%. More loaded implants were lost in the maxillas in the test group (p < .01), but this difference was not significant on the patient/prosthesis level (p > .05). Smokers lost more implants than nonsmokers lost (p < .01). Similar survival rates were observed for implants in the mandible. One prosthesis was lost in each group because of the loss of implants. Metal fractures were seen only in the control group, and resin veneer fractures were more frequent in the maxilla in the gold alloy group (p < .05). In the test group, the mean marginal bone loss was 0.5 mm (SD, 0.44) in the maxilla and 0.4 mm (SD, 0.50) in the mandible. A similar pattern of bone reaction was observed in the control group. Mean marginal bone loss was similar for smokers and nonsmokers (p > .05).

Conclusion:

Computer numeric control‐milled titanium frameworks are a viable alternative to gold alloy castings in the edentulous jaw and present clinical and radiologic performances similar to those of conventional gold alloy frameworks during the first 5 years of function.
Stability of the Implant/Abutment Joint in a Single‐Tooth External‐Hexagon Implant System: Clinical and Mechanical Review
Authors: Khraisat Ameen , Abu‐Hammad Osama , Al‐Kayed Awni M. , Dar‐Odeh Najla
Published: October 2006

Rigorous efforts have recently been made to reduce the recurrence of implant/abutment joint failure in single‐tooth implant restorations. However, the current knowledge about the stability of implant/abutment joints in an external hexagon implant system is incomplete. We reviewed clinical data regarding single‐tooth implant treatment with Brånemark implants, specifically the CeraOne abutment system (Nobel Biocare AB, Göteborg, Sweden). In vitro studies on joint stability were systematically assessed. Bending overload and the presence of misfit at the implant/abutment joint interface are the critical mechanical conditions that can make the joint unstable. Appropriate joint fitness and proper alignment of the implant should be assessed, and occlusal adjustment by narrowing the restoration width and flattening cuspal inclination should be applied to avoid bending moments caused by the lateral component of occlusal forces. Sufficient clinical reports of longer duration that evaluate and verify longer‐term success of the newly manufactured joint components were unavailable.
Clinical Evaluation of a 3% Hydrogen Peroxide Tooth‐Whitening Gel
Authors: MYERS MICHAEL L. , BROWNING WILLIAM D. , DOWNEY MARY C. , HACKMAN STEVEN T.
Published: October 2006

Purpose: The purpose of this randomized double‐blind investigation was to clinically evaluate the effectiveness of a commercially available 3% hydrogen peroxide tooth‐whitening material (ADS Tooth Whitening Gel, Applied Dental Sciences, Inc., Lee, MA). The material was used over 2 weeks in a dentist‐supervised, patient‐applied application.

Materials and Methods: The evaluation was carried out in accordance with American Dental Association (ADA) Council on Scientific Affairs Acceptance Program Guidelines for Home‐Use Tooth Whitening Products (May 1998). Sixty‐five participants were randomized into two groups (active and placebo) for a double‐blind, placebo‐controlled study. A custom application tray, scalloped without reservoirs, was fabricated for each participant. Tooth shades were documented by matching with the Vita shade guide ordered according to value and assigned a numeric ranking from 1 to 16, darkest to lightest. Participants were supplied with the treatment solutions to use in the application tray. Duration of active treatment was 30 minutes 3 times a day for 2 weeks. Participants were evaluated at baseline, 1 week and 2 weeks treatment, and 12 and 26 weeks post‐treatment. The statistical analysis used at each time point to determine the difference between the active and placebo groups based on the change in value was the two‐sample f‐test. Plaque and soft tissue indices were also recorded.

Results: The teeth treated with 3% hydrogen peroxide were significantly lighter at 2, 12, and 26 weeks (p≤ .0140, .0004, and .0001, respectively) compared with the placebo group. The mean shade change was 4.2 Vita shade tabs at 2 weeks. At 26 weeks (6 months), the degree of whitening was 4.1 tabs.

CLINICAL SIGNIFICANCE

This study demonstrated that a 3% hydrogen peroxide gel used for 30 minutes 3 times a day is effective in lightening teeth after 2 weeks of active treatment. The color change was effectively maintained at 6 months.
Esthetic Techniques and Restorative Systems Used in the Second‐Year Undergraduate Dental Curriculum
Authors: RAIGRODSKI ARIEL J. , HARRISON JAMES D.
Published: October 2006

Metal‐free tooth‐colored restorative systems for fabricating indirect intracoronal and extracoronal restorations have been developed because of patients' demand for superior esthetics. During the past decade, long‐term clinical studies have demonstrated the success of many of these types of restorations in terms of function and esthetics. Ceramic veneers, all‐ceramic crowns, ceramic onlays, and composite‐resin inlays are becoming an integral part of contemporary clinical practice. The constant evolution in bonding techniques, adhesive systems, and cements plays a major role in the success of these metal‐free restorations. In addition, home‐bleaching procedures have become an integral part of the esthetically oriented dental practice. This article discusses the rationale, scientific basis, and implementation of a new undergraduate preclinical esthetics course for second‐year dental students at the Louisiana State University Health Sciences Center School of Dentistry.

CLINICAL SIGNIFICANCE

Changes in the undergraduate dental curriculum are ultimately necessary to provide undergraduate students with the adequate theoretic knowledge and clinical skills they require to face challenging practice demands and patients' requests for esthetic restorations. The implementation of the Preclinical Esthetics course at Louisiana State University School of Dentistry gives undergraduate dental students a foundation for restoring patients with indirect tooth‐colored restorations, such as composite‐resin inlays, ceramic onlays, ceramic veneers, and all‐ceramic crowns, and vital bleaching procedures.
Effect of Resin Surface Sealers on Improvement of Stain Resistance for a Composite Provisional Material
Authors: DORAY PAMELA G. , ELDIWANY MAGDA S. , POWERS JOHN M.
Published: October 2006

Background: Resistance to staining is desirable to maintain the esthetic appearance of a provisional material. A resin sealant may improve stain resistance.

Purpose: Color changes of a resin composite provisional material were measured by reflection spectrophotometry after storage in three staining solutions and water to determine stain resistance when treated with three methacrylate or urethane dimethacrylate resin surface sealants and when left untreated.

Materials and Methods: Specimens of a resin composite provisional material received one of three resin sealants (Fortify Plus°, Bisco, Inc., Schaumburg, IL; Jet Seal°, Lang Dental Manfacturing, Wheeling, IL; Triad LC°, Dentsply International, York, PA, USA) or no surface sealer and then were stored for 72 hours in one of four staining solutions (water [control], black coffee, cranberry juice, red wine). Color was measured by CIE L*a*b*on a reflection spectrophotometer (Color‐Eye° 7000, Macbeth Division, Kollmorgen Instruments, Newburgh, NY, USA) at baseline and after storage. Color change (ΔE*) was calculated and analyzed statistically by two‐factor analysis of variance, with four solutions and four surface treatments as independent variables.

Results:ΔE* ranged from 0.7 to 1.7 in water, from 1.1 to 5.5 in cranberry juice, from 1.1 to 6.5 in black coffee, and from 1.5 to 3.9 in red wine. Statistically significant differences were observed (p <.05), with Fortify Plus showing increased staining (AE* > 3.3) and Jet Seal and Triad LC showing decreased staining (AE* < 2.0) in cranberry juice and coffee compared with staining of the unsealed specimens. Only Jet Seal provided resistance to staining in red wine.

Conclusions: Specimens without a surface sealer had statistically higher (p <.05) and perceptible or nearly perceptible color changes in cranberry juice, black coffee, and red wine than in water. Specimens coated with Jet Seal had statistically lower (p < .05) color changes than uncoated specimens in cranberry juice, black coffee, and red wine. When coated, the color changes of the stained specimens were not perceptible. Specimens coated with Triad LC had statistically lower (p < .05) color changes than unsealed specimens in cranberry juice and black coffee. When sealed, the color changes of the specimens stained with cranberry juice and black coffee were not perceptible. Both unsealed and sealed specimens stained with red wine were nearly perceptible. Specimens coated with Fortify Plus had statistically higher (p <.05) color changes than uncoated specimens in cranberry juice and black coffee but statistically the same (p <.05) color change as uncoated specimens in red wine. These specimens had perceptible color changes in cranberry juice, black coffee, and red wine.

CLINICAL SIGNIFICANCE

Surface sealers of methacrylate or dimethacrylate resins can improve resistance of a resin composite provisional material to staining caused by cranberry juice, black coffee, and red wine.
Abfraction Lesions: Myth or Reality?
Authors: REES J.S. , JAGGER D.C.
Published: October 2006

Loss of tooth substance in the cervical region is usually attributed to toothbrush abrasion, erosion, or a combination of both factors. Recently the role of occlusal loading has become increasingly prominent. It is suggested that high occlusal loads cause large cervical stress concentrations, resulting in a disruption of the bonds between the hydroxyapatite crystals and the eventual loss of cervical enamel. This process has been called noncarious cervical tooth loss or abfraction.

This article reviews the available evidence to support the thesis that occlusal loading can contribute to the process of abfraction. It also reviews the potential interactions between occlusal loading and erosion that may contribute to abfraction lesion formation.

CLINICAL SIGNIFICANCE

It is important to recognize the potential role of occlusal loading in the loss of cervical tooth tissue so that management of the occlusion can be incorporated into a treatment plan for a patient with abfraction lesions.
Perioesthetic Approach to the Diagnosis and Treatment of Carious and Noncarious Cervical Lesions: Part II
Authors: TERRY DOUGLAS A. , McGUIRE MICHAEL K. , MCLAREN EDWARD , FULTON RUDOLPH , SWIFT EDWARD J.
Published: October 2006

Several classes of tooth‐colored materials are available for restoring carious and noncarious cervical lesions. Included are the composite resins, which can be bonded into the cervical area to provide predictable form, function, and esthetics. Part I of this two‐part report reviewed the etiology of noncarious cervical lesions and provided a series of clinical case reports showing the importance of the periodontal aspect of lesion management. In part II we present information about adhesive preparation design and esthetic restoration of the noncarious cervical lesion.

CLINICAL SIGNIFICANCE

When used with proper attention to preparation design and restoration placement and finishing, resin composites can be used to successfully restore form, function, and esthetics to defective cervical areas of teeth.
Long‐Term Resin Bond to Densely Sintered Aluminum Oxide Ceramic
Authors: BLATZ MARKUS B. , SADAN AVISHAI , SOIGNET DONOVAN , BLATZ ULRIKE , MERCANTE DONALD , CHICHE GERARD
Published: October 2006

Background: Densely sintered aluminium oxide ceramic is a popular material for ceramic copings and all‐ceramic restorations. A strong, predictable, and long‐term durable resin bond is key for long‐term clinical success of bonded alumina‐based restorations.

Purpose: The purpose of this study was to measure and compare in vitro shear bond strengths of three resin cements with and without their corresponding silane coupling/bonding agent to air particle‐abraded densely sintered aluminum oxide ceramic after long‐term water storage and thermocycling.

Materials and Methods: Composite resin cylinders were bonded to air particle‐abraded samples of densely sintered aluminum oxide ceramic with Noribond DC® (Noritake Dental Supply, Inc., Aichi, Japan), Panavia 21® EX (Kuraray, Osaka, Japan), and Variolink II® (Ivoclar Vivadent, Schaan, Liechtenstein), which were used with and without their corresponding silane coupling and bonding agents (n= 15). All specimens (N= 90) were stored for 180 days in water and subjected to repeated thermocycling for a total of 12,000 cycles before shear bond strength was tested. Data were analyzed with the Kruskal‐Wallis test and the Wilcoxon two‐sample rank sum test at the 5% level of significance.

Results: Most groups had no or only minimal bond strength to densely sintered alumina after simulated aging. Panavia had the highest bond strength without silane/bonding agent application. Noribond with its silane/bonding agent revealed the highest overall bond strength, which was significantly greater than that of either Variolink or Panavia after silanization.

Conclusions: Resin cements revealed significantly different bond strengths, and the use of silane coupling and bonding agents had various effects on the resin bond to pure densely sintered alumina.

CLINICAL SIGNIFICANCE

Selection of the proper cement/bonding system is fundamental to clinical long‐term success of bonded alumina‐based restorations. Noribond with its bonding agent and ceramic primer seem to fulfill these requirements under clinically relevant testing conditions.
Use of Shade Guides for Color Measurement in Tooth‐Bleaching Studies
Authors: BROWNING WILLIAM D.
Published: October 2006

Several different methods are used to measure tooth color in bleaching studies. The ADA Acceptance Program Guidelines for Home Use Tooth Whitening Products specify the use of a value‐oriented shade guide and/or electronic color measurement devices. Since people perceive color differently, shade guides are a subjective measure. Differences between raters and by the same rater are well documented in the dental literature. The purposes of this article will be to discuss the advantages and disadvantages using shade guides to measure color change related to tooth whitening, and to evaluate the correlation of data gathered from the use of shade guides to electronic color measurement devices.

Using an order published by the manufacturer, both the TRUBYTE® Bioform and Vita Classical guides can be arranged by value. A study by O'Brien demonstrated however, that the order is flawed and the change in brightness from tab to tab varies greatly. Despite these disadvantages, a review of data from several clinical trials demonstrates that Vita Classical shade guide data is consistent with data gathered using electronic color measurements. Furthermore, the O'Brien data can be used to make both these guides better measurement systems.

The ADA Certification program standards define the degree of overall color change that should be considered clinically important. This issue is as critical as the measurement system used. Reporting color changes that are neither detectable to the human eye nor considered by the public to be important offers the profession little usable information. Given that any standard for color change during bleaching must relate to the abilities of the human eye, it is the conclusion of the author that shade guides should remain a critical element of any bleaching study.

CLINICAL SIGNIFICANCE

Clinicians are frequently exposed to reports of bleaching agents that have been shown to result in a change of 6, 7, 8, etc., tabs. Without understanding the limitations of the shade guide used, reports of a specific shade tab change are of little use and may actually be misleading.
Influence of Cavity Configuration on Microleakage around Class V Restorations Bonded with Seven Self‐Etching Adhesives
Authors: SANTINI ARIO , IVANOVIC VLADIMIR , IBBETSON RICHARD , MILIA EGLE
Published: October 2006

Purpose::

The purpose of this study was to evaluate microleakage around Class V resin composite restorations with different cavity configurations, bonded with one of seven self‐etching materials or with an adhesive using the total‐etch technique.

Materials and Methods:

Ninety‐six human molars and premolars were randomly assigned to eight groups and bonded with one of seven self‐etching adhesives—Prompt‐L‐Pop™ (3M ESPE, St. Paul, MN, USA), Adper Prompt‐L‐Pop™ (3M ESPE), Clearfil SE Bond® (Kuraray Medical, Okayama, Japan), Prime & Bond® NT/NRC (Dentsply DeTrey, Konstanz, Germany), Xeno® III (Dentsply DeTrey), One‐Up Bond® (Tokuyama Dental, Tokuyama, Japan), AdheSE® (Ivoclar Vivadent, Schaan, Liechtenstein)—or with Prime & Bond® NT (Dentsply DeTrey) using a separate total‐etch technique. Cavities were cut in both the lingual and buccal surfaces and were approximately 3 mm mesiodistally, 1.5 mm deep, and 2.0 mm occlusogingivally. Selected at random, box‐shaped cavities were cut on one side and V‐shaped cavities were cut on the contralateral side. After bonding, the cavities were incrementally filled with a microhybrid composite (Tetric Ceram®, Ivoclar Vivadent), cured, and immediately polished with Sof‐Lex™ (3M ESPE) disks. The teeth were thermocycled, and the specimens were examined for microleakage using Procion Brilliant Red® (ICI, Slough, UK) as a marker.

Results:

Comparisons of both gingival and enamel margins within each of the groups showed no significant difference owing to configuration factor (C‐factor; p < .5 in all cases, calculated with Kruskal‐Wallis nonparametric analysis of variance [ANOVA]) and Dunn's multiple comparison test). All groups showed microleakage at the gingival margins irrespective of C‐factor or bonding agent (box‐shaped cavities, p < =.8862; V‐shaped cavities, p < =.9623; using the ANOVA).

Microleakage was not observed at all enamel margins regardless of C‐factor or bonding agent, and there were no significant differences between the groups (box‐shaped cavities, p < =.9869; V‐shaped cavities, p < =.9550; using the Kruskal‐Wallis nonparametric ANOVA).
Impression Matrix Technique for Cusp Replacement Using Direct Composite Resin
Authors: DENEHY GERALD , COBB DEBORAH
Published: October 2006

Placement of Class II composite resin restorations often presents unique challenges in achieving proper contour and contact. Although the use of sectional bands has provided solutions to these problems, their use typically is limited to more ideal cavity preparations. With more extensive loss of tooth structure, recreating the natural tooth contours and contacts with direct resin composite can be difficult. Typically an indirect restoration is the treatment of choice when a cusp is lost. However, situations may arise that require the use of direct resins for cusp replacement. This article describes the use of an impression matrix to facilitate the replacement of missing tooth structure and allow the dentist to use sectional bands in certain cusp loss situations.