Comparison of gingival resection with electrosurgery and periodontal knives--a biometric and histologic study

Comparison of four cordless gingival displacement systems: A clinical study

STATEMENT OF PROBLEM

Although the conventional chemicomechanical cord technique is widely used, packing the cord into the sulcus may cause pain and bleeding. Cordless displacement techniques have been introduced, but a comparison of these systems is lacking.

PURPOSE

The purpose of this clinical study was to evaluate the efficiency and gingival response of 4 cordless gingival displacement systems.

MATERIAL AND METHODS

One hundred twenty teeth in 30 participants were allocated to 4 groups according to the material used: Tr (Traxodent; Premier Dental Products Co), Es (Expasyl; Acteon UK), Ez (Expazen; Acteon UK), and Mr (3M Retraction; 3M ESPE). Baseline measurements of periodontal indices and a digital scan were acquired. The cordless displacement pastes were applied according to the manufacturer's instructions. After removal, a second scan was acquired. Participants were recalled on the 2nd and 14th day to measure periodontal indices and for scans. Screenshots were superimposed to measure changes in the gingiva. Statistical differences among the different materials in achieving lingual and buccal vertical gingival displacement were tested using the related-samples Friedman 2-way ANOVA test by ranks at 3 time points such as immediate, at 2 days, and at 14 days (α=.05).

RESULTS

Immediate gingival displacement varied with the system used. For horizontal displacement, median values ranged between 150 μm (Tr) and 725 μm (Ez) for buccal displacement and between 93 μm (Tr) and 550 μm (Ez) for lingual displacement. Minimum and maximum displacements also varied and followed a similar trend, with Traxodent providing the lowest displacement. The plaque index and attachment level did not statistically differ before and after the treatment. The periodontal parameters were not statistically significant among the groups at all time intervals, except for the gingival index that increased for all the groups after 2 days.

CONCLUSIONS

Significant differences were found among the 4 tested systems in both vertical and horizontal gingival displacement. Expasyl, Expazen, and 3M Retraction exceeded the 200-μm requirements for horizontal displacement. Traxodent provided the least displacement in both vertical and horizontal dimensions.

Severe gingival enlargement with coexisting erosive lichen planus in severe chronic periodontitis patient

Plaque induced gingival enlargement is most commonly seen and when encountered simultaneously with erosive lichen planus poses a challenge to the treating dentist. Prognosis of one condition may influence the prognosis of another condition. The presented case highlights the significance of proper diagnosis and the management of simultaneously occurring gingival lesions. A 49-year-old hypertensive female presented with painful enlarged bleeding and suppurating gums with burning sensation on eating food along with long-term usage of antihypertensive drug amlodipine known for its gingival enlargement effect. All these multiple factors led to diagnostic dilemma. Effective management of the gingival enlargement was done by using electrocautery to rehabilitate the functions and esthetics of the patient. Gingival condition was also complicated by the presence of coexisting lichen planus which was predominantly erosive for which topical corticosteroid, antifungal, and antimicrobial agents were prescribed. Eight-month follow-up did not show recurrence of gingival enlargement. Electrocautery is an effective tool for the gingivectomy in severe inflammatory type of gingival enlargement because of rapid postoperative hemostasis. For the management of erosive lichen planus, long-term use of topical corticosteroids is an effective approach. Maintenance of oral hygiene and regular follow-ups are essential for these conditions.

An Immunomodulatory Protein (Ling Zhi-8) from a Ganoderma lucidum Induced Acceleration of Wound Healing in Rat Liver Tissues after Monopolar Electrosurgery

The purpose of this study was to investigate the effect of an immunomodulatory protein (Ling Zhi-8, LZ-8) on wound healing in rat liver tissues after monopolar electrosurgery. Animals were sacrificed for evaluations at 0, 3, 7, and 28 days postoperatively. It was found that the wound with the LZ-8 treatment significantly increases wound healing. Western blot analysis clearly indicated that the expression of NF-κB was decreased at 3, 7, and 28 days when liver tissues were treated with LZ-8. Moreover, caspase-3 activity of the liver tissue also significantly decreases at 7 and 28 days, respectively. DAPI staining and TUNEL assays revealed that only a minimal dispersion of NF-κB was found on the liver tissue treated with LZ-8 at day 7 as compared with day 3 and tissues without LZ-8 treatment. Similarly, apoptosis was decreased on liver tissues treated with LZ-8 at 7 days when compared to the control (monopolar electrosurgery) tissues. Therefore, the analytical results demonstrated that LZ-8 induced acceleration of wound healing in rat liver tissues after monopolar electrosurgery.

Gingival displacement for impression making in fixed prosthodontics: contemporary principles, materials, and techniques

The clinical success and longevity of indirect restorations depend on the careful and accurate completion of several procedures. One of the challenging procedures is management of the gingival tissues and gingival esthetics. The goal for management of gingival tissues and gingival esthetics is to maintain the normal appearance of healthy gingival. Achieving this goal requires optimal health before treatment and minimal trauma during treatment. The best way of optimizing health and minimizing trauma is to avoid contacting the gingiva with restorative materials.

Gingival tissue healing following Er:YAG laser ablation compared to electrosurgery in rats

The erbium-doped yttrium aluminum garnet (Er:YAG) laser is currently used for periodontal soft tissue management with favorable outcomes. However, the process of wound healing after Er:YAG laser (ErL) treatment has not been fully elucidated yet. The aim of this study was to investigate the gingival tissue healing after ErL ablation in comparison with that after electrosurgery (ElS). Gingival defects were created in 28 rats by ablation with ErL irradiation or ElS. The chronological changes in wound healing were evaluated using histological, histometrical, and immunohistochemical analyses. The ErL-ablated gingival tissue revealed much less thermal damage, compared to the ElS. In the ElS sites, the postoperative tissue destruction continued due to thermal damage, while in the ErL sites, tissue degradation was limited and the defects were re-epithelialized early. Heat shock protein (Hsp) 72/73 expression was detected abundantly remote from the wound in the ElS, whereas it was slightly observed in close proximity to the wound in the ErL sites. Hsp47 expression was observed in the entire connective tissue early in the wound healing and was found limited in the wound area later. This phenomenon proceeded faster in the ErL sites than in the ElS sites. Expression of proliferating cell nuclear antigen (PCNA) persisted in the epithelial tissue for a longer period in the ElS than that in the ErL. The ErL results in faster and more favorable gingival wound healing compared to the ElS, suggesting that the ErL is a safe and suitable tool for periodontal soft tissue management.

Efficacy of two gingival retraction systems on lateral gingival displacement: A prospective clinical study

PURPOSE

Gingival management is a substantive procedure in fixed dental prosthesis treatment. Various new retraction cord systems are available and used. This study aimed to compare the efficacy of a new retraction cord (Stay-Put, Coltene Whaledent AG) and a conventional retraction cord (Ultrapak, Ultradent Products Inc., South Jordan, Utah) on lateral gingival displacement in continuation with the treatment protocol of the subjects fixed dental prosthesis for various partial edentulous conditions requiring fixed dental prosthesis.

METHOD

Thirty subjects were selected who needed bilateral fixed dental restoration. In selected subjects both gingival retraction cords were placed bilaterally buccolingually by simple randomization method. After removing the cords, impressions were made and undamaged definitive casts were retrieved. The abutment teeth were sectioned buccolingually at the buccal ridge followed by decimal measurement of the width (in millimeter) of the retracted gingival sulcus, under a traveling microscope.

RESULTS

Data was analyzed using SPSS version. Paired "t" test was used to compare the difference between the displaced gingival width in two retraction group (p > 0.05).

CONCLUSION

Although mean gingival retraction in Stay-Put system (0.528 ± 0.12 mm) was higher as compared to that in Ultrapak (0.487 ± 0.10 mm), the difference between the two systems (0.041 ± 0.11) was not significant statistically (p = 0.057).

Effects of steel scalpel, ultrasonic scalpel, CO2 laser, and monopolar and bipolar electrosurgery on wound healing in guinea pig oral mucosa

OBJECTIVE

The study's objective was to compare instrument performance and tissue healing when steel scalpel, ultrasonic scalpel, monopolar or bipolar electrosurgical instruments, or CO2 laser was used in an animal oral surgery model.

STUDY DESIGN

Prospective, blinded, randomized.

METHODS

Adult guinea pigs (N = 70) were randomly assigned to 5 groups (14 animals per group) for excision of 2-cm, full-thickness oral mucosa using steel scalpel, ultrasonic scalpel, monopolar or bipolar electrosurgical instruments, or CO2 laser. Postoperative pain was measured indirectly using weekly body weight changes. Animals from each group were killed on days 0, 7, 14, 21, and 28. Specimens were harvested for blinded histopathological study and tensile strength measurement. Instrument performance (hemostasis, tissue coagulation, tissue sticking) and wound healing (tissue re-epithelialization, degree of inflammation) were primary outcomes. Statistical analysis was performed using analysis of variance.

RESULTS

The ultrasonic scalpel was the best tool in controlling hemostasis, tissue coagulation, and tissue sticking. Significantly higher body weight gain ( P<.05) was noted at day 7 for monopolar and CO2 laser groups. Greatest tensile strength was seen in the steel scalpel and ultrasonic scalpel groups at the end of 28 days. Tissue re-epithelialization was fastest for the steel scalpel and ultrasonic scalpel groups (complete by day 7). Complete re-epithelialization of wounds of all treatment groups occurred by day 28. All groups had acute inflammation. Complete resolution of inflammation by day 14 took place in the steel scalpel and ultrasonic scalpel groups only.

CONCLUSION

Use of the ultrasonic scalpel produced faster re-epithelialization and greater tensile strength than laser or electrosurgical instruments, with results comparable to those seen with the steel scalpel.

Role of "Bovie" in spinal surgery: historical and analytical perspective

INTRODUCTION

Several surgeons use electrocautery (Bovie) discreetly or avoid it completely with the fear of increasing the chances of postoperative infection and delaying wound healing. However, the experience of many other surgeons is different. The current authors have used Bovie extensively to perform a broad array of spinal surgeries. Their rate of infection in spinal surgery can be positively compared with the existing literature where Bovie has been used to variable extent. The purpose of this study is to project the authors' concept that the use of Bovie dissection in spinal surgery does not increase the chances of postoperative wound infection.

METHODS

A MEDLINE search was carried out to determine various aspects of Bovie, including historical perspectives, circuit design, tissue response, effect on wound healing, determination of wound infection, and role of surgical smoke. The search also included the rate of infection after various spinal surgeries in the existing literature (up to 15%).

MATERIALS

In the span of 5 years (1996-2000), 322 spinal surgeries of various kinds were performed at Children's Hospital Medical Center (Cincinnati, Ohio). Most of them were performed by the senior author (A.H.C.). There were 102 cases of idiopathic scoliosis (two infected [2%]), 53 cases of neuromuscular scoliosis (two infected [4%]), and 167 cases of other spinal surgeries (three infected [1.8%]). Of these seven patients who developed wound infection in the postoperative period, one had superficial and six had deep infection. The overall rate of wound infection was 2%. Development of infection elsewhere in the body after surgery, such as respiratory, pleural, or urinary tract infections, has not been included in this analysis.

RESULTS

Despite the fact that the authors have extensively used Bovie in spinal surgery, their rate of postoperative wound infection is comparable with the rate of infection cited in the available literature where Bovie was used to a variable extent. It strongly suggests that the use of Bovie does not increase the chances of postoperative wound infection.

DISCUSSION

The role of Bovie for musculoskeletal surgery in general and spinal surgery in particular is not well defined. A review of the available literature indicates that Bovie delays the wound healing and increases the chances of infection. The authors' experience with the Bovie and this indirect method of analysis suggest that Bovie does not increase the chances of infection. A detailed search of the literature has been presented along with historical and analytical perspectives. More clinical and experimental studies are needed to further substantiate this claim. If future publications describe the exact surgical technique, extent of the use of Bovie, infection containment (antibiotic) method used before, during, and after surgery, length of the operative exposure, duration of the surgery, and rate of infection, then a meta-analysis of the published clinical material from different centers could be performed, which would provide more comprehensive information.

Tissue management with a new gingival retraction material: a preliminary clinical report

A new retraction material (Merocel) was evaluated in a clinical trial with 10 selected abutments. Each selected abutment required an anterior single unit. A comparison of probing attachment level, bleeding on probing, and plaque index demonstrated highly successful periodontal maintenance. The main advantage of Merocel retraction material is that it is capable of innocuously expanding the gingival sulcus. This preliminary study suggested that a Merocel strip was a predictable retraction material in conjunction with impression procedures. The material was also evaluated by scanning electron microscopy and demonstrated promise in this investigation. The Merocel strip shows potential for other applications, but limitations of this material indicated that evolution of atraumatic gingival retraction should continue.

The orthodontic/restorative interface. Restorative procedures to aid orthodontic treatment

Restorative procedures which complement orthodontic treatment and which may be carried out by the orthodontist are summarized. The importance of planning, with the restorative requirements in mind and the maintenance of prepared space (individual tooth or abutment positions) in all three planes of space during the period of retention, is described. The importance of liaison regarding the timing of the placement of the definitive restoration, if it is to be carried out by another dental surgeon, is stressed.

Improved wound healing with a modified electrosurgical electrode

Previous studies comparing standard electrosurgical (ES) electrode and steel scalpel (SS) wound healing have reported poor initial tensile strength, a delay in reaching maximum tensile strength and an increased inflammatory response in the ES wounds. The hypothesis that a smaller needle (modified) electrode would give better wound healing than a standard electrode was tested. Using histology as a parameter of wound healing, incisions created by a modified electrode, a standard electrode and a steel scalpel were compared. Sixty Sha Sha mice were divided into 10 groups. Standardised dorsal skin incisions were made using steel scalpel, standard and modified electrosurgical cutting electrodes. Mice were sacrificed on days 0, 1, 2, 3, 5, 7, 9, 14, 28 and 42. The incised skin was processed for standard and immunohistochemical staining. The standard ES wound had significantly higher numbers of polymorphonuclear leukocytes in comparison to the SS and modified ES wounds (p less than or equal to 0.01). However, macrophage numbers were found to be significantly lower in the ES wounds when compared to the SS wounds on days two and five (p less than or equal to 0.05). The fibroblast response was delayed by up to two days in the ES wounds when compared to the SS wounds. Epithelialisation was completed by day two in the SS and modified ES groups but was only complete by day three in the standard ES group (p less than or equal to 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Lengthening clinical crowns

Finding a solution to the short clinical crown is based on an appreciation of the biological width of attachment plus the dimensional requirements of sound restorative procedures. The collective talents of restorative dentist, orthodontist, and periodontist often are needed to cope with the problem.

Comparison of electrosurgery with conventional fiberotomies on rotational relapse and gingival tissue in the dog

The relapse tendency of orthodontically rotated teeth after electrosurgical circumferential fiberotomies and after conventional scalpel blade surgical procedures was demonstrated with a split-mouth procedure involving the maxillary second incisors of five mongrel dogs. The second incisors were rotated orthodontically an average of 63.5 degrees over a 4-month period. Electrosurgical circumferential fiberotomies were performed on the designated second incisors, and circumferential fiberotomies with a scalpel blade were performed on the contralateral incisors. The teeth were retained for 1 month and relapse was measured 2 months postretention. Wound healing was demonstrated by measurement of sulcus depths and facial gingival recession preoperatively and at 1, 2, 3, 4, and 9 weeks after surgery. In both groups, the sulcus depths had decreased about 2 mm and the facial gingiva had receded 0.3 mm 9 weeks after surgery. Two months postretention there was an average 25% relapse in the teeth treated by means of a circumferential fiberotomy with a scalpel blade compared to an average 23% relapse in those treated by means of a circumferential fiberotomy with electrosurgery. No significant difference was seen between the two techniques.

Electrosurgery--a biological approach

Electrosurgery has been used in dentistry for more than 50 years. Both opponents and advocates of electrosurgery have presented a variety of clinical studies in favour of their respective opinions, which are discussed in the following review. In some studies, wounds created by electrosurgical techniques were observed through the healing stages, in comparison to those following incision by a surgical blade, with no significant difference being discovered. Other studies reported that the histologic response of oral connective tissue to electrosurgery was adverse in some animal and human models. However, neither of these groups used methods that allowed documentation or control of operating variables. A critical evaluation of controlled clinical studies shows that adverse responses of (connective) tissue, epithelium, bone, cementum, and periodontal attachment are related to an excessive lateral heat production during the procedure. With electrosurgery, the clinician can control the inherent variables. Waveform, frequency, size of the electrode, time of contact and cooling periods are some of those considered to be of importance in the studies. On the basis of the research reports, clinical guidelines have been developed to give practical advice to the clinician using electrosurgery. Providing that these safeguards are adhered to, scientific evidence supports the biological compatibility of electrosurgery for intraoral surgical procedures.

A comparison of healing and pain following excision of inflammatory papillary hyperplasia with electrosurgery and blade-loop knives in human patients

Twenty human patients participated in a study designed to compare electrosurgery with blade-loop knives for the excision of inflammatory papillary hyperplasia in a split-mouth study. Questionnaires were used to assess pain and patient preference during a 2-week postoperative period, and photographs were made to chronicle the healing process. Healing occurred at approximately the same rate following each procedure. The majority of subjects did not perceive a difference in discomfort with either technique on the day of surgery or at any time during follow-up. Of those who did have a preference, a significant majority favored electrosurgery on the day of treatment. This preference became statistically insignificant on the second postoperative day and beyond.

Electrosurgery and wound healing: a review of the literature

This literature review and discussion has presented evidence that some additional research needs to be done in this area. Particular attention should be paid to control certain variables: kind and type of waveform, shape and size of electrode, and speed of the electrode through the tissue so that meaningful results may be given to the dental profession. The evaluation of the literature seems to show that when the variables are controlled, untoward results of wound healing after electrosurgery seem unwarranted.

Histometric evaluation of interproximal bone responses to electrosurgical mucoperiosteal incisions in dogs

The periosteal and endosteal interproximal bone remodeling activity following clinically simulated blade and electrosurgical mucoperiosteal incisions was investigated by histologic and morphometric analyses. Undecalcified histologic sections were prepared and evaluated using standard bone morphometric techniques. Periosteal and endosteal bone surfaces subjacent to incisions were examined and the percentages of forming, resorbing, and quiescent surfaces, and the number of osteoclasts per millimeter of bone surface, were calculated. Based on indices of bone remodeling activity, the potentials for activation of interproximal bone remodeling by clinically appropriate blade and electrosurgery incisions in dogs appear to be similar.

Comparative study of gingival retraction methods

The effects of electrosurgery, retraction cord, and the rotary gingival curettage technique were tested clinically and histologically in dogs. Postoperative periods analyzed ranged from 6 hours to 14 days. All methods induced some kind of minor damage. Recession of clinical magnitude was induced only by rotary gingival curettage. Apical migration of the junctional epithelium was not seen.

Epithelial and connective tissue healing following electrosurgical incisions in human gingiva

Electrosurgery is used for intraoral incisions by many clinicians. Much controversy surrounds the effect of lateral heat produced during the electrosurgical incision upon the healing of adjacent connective tissue. Ten electrosurgical incisions were made in the gingiva in each of five adult male volunteers. The duration of incision and actual energy production for each incision were calculated. Excisional biopsies of the incisions were obtained at 0-504 hours. At the light microscopic level, epithelium, totally degenerated immediately following the electrosurgery incision, showed extensive activity at 24-48 hours and had covered all wounds by 72 hours. Early hour specimens showed a homogenous connective tissue region, adjacent to the wound site, devoid of cells and fibers. This zone of denatured connective tissue gradually diminished until it was no longer present at 396 hours.

Pulpal effects of electrosurgery involving based and unbased cervical amalgam restorations

The pulpal effects of electrosurgery involving unrestored enamel, cementum, calcium hydroxide-copal varnish-based restorations and unbased restorations were evaluated in extracted human teeth and posterior teeth of cynomolgus monkeys. Electrosurgery for all studies was performed with a fully rectified filtered unit under conditions of normal clinical usage. Studies in extracted human teeth measured the voltage potential generated between a reference probe in apical pulp tissue and an activated electrosurgery electrode placed on enamel, cementum, based restorations, and unbased restorations. Placement of a base reduced but did not prevent passage of electrosurgical current, and no measurable potential was associated with activated electrode contact on cementum or enamel. Studies in three cynomolgus monkeys included electrosurgery of based and unbased cervical silver amalgam restorations, electrosurgery of unrestored enamel, restored teeth not subjected to electrosurgery and teeth that were neither restored nor subjected to electrosurgery. Electrosurgery of restored teeth, regardless of the presence of a base, consistently resulted in pulpal damage characterized by an altered dentin matrix, necrosis adjacent to the cavity preparation, and a transition zone between necrotic and apparently vital pulp tissue. By 8 weeks following electrosurgery, the majority of specimens showed replacement of the odontoblastic layer and adjacent pulp tissue by dense connective tissue with areas of irregular calcification.

Effects of electrosurgery on dog pulps under cervical metallic restorations

Fifty-four Class V amalgam restorations were placed in nine beagle dogs to determine whether electrosurgical effects on pulp tissue could be altered by the presence of metallic restorations. An electrosurgical technique was performed, simulating clinical procedures for tissue removal while traversing the restorations. Time and power-use measurements were recorded for each operation. All operations that were performed within a time range imitating clinical procedures failed to produce changes in pulpal histology. When electrosurgical exposures were extended beyond 0.4 second contact with restorations, pulpal alterations occurred in the majority of specimens.

Healing of electrosurgical incisions in gingiva: early histologic observations in adult men

The healing of electrosurgical incisions in the gingivae of adult men was investigated at 6-hour intervals. Clinical observation indicated that incisions healed progressively until 72 hours, when they were barely discernible. Clinical evidence of inflammation associated with the wounds was negligible. At a light microscopic level, initial reaction to electrosurgical incisions included disruption of the surface epithelium and denaturation of the connective tissue lateral to the incision. The zone of denatured connective tissue remained for the entire 72-hour period of this study. Young fibroblasts and vascular proliferation were evident in the connective tissue at 30 hours. Epithelium exhibited complete bridging of the wound surface in some specimens as early as 30 hours after incision. All specimens had an intact epithelial surface at 48 hours. Mild-to-moderate accumulations of inflammatory cells, consisting primarily of lymphocytes, surrounded the wound edges. Acute inflammation with polymorphonuclear leukocytic infiltration was not observed, except for moderate accumulation at 6 to 12 hours. Subepithelial hematoma formation within the connective tissue was evident in four of the size specimens at 72 hours.

Effect of retraction procedures on the periodontium in humans

On the basis of wound healing and gingival recession caused by the three procedures, the copper-band retraction method was the most satisfactory. This tentative conclusion is based on the following reasons: 1. Retraction methods must be evaluated relative to the impression procedure and fit of the restoration. The long-range effects of the marginal fit are probably the most important factor for enhancing periodontal health. 2. This study involved only healthy periodontia of adolescent patients. Different healing might be observed in tissues characterized by gingivitis or periodontitis. 3. A broader study involving a greater range of procedures and conditions is recommended to evaluate each retraction technique. 4. This study involved teeth which had an adequate zone of attached gingiva. More complicated healing and perhaps altered sequences might be observed if the procedures were performed on gingival margins of alveolar mucosa, thin gingival walls, or areas of root prominence and thin cortical bone.

Pulpal and periodontal effects of electrosurgery involving cervical metallic restorations

The pulpal and periodontal effects of electrosurgery involving teeth restored with Class V cervical amalgams and nonrestored teeth were evaluated in three cynomolgus monkeys. Electrosurgical current was delivered for 1 second with a fully rectified unit at an output intensity consistent with normal clinical usage. Experimental conditions included electrosurgery involving restored teeth, electrosurgery involving unrestored enamel, restored teeth not subjected to electrosurgery, and teeth which were neither restored nor subjected to electrosurgery. No pulpal or periodontal tissue changes were observed in the latter three groups of teeth. Electrosurgery involving cervical restorations consistently resulted in coagulation necrosis of the pulp and extensive resorption of cementum, dentin, and interradicular bone in the furcation area of multirooted teeth. The results suggest that inadvertent contact with cervical restorations during electrosurgical procedures may endanger both the pulp and the periodontal attachment apparatus.

The effects of retraction cords and electrosurgery upon blood pressure and tissue regeneration in rhesus monkeys

evices were used for gingival retraction prior to impression-taking procedures. The effects of these retraction methods upon blood pressure and loss of gingival tissue height were evaluated on three Rhesus monkeys. Chamfer finishing lines were prepared on all of the teeth and penetrating into the gingival sulcus. All the retraction devices were used to produce the desired amount of retraction which would allow an acceptable impression. Contralateral teeth, on which a chamfer was cut but no retraction performed were used as control teeth.

The only retraction device which had no effect on blood pressure and caused no tissue loss was the nonepinephrine retraction cord. The 8% r-epinephrine string and the two electrosurgical devices caused elevated blood pressures. With the 8% r-epinephrine retraction cord, no tissue loss was observed and complete healing occurred within nine days. Both electrosurgical devices caused tissue loss. The fully rectified current device caused a slight loss in gingival tissue height, while the spark gap generator caused a marked amount of tissue height to be lost. The Hyfrecator should not be used for gingival retraction because of the tissue damage that results. It appears that the safest retraction device is the retraction cord, when used properly. Further research is recommended to establish the possible systemic effects of the electrosurgical techniques.

Reason and remedy for conflicting reports on comparative effects of steel scalpel and electrosurgical cutting on gingival tissues and alveolar bone

The fact that electrosurgical cutting is governed by factors that have no influence on steel scalpel cutting is responsible for discrepancies among the results of investigations of the modalities. The investigator's equal expertise in the use of both modalities is a prerequisite for accurate comparative investigations of the effects of electrosurgical and steel scalpel cutting. Eleven specific factors that govern the efficacy and quality of electrosurgical cutting and that can, therefore, ensure consistently reliable histologic results and accurate conclusions have been mentioned.

A histologic comparison of effects of electrosurgical resection using different electrodes

Electrosurgery is a helpful adjunct to restorative dentistry, yet there often is damage to underlying connective tissue. In this study, small loop electrodes demonstrated a wider area of coagulation necrosis than was found with needle electrodes. In all instances, coagulation necrosis as a result of heat was noted. To help minimize tissue damage, very fine wire electrodes should be used, and entry into deep tissue layers should be avoided.

The present status of the gingivectomy procedure

The use of the conventional gingivectomy procedure is indicated to achieve optimum gingival contour and to eliminate supra-alveolar pockets where these do not extend beyond the muco-gingival junction. The instrument of choice for the procedure is a gingivectomy knife. Where a blood-free field is required, electrosurgery may be used provided the instrument is not brought into contact with bone. The maintenance of good oral hygiene is essential.

Periodontal considerations in operative dentistry

Periodontal and preventive considerations, other marginal fit and occlusion, are discussed as they relate to the fabrication of restorations in operative dentistry. The development of buccal, lingual, proximal, and transitional line contours is presented as related to maintenance of healthy periodontal tissues. Proximal contacts and marginal ridge relationships are related to food retention and arch integrity. The gingival attachment is described, as it determines certain techniques of tooth preparation and impression making.

A histologic and electronic evaluation of electrosurgical currents: nonfiltered full-wave modulated vs. filtered current

A controlled system for examining the tissue alteration and healing of electrosurgically produced wounds was established. Standardization of width, depth, stroke, amperage, average voltage, and wave form was achieved. A histologic comparison of tissue alteration and healing produced by a conventional blade and two electrosurgical currents was carried out. The need for standarization of instrumentation and clinical procedures is discussed.

Histological evaluation of effects produced in alveolar bone following gingival incision with an electrosurgical scalpel

Gingival incisions were performed distal to each of the two lower incisors on 25 adult male guinea pigs. For every animal, electrosection with an electrosurgical scalpel was used on one side, and a conventional scalpel was used on the other. The surgical instruments in all cases were brought into direct contact with periosteum. Five animals were sacrificed at each postoperative period (12, 24, 48, 72, and 96 hours), and sections of the areas of surgery were prepared by standard laboratory procedures. At 12 hours postoperatively there were far more soft tissue necrosis, a more extensive inflammatory reaction, and greater destruction of periosteum after electrosurgery. No significant changes in osteocyte viability were seen after either technique. However, by 24 hours, many empty lacunae were observed in the bone associated with electrosurgery, such necrosis being even more extensive by 48 hours. In contrast, only very minor, localised areas devoid of some osteocytes were seen after use of the conventional scalpel. By 96 hours the electrosurgical connective tissue wounds were still lined by coagulum, but repair of the scalpel wounds had begun. The periosteum and bone had the same features that were seen at 48 hours. Throughout the study, no increase in osteoclasts was seen in any section, nor were significant changes in adjacent bone marrow observed.