Electron microscopic evaluation of electrosurgery

Efficacy of three surgical methods for gingivectomy of permanent anterior teeth with delayed tooth eruption in children

OBJECTIVE

To compare the efficacy of three surgically assisted permanent anterior tooth eruption methods (laser surgery, electrosurgery and routine surgery) in children.

METHOD

Sixty-three orthodontic children with retarded permanent anterior tooth were selected and according to the random number table divided into three groups: laser surgery group (group A), electrosurgery group (group B) and routine surgery group (group C). The total operative time (min), the duration of pain after gingival excision (d), Visual Analogue Scale (VAS) pain intensity scores (0-10 cm), and gingival healing time (d) were all recorded. Six months after treatment, periodontal indexes of the three groups, including gingival indexes (GI), plaque indexes (PLI), probing depth (PD) were checked by the same periodontist and recorded.

RESULTS

Surgical records showed that compared with group C, there were statistically significant differences in operative time, pain duration, pain intensity and healing time in group A and B (P < 0.05). There was no significant difference in these four results between group A and group B. Periodontal examination indicators 6 months after surgery showed no statistical differences in GI, PLI and PD among group A, B and C. Oral clinical examination found that the three groups of patients with different treatment, dental eruption was normal.

CONCLUSION

All the three treatments can effectively solve the problem of delayed eruption of permanent anterior teeth in children. Particularly, laser surgery and high-frequency electrosurgery have good efficacy, little pain and high operability, which can be considered as a better method to aid teeth eruption.

Electrosurgical microneedle versus scalpel skin incisions in the facial region

Objective: Electrosurgery is widely used in surgical procedures, but mainly for subcutaneous and deep layer dissections. The aim of this study was to clinically evaluate the results of routine use of electrosurgical microneedle in performing skin incisions in the facial regions. Material and methods: Eighty patients with both benign and malignant skin lesions in the facial regions undergoing surgery were enrolled in this study. In group A comprising 40 patients, cold steel surgical scalpel N° 15 was used for the surgical procedure. Electrosurgical microneedle with 0.06 mm tip radius and generator unit KLS Martin Electrosurgical Unit ME MB 2 set on cutting mode, power 12 W was used for performing the surgery in group B including the same number of patients. Differences between incision time, excision time, blood loss and the wound related complications were evaluated. Results: The two groups did not significantly differ in the speed of incision and speed of excision although both the speed of incision and the speed of excision were found to be slightly faster in the electrosurgery group. There was significantly less blood loss in the electrosurgery group compared with the scalpel group.Statistical analysis did not confirm as significant the difference in complications between the two groups although most of the complications were associated with the patients operated with scalpel. Conclusion: Electrosurgery presents safe and effective way of work. In that manner, it is very important to choose the right generator unit's settings and the right type of electrode.

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.

Safety of colorado microdissection needle (stryker) for skin opening in craniomaxillofacial surgery

PURPOSE

Diathermy is used widely in surgical procedures, mainly for subcutaneous and deeper layers dissection. The use on craniomaxillofacial skin has been precluded by the fear of scar formation, alopecia and wound dehiscence. The aim of this study was to clinically evaluate the safety of Colorado Microdissection needle (Stryker) for skin opening in craniomaxillofacial surgery.

MATERIALS AND METHODS

117 skin incisions for craniomaxillofacial procedures were performed using the Stryker Colorado microdissection needle (CMN). The incisions included Coronal, Hemicoronal, Preauricular, Subciliary, Lateral brow's, Submandibular, Retromandibular, Risdon's, Modified Blair's and Schoebinger's incision. The reason for the craniomaxillofacial operative intervention included: Craniofacial trauma, removal of benign and malignant pathology, craniofacial reconstruction and Temporomandibular joint surgeries. 115 incisions were performed in patients in the adult age group and 02 in the pediatric age group.

RESULTS

All the patients tolerated the procedures well, with no increased risk from the use of the CMN. Only one incision had wound infection and dehiscence. All other patients had usual wound healing. At 6 months follow-up postoperative scar and alopecia was evaluated. Only on close up inspection minimal area of alopecia was noticed along the incision line. The postoperative scar was healthy in all the cases.

CONCLUSION

The findings of this study recommend the use of the CMN in all craniomaxillofacial procedures.

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.

Vaporization of atherosclerotic plaques by spark erosion

An alternative to the laser irradiation of atherosclerotic lesions has been developed. A pulsed electrocardiogram R wave-triggered electrical spark erosion technique is described. Controlled vaporization of fibrous and lipid plaques with minimal thermal side effects was achieved and documented histologically in vitro from 30 atherosclerotic segments of six human aortic autopsy specimens. Craters with a constant area and a depth that varied according to the duration of application were produced. The method was confirmed to be electrically safe during preliminary in vivo trials in the coronary arteries of seven anesthetized pigs. The main advantages of this technique are that it is simpler to execute than laser irradiation and potentially more controllable.

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.

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.

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.

A method to measure operating variables in electrosurgery

Variables affecting tissue response to electrosurgical wounding have been identified and discussed. An electronic measuring device was designed and built to record actual power generated at the active electrode during surgical use of an electrosurgery instrument. In addition, this electronic device measures the amount of time the active electrode is in contact with tissue. Coupled with an electrosurgery unit producing a documented waveform and an electrosurgery electrode having a controlled-depth gauge, variables affecting tissue response to electrosurgery wounding may be measured.

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.

The destructive potential of electrosurgery on the periodontium

Three cases have been presented illustrating the complications which may arise from the use of electrosurgery. These cases provide clinical evidence of the potential for severe periodontal destruction, a potential that must be weighed carefully by any practitioner who uses an electrosurgical instrument. It is suggested that new scientific studies be initiated to establish basic principles that will eliminate the hazards that now exist in the routine use of electrosurgery.

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.

Effects of electrosurgery on the gingival attachment in rhesus monkeys

A biometric and histometric study of electrosurgical gingival "troughing" with a fully rectified current was accomplished in four Rhesus monkeys. The operation resulted in a statistically significant recession of the free gingival margin and loss of connective tissue attachment associated with apical migration of the junctional epithelium. Burn marks from contacts with the electrodes were observed on the cemental surfaces and in the dentin under the enamel close to the cemento-enamel junction. The cemental burn marks usually were covered by epithelium, which may explain the apical migration of the junctional epithelium observed in the experiemtal teeth. A slight loss of crestal alveolar bone occurred in the experimental areas and a bone sequestrum formed in one instance. Secondary dentin was found in response to electrosurgical contact of the cemental surface.

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.