Gingival wound healing following experimental electrosurgery: an electron microscopic investigation

Comparison of Radiofrequency and Electrocautery With Conventional Scalpel Incisions

PURPOSE

The disadvantages of conventional scalpels, including insufficient control of bleeding, prompted us to search for new alternative methods such as electrosurgery and radiosurgery. In this study, the conventional scalpel was compared with radiosurgery and electrosurgery for wound healing with assessment of lateral heat production, inflammation, and instrument performance.

MATERIALS AND METHODS

Incisions were made in the palatal mucosa of 42 Wistar rats using a scalpel, electrocautery instrument, or radiofrequency instrument. Postoperative hemostasis, tissue coagulation, and tissue sticking were measured, and pain evaluation through weight loss was recorded. Gingival biopsy specimens from the surgical area were obtained at the time of surgery and 2, 4, 7, and 14 days postoperatively and were evaluated immunohistochemically for inducible nitric oxide synthase and heat shock protein 70. Kruskal-Wallis, 1-way analysis of variance, and Mann-Whitney U tests were used for statistical evaluation.

RESULTS

The rats in the electrosurgery and radiosurgery groups had aggressively greater weight loss when compared with the scalpel group in the first 7 days. Hemostasis was better in the electrocautery group, tissue coagulation was greater in the radiofrequency group (P < .001), and tissue sticking was lesser in the scalpel group (P < .001) compared with the other groups. Inducible nitric oxide synthase expression and heat shock protein 70 expression were similar in all 3 groups.

CONCLUSIONS

Electrosurgery performed better regarding hemostasis, whereas a scalpel was superior in terms of tissue sticking and tissue coagulation. Radiosurgery was superior regarding hemostasis when compared with a conventional scalpel, but it was not as successful as electrosurgery.

Scalpel versus electrosurgery: Comparison of gingival perfusion status using ultrasound Doppler flowmetry

The main prerequisites of any surgical procedure are achievement of good visibility and access to the site with minimal bleeding and rapid and painless healing. With the advancement of technology the armamentarium for oral surgical procedures has also widened. The use of alternate methods to the traditional scalpel such as electrosurgery, laser, and chemicals has been widely experimented with. This article aims to report the gingival perfusion pre-operatively and post-operatively, comparing the use of scalpel and electrosurgery in different anatomic sites in patient. Since wound healing is influenced by its revascularization rate, which follows the pattern of new connective tissue formation, the perfusion status of the gingiva has been studied using ultrasound spectral Doppler. The results of our study show that there was 30% more blood flow by 7(th) day, 19% more blood flow by 15(th) day and 11% more blood flow by 30(th) day in sites where the scalpel was used compared with sites where electrosurgery technique was used.

Neutrophils in the molar tooth extraction wound in the rat: a transmission electron microscope (TEM) study

Neutrophils have been ascribed a number of functions from ultrastructural studies of healing wounds. All of the wounds so far examined have been relatively aseptic. This study investigates, by TEM, the structure of neutrophils in healing molar tooth sockets in rats. Prior to epithelial coverage, a dense infiltrate of neutrophils separated the viable wound tissues from the overlying debris and bacteria. The more deeply situated neutrophils contained many granules and only occasional phagosomes. More superficial neutrophils contained fewer granules and phagosomes with engulfed bacteria undergoing lysis. The most superficial neutrophils were degenerate, lacked granules and often contained viable bacteria. There were varying numbers of neutrophils containing granules in the blood clot, granulation tissue, wound epithelium and adjacent tissue. No extracellular neutrophil granules nor extracellular discharge of granules was found. These findings differ from those of previous ultrastructural studies of relatively aseptic healing wounds. Ultrastructurally, the only function of neutrophils in healing tooth extraction wounds appears to be phagocytosis of bacteria, which supports a role in the prevention of infection.

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.

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.

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.

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.

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.

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.