Pulpal and periodontal effects of electrosurgery involving cervical metallic restorations

A Comparative Analysis of Post-Retraction Changes in Gingival Height after Conventional and Surgical Gingival Displacement: Rotary Curettage, Diode and Er:YAG Laser Troughing

The aim of the current article is to analyze and compare post-retraction gingival height changes resulting from six different types of gingival-displacement methods, encompassing both conventional and surgical approaches. The study involved a comparative analysis of 263 teeth (consisting of 128 front teeth, 69 premolars, and 66 molars) from 23 patients. For the investigation, three classic retraction methods were utilized, namely the single-cord technique, retraction paste Expasyl, and retraction paste Astringent. Additionally, three surgical techniques were employed, which included ceramic bur rotary curettage, Er:YAG laser troughing, and diode laser troughing. A randomized split-mouth design was implemented, and a significance level of 0.05 was used for the study. The recovery of the free gingival margin height was assessed on gypsum models that were scanned using an intraoral scanner during the first and second week after the retraction procedure. The results revealed that all retraction methods, except for ceramic bur rotary curettage, led to clinically insignificant levels of gingival recession. The article provides insights into the effectiveness and safety of various gingival-displacement techniques, highlighting that most methods tested in the study resulted in minimal or negligible gingival recession post-retraction.

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.

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.

Comparison of monopolar and bipolar electrosurgical modes for restorative dentistry: a review of the literature

This review of the literature was undertaken as part of a wider investigation of effective hemostasis in vital pulp therapy. Two general types of electrosurgical units are available: monopolar and bipolar. This review compares the features of both systems. An important hazard referred to as channeling, funneling, or current crowding is described and associated with pulp therapy injury for the first time. Important safety features of bipolar electrocoagulation are identified and applied to dental procedures. Articles were selected by means of a search of MEDLINE, the U.S. National Library of Medicine's bibliographic database, for literature published between 1966 and 2001 on the topics of electrosurgery, electrocautery, electrolysis, and lasers. A search also was completed from a pulp therapy perspective to determine the use of electrosurgery on the pulp. Numerous articles and texts published between 1900 and 1965 had been reviewed previously; their bibliographies were explored and cross-referenced for pertinent reports. Laparoscopic applications of electrosurgery were reviewed for general background information and for clarification of safety and hazard issues; no exclusionary criteria or date limitations were imposed. Beyond the literature review, numerous authors and developers in the field of electrosurgery were contacted for clarification of concepts and controversies. More than 120 articles and texts related to electrosurgery were reviewed, and another 100+ articles were reviewed in the area of pulp therapy.

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.

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.

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.