Removal of partially erupted third molars using an Erbium (Er):YAG laser: a randomised controlled clinical trial

Comparative Study of the Surgical Excision of Impacted Mandibular Third Molars Using Surgical Burs and an Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) Laser

Background The use of lasers has increased in the field of dentistry in recent years. However, in the field of oral and maxillofacial surgery, the use of lasers has been largely restricted to soft tissue, and less focus is placed on the use of lasers for hard tissues. Aim The present study aimed to comparatively evaluate the efficacy of a erbium-doped yttrium aluminum garnet (Er:YAG) laser for cutting the bone while removing the impacted mandibular third molar with the use of a surgical bur. Methods The study assessed 80 subjects undergoing removal of impacted mandibular third molars. The subjects were recruited from the Department of Oral and Maxillofacial Surgery, Luxmi Bai Institute of Dental Sciences and Hospital, Patiala, Punjab, India. They were randomly divided into two groups, each consisting of 40 subjects. Group I used an Er:YAG laser to remove the bone, while Group II used a surgical bur. Assessments and comparisons were made for complications, wound healing, trismus, edema, bleeding, and pain. Results The study examined the efficacy of the Er:YAG laser for cutting the bone and extracting the impacted mandibular third molars using a surgical bur in two groups of 80 patients each. When the laser was used in place of a surgical bur, Group I patients experienced less edema, bleeding, and discomfort; nevertheless, the difference was not statistically significant. Time taken by laser for bone cutting was significantly higher compared to the surgical bur. In Group I (laser), trismus existed for a longer time. For mouth opening, the preoperative mouth opening was comparable in the two groups with p = 0.87. Conclusion Pain, hemorrhage, and edema were lesser, and the time required for bone cutting was substantially longer in the laser group. Apart from these, laser-assisted intra-oral bone cutting should be preferred because of its less invasive nature, simpler procedure, and simpler osteotomy when compared to traditional surgical burs and also in anxiety-prone patients.

Conventional drilling versus ultrasound and laser osteotomy in mandibular third molar surgery: A comparative study

BACKGROUND

There are few research works with in-depth studies and direct simultaneous comparisons of the effects on tissue reactions and patients' recovery following in vivo conventional drilling, ultrasound- and laser-assisted osteotomy in humans.

OBJECTIVE

The current study aims to compare bone cutting duration, pain, swelling, and trismus in patients following surgical mandible third molar extraction by bone removal using three different osteotomes-a conventional rotary device, an ultrasonic unit, and an Er:YAG laser.

METHODS

A prospective, randomized three-group comparative clinical trial was performed. As an experimental setting for the study, аn open mandible third molar surgery was chosen because osteotomy is included in its protocol. Patients were divided into three groups according to the used device for bone removal. Bone cutting time intraoperatively, facial swelling, trismus, and pain on the first, second, and third postoperative days were assessed. The statistical analyses were performed using the SPSS v. 17.0-Kolmogorov-Smirnov test, one-way ANOVA, Student's t-test, Mann-Whitney test, and χ2  test. Statistical results were considered significant at p < 0.05 (confidence interval of difference, 95% CI).

RESULTS

Eighty patients (34 males and 46 females with an average age of 25.18 years) were included in the study. The average time for bone removal by the conventional low-speed device (4.95 min), by the ultrasonic unit (5.13 min), and by the Er:YAG laser (9.00 min) differed significantly (p = 0.001). The mean postoperative facial swelling showed a marked difference between the groups (p < 0.05), in favor of the laser and piezo groups. The osteotome proved to influence pain intensity not only immediately after surgery (p = 0.002), but also during the followed-up period (p = 0.001), again in favor of the two above-mentioned groups. No association was found between trismus and the osteotome used by the followed-up patients (p > 0.05).

CONCLUSION

Bone-cutting mechanism and the biological influence of the laser beam and ultrasound on living tissues proved to be favorable factors for patients' pain levels and tissue swelling postoperatively independent of the longer osteotomy duration compared to conventional drilling.

A Clinical Comparison of Er:YAG Laser, Piezosurgery, and Conventional Bur Methods in the Impacted Third Molar Surgery

Objective: The aim of this study is to investigate whether Er:YAG laser and piezosurgery methods can be an alternative to the conventional bur method. Background: The purpose of this study is to compare the postoperative pain, swelling, trismus and patient satisfaction between Er:YAG laser, piezosurgery device, and conventional bur methods that are used to remove bone barrier during extraction of the impacted lower third molar. Methods: Thirty healthy patients who have bilateral, asymptomatic, vertically impacted mandibular third molar teeth according to Pell and Gregory classification Class II and Winter Class B were selected. Patients were randomly divided into two groups. In 30 patients one side of the bony cover around the tooth was removed by the conventional bur technique, on the other side 15 patients were treated with the Er:YAG laser (VersaWave dental laser; HOYA ConBio) 200 mJ, 30 Hz, 4.5-6 W, noncontact mode, SP and R-14 handpiece tip, under air and saline solution, and 15 patients with the piezosurgery technique (VarioSurg Piezo; NSK) with frequency 20-100 kHz, 10-80% power range in Surgery (S), continuous mode, with SG17 and SG5 handpiece tip blade. Preoperative, 48th hour and 7th day measurements were made and recorded about pain, swelling, and trismus. At the end of the treatment, patients were asked to fill out a satisfaction questionnaire. Results: The pain observed at the postoperative 24th hour was statistically significantly lower in the laser group than in the piezosurgery group (p < 0.05). Only in the laser group swelling was seen with statistically significant differences between preoperative and postoperative 48th h (p < 0.05). Postoperative 48th h trismus value was seen as the highest in the laser group than others. Patient satisfaction was found to be higher in the laser and piezo technique compared with the bur technique. Conclusions: Er:YAG laser and piezo methods can be a good alternative to the conventional bur method when postoperative complications are compared. We believe that laser and piezo methods will be preferred for patients due to increased patient satisfaction. Clinical Trial Registration number: B.30.2.ANK.0.21.63.00/08 date: 28.01.10 no:150/3.

Is the Er: YAG Laser Effective in Reducing Pain, Edema and Trismus After Removal of Impacted Mandibular Third Molars? A Meta-Analysis

PURPOSE

Removal of impacted third molars, can be associated with complications such as pain, edema, trismus, that can increase the morbidity of this procedure. The purpose of this study is to determine whether the Er: YAG laser is effective in reducing pain, swelling and trismus compared to rotary instruments in removing impacted lower third molars (3 LM`s).

METHODS

For this systematic review the searches were carried out independently by 2 researchers and the articles were selected according to the inclusion and exclusion criteria previously established. The predictor variable was the study group (Er: YAG laser versus rotatory instruments). The main outcome was the analysis of post-operative pain, edema and trismus after third molars extractions. Data analysis included the risk of bias evaluation (RoB 2 Cochrane) and meta-analysis with random effects I² based heterogeneity and 95% confidence.

RESULTS

In the initial results, 1,371 articles were found and 6 RCT were selected to compose this study. A total of 299, 3 LM`s were removed, 126 with the Er: YAG laser, 142 with a drill and 31 with a piezoelectric instrument. The results of this meta-analysis showed that in the laser group there was a significant reduction in edema (1.82 [CI95% = -3.06 to -0.57] cm (P = .004)) and complications (P = .0004), a slight reduction in pain after 2 days (P = .030) and there was no variation in trismus (P = .200) when compared to the drill group. The surgery and/or osteotomy time was shorter in the drill group. Only 1 study presented low risk of bias.

CONCLUSIONS

The Er: YAG laser has been shown to be effective in reducing edema, pain and complications in impacted lower third molar surgeries. however due to the lack of standardization in Er: YAG laser therapy, new controlled and standardized studies should be performed with the aim of proving the efficacy of this therapeutic modality.

Oral cancer awareness in North-Western Spain: a population-based study

Background

An early diagnosis depends greatly on patient awareness. Thus, the aim of this study was to investigate general awareness of oral cancer and knowledge about its risk factors, signs and symptoms.

Material and Methods

Cross-sectional population-based survey of randomly selected respondents conducted from March 1, 2015 to 30 June 2016.

Results

A total of 5,727 people entered the survey (response rate: 53%). When asked what cancers participants had heard about, 20.3% mentioned oral cancer. Regarding risk factors, tobacco was mentioned by 55.3% of the sample (n=3,169), followed by alcohol (12.5%; n=708), poor oral hygiene (10.8%; n=618), diet (6.5%; n=377), and genetics (4.5%; n=248).

Conclusions

General population has low awareness of oral cancer with poor knowledge of risk factors and main alarm signs. In addition, individuals in the risk group scored lower values in the main variables analysed; even those highly educated showed insufficient awareness and knowledge of oral cancer. In these circumstances, there is clear need for educational interventions tailored to the target audience and aimed at increasing knowledge and awareness of oral cancer to promote primary prevention of oral cancer and minimising the time interval of patients with symptomatic oral cancer in their path to treatment.

Key words:Oral cancer, awareness, risk factors, surveys and questionnaires, Spain.

Comparison of postoperative morbidity between piezoelectric surgery and conventional rotary instruments in mandibular third molar surgery: a split-mouth clinical study

Background

The extraction of impacted third molar teeth is a common procedure in maxillofacial surgery. The aim of this study was to compare of piezoelectric surgical technique with the one with conventional rotary instruments in terms of edema, trismus and pain, in mandibular third molar surgery.

Material and Methods

20 individuals with symmetrically impacted lower mandibular third molars and 40 teeth were included in the study. Third molars on the left side of each patient were removed with piezosurgery, while the counterparts on the right side were removed with conventional rotary instruments. Postoperatively, the same antibiotic, analgesic, and mouthwash were recommended to both groups. Ultrasound, edema, trismus measurements were performed before surgery, postoperative, postoperative day 2 and postoperative day 7. VAS scale was used to evaluate the pain.

Results

The average age of 20 individuals included in the study was found to be 21.85 ± 3.08 years. The operation time of the individuals who underwent the surgery with conventional rotary instruments was found to be 12 minutes 31.70 ± 167.03 seconds, and the operation time in the Piezosurgery group was 19 minutes 10.60 ± 306.59 seconds. There was no significant difference between the two groups in terms of trismus, edema, and pain.

Conclusions

Piezosurgery is a safe method that can be used in molar removal, but in this split-mouth study, it is not found advantageous in terms of postoperative morbidity due to the longer working time compared to the one performed with conventional rotary instruments.

Key words:Edema, impacted third molar, pain, piezosurgery, trismus.

Postoperative evaluation of Er:YAG laser, piezosurgery, and rotary systems used for osteotomy in mandibular third-molar extractions

OBJECTIVE

This study compared patient postoperative pain, swelling, and trismus after usage of rotary instruments, piezosurgery, and Er:YAG lasers in mandibular third-molar extraction.

MATERIALS AND METHODS

This prospective study was executed with class II and position B vertically impacted mandibular third molars. Patients were divided into three groups according to the osteotomy system used to remove retentive bone: rotary instruments, piezosurgery, and Er:YAG laser. Postoperative pain was evaluated using VAS questionnaires at 12 h, 24 h, 48 h, and 7 days after procedures. Trismus was evaluated by measuring the distance between the maxillary and mandibular incisors at maximum mouth opening, and comparing preoperative measurements with those for postoperative days 2 and 7. Analyses of swelling were carried out via a stereophotogrammetry system. Operation times were measured using a digital stopwatch from the initial incision to the final suture.

RESULTS

There were no statistically significant differences between the groups in terms of pain, trismus, or swelling (p > 0.05). Pain persisted more in the rotary instrument group 24 h later (0 ± 1.3; p = 0.001). The pain scores obtained after 48 h for the piezosurgery (1.81 ± 2.29) and rotary (2.2 ± 2.12) groups were observed at 24 h in the laser group (2.19 ± 1.52). The mean operation time was highest using the laser (19.1 ± 3.85 min; p = 0.001) and lowest using rotary instruments (9.88 ± 2.97 min; p = 0.001).

CONCLUSION

Piezosurgery and Er:YAG laser are good alternatives to rotary instrument systems in third-molar extraction, but both systems are slower than traditional rotary instruments.

Surgical techniques for the removal of mandibular wisdom teeth

BACKGROUND

Pathology relating to mandibular wisdom teeth is a frequent presentation to oral and maxillofacial surgeons, and surgical removal of mandibular wisdom teeth is a common operation. The indications for surgical removal of these teeth are alleviation of local pain, swelling and trismus, and also the prevention of spread of infection that may occasionally threaten life. Surgery is commonly associated with short-term postoperative pain, swelling and trismus. Less frequently, infection, dry socket (alveolar osteitis) and trigeminal nerve injuries may occur. This review focuses on the optimal methods in order to improve patient experience and minimise postoperative morbidity.

OBJECTIVES

To compare the relative benefits and risks of different techniques for surgical removal of mandibular wisdom teeth.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health Trials Register (to 8 July 2019), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library; 2019, Issue 6), MEDLINE Ovid (1946 to 8 July 2019), and Embase Ovid (1980 to 8 July 2019). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. We placed no restrictions on the language or date of publication.

SELECTION CRITERIA

Randomised controlled trials comparing different surgical techniques for the removal of mandibular wisdom teeth.

DATA COLLECTION AND ANALYSIS

Three review authors were involved in assessing the relevance of identified studies, evaluated the risk of bias in included studies and extracted data. We used risk ratios (RRs) for dichotomous data in parallel-group trials (or Peto odds ratios if the event rate was low), odds ratios (ORs) for dichotomous data in cross-over or split-mouth studies, and mean differences (MDs) for continuous data. We took into account the pairing of the split-mouth studies in our analyses, and combined parallel-group and split-mouth studies using the generic inverse-variance method. We used the fixed-effect model for three studies or fewer, and random-effects model for more than three studies.

MAIN RESULTS

We included 62 trials with 4643 participants. Several of the trials excluded individuals who were not in excellent health. We assessed 33 of the studies (53%) as being at high risk of bias and 29 as unclear. We report results for our primary outcomes below. Comparisons of different suturing techniques and of drain versus no drain did not report any of our primary outcomes. No studies provided useable data for any of our primary outcomes in relation to coronectomy. There is insufficient evidence to determine whether envelope or triangular flap designs led to more alveolar osteitis (OR 0.33, 95% confidence interval (CI) 0.09 to 1.23; 5 studies; low-certainty evidence), wound infection (OR 0.29, 95% CI 0.04 to 2.06; 2 studies; low-certainty evidence), or permanent altered tongue sensation (Peto OR 4.48, 95% CI 0.07 to 286.49; 1 study; very low-certainty evidence). In terms of other adverse effects, two studies reported wound dehiscence at up to 30 days after surgery, but found no difference in risk between interventions. There is insufficient evidence to determine whether the use of a lingual retractor affected the risk of permanent altered sensation compared to not using one (Peto OR 0.14, 95% CI 0.00 to 6.82; 1 study; very low-certainty evidence). None of our other primary outcomes were reported by studies included in this comparison. There is insufficient evidence to determine whether lingual split with chisel is better than a surgical hand-piece for bone removal in terms of wound infection (OR 1.00, 95% CI 0.31 to 3.21; 1 study; very low-certainty evidence). Alveolar osteitis, permanent altered sensation, and other adverse effects were not reported. There is insufficient evidence to determine whether there is any difference in alveolar osteitis according to irrigation method (mechanical versus manual: RR 0.33, 95% CI 0.01 to 8.09; 1 study) or irrigation volume (high versus low; RR 0.52, 95% CI 0.27 to 1.02; 1 study), or whether there is any difference in postoperative infection according to irrigation method (mechanical versus manual: RR 0.50, 95% CI 0.05 to 5.43; 1 study) or irrigation volume (low versus high; RR 0.17, 95% CI 0.02 to 1.37; 1 study) (all very low-certainty evidence). These studies did not report permanent altered sensation and adverse effects. There is insufficient evidence to determine whether primary or secondary wound closure led to more alveolar osteitis (RR 0.99, 95% CI 0.41 to 2.40; 3 studies; low-certainty evidence), wound infection (RR 4.77, 95% CI 0.24 to 96.34; 1 study; very low-certainty evidence), or adverse effects (bleeding) (RR 0.41, 95% CI 0.11 to 1.47; 1 study; very low-certainty evidence). These studies did not report permanent sensation changes. Placing platelet rich plasma (PRP) or platelet rich fibrin (PRF) in sockets may reduce the incidence of alveolar osteitis (OR 0.39, 95% CI 0.22 to 0.67; 2 studies), but the evidence is of low certainty. Our other primary outcomes were not reported.

AUTHORS' CONCLUSIONS

In this 2020 update, we added 27 new studies to the original 35 in the 2014 review. Unfortunately, even with the addition of these studies, we have been unable to draw many meaningful conclusions. The small number of trials evaluating each comparison and reporting our primary outcomes, along with methodological biases in the included trials, means that the body of evidence for each of the nine comparisons evaluated is of low or very low certainty. Participant populations in the trials may not be representative of the general population, or even the population undergoing third molar surgery. Many trials excluded individuals who were not in good health, and several excluded those with active infection or who had deep impactions of their third molars. Consequently, we are unable to make firm recommendations to surgeons to inform their techniques for removal of mandibular third molars. The evidence is uncertain, though we note that there is some limited evidence that placing PRP or PRF in sockets may reduce the incidence of dry socket. The evidence provided in this review may be used as a guide for surgeons when selecting and refining their surgical techniques. Ongoing studies may allow us to provide more definitive conclusions in the future.

Use of piezoelectric surgery and Er:YAG laser:which one is more effective during impacted third molar surgery?

Background

Reduction in postoperative complications is of vital considerations in impacted third molar teeth surgery. The aim of this study was to compare postoperative complications of impacted third molar surgeries for bone removal using laser, piezoelectric equipment, and conventional rotary instruments.

Methods

To address the research purpose, the investigator designed the prospective double-blind clinical trial study. The sample size was determined 20 (40 teeth) by sampling formula in any kind of operation. The data of patients were obtained in the different periods in terms of pain, trismus, swelling, ecchymosis, and patient's satisfaction and then analyzed using SPSS 20 software via paired t test and Wilcoxon and McNemar's tests.

Results

The pain immediately after surgery and 2 days and 7 days after surgery was higher in the laser group. The swelling immediately after surgery was more in the laser group but not significant. The amount of mouth opening immediately after surgery and 2 days and 7 days after surgery was significantly lower in the laser group than in the piezosurgery group. The total duration of surgery and duration of osteotomy were significantly longer in the laser group. The patient's satisfaction from surgery with piezosurgery was more than that with laser, but this difference was not significant.

Conclusion

Due to the rising demand for impacted wisdom tooth surgery, the present study suggests that hard tissue laser surgery and piezosurgery can clear the future of impacted molar surgery, and these approaches are more efficient in reducing postoperative complications compared to the conventional surgeries.

Periodontal and peri-implant wound healing following laser therapy

Laser irradiation has numerous favorable characteristics, such as ablation or vaporization, hemostasis, biostimulation (photobiomodulation) and microbial inhibition and destruction, which induce various beneficial therapeutic effects and biological responses. Therefore, the use of lasers is considered effective and suitable for treating a variety of inflammatory and infectious oral conditions. The CO2 , neodymium-doped yttrium-aluminium-garnet (Nd:YAG) and diode lasers have mainly been used for periodontal soft-tissue management. With development of the erbium-doped yttrium-aluminium-garnet (Er:YAG) and erbium, chromium-doped yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers, which can be applied not only on soft tissues but also on dental hard tissues, the application of lasers dramatically expanded from periodontal soft-tissue management to hard-tissue treatment. Currently, various periodontal tissues (such as gingiva, tooth roots and bone tissue), as well as titanium implant surfaces, can be treated with lasers, and a variety of dental laser systems are being employed for the management of periodontal and peri-implant diseases. In periodontics, mechanical therapy has conventionally been the mainstream of treatment; however, complete bacterial eradication and/or optimal wound healing may not be necessarily achieved with conventional mechanical therapy alone. Consequently, in addition to chemotherapy consisting of antibiotics and anti-inflammatory agents, phototherapy using lasers and light-emitting diodes has been gradually integrated with mechanical therapy to enhance subsequent wound healing by achieving thorough debridement, decontamination and tissue stimulation. With increasing evidence of benefits, therapies with low- and high-level lasers play an important role in wound healing/tissue regeneration in the treatment of periodontal and peri-implant diseases. This article discusses the outcomes of laser therapy in soft-tissue management, periodontal nonsurgical and surgical treatment, osseous surgery and peri-implant treatment, focusing on postoperative wound healing of periodontal and peri-implant tissues, based on scientific evidence from currently available basic and clinical studies, as well as on case reports.

Surgical techniques for the removal of mandibular wisdom teeth

BACKGROUND

The surgical removal of mandibular wisdom teeth is one of the most common operations undertaken in oral and maxillofacial surgery. The most common indication for surgery is infection about a partially erupted tooth that is impacted against bone or soft tissues. Other indications include unrestorable caries, pulpal and periapical pathology, fracture of the tooth and cyst development, amongst others. Most commonly the benefits of surgical removal of a wisdom tooth include alleviation of the symptoms and signs of pericoronitis and its potential consequences. However, surgery is frequently associated with postoperative pain, swelling and trismus. Less commonly complications include infection, including dry socket, trigeminal nerve injuries and rarely fracture of the mandible.

OBJECTIVES

To compare the relative benefits and risks of different techniques for undertaking various aspects or stages of the surgical extraction of mandibular wisdom teeth.

SEARCH METHODS

We searched the Cochrane Oral Health Group's Trials Register (to 21 March 2014), CENTRAL (The Cochrane Library 2014, Issue 1), MEDLINE (OVID) (1946 to 21 March 2014) and EMBASE (OVID) (1980 to 21 March 2014). We searched ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform for ongoing trials. There were no restrictions regarding language or date of publication in the electronic searches.

SELECTION CRITERIA

RCTs comparing surgical techniques for removal of mandibular wisdom teeth.

DATA COLLECTION AND ANALYSIS

Two review authors conducted assessment of relevance, risk of bias and data extraction. Study authors were contacted for additional information. RRs were used for dichotomous data and MDs for continuous data, unless the event rate was very low and Peto ORs were used. The pairing of the split-mouth studies was taken into account in the analysis for both dichotomous and continuous outcomes, and parallel group and split-mouth studies were combined using the generic inverse variance method. Random-effects models were used provided there were more than three studies (fixed-effect models otherwise).

MAIN RESULTS

A total of 35 trials (2569 patients) were included. The interventions under consideration fell into seven broad categories, with many comparisons including only a small number of trials. Twenty-one of the trials were assessed at high risk of bias, the remaining 14 as unclear. The results are described in the summary of findings tables.Triangular flaps were associated with a 71% reduction in alveolar osteitis at one week (RR 0.29, 95% CI 0.11 to 0.78; three trials, moderate quality) and reduction in pain at 24 hours (MD -0.21, 95% CI -0.32 to -0.10; two trials, moderate quality) compared with envelope flaps. There was no evidence of a difference in overall infection rates, in maximum mouth opening or in permanent sensation. However, there was some evidence that residual swelling after one week was slightly increased in the triangular flap groups compared to envelope flap types (MD 0.66 mm, 95% CI 0.26 to 1.07; two trials, low quality). We found no data on temporary sensation, or adverse events.There was low quality evidence from two studies, looking at the use of a retractor during third molar surgery, to indicate more cases of temporary altered sensation (up to one month) when a retractor was used (Peto OR 5.19, 95% CI 1.38 to 19.49; two trials, low quality). One study reported that this did not persist for more than six months in either group. We found no data for use of a retractor on other primary outcomes or adverse effects (including fracture of the mandible).Due to the small number of studies, the different comparisons evaluated, the variable outcomes reported and the paucity of useful data for all primary outcomes we were not able to draw any conclusions concerning bone removal in third molar surgery.There was insufficient evidence from single studies of very low quality on irrigation method (manual versus mechanical) or irrigation volume (low or high) to determine whether there were differences or not for the outcomes of alveolar osteitis or postoperative infection. We found no data for any of the other primary outcomes.There was insufficient evidence (low to very low quality) that any wound closure technique (primary versus secondary) was superior to another for the outcomes of alveolar osteitis, postoperative infection or maximum mouth opening achieved after seven days, or reactionary bleeding. There was evidence that secondary wound closure was associated with reduced pain at 24 hours (MD 0.79, 95% CI 0.35 to 1.24; four trials, moderate quality) and slightly reduced swelling after one week (MD 0.33, 95% CI 0.09 to 0.57; seven trials, moderate quality).We found no data on other primary outcomes.There was some evidence that the use of a surgical drain was associated with less postoperative swelling (MD -0.90, 95% CI -1.62 to -0.19; five trials, moderate quality) and greater maximum mouth opening one week after surgery (MD 3.72 mm, 95% CI 2.84 to 4.59; two trials, moderate quality). There was insufficient evidence from a single study (low quality) to determine whether the presence of a drain made any difference to pain at 24 hours postoperation. There were no data for the other primary outcomes.Although two RCTs compared coronectomy with complete extraction, flaws in the design and the unit of analysis of these studies meant that there were no reliable data available for inclusion.

AUTHORS' CONCLUSIONS

The thirty-five included trials looked at a range of different surgical techniques. The comparisons related to seven broad aspects of the surgical procedures for impacted mandibular third molars: type of surgical flap raised, use of retractors, techniques for bone removal, wound irrigation, wound closure, wound drainage, and complete/incomplete tooth removal. The quality of the body of evidence for each of these comparisons was very low to moderate due to the small number of trials and patients, and the majority of the trials being at high risk of bias (65%) with the remainder at unclear risk of bias.The evidence for making changes to surgical practice is therefore limited. However, it is useful to describe the state of the research evidence supporting practice so that surgeons can make an informed choice in adopting new techniques, or continuing with established techniques.

Laser vs bur for bone cutting in impacted mandibular third molar surgery: A randomized controlled trial

BACKGROUND

The aim of this study was to assess the feasibility of Er: YAG laser in bone cutting for removal of impacted lower third molar teeth and compare its outcomes with that of surgical bur.

MATERIALS & METHODS

The study comprised 40 subjects requiring removal of impacted mandibular third molar, randomly categorized into two equal groups of 20 each, who had their impacted third molar removed either using Er: YAG laser or surgical bur as per their group, using standard methodology of extraction of impacted teeth. Clinical parameters like pain, bleeding, time taken for bone cutting, postoperative swelling, trismus, wound healing and complications were compared for both groups.

OBSERVATION & RESULT

Clinical parameters like pain, bleeding and swelling were lower in laser group than bur group, although the difference was statistically not significant. However, postoperative swelling showed significant difference in the two groups. Laser group required almost double the time taken for bone cutting with bur. Trismus persisted for a longer period in laser group. Wound healing and complications were assessed clinically and there was no significant difference in both the groups.

CONCLUSION

Based on the results of our study, the possibility of bone cutting using lasers is pursued, the osteotomy is easily performed and the technique is better suited to minimally invasive surgical procedures. The use of Er: YAG laser may be considered as an alternative tool to surgical bur, specially in anxious patients.

Influence of effective number of pulses on the morphological structure of teeth and bovine femur after femtosecond laser ablation

Femtosecond lasers have been widely used in laser surgery as an instrument for contact-free tissue removal of hard dental, restorative materials, and osseous tissues, complementing conventional drilling or cutting tools. In order to obtain a laser system that provides an ablation efficiency comparable to mechanical instruments, the laser pulse rate must be maximal without causing thermal damage. The aim of this study was to compare the different morphological characteristics of the hard tissue after exposure to lasers operating in the femtosecond pulse regime. Two different kinds of samples were irradiated: dentin from human extracted teeth and bovine femur samples. Different procedures were applied, while paying special care to preserving the structures. The incubation factor S was calculated to be 0.788±0.004 for the bovine femur bone. These results indicate that the incubation effect is still substantial during the femtosecond laser ablation of hard tissues. The plasma-induced ablation has reduced side effects, i.e., we observe less thermal and mechanical damage when using a superficial femtosecond laser irradiation close to the threshold conditions. In the femtosecond regime, the morphology characteristics of the cavity were strongly influenced by the change of the effective number of pulses.

Effects of femtosecond laser irradiation on osseous tissues

BACKGROUND AND OBJECTIVE

Few studies have investigated femtosecond (fs) lasers for cutting bone tissue.

STUDY DESIGN/MATERIALS AND METHODS

A 775 nm, 1 kHz, 200 femtosecond, up to 400 microJ laser system was used to irradiate in vitro calcified cortical bone samples and bone tissue culture samples.

RESULTS

The ablation threshold in cortical bone was 0.69+/-0.08 J/cm(2) at 775 nm and 0.19+/-0.05 J/cm(2) at 387 nm. Plasma shielding experiments determined that the ablation plume and the plasma significantly affect material removal at high repetition rates and appear to generate thermal transients in calcified tissue. Confocal analysis revealed intact enzymatic activity on the surface of cells immediately adjacent to cells removed by fs laser irradiation.

CONCLUSIONS

These experiments demonstrate that fs lasers used for bone tissue cutting do not appear to generate significant temperature transients to inactivate proteins and that cellular membrane integrity is disrupted for only a few cell layers.

Er:YAG laser osteotomy based on refined computer-assisted presurgical planning: first clinical experience in oral surgery

OBJECTIVE

This case report was aimed at primary clinical experience concerning surgical extraction of a displaced tooth with the help of the Er:YAG laser based on refined computer-assisted presurgical planning.

METHODS

The case refers to the extraction of a displaced maxillary canine in a female patient. For the osteotomy, a pulsed Er:YAG laser was applied with pulse energy of 500 mJ, pulse duration of 250 microsec and pulse frequency of 12 Hz. The fiber tip (1000 microm) was kept with a 1-2 mm distance to the bone surface. Refined presurgical computer-assisted planning was performed with regard to minimization of bone loss, especially for the sake of preservation of the alveolar ridge. Based on a detailed three-dimensional (3D) reconstruction of the patient's anatomy, dynamical simulations of a buccal and a palatinal variant of access osteotomy were provided. Additionally, a volumetric profile of bone tissue quality based on Hounsfield values was generated.

RESULTS

By means of the 3D reconstruction and the tissue quality profile, both bone thickness and quality was evaluated as superior in the palatinal rather than in the vestibular part. Therefore, a classical buccal access window was chosen. The laser osteotomy allowed an exact cut geometry without any thermal damage and merely minimal bone loss.

CONCLUSION

The enhanced possibilities by laser osteotomy allowed for full exploitation of presurgical planning. As regards the actual case, computer-assisted planning was of benefit for an appropriate choice of access osteotomy by enabling evaluation of the consistency of the bony structures.

Microtomographic analysis of healing of femtosecond laser bone calvarial wounds compared to mechanical instruments in mice with and without application of BMP-7

BACKGROUND AND OBJECTIVE

This study investigated the healing of femtosecond laser created wounds in an animal model.

STUDY DESIGN

We have assessed the healing of critical size wounds in mice calvaria using three different wounding techniques: carbide bur, diamond end-cutting bur, and ultrafast femtosecond laser, and in the presence or absence of bone morphogenetic protein-7 (BMP). Wound closure was examined using microcomputerized tomography at 3, 6, 9, and 12 weeks.

RESULTS

Results have shown partial closure at up to 12 weeks with all techniques that did not involve the use of BMP, with the least closure noted in the laser groups as suggested by two-dimensional radiographic analysis. Bone volume measurements appeared slightly lower for the laser than for the mechanical groups, however statistically significant differences were seen only at week 6. No significant differences in closure were noted for the different methods in the BMP treated groups.

CONCLUSIONS

Femtosecond laser cutting demonstrated an unsurpassed precision when compared to mechanical instruments. The addition of BMP led to very rapid healing with complete closure seen as early as 3 weeks and overcomes any potential healing delays that may arise from laser tissue cutting.

Evaluation of the clinical behaviour of a polyvinylpyrrolidone and sodium hyalonurate gel (Gelclair) in patients subjected to surgical treatment with CO2 laser

This experimental study was undertaken to evaluate the efficacy of Gelclair, a concentrated oral gel consisting of sodium hyalonurate and polyvinylpyrrolidone, in decreasing postoperative pain in patients subjected to surgical treatment by extirpation and/or vapourization of oral lesions with CO(2) laser. After the surgery, 60 consecutive patients (30 in control group and 30 in experimental group) were prescribed 600 mg ibuprofen 3 times per day for 4 days. In the experimental group a protocol was established for the application of 15 ml of Gelclair directly onto the wound 3 times per day, 1 h before meals, for 1 week. Spontaneous pain and pain on swallowing were evaluated using a visual analogue scale at 24 h and 7 days after the intervention. The experimental group had less spontaneous pain at 24h (P=0.000) and at 1 week (P=0.012), and also less pain on swallowing at 24 h and 1 week (P=0.029 and P=0.000, respectively) after the intervention. In conclusion, the effectiveness of the barrier mechanism that Gelclair provides improves the postoperative experience of patients who have undergone oral CO(2) laser surgery.